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Alghauli MA, Alqutaibi AY, Wille S, Kern M. The physical-mechanical properties of 3D-printed versus conventional milled zirconia for dental clinical applications: A systematic review with meta-analysis. J Mech Behav Biomed Mater 2024; 156:106601. [PMID: 38810545 DOI: 10.1016/j.jmbbm.2024.106601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/12/2024] [Accepted: 05/23/2024] [Indexed: 05/31/2024]
Abstract
AIM OF STUDY This systematic review aimed to compare the physical-mechanical properties of 3D-printed (additively manufactured (AM)) zirconia compared to conventionally milled (subtractive manufactured: SM) zirconia specimens. MATERIALS AND METHODS A thorough search of Internet databases was conducted up to September 2023. The search retrieved studies that evaluated AM zirconia specimens and restorations regarding the physical-mechanical properties and mechanical behavior of zirconia. The main topic focused on 3Y-TZP. However, records of 4YSZ and 5YSZ were also included to gather more comprehensive evidence on additively manufactured zirconia ceramic. The quality of studies was assessed using the ROB2 tool, Newcastle Ottawa scale, and the Modified Consort Statement. Of 1736 records, 57 were assessed for eligibility, and 38 records were included in this review, only two clinical trials meet the inclusion criteria and 36 records were laboratory studies. There were no signs of mechanical complications and wear to antagonists with short-term clinical observation. SM thin specimens ≤1.5 mm showed statistically significant higher flexural strength than AM zirconia (p ≤ 0.01), while thicker specimens showed comparable outcomes (p > 0.5). The fracture resistance of dental restorations was dependent on the aging protocol, restoration type, and thickness. The bond strength of veneering ceramic to zirconia core was comparable. CONCLUSIONS The results pooled from two short-term clinical trials showed no signs of mechanical or biological complications of additively manufactured 3Y-TZP zirconia crowns. The flexural strength might depend on the specimens' thickness, but it showed promising results to be used in clinical applications, taking into account the printing technique and orientation, material composition (yttria content), solid loading, and sintering parameters. 3D-printed restorations fracture resistance improved when adhered to human teeth. The veneering ceramic bond was comparable to milled zirconia specimens. Long-term RCTs are recommended to confirm the mechanical behavior of 3D-printed restorations.
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Affiliation(s)
- Mohammed Ahmed Alghauli
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany; Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen.
| | - Ahmed Yaseen Alqutaibi
- Department of Prosthodontics, Faculty of Dentistry, Ibb University, Ibb, Yemen; Department of Substitutive Dental Science, College of Dentistry, Taibah University, Al-Madinah, Saudi Arabia
| | - Sebastian Wille
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
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Zhu H, Jiang J, Wang Y, Wang S, He Y, He F. Additive manufacturing of dental ceramics in prosthodontics: The status quo and the future. J Prosthodont Res 2024; 68:380-399. [PMID: 38346729 DOI: 10.2186/jpr.jpr_d_23_00119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
PURPOSE This review aims to summarize the available technologies, material categories, and prosthodontic applications of additive manufacturing (AM) dental ceramics, evaluate the achievable accuracy and mechanical properties in comparison with current mainstream computer-aided design/computer-aided manufacturing (CAD/CAM) subtractive manufacturing (SM) methods, and discuss future prospects and directions. STUDY SELECTION This paper is based on the latest reviews, state-of-the-art research, and existing ISO standards on AM technologies and prosthodontic applications of dental ceramics. PubMed, Web of Science, and ScienceDirect were amongst the sources searched for narrative reviews. RESULTS Relatively few AM technologies are available and their applications are limited to crowns and fixed partial dentures. Although the accuracy and strength of AM dental ceramics are comparable to those of SM, they have the limitations of relatively inferior curved surface accuracy and low strength reliability. Furthermore, functionally graded additive manufacturing (FGAM), a potential direction for AM, enables the realization of biomimetic structures, such as natural teeth; however, specific studies are currently lacking. CONCLUSIONS AM dental ceramics are not sufficiently developed for large-scale clinical applications. However, with additional research, it may be possible for AM to replace SM as the mainstream manufacturing technology for ceramic restorations.
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Affiliation(s)
- Han Zhu
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Jimin Jiang
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yujie Wang
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Sijie Wang
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yong He
- State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou, PR China
| | - Fuming He
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
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Refaie A, Bourauel C, Elshazly T, Evers-Dietze B, Alhotan A, Aldesoki M. Trueness and precision of digital light processing fabricated 3D printed monolithic zirconia crowns. J Dent 2024; 148:105151. [PMID: 38909644 DOI: 10.1016/j.jdent.2024.105151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 06/25/2024] Open
Abstract
OBJECTIVES The present study aimed to evaluate the trueness and precision of monolithic zirconia crowns (MZCs) fabricated by 3D printing and milling techniques. METHODS A premolar crown was designed after scanning a prepared typodont. Twenty MZCs were fabricated using milling and 3D-printing techniques (n = 10). All the specimens were scanned with an industrial scanner, and the scanned data were analyzed using 3D measurement software to evaluate the trueness and precision of each group. Root mean square (RMS) deviations were measured and statistically analyzed (One-way ANOVA, Tukey's, p ≤ 0.05). RESULTS The trueness of the printed MZC group (140 ± 14 μm) showed a significantly higher RMS value compared to the milled MZCs (96 ± 27 μm,p < 0.001). At the same time, the precision of the milled MZCs (61 ± 17 μm) showed a significantly higher RMS value compared to that of the printed MZCs (31 ± 5 μm,p < 0.001). CONCLUSIONS The Fabrication techniques had a significant impact on the accuracy of the MZCs. Milled MZCs showed the highest trueness, while printed MZCs showed the highest precision. All the results were within the clinically acceptable error values. CLINICAL SIGNIFICANCE Although the trueness of the milled MZCs is higher, the manufacturing accuracy of the 3D-printed MZCs showed clinically acceptable results in terms of trueness and precision. However, additional clinical studies are recommended. Furthermore, the volumetric changes of the material should be considered.
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Affiliation(s)
- Ashraf Refaie
- Oral Technology, Dental School, University Hospital Bonn, Bonn, Germany; Department of Fixed Prosthodontics, Faculty of Dentistry, Fayoum University, Egypt.
| | | | - Tarek Elshazly
- Oral Technology, Dental School, University Hospital Bonn, Bonn, Germany
| | - Bernd Evers-Dietze
- Department of Electrical Engineering, Mechanical Engineering and Technical Journalism (EMT), Bonn-Rhein-Sieg University of Applied Sciences, Sankt Augustin, Germany
| | - Abdulaziz Alhotan
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Mostafa Aldesoki
- Oral Technology, Dental School, University Hospital Bonn, Bonn, Germany
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Xiao P, Zheng Z, Zhang Y, Zeng Y, Yan W. Accuracy and adaptation of one-piece endodontic crowns fabricated through 3D printing and milling. J Prosthet Dent 2024:S0022-3913(24)00363-9. [PMID: 38880678 DOI: 10.1016/j.prosdent.2024.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/18/2024]
Abstract
STATEMENT OF PROBLEM High-level evidence regarding the accuracy and adaptation of 1-piece endodontic crowns fabricated by using 3-dimensional (3D) printing technology is lacking. PURPOSE The purpose of this in vitro study was to compare the accuracy and adaptation of 1-piece endodontic crowns produced through 3D printing and computer-numerical-control milling technology and to explore the influence of trueness on 1-piece endodontic crown adaptation. MATERIAL AND METHODS One-piece endodontic crowns were prepared for a typodont right mandibular first molar, scanned with a 3Shape E3 scanner, and designed with a computer-aided design software program. Two types of 1-piece endodontic crowns were fabricated: 3D printed by using resin and zirconia slurry and milled from Grandio and zirconia blocks. A reverse engineering software program was used to superimpose 4 groups of crowns with the reference crowns used for accuracy analysis. Microcomputed tomography was used to measure 1-piece endodontic crown adaptation. The correlation between trueness and adaptation was evaluated through the Spearman correlation test (α=.05). RESULTS Milled resin-based 1-piece endodontic crowns demonstrated better trueness on marginal and occlusal surfaces compared with 3D printed ones (P<.001). However, no significant difference was observed in the trueness of intaglio surfaces between the 2 groups (P>.05). The milled group exhibited better adaptations than the printed one (P<.05). For zirconia 1-piece endodontic crowns, no significant differences were found in trueness or adaptation between the milled and printed groups (P>.05). Notably, the trueness of the axial wall had the greatest impact on overall crown adaptation, with its adaptation closely linked to the trueness of each area, particularly the axial wall. CONCLUSIONS Milled resin-based 1-piece endodontic crowns exhibited higher levels of trueness and adaptation compared with 3D printed ones, while 3D printed zirconia 1-piece endodontic crowns were comparable with milled ones.
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Affiliation(s)
- Ping Xiao
- Graduate student, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China
| | - Ziting Zheng
- Graduate student, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China
| | - Yanli Zhang
- Doctoral student, Stomatological Hospital, Southern Medical University, Guangzhou, PR China
| | - Yuting Zeng
- Graduate student, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China
| | - Wenjuan Yan
- Professor, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, PR China.
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Cho SM, Young Kim RJ, Park JM, Chung HM, Kim DY. Trueness, physical properties, and surface characteristics of additive-manufactured zirconia crown. J Mech Behav Biomed Mater 2024; 154:106536. [PMID: 38579394 DOI: 10.1016/j.jmbbm.2024.106536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/29/2024] [Accepted: 03/31/2024] [Indexed: 04/07/2024]
Abstract
OBJECTIVE This study aimed to conduct a comparison of trueness and physical and surface properties among five distinct types of additive manufactured (AM) zirconia crowns and zirconia crowns produced using the subtractive manufacturing (SM). MATERIAL AND METHODS Zirconia crowns were fabricated using five distinct techniques, each varying in the method of slurry transfer and photocuring source. Each experimental group utilized either one of the four digital light processing (DLP)-based techniques (DLP spreading, DLP spreading gradation, DLP vat and DLP circular spreading) or the stereolithography (SLA)-based technique (SLA spreading). The control (CON) group employed SM. To assess accuracy, trueness was measured between the scan and reference data. To analyze the physical properties, voids were examined using high-energy spiral micro-computed tomography scans, and the crystal structure analysis was performed using X-ray diffraction (XRD). Surface roughness was assessed through laser scanning microscopy. RESULTS Differences in the trueness of internal surfaces of crowns were found among the groups (P < 0.05). Trueness varied across the measurement surfaces (occlusal, lateral, and marginal) in all the groups except for the DLP spreading gradation group (P < 0.05). Voids were observed in all AM groups. All groups showed similar XRD patterns. All AM groups showed significantly greater surface roughness compared to the CON group (P < 0.001). CONCLUSION The AM zirconia crowns showed bubbles and a rougher surface compared to the SM crowns. All groups exhibited typical zirconia traits and trueness levels within clinically acceptable limits, suggesting that current zirconia AM techniques could be suitable for dental applications.
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Affiliation(s)
- Su-Min Cho
- Dental Research Institute, Seoul National University School of Dentistry, 101, Daehak-ro, Jongno-gu, Seoul, Republic of Korea.
| | - Ryan Jin Young Kim
- Dental Research Institute, Seoul National University School of Dentistry, 101, Daehak-ro, Jongno-gu, Seoul, Republic of Korea.
| | - Ji-Man Park
- Department of Prosthodontics & Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
| | - Hye-Min Chung
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, 50-1, Yonsei-ro, Seodaemun-gu, Seoul, Republic of Korea.
| | - Deok-Yeong Kim
- Dental Research Institute, Seoul National University School of Dentistry, 101, Daehak-ro, Jongno-gu, Seoul, Republic of Korea.
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Mosaddad SA, Peláez J, Panadero RA, Ghodsi S, Akhlaghian M, Suárez MJ. Do 3D-printed and milled tooth-supported complete monolithic zirconia crowns differ in accuracy and fit? A systematic review and meta-analysis of in vitro studies. J Prosthet Dent 2024:S0022-3913(24)00283-X. [PMID: 38772783 DOI: 10.1016/j.prosdent.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 05/23/2024]
Abstract
STATEMENT OF PROBLEM Additive (3-dimensional printing) and subtractive (milling) methods are digital approaches to fabricating zirconia restorations. Comparisons of their resultant fabrication accuracy and restoration fit are lacking. PURPOSE The purpose of this systematic review and meta-analysis was to evaluate the accuracy and fit of monolithic zirconia crowns fabricated by 3-dimensional printing and milling. MATERIAL AND METHODS The PubMed (Medline), Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar databases were searched up to August 2023. Eligible records were included, and the standardized mean difference (SMD) analyzed 4 outcomes: marginal fit, intaglio fit, trueness, and precision. Publication bias was analyzed with Trim-and-fill, the Egger regression test, and Begg funnel plot. Methodological quality was rated using the QUIN tool. RESULTS A total of 15 publications were found eligible out of the initial 6539 records. The 3-dimensional printing group demonstrated a lower marginal fit (SMD=1.46, 95% CI=[0.67, 2.26], P<.001; I2=83%, P<.001) and trueness (SMD=0.69, 95% CI=[0.20, 1.18], P=.006; I2=88%, P<.001) and a significantly higher precision (SMD=-2.19, 95% CI=[-2.90, -1.48], P<.001; I2=56%, P=.045). The intaglio fit did not differ significantly across the study groups (SMD=0.77, 95% CI=[-0.22, 1.77], P=.127; I2=87%, P<.001). CONCLUSIONS Given the high degree of heterogeneity, it can be cautiously concluded that while 3-dimensional printing led to greater precision, the outcomes of the 2 accuracy and adaptation parameters most crucial to the longevity of the restorations-trueness and marginal fit-showed the superiority of the milling technique.
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Affiliation(s)
- Seyed Ali Mosaddad
- Researcher, Department of Conservative Dentistry and Bucofacial Prosthesis, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain; and Adjunct Faculty Member, Department of Research Analytics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India.
| | - Jesús Peláez
- Adjunct Professor, Department of Conservative Dentistry and Bucofacial Prosthesis, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain.
| | - Rubén Agustín Panadero
- Professor, Department of Stomatology, Faculty of Medicine and Dentistry, Valencia University, Valencia, Spain
| | - Safoura Ghodsi
- Associate Professor, Dental Research Center, Dentistry Research Institute, Department of Prosthodontics, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Akhlaghian
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - María J Suárez
- Professor, Department of Conservative Dentistry and Bucofacial Prosthesis, Faculty of Odontology, Complutense University of Madrid, Madrid, Spain
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Tseng CW, Lin WS, Sahrir CD, Lin WC. The impact of base design and restoration type on the resin consumption, trueness, and dimensional stability of dental casts additively manufactured from liquid crystal display 3D printers. J Prosthodont 2024. [PMID: 38706414 DOI: 10.1111/jopr.13864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/13/2024] [Indexed: 05/07/2024] Open
Abstract
PURPOSE To evaluate the effects of two base types and three restoration designs on the resin consumption and trueness of the 3D-printed dental casts. Additionally, the study explored the dimensional stability of these 3D-printed dental casts after 1 year of storage. MATERIALS AND METHODS Various types of reference dental casts were specifically designed to represent three types of dental restoration fabrications, including full-arch (FA), long-span (LS), and single-unit (SU) prostheses. The reference casts were digitized with a dental laboratory scanner and used to create flat and hollow base designs (N = 18) for the 3D-printed study casts. The 3D-printed study casts were digitized and evaluated against their corresponding references immediately after 3D printing and again after 1 year of storage, with the trueness quantified using the root mean square error (RMSE) at both time points. Volumes of resin used were recorded to measure resin consumption, and the weights of the 3D-printed study casts were also measured. The data were analyzed using two-way ANOVA and a Tukey post hoc test, α = 0.05. RESULTS Volumetric analysis showed the flat-base design had significantly higher resin consumption with weights for the FA group at 42.51 ± 0.16 g, the LS group at 31.64 ± 0.07 g, and the SU group at 27.67 ± 0.31 g, as opposed to 26.22 ± 1.01 g, 22.86 ± 0.93 g, and 20.10 ± 0.19 g for the hollow designs respectively (p < 0.001). Trueness, assessed through two-way ANOVA, revealed that the flat-base design had lower RMSE values indicating better trueness in the LS (54 ± 6 µm) and SU (59 ± 7 µm) groups compared to the hollow-base design (LS: 73 ± 5, SU: 99 ± 11 µm, both p < 0.001), with no significant difference in the FA group (flat-base: 50 ± 3, hollow: 47 ± 5 µm, p = 0.398). After 1 year, the flat-base design demonstrated superior dimensional stability in the LS (flat base: 56 ± 6 µm, hollow base: 149 ±45 µm, p < 0.001) and SU groups (flat base: 95 ± 8 µm, hollow base: 183 ±27 µm, p < 0.001), with the FA group showing no significant difference in the base design (flat base: 47 ± 9, hollow base: 62 ± 12 µm, p = 0.428). CONCLUSIONS The hollow-base design group showed lower resin consumption than the flat-base design group. However, the flat-base designs exhibited superior trueness and less distortion after 1 year of storage. These findings indicate that despite the higher material usage, flat-base designs provide better initial accuracy and maintain their dimensional stability over time for most groups.
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Affiliation(s)
- Chih-Wei Tseng
- Department of Dentistry, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Wei-Shao Lin
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Indiana, USA
| | - Citra Dewi Sahrir
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Wei-Chun Lin
- Department of Dentistry, Wan-Fang Hospital, Taipei Medical University, Taipei, Taiwan
- School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
- Center for Tooth Bank and Dental Stem Cell Technology, Taipei Medical University, Taipei, Taiwan
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Alghauli M, Alqutaibi AY, Wille S, Kern M. 3D-printed versus conventionally milled zirconia for dental clinical applications: Trueness, precision, accuracy, biological and esthetic aspects. J Dent 2024; 144:104925. [PMID: 38471580 DOI: 10.1016/j.jdent.2024.104925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/11/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
OBJECTIVES This systematic review aimed to compare the clinical outcome, internal gap, trueness, precision, and biocompatibility of 3D-printed (AM) compared to milled (SM) zirconia restorations. DATA SOURCE A thorough search of Internet databases was conducted up to September 2023. The search retrieved studies compared AM zirconia to SM zirconia restorations regarding clinical outcome, fit, trueness, precision, and biocompatibility. STUDY SELECTION Of 1736 records, only 59 were screened for eligibility, and 22 records were included in this review. The quality of studies was assessed using the revised Cochrane risk-of-bias tool (ROB2), and the Modified Consort Statement. One clinical study exhibited a low risk of bias. All laboratory studies revealed some bias concerns. Short-term observation showed 100 % survival with no signs of periodontal complications. 3D-printed zirconia crowns showed statistically significant lower ΔE and a better match to adjacent teeth (p ≤ 0.5). The fit, trueness, and precision vary with the printing technique and the tooth surface. CONCLUSIONS 3D-printed zirconia crowns provide better aesthetic color and contour match to adjacent natural teeth than milled crowns. Both 3D printing and milling result in crowns within the clinically acceptable internal and marginal fit. Except for nanoparticle jetting, the marginal gap of SM crowns was smaller than AM crowns, however, both were clinically acceptable. Laminate veneers might be more accurately produced by 3D printing. 3D-printed axial surface trueness was better than milled axial surfaces. Long-term RCTs are recommended to confirm the clinical applicability of 3D-printed restorations. CLINICAL SIGNIFICANCE Internal fit and gap, precision, and trueness are fundamental requirements for successful dental restorations. Both techniques produce restorations with clinically acceptable marginal and internal fit. Axial surfaces and narrow or constricted areas favored 3D-printed than conventionally milled zirconia.
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Affiliation(s)
- Mohammed Alghauli
- Prosthodontics Department, College of Dentistry, Ibb University, Yemen; Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany.
| | - Ahmed Yaseen Alqutaibi
- Prosthodontics Department, College of Dentistry, Ibb University, Yemen; Prosthodontics Department, College of Dentistry, Taibah University, Al-Madinah, Saudi Arabia
| | - Sebastian Wille
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontic, Propaedeutic and Dental Materials, Faculty of Dentistry, Kiel University, Kiel, Germany
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Cameron AB, Choi JJE, Ip A, Lyons N, Yaparathna N, Dehaghani AE, Feih S. Assessment of the trueness of additively manufactured mol3% zirconia crowns at different printing orientations with an industrial and desktop 3D printer compared to subtractive manufacturing. J Dent 2024; 144:104942. [PMID: 38494044 DOI: 10.1016/j.jdent.2024.104942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/03/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024] Open
Abstract
OBJECTIVES This study endeavours to investigate the effect of printing orientation on the trueness of additively manufactured molar zirconia crowns. The areal surface roughness and the characteristics of the marginal regions of the crowns were also considered. METHODS Twelve molar crowns were manufactured at 0°, 45°, and, 90° printing orientations in a Lithoz and AON zirconia printer, respectively. Twelve milled crowns were used as a comparison. Samples were scanned and analysed in metrology software to determine the trueness of the groups. Regions of interest were defined as the margins, intaglio surface and contact points. Areal surface roughness and print layer thickness were further analysed using a confocal laser scanning microscope. RESULTS The results indicate that there are clear differences between the investigated desktop (AON) and industrial (Lithoz) 3D printer. The 45° Lithoz group is the only sample group showing no significantly different results in trueness for all regions analysed compared to the milled group. Areal surface roughness analysis indicates that the print layers in the marginal regions are within clinically tolerable limits and surface characteristics. CONCLUSIONS The printing orientation for zirconia crowns is critical to trueness, and differences are evident between different AM apparatuses. Considerations for design and orientation between different apparatuses should therefore be considered when utilising direct additive manufacturing processes. The areal surface roughness of the marginal regions is within acceptable clinical limits for all manufacturing processes and print orientations considered. CLINICAL SIGNIFICANCE The materials and apparatuses for additive manufacturing of zirconia crowns are now clinically acceptable from the perspective of the trueness of a final crown for critical functional surfaces and areal surface roughness of the marginal regions.
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Affiliation(s)
- Andrew B Cameron
- School of Medicine and Dentistry, Griffith University, Southport, Queensland, 4222, Australia; Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Menzies Health Institute, Griffith University, Southport, Queensland, 4222, Australia.
| | - Joanne Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
| | | | - Nathan Lyons
- Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Menzies Health Institute, Griffith University, Southport, Queensland, 4222, Australia; Queensland College of Art, Griffith University, Southport, Queensland, 4222, Australia
| | - Navodika Yaparathna
- School of Medicine and Dentistry, Griffith University, Southport, Queensland, 4222, Australia
| | - Ali Ebrahimzadeh Dehaghani
- Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Menzies Health Institute, Griffith University, Southport, Queensland, 4222, Australia; Advanced Design and Prototyping Technologies (ADaPT) Institute, Griffith University, Southport, Queensland, 4222, Australia
| | - Stefanie Feih
- Griffith Centre of Biomedical and Rehabilitation Engineering (GCORE), Menzies Health Institute, Griffith University, Southport, Queensland, 4222, Australia; School of Engineering and Built Environment, Griffith University, Southport, Queensland, 4222, Australia; Advanced Design and Prototyping Technologies (ADaPT) Institute, Griffith University, Southport, Queensland, 4222, Australia
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Handermann R, Zehender N, Rues S, Kobayashi H, Rammelsberg P, Schwindling FS. Load-bearing capacity of 3D-printed incisor partial-coverage crowns made from zirconia and composite. J Prosthodont Res 2024:JPR_D_23_00028. [PMID: 38684407 DOI: 10.2186/jpr.jpr_d_23_00028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
PURPOSE This study investigated the fracture resistance of 0.5-mm-thick restorations for minimally invasive therapy. Anterior partial-coverage crowns composed of three-dimensional (3D)-printed 3-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP; Lithacon 3Y210, Lithoz) and 3D-printed composite (Varseo Smile Crown plus, Bego) were compared with a control group made from milled 3Y-TZP (Cercon ht, DentsplySirona). METHODS Three groups each with 27 restorations were produced. For milled 3Y-TZP partial-coverage crowns, drill compensation was needed so the milling bur could access the inner surface at the incisal edge. Restoration fit was verified by cross-sectioning 12 specimens in each group. The remaining 15 restorations were sandblasted (Al2O3, 0.1 MPa) and adhesively cemented (Panavia SA, Kuraray) onto CoCr teeth. Static load-to-failure tests were performed. The load was induced on the incisal edge. The forces needed to fracture the specimens were analyzed using the Welch analysis of variance and post hoc Dunnet-T3 tests. The Weibull parameters were also calculated. RESULTS Drill compensation increased cement thickness at the loading area by 200 µm in milled 3Y-TZP restorations compared with the 3D-printed partial-coverage crowns. Fracture resistance was the highest in 3D-printed 3Y-TZP restorations (1570±661N) followed by milled 3Y-TZP (886±164N) and 3D-printed composite partial-coverage crowns (570±233 N). Milled 3Y-TZP was associated with a substantially higher Weibull modulus (m=6) than the 3D-printed materials (m=2), suggesting greater reliability. CONCLUSIONS Fracture resistance increased with tighter fit, demonstrating the benefit of the geometric freedom associated with 3D-printing. Future research should focus on making 3D-printed 3Y-TZP more reliable to increase its safety in clinical use.
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Affiliation(s)
- Rebecca Handermann
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Hiro Kobayashi
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
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Toksoy D, Önöral Ö. Influence of glazing and aging on the marginal, axial, axio-occlusal, and occlusal fit of 3-unit monolithic zirconia restorations fabricated using additive and subtractive techniques. J Prosthet Dent 2024; 131:658.e1-658.e9. [PMID: 38342643 DOI: 10.1016/j.prosdent.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/13/2024]
Abstract
STATEMENT OF PROBLEM Studies are sparse on how glazing and aging influence the fit of additively fabricated monolithic zirconia restorations. PURPOSE The purpose of this in vitro study was to assess the effect of glazing and aging on the fit of 3-unit monolithic zirconia restorations fabricated using different techniques. MATERIAL AND METHODS A total of 32 monolithic zirconia restorations were fabricated for a typodont model by using 4 distinct techniques (subtractive fabrication [SF], stereolithography [SLA], digital light processing [DLP], and lithography-based ceramic manufacturing [LCM]). The silicone replica approach was adopted to measure the discrepancy values for premolar and molar abutments after sintering, glazing, and 1 year of aging. The silicone replicas were sliced into mesiodistal and buccopalatal cross-sections, and digital micrographs of the cross-sections were made with a ×80 stereomicroscope. An inherent measuring program was run to record the discrepancy values (µm). Repeated-measures 2-way ANOVAs with the Bonferroni post hoc test were used to statistically analyze the acquired data. (α=.05). RESULTS From the repeated measures 2-way ANOVAs, both the glazing×fabrication technique and the aging×fabrication technique interactions were not statistically significant (P>.05). Glazing significantly influenced premolar abutment marginal (P=.022) and occlusal (P=.007) discrepancy values, as well as molar abutment marginal discrepancy values (P=.047). Aging had a statistically significant effect on premolar abutment marginal (P=.008) and occlusal (P=.011) discrepancy values, as well as molar abutment occlusal discrepancy values (P=.039). In both the glazing and aging data, for all areas of interest, statistically significant differences were detected among the fabrication techniques (P<.05). The LCM group had the lowest discrepancy values, followed by the SLA, SF, and DLP groups. CONCLUSIONS The LCM and SLA groups outperformed the other groups in terms of fit accuracy. The glazing and aging procedures altered the discrepancy values. The marginal discrepancy values of all groups were below the threshold of clinical acceptability (<120 µm).
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Affiliation(s)
- Dilem Toksoy
- Research Assistant, Department of Prosthetic Dentistry, Faculty of Dentistry, Near East University, Nicosia, North Cyprus
| | - Özay Önöral
- Associate Professor, Department of Prosthetic Dentistry, Faculty of Dentistry, Near East University, Nicosia, North Cyprus.
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Rues S, Herpel C, Ilani A, Schmitt C, Rammelsberg P, Schwindling FS. Effect of firing time and wall thickness on the biaxial flexural strength of 3D-printed zirconia. Dent Mater 2024; 40:484-492. [PMID: 38155019 DOI: 10.1016/j.dental.2023.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
OBJECTIVES To evaluate the effect of accelerated firing on 3D-printed zirconia. METHODS To check if formulae provided by ISO 6872 can be extended to thin samples, finite element analyses were carried out in advance of fabricating 3-mol% yttria-stabilized tetragonal zirconia polycrystal discs by milling and by 3D-printing. Four groups (n = 38 each) of 3D-printed specimens were produced with two nominal thicknesses (0.6 mm and 1.2 mm) and two firing strategies (long: 51 h, accelerated: 14.5 h). In the milled group (thickness 1.2 mm, n = 30), a standard firing program (9.8 h) was selected. Biaxial flexural strength tests were applied and mean strength, characteristic strength, and Weibull modulus were calculated for each group. Differences were analyzed using Welch ANOVA and Dunnett-T3 post-hoc tests. RESULTS Maximum tensile stresses occurring during biaxial strength testing can be calculated according to ISO 6872 for thin samples with b > 0.3 mm. Variability of measured strengths values was smaller for milled zirconia compared with 3D-printed zirconia. The 1.2-mm-thick 3D-printed samples had significantly decreased strength after accelerated firing than after long firing. However, for the 0.6-mm-thick samples, comparable mean biaxial strength values of about 1000 MPa were measured for both firing protocols. SIGNIFICANCE At the moment, long fabrication time for zirconia restorations is a major drawback of 3D-printing when compared with milling technology. This investigation showed that the strength of 0.6-mm-thick zirconia discs fabricated by 3D-printing was not impaired by accelerated firing. Thus, overnight firing of thin-walled 3D-printed zirconia restorations could be possible.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
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Zandinejad A, Khurana S, Liang Y, Liu X. Comparative evaluation of gingival fibroblast growth on 3D-printed and milled zirconia: An in vitro study. J Prosthodont 2024; 33:54-60. [PMID: 36693242 DOI: 10.1111/jopr.13650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/25/2023] Open
Abstract
PURPOSE The purpose of this study was to analyze the fibroblast growth and proliferation on 3D-printed zirconia in presence and absence of porosities. MATERIAL AND METHODS A total of 40 bars (8 × 4 × 3) were included in this study. Thirty 3D-printed and 10 milled zirconia samples were prepared. The 3D-printed samples had different porosities, 0% (PZ0), 20% (PZ20), and 40% (PZ40) with 10 specimens in each group. Milled zirconia samples were used as the control (MZ). Rat gingival fibroblasts were cultured for 48 h, and the proliferation of fibroblasts on each sample in each group (n = 10) was determined by MTT assays. The differences among the four groups were compared by one-way ANOVA. To test the significance of the observed differences between two groups, an unpaired Student's t-test was applied. The significance level was set at p < 0.05. Qualitative analysis for the cell culture was performed using scanning electron microscopy. RESULTS One-way ANOVA showed that the numbers of the fibroblasts among the four groups had a statistical difference. Post hoc Bonferroni test revealed that there was no significant difference between PZ0 and MZ; however, all other groups and among groups were significantly different. CONCLUSIONS Fibroblasts had a better affinity toward the MZ and PZ0 in a short period of cell culture time.
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Affiliation(s)
- Amirali Zandinejad
- Implant Dentistry Associations of Arlington, Arlington, Texas, USA
- Department of Comprehensive Dentistry, College of Dentistry, Texas A&M University, Dallas, Texas, USA
| | - Saumya Khurana
- Department of Biomedical Science, College of Dentistry, Texas A&M University, Dallas, Texas, USA
| | - Yongxi Liang
- Department of Biomedical Science, College of Dentistry, Texas A&M University, Dallas, Texas, USA
| | - Xiaohua Liu
- Department of Biomedical Science, College of Dentistry, Texas A&M University, Dallas, Texas, USA
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Su G, Zhang Y, Jin C, Zhang Q, Lu J, Liu Z, Wang Q, Zhang X, Ma J. 3D printed zirconia used as dental materials: a critical review. J Biol Eng 2023; 17:78. [PMID: 38129905 PMCID: PMC10740276 DOI: 10.1186/s13036-023-00396-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
In view of its high mechanical performance, outstanding aesthetic qualities, and biological stability, zirconia has been widely used in the fields of dentistry. Due to its potential to produce suitable advanced configurations and structures for a number of medical applications, especially personalized created devices, ceramic additive manufacturing (AM) has been attracting a great deal of attention in recent years. AM zirconia hews out infinite possibilities that are otherwise barely possible with traditional processes thanks to its freedom and efficiency. In the review, AM zirconia's physical and adhesive characteristics, accuracy, biocompatibility, as well as their clinical applications have been reviewed. Here, we highlight the accuracy and biocompatibility of 3D printed zirconia. Also, current obstacles and a forecast of AM zirconia for its development and improvement have been covered. In summary, this review offers a description of the basic characteristics of AM zirconia materials intended for oral medicine. Furthermore, it provides a generally novel and fundamental basis for the utilization of 3D printed zirconia in dentistry.
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Affiliation(s)
- Guanyu Su
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Yushi Zhang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Chunyu Jin
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Qiyue Zhang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Jiarui Lu
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Zengqian Liu
- Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
- School of Materials Science and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Qiang Wang
- Liaoning Provincial Key Laboratory of Oral Diseases, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China
| | - Xue Zhang
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China.
| | - Jia Ma
- Department of Orthodontics, School and Hospital of Stomatology, China Medical University, No. 117 Nanjing North Street, Shenyang, 110001, China.
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Li R, Xu T, Wang Y, Sun Y. Accuracy of zirconia crowns manufactured by stereolithography with an occlusal full-supporting structure: An in vitro study. J Prosthet Dent 2023; 130:902-907. [PMID: 35183363 DOI: 10.1016/j.prosdent.2022.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/31/2021] [Accepted: 01/04/2022] [Indexed: 10/19/2022]
Abstract
STATEMENT OF PROBLEM Additive manufacturing is emerging as an alternative method of fabricating dental restorations, but the support design needs to be optimized. PURPOSE The purpose of this in vitro study was to evaluate the 3-dimensional trueness and adaptations of zirconia crowns manufactured by stereolithography (SLA) with an occlusal full-supporting structure, compared with those SLA-printed with pillar supports, and those made by milling. MATERIAL AND METHODS A zirconia abutment was prepared, and an anatomic contour crown was designed. The crowns were manufactured by SLA and milling (n=6). For SLA manufacturing, a full-supporting base and pillar supports were designed. The 3-dimensional (3D) trueness of the fabricated crowns was characterized by 3D deviation analysis. The adaptations of crowns in the SLA-base and milling groups were measured by using a triple-scan method. Color-difference maps and the root mean square (RMS) values were used to characterize the 3D trueness. One-way analysis of variance (ANOVA) and Tukey post hoc test were used to analyze the difference in RMS values among the 3 groups, and Student t test was used to analyze the difference in cement-gap width between the milling group and the SLA group with the full-supporting base (α=.05). RESULTS The 3D deviation analysis showed that in the external area, the RMS value of the SLA-pillar group was significantly higher than that of the SLA-base and the milling groups (P<.05). In the intaglio area, the milling group showed a lower RMS value than the 2 SLA groups (P<.05). The color-difference maps showed the SLA-base group had smaller positive errors at the cusp inclines than the SLA-pillar group. No statistically significant difference was found in adaptations between the SLA-base and milling groups (P>.05). CONCLUSIONS The occlusal full-supporting base provided improved support in fabricating the crowns, and no remnants were left after removal. The zirconia crowns manufactured by SLA with an occlusal full-supporting structure had good external 3D trueness and clinically acceptable adaptation.
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Affiliation(s)
- Rong Li
- Doctoral student, Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology, National Clinical Research Center for Oral Disease, Beijing, PR China
| | - Tan Xu
- Engineer, Porimy 3D Printing Technology Co. Ltd, Kunshan, PR China
| | - Yong Wang
- Professor, Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology & National Clinical Research Center for Oral Disease, Beijing, PR China
| | - Yuchun Sun
- Professor, Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology & National Clinical Research Center for Oral Disease, Beijing, PR China.
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Zhai Z, Sun J. Research on the low-temperature degradation of dental zirconia ceramics fabricated by stereolithography. J Prosthet Dent 2023; 130:629-638. [PMID: 34933748 DOI: 10.1016/j.prosdent.2021.11.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM Stereolithography is a promising method of fabricating zirconia ceramics with high strength and accuracy. However, studies of the aging effects on zirconia ceramics fabricated by this technique are lacking. PURPOSE The purpose of this in vitro study was to evaluate the aging effects on the crystalline content, microstructure, and mechanical properties of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) printed by stereolithography apparatus (SLA) and digital light processing (DLP) compared with those of zirconia milled by computer numerical control (CNC). MATERIAL AND METHODS Bar-shaped specimens were fabricated after layer-by-layer printing, debinding, and sintering by SLA and DLP. Specimens milled and sintered by CNC were used as controls (n=24/material). The specimens were divided into 12 groups (n=6) and aged (0/5/10/15 hours, 134 °C, 0.2 MPa), after which the crystalline content, microstructure, and mechanical properties were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and 3-point bend tests. The flexural strength and monoclinic (m) phase content were statistically evaluated (α=.05). RESULTS The XRD results showed that an m peak was not detected for any of the tested materials before aging. The m-phase content was the highest for SLA (5/10/15 hours: 19.64%/34.76%/41.88%), followed by DLP (5/10/15 hours: 9.62%/21.76%/28.43%) and CNC (5/10/15 hours: 2.29%/7.77%/7.66%). The SEM images showed zirconia grain fragments for DLP and grain pullout for SLA, while surface defects were not obvious for CNC. Within the materials, the flexural strength was the highest for SLA after aging for 5 hours (1010.3 MPa), followed by 10 hours (913.06 MPa) and 15 hours and 0 hours, which exhibited no difference (0/15 hours: 776.71/814.28 MPa) (P<.001). The flexural strength for CNC and DLP did not significantly change after aging for 5 hours, 10 hours, and 15 hours (P>.05). The flexural strength for CNC was always more than 1200 MPa, and that for DLP was approximately 800 MPa before and after aging. CONCLUSIONS Although the m-phase content for SLA and DLP increased with the aging time, the mechanical properties did not significantly decrease, indicating the stability of both materials.
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Affiliation(s)
- Zidi Zhai
- Graduate student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center of Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, PR China
| | - Jian Sun
- Professor, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center of Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai, PR China.
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Giugliano TS, Zhang Y, Janal MN, Lim CH, Smith RM, Choi M. In vitro comparison of physical characteristics of milled versus printed zirconia discs. J Prosthodont 2023:10.1111/jopr.13778. [PMID: 37776103 PMCID: PMC10980599 DOI: 10.1111/jopr.13778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023] Open
Abstract
PURPOSE The purpose of this study was to compare the dimensional accuracy, translucency, and biaxial flexural strength of milled zirconia (MZ) versus 3D-printed zirconia (PZ) discs. MATERIALS & METHODS A circular disc measuring 14.0 mm in diameter and 1.20 mm in thickness was designed using computer-aided design (CAD) software. The resulting standard tessellation language (STL) file was used both as a control and to fabricate 36 zirconia (3Y-TZP) disc specimens (n = 36): 18 were milled (group MZ) and 18 were 3D-printed (group PZ). The diameter and thickness of each disc were measured using a digital caliper. Translucency was evaluated using a calibrated dental colorimeter. The flexural strength was determined using the piston-on-three-ball biaxial flexure test. All measurements were done by one blinded examiner. The statistical significance level was set to α = 0.05. RESULTS The MZ discs had significantly more accurate dimensions than the PZ discs in both diameter and thickness when compared to the control CAD software-designed disc. The MZ discs exhibited significantly higher translucency (translucency parameter (TP) = 16.95 ±0.36 vs. 9.24 ±1.98) and biaxial flexural strength (996.16 ±137.37 MPa vs. 845.75 ±266.16 MPa) than the PZ discs. Finally, MZ possessed a significantly higher Weibull modulus relative to PZ. CONCLUSIONS The results showed that the milled specimens achieved better dimensional accuracy and were more translucent, stronger, and less prone to failure than printed specimens.
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Affiliation(s)
- Thomas S. Giugliano
- Department of Prosthodontics, New York University College of Dentistry, New York, NY
| | - Yu Zhang
- Laboratories for Microstructure Physics & Mechanics of Materials, Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA
| | - Malvin N. Janal
- Department of Epidemiology & Health Promotion, New York University College of Dentistry, New York, NY
| | - Chek Hai Lim
- Laboratories for Microstructure Physics & Mechanics of Materials, Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ruby M. Smith
- Post-Graduate Student, Department of Prosthodontics, New York University College of Dentistry, New York, NY
| | - Mijin Choi
- Department of Prosthodontics, New York University College of Dentistry, New York, NY
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Ioannidis A, Pala K, Strauss FJ, Hjerppe J, Jung RE, Joda T. Additively and subtractively manufactured implant-supported fixed dental prostheses: A systematic review. Clin Oral Implants Res 2023; 34 Suppl 26:50-63. [PMID: 37750533 DOI: 10.1111/clr.14085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 09/27/2023]
Abstract
AIM To compare and report on the performance of implant-supported fixed dental prostheses (iFDPs) fabricated using additive (AM) or subtractive (SM) manufacturing. METHODS An electronic search was conducted (Medline, Embase, Cochrane Central, Epistemonikos, clinical trials registries) with a focused PICO question: In partially edentulous patients with missing single (or multiple) teeth undergoing dental implant therapy (P), do AM iFDPs (I) compared to SM iFDPs (C) result in improved clinical performance (O)? Included were studies comparing AM to SM iFDPs (randomized clinical trials, prospective/retrospective clinical studies, case series, in vitro studies). RESULTS Of 2'184 citations, no clinical study met the inclusion criteria, whereas six in vitro studies proved to be eligible. Due to the lack of clinical studies and considerable heterogeneity across the studies, no meta-analysis could be performed. AM iFDPs were made of zirconia and polymers. For SM iFDPs, zirconia, lithium disilicate, resin-modified ceramics and different types of polymer-based materials were used. Performance was evaluated by assessing marginal and internal discrepancies and mechanical properties (fracture loads, bending moments). Three of the included studies examined the marginal and internal discrepancies of interim or definitive iFDPs, while four examined mechanical properties. Based on marginal and internal discrepancies as well as the mechanical properties of AM and SM iFDPs, the studies revealed inconclusive results. CONCLUSION Despite the development of AM and the comprehensive search, there is very limited data available on the performance of AM iFDPs and their comparison to SM techniques. Therefore, the clinical performance of iFDPs by AM remains to be elucidated.
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Affiliation(s)
- Alexis Ioannidis
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Kevser Pala
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Franz J Strauss
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Jenni Hjerppe
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Ronald E Jung
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Tim Joda
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
- Department of Reconstructive Dentistry, University Center for Dental Medicine Basel, University of Basel, Basel, Switzerland
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Dewan H. Clinical Effectiveness of 3D-Milled and 3D-Printed Zirconia Prosthesis-A Systematic Review and Meta-Analysis. Biomimetics (Basel) 2023; 8:394. [PMID: 37754145 PMCID: PMC10526775 DOI: 10.3390/biomimetics8050394] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/05/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND Additive manufacturing (three-dimensional (3D) printing) has become a leading manufacturing technique in dentistry due to its various advantages. However, its potential applications for dental ceramics are still being explored. Zirconia, among ceramics, has increasing popularity and applications in dentistry mostly due to its excellent properties. Although subtractive manufacturing (3D milling) is considered the most advanced technology for the fabrication of zirconia restorations, certain disadvantages are associated with it. METHODS A systematic review was piloted to compare the clinical performance of zirconium crowns that were fabricated using three-dimensional (3D) milling and 3D printing. A meta-analysis was performed, and studies published up to November 2022 were identified. The terms searched were "Zirconium crowns", "3D printing", "CAD/CAM" (Computer-Aided Design and Computer-Aided Manufacturing), "Milling", "dental crowns", and "3D milling". The characteristics that were compared were the year in which the study was published, study design, age of the patient, country, the number of crowns, the type of crown fabrication, marginal integrity, caries status, and outcomes. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to structure this systematic review. Out of eleven hundred and fifty titles identified after a primary search, nine articles were included in the quantitative analysis. The research question based on PICO/PECO (Participant, Intervention/exposure, Comparison, and Outcome) was "Do 3D-printed and milled (P) zirconia crowns and FDPs (I) have a better survival rate (O) when conventional prosthesis is also an option (C)"? The data collected were tabulated and compared, and the risk of bias and meta-analysis were later performed. Only nine articles (clinical research) were selected for the study. Since there were no clinical studies on the 3D printing of zirconium crowns, six in vitro studies were considered for the comparison. Zirconium crowns in the milling group had an average minimum follow-up of 6 months. RESULTS A moderate risk of bias was found, and survival was significant. A high heterogeneity level was noted among the studies. Marginal integrity, periodontal status, and survival rate were high. Linear regression depicted no statistical correlation between the type of cement used and the survival rate. CONCLUSIONS It can be concluded that the milled crowns had a higher performance and satisfactory clinical survival.
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Affiliation(s)
- Harisha Dewan
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia
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Zhu H, Zhou Y, Jiang J, Wang Y, He F. Accuracy and margin quality of advanced 3D-printed monolithic zirconia crowns. J Prosthet Dent 2023:S0022-3913(23)00444-4. [PMID: 37591717 DOI: 10.1016/j.prosdent.2023.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/19/2023]
Abstract
STATEMENT OF PROBLEM Nanoparticle jetting (NPJ) is a novel ceramic 3D-printing technology with high printing accuracy. However, studies reporting the accuracy of zirconia crowns manufactured by NPJ and comparing them with conventional zirconia crowns are lacking. PURPOSE The purpose of this in vitro study was to evaluate and compare the trueness, crown fit, and margin quality of monolithic zirconia crowns manufactured by NPJ with those milled by a computer numerical control system. MATERIAL AND METHODS A gypsum left mandibular first molar was prepared and scanned with an intraoral scanner (TRIOS 4). Three types of monolithic crowns were manufactured through 3D printing and subtractive manufacturing (SM): NPJ (3D printing), VITA (milling), UPCERA (milling). The crowns were scanned, and the dimensional deviation (trueness) was evaluated and compared by using a software program. The triple scan method was used to measure crown fit and uniform index through precise alignment in the software program, and margin quality was also observed with an optical microscope. The data were analyzed with 1-way analysis of variance and the Tukey post hoc test (α=.05). RESULTS The NPJ group reported better trueness of all crown and axial surfaces compared with the other SM group (P<.001), but marginal trueness (P=.601), intaglio surface (P=.596), and occlusal surface (P=.641) were statistically similar compared with the Vita milled group. All 3 groups reported clinically acceptable crown fit and uniformity with statistically similar values (P>.05). The NPJ group had more crowns judged to have flawless margin quality compared with the milled groups. CONCLUSIONS All 3 manufacturing methods can fabricate zirconia crowns with a clinically acceptable crown fit. The NPJ system could be used to manufacture monolithic zirconia crowns with better margin quality and proximal surface trueness than milled crowns.
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Affiliation(s)
- Han Zhu
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yi Zhou
- Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Jimin Jiang
- Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Yujie Wang
- Department of Periodontics, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China
| | - Fuming He
- Department of Prosthodontics and Implantology, Department of Prosthodontics, Department of Periodontics, Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Zhejiang Provincial Clinical Research Center for Oral Diseases, Key Laboratory of Oral Biomedical Research of Zhejiang Province, Cancer Center of Zhejiang University, Engineering Research Center of Oral Biomaterials and Devices of Zhejiang Province, Hangzhou, PR China.
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Refaie A, Fouda A, Bourauel C, Singer L. Marginal gap and internal fit of 3D printed versus milled monolithic zirconia crowns. BMC Oral Health 2023; 23:448. [PMID: 37403169 DOI: 10.1186/s12903-023-03184-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 06/28/2023] [Indexed: 07/06/2023] Open
Abstract
BACKGROUND This study aimed to evaluate and compare the marginal gap using two different methods and the internal fit of 3D printed and zirconia crowns. METHODS 3Y-TZP zirconia crowns (n = 20) were manufactured using subtractive milling (group M) and 3D printed (group P). The marginal gap was measured at 60 points using vertical marginal gap technique (VMGT). On the other hand, the silicone replica technique (SRT) was used to evaluate the internal fit and was divided into 4 groups: marginal gap, cervical gap, axial gap, and occlusal gap where the thickness of light impression was measured at 16 references. The numerical data was tested for normality using Shapiro-Wilk's test. They were found to be normally distributed and were analyzed using an independent t-test. RESULTS Using VMGT, group P had significantly higher mean marginal gap values of 80 ± 30 µm compared to group M = 60 ± 20 µm (p < 0.001). Also, with the SRT, the marginal gap of group P (100 ± 10 µm) had significantly higher values compared to group M (60 ± 10 µm). The internal fit showed significant difference between the tested groups except for Axial Gap. CONCLUSIONS Although milled crowns showed better results. The 3D printed zirconia crowns offer clinically acceptable results in terms of marginal adaptation and internal fit. Both VMGT and SRT are reliable methods for the assessment of the marginal gap.
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Affiliation(s)
- Ashraf Refaie
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany.
- Department of Fixed Prosthodontics, Faculty of Dentistry, Fayoum University, Faiyum, Egypt.
- Faculty of Oral and Dental Medicine, British University in Egypt, Cairo, Egypt.
| | - Ahmed Fouda
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany
| | | | - Lamia Singer
- Oral Medicine Technology, University Hospital Bonn, Bonn, Germany
- Department of Orthodontics, University Hospital Bonn, Bonn, Germany
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Liebermann A, Schultheis A, Faber F, Rammelsberg P, Rues S, Schwindling FS. Impact of post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of 3D-printed zirconia. Dent Mater 2023; 39:625-633. [PMID: 37179237 DOI: 10.1016/j.dental.2023.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To analyze the impact of different post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of additively manufactured zirconia. METHODS Disc-shaped specimens (N = 100) were 3D-printed from 3 mol%-yttria-stabilized zirconia (material: LithaCon 3Y 210; printer: CeraFab 7500, Lithoz) and were cleaned with five different methods (n = 20): (A) 25 s of airbrushing with the dedicated cleaning solution (LithaSol 30®, Lithoz) and 1-week storage in a drying oven (40 °C); (B) 25 s airbrushing (LithaSol 30®) without drying oven; (C) 30 s ultrasonic bath (US) filled with Lithasol30®; (D) 300 s US filled with LithaSol 30®; (E) 30 s US filled with LithaSol 30® followed by 40 s of airbrushing (LithaSol 30®). After cleaning, the samples were sintered. Geometry, transmission, roughness (Ra, Rz), characteristic strengths (σ0), and Weibull moduli (m) were analyzed. Statistical analyses were performed using Kolmogorov-Smirnov-, t-, Kruskal-Wallis-, and Mann-Whitney-U-tests (α < 0.05). RESULTS Short US (C) resulted in the thickest and widest samples. Highest transmission was found for US combined with airbrushing (E, p ≤ 0.004), followed by D and B (same range, p = 0.070). Roughness was lowest for US combined with airbrushing (E, p ≤ 0.039), followed by A and B (same range, p = 0.172). A (σ0 = 1030 MPa, m = 8.2), B (σ0 = 1165 MPa, m = 9.8), and E (σ0 = 1146 MPa, m = 8.3) were significantly stronger (p < 0.001) and substantially more reliable than C (σ0 = 480 MPa, m = 1.9) and D (σ0 = 486 MPa, m = 2.1). SIGNIFICANCE For 3D-printed zirconia, cleaning strategy selection is important. Airbrushing (B) and short US combined with airbrushing (E) were most favorable regarding transmission, roughness, and strength. Ultrasonic cleaning alone was ineffective (short duration) or detrimental (long duration). Strategy E could be particularly promising for hollow or porous structures.
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Affiliation(s)
- A Liebermann
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
| | - A Schultheis
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - F Faber
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - P Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - S Rues
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - F S Schwindling
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
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Yoo LG, Pang NS, Kim SH, Jung BY. Mechanical properties of additively manufactured zirconia with alumina air abrasion surface treatment. Sci Rep 2023; 13:9153. [PMID: 37280320 DOI: 10.1038/s41598-023-36181-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/29/2023] [Indexed: 06/08/2023] Open
Abstract
This study aimed to evaluate the mechanical properties of zirconia fabricated using additive manufacturing technology and compare them to those of zirconia fabricated using subtractive manufacturing technology. Sixty disc-shaped specimens were fabricated for the additive (n = 30) and subtractive manufacturing groups (n = 30), and each group was divided into two subgroups according to their air-abrasion surface treatment: control (n = 15) and air-abrasion groups (n = 15). Mechanical properties including the flexural strength (FS), Vickers hardness, and surface roughness were determined, and the values were analyzed by one-way ANOVA and Tukey's post hoc test (α = 0.05). X-ray diffraction and scanning electron microscopy were used for phase analysis and surface topography evaluation, respectively. The SMA group exhibited the highest FS (1144.97 ± 168.1 MPa), followed by the SMC (944.58 ± 141.38 MPa), AMA (905.02 ± 111.38 MPa), and AMC groups (763.55 ± 68.69 MPa). The Weibull distribution showed the highest scale value (1213.55 MPa) in the SMA group, with the highest shape value in the AMA group (11.69). A monoclinic peak was not detected in both the AMC and SMC groups, but after air abrasion, the monoclinic phase content ([Formula: see text]) reached 9% in the AMA group, exceeding that in the SMA group (7%). The AM groups exhibited statistically lower FS values than those of the SM groups under the same surface treatment (p < 0.05). Air-abrasion surface treatment increased the monoclinic phase content and FS (p < 0.05) in both the additive and subtractive groups, while it increased the surface roughness (p < 0.05) only in the additive group and did not affect the Vickers hardness in either group. For zirconia manufactured using additive technology, the mechanical properties are comparable to those of zirconia manufactured using subtractive technology.
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Affiliation(s)
- Lee-Gang Yoo
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea
| | - Nan-Sim Pang
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea
| | - So-Hyun Kim
- Department of Dentistry, Inha University Hospital, Inha University School of Medicine, Incheon, Korea
| | - Bock-Young Jung
- Department of Advanced General Dentistry, College of Dentistry, Yonsei University, 50 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722, South Korea.
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Revilla-León M, Fry E, Supaphakorn A, Barmak AB, Kois JC. Manufacturing accuracy of the intaglio surface of definitive resin-ceramic crowns fabricated at different print orientations by using a stereolithography printer. J Prosthet Dent 2023:S0022-3913(23)00267-6. [PMID: 37246096 DOI: 10.1016/j.prosdent.2023.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/30/2023]
Abstract
STATEMENT OF PROBLEM Stereolithography (SLA) procedures can be chosen for manufacturing definitive crowns; however, how the print orientation impacts the trueness and precision of the intaglio surface of the printed definitive restorations is unclear. PURPOSE The purpose of this in vitro investigation was to calculate the manufacturing accuracy of the intaglio surface of SLA definitive resin-ceramic crowns fabricated at varying print orientations (0, 45, 75, or 90 degrees). MATERIAL AND METHODS The standard tessellation language (STL) file of an anatomic contour molar crown was obtained and used to fabricate all the crowns by using a definitive resin-ceramic material (Permanent Crown) and an SLA printer (Form 3B+). Four groups were developed depending on the print orientation selected to manufacture the crowns: 0-, 45-, 70-, and 90-degree print orientation (n=30). Each crown specimen was digitized without the use of scanning powder by using a desktop scanner (T710). The crown design file was determined as the reference (control) group and used to calculate the fabricating trueness and precision of the intaglio surface of the specimens using the root mean square (RMS) error computation. Trueness data were examined by using 1-way ANOVA and post hoc pairwise multiple comparison Tukey tests, while precision data were analyzed using the Levene test (α=.05). RESULTS The mean ±standard deviation RMS error discrepancies ranged from 37 ±3 μm to 113 ±11 μm. One-way ANOVA exposed significant trueness (P<.001) differences among the groups considered in this study. Furthermore, all the print orientation groups tested were different from each other (P<.001). The 0-degree group presented the best trueness value (37 μm), while the 90-degree group obtained the worst trueness value (113 μm). The Levene test exposed significant precision differences among the groups assessed (P<.001). The 0-degree group had a significantly lower standard deviation (higher precision) (3 μm) than the other groups, with no difference among the other groups tested (P>.05). CONCLUSIONS The fabricating trueness and precision of the intaglio surface of the SLA resin-ceramic crowns was impacted by the varying print orientations assessed.
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Affiliation(s)
- Marta Revilla-León
- Affiliate Assistant Professor, Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash; Faculty and Director of Research and Digital Dentistry, Kois Center, Seattle, Wash; and Adjunct Professor, Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, Mass.
| | - Elisabeth Fry
- Director of Clinical Operations, Kois Center, Seattle, Wash
| | | | - Abdul B Barmak
- Assistant Professor, Clinical Research and Biostatistics, Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, NY
| | - John C Kois
- Director, Kois Center, Seattle, Wash; Affiliate Professor, Graduate in Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash; and Private Practice, Seattle, Wash
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Lyu J, Yang X, Li Y, Tan J, Liu X. Dimensional accuracy and clinical adaptation of monolithic zirconia crowns fabricated with the nanoparticle jetting technique. J Prosthet Dent 2023:S0022-3913(23)00260-3. [PMID: 37217418 DOI: 10.1016/j.prosdent.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 05/24/2023]
Abstract
STATEMENT OF PROBLEM The nanoparticle jetting (NPJ) technique is a recently developed additive manufacturing method that may have useful dental applications. The manufacturing accuracy and clinical adaptation of zirconia monolithic crowns fabricated with NPJ are unknown. PURPOSE The purpose of this in vitro study was to compare the dimensional accuracy and clinical adaptation of zirconia crowns fabricated with NPJ and those fabricated with subtractive manufacturing (SM) and digital light processing (DLP). MATERIAL AND METHODS Five standardized typodont right mandibular first molars were prepared for ceramic complete crowns, and 30 zirconia monolithic crowns were fabricated using SM, DLP, and NPJ (n=10) with a completely digital workflow. The dimensional accuracy at the external, intaglio, and marginal areas was determined by superimposing the scanned data and computer-aided design data of the crowns (n=10). Occlusal, axial, and marginal adaptations were evaluated by using a nondestructive silicone replica and dual scanning method. The 3-dimensional discrepancy was evaluated to determine clinical adaptation. Differences among test groups were analyzed by using a MANOVA and the post hoc least significant difference test for normally distributed data or the Kruskal-Wallis test with Bonferroni correction for nonnormally distributed data (α=.05). RESULTS Significant differences were found in the dimensional accuracy and clinical adaptation among the groups (P<.001). The NPJ group had a lower overall root mean square (RMS) value for dimensional accuracy (22.9 ±1.4 μm) than the SM (27.3 ±5.0 μm) and DLP (36.4 ±5.9 μm) groups (P<.001). The NPJ group had a lower external RMS value (23.0 ±3.0 μm) than the SM group (28.9 ±5.4 μm) (P<.001) and equivalent marginal and intaglio RMS values than the SM group. The DLP group had larger external (33.3 ±4.3 μm), intaglio (36.1 ±10.7 μm), and marginal (79.4 ±12.9 μm) deviations than the NPJ and SM groups (P<.001). With regard to clinical adaptation, the marginal discrepancy was smaller in the NPJ group (63.9 ±27.3 μm) than in the SM group (70.8 ±27.5 μm) (P<.001). No significant differences were found between the SM and NPJ groups in terms of the occlusal (87.2 ±25.5 and 80.5 ±24.2 μm, respectively) and axial (39.1 ±19.7 and 38.4 ±13.7 μm, respectively) discrepancies. The DLP group had larger occlusal (239.0 ±60.1 μm), axial (84.9 ±29.1 μm), and marginal (140.4 ±84.3 μm) discrepancies than the NPJ and SM groups (P<.001). CONCLUSIONS Monolithic zirconia crowns fabricated using NPJ have higher dimensional accuracy and clinical adaptation than those fabricated using SM or DLP.
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Affiliation(s)
- Jizhe Lyu
- Graduate student, Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China
| | - Xu Yang
- Clinical Associate Professor, Department Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yi Li
- Graduate student, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
| | - Jianguo Tan
- Professor, Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xiaoqiang Liu
- Associate Professor, Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China.
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Zhai Z, Qian C, Jiao T, Sun J. In vitro fracture and fatigue resistance of monolithic zirconia crowns fabricated by stereolithography. J Prosthet Dent 2023:S0022-3913(23)00127-0. [PMID: 36966099 DOI: 10.1016/j.prosdent.2023.02.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/22/2023] [Accepted: 02/22/2023] [Indexed: 03/27/2023]
Abstract
STATEMENT OF PROBLEM Stereolithography has been used to print zirconia ceramic crowns with acceptable dimensional accuracy and fracture force. However, studies that compared the fatigue resistance of zirconia crowns fabricated by stereolithography are lacking. PURPOSE The purpose of this in vitro study was to compare the fracture and fatigue resistance of monolithic zirconia crowns printed by stereolithography apparatus (SLA) and digital light processing (DLP) with those of zirconia crowns milled by computer numerical control (CNC). MATERIAL AND METHODS A total of 120 crowns were fabricated (n=40/material) and underwent 0, 104, 105, or 106 dynamic loading cycles of 30 to 300 N in artificial saliva, followed by a static fracture loading test (n=10). After fracture, 1 crown from each group was selected for fractography analysis by scanning electron microscopy (SEM). Data were statistically analyzed through 2-way ANOVA and post hoc analysis for multiple comparisons (α=.05). RESULTS The 2-way ANOVA results showed that the mean ±standard deviation force at fracture was the highest for CNC (before fatigue loading: 5154 ±568 N, 104: 5735 ±1231 N, 105: 5523 ±797 N, and 106: 6007 ±1258 N), followed by DLP (before fatigue loading: 3381 ±612 N, 104: 4046 ±1146 N, 105: 2929 ±559 N, and 106: 3223 ±739 N), and the lowest for SLA (before fatigue loading: 2956 ±598 N, 104: 2757 ±421 N, 105: 3326 ±391 N, and 106: 3103 ±246 N) (P<.01). The fracture force of the crowns was not significantly affected by the number of fatigue cycles (P>.05). Fractography analysis showed that the number of arrest lines increased for crowns of all 3 materials. SEM images also showed the steps of SLA and DLP from their layer-by-layer printing and small cracks between layers of SLA after 106 loading cycles. CONCLUSIONS The fracture force of monolithic zirconia crowns milled by CNC was significantly higher than that of zirconia crowns printed by stereolithography. Zirconia crowns printed by SLA and DLP could withstand typical clinical conditions, and their fracture and fatigue resistance exceeded the clinically estimated average occlusal forces.
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Affiliation(s)
- Zidi Zhai
- Graduate student, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; and Shanghai Research Institute of Stomatology, Shanghai, PR China
| | - Chao Qian
- Senior Lecturer, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; and Shanghai Research Institute of Stomatology, Shanghai, PR China
| | - Ting Jiao
- Professor, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; and Shanghai Research Institute of Stomatology, Shanghai, PR China
| | - Jian Sun
- Professor, Department of Prosthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; and Shanghai Research Institute of Stomatology, Shanghai, PR China.
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Shear bond strength of porcelain to milled and stereolithography additively manufactured zirconia with and without surface treatment: An in vitro study. J Prosthet Dent 2023:S0022-3913(23)00113-0. [PMID: 36932021 DOI: 10.1016/j.prosdent.2023.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 03/17/2023]
Abstract
STATEMENT OF PROBLEM Delamination of veneering ceramic is one of the most common challenges relating to veneered zirconia restorations. Additive manufacturing (AM) is a fast-expanding technology that has gained widespread acceptance in dentistry and is increasingly being used to produce dental restorations. However, information about bonding of porcelain to AM zirconia is lacking. PURPOSE The purpose of this in vitro study was to investigate the shear bond strength (SBS) of porcelain to milled and additively manufactured zirconia, and the effect of surface treatment on bond strength. MATERIAL AND METHODS A Ø12×5-mm disk was designed virtually to fabricate all specimens, which were divided into 2 groups according to the manufacturing technique: additively manufactured or milled zirconia. The effect of airborne-particle abrasion and a zirconia liner before porcelain application was investigated in both groups. Veneering porcelain was fired into an alumina ring mold on the zirconia surface. SBS was measured by using a universal testing machine at a crosshead speed of 1 mm/min before and after aging (n=10). SBS data were analyzed with 3-way ANOVA (α=.05) RESULTS: A significant difference was found between milled and AM zirconia. The SBS of porcelain to milled zirconia was significantly higher (1.38 MPa) than to AM zirconia (0.68 MPa) (P<.001). The surface treatment of zirconia had no significant effect on porcelain SBS in either group (P=.254), whereas thermocycling significantly reduced the SBS of porcelain to zirconia in both milled and AM groups (P=.001). CONCLUSIONS Porcelain bonding to milled zirconia was better than to AM zirconia. Pretreating the zirconia substrate before porcelain application did not improve the porcelain bond.
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Rues S, Zehender N, Zenthöfer A, Bömicke W, Herpel C, Ilani A, Erber R, Roser C, Lux CJ, Rammelsberg P, Schwindling FS. Fit of anterior restorations made of 3D-printed and milled zirconia: An in-vitro study. J Dent 2023; 130:104415. [PMID: 36640843 DOI: 10.1016/j.jdent.2023.104415] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/23/2022] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES To evaluate the fit of zirconia veneers made by either 3D printing or milling. METHODS A typodont maxillary central incisor was prepared for a 0.5-mm-thick veneer and was reproduced 36 times from resin. Restorations were designed with a 20-µm-wide marginal and a 60-µm-wide internal cement gap, and were made from 3D-printed zirconia (LithaCon 3Y 210, Lithoz, n = 24) and milled zirconia (Cercon ht, DentsplySirona, n = 12). For milled zirconia, a drill compensation was needed to give the milling bur access to the intaglio surface. The restorations were cemented, cross-sectioned, and the cement gap size was analyzed by two raters. Inter-rater reliability was studied at 12 3D-printed veneers (intraclass correlation coefficient, ICC, mixed model, absolute agreement). Twelve remaining 3D-printed restorations were compared with 12 milled restorations regarding fit at three locations: marginally, labially, and at the incisal edge (Mann-Whitney U-tests, α<0.05). RESULTS Inter-rater reliability was excellent, with an ICC single-measure coefficient of 0.944 (95%-confidence interval: [0.907; 0.966]). Gap sizes (mean ± SD / maximum) were 55 ± 9 / 143 µm at the margins, 68 ± 14 / 130 µm labially, and 78 ± 19 / 176 µm at the incisor edge for 3D-printed veneers. For milled veneers, gap sizes were 44 ± 11 / 141 µm at the margins, 85 ± 19 / 171 µm labially, and 391 ± 26 / 477 µm at the incisor edge. At the margins, the milled veneers outperformed the 3D-printed restorations (p = 0.011). The cement gap at the incisor edge was significantly smaller after 3D printing (p < 0.001). CONCLUSIONS 3D-printed zirconia restorations showed clinically acceptable mean marginal gaps below 100 µm. Because drill compensation could be omitted with 3D printing, the fit at the sharp incisal edge was significantly tighter than with milling. CLINICAL SIGNIFICANCE The fit of 3D-printed ceramic anterior restorations meets clinical standards. In addition, 3D printing is associated with a greater geometrical freedom than milling. With regard to fit this feature allows tighter adaptation even after minimally invasive preparation.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Andreas Zenthöfer
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Wolfgang Bömicke
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ralf Erber
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christoph Roser
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher J Lux
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
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Cho JH, Yoon HI, Oh JH, Kim DH. Effect of maximum support attachment angle on intaglio surface trueness of anatomic contour monolithic prostheses manufactured by digital light processing and zirconia suspension. J Prosthet Dent 2023; 129:478-485. [PMID: 36621357 DOI: 10.1016/j.prosdent.2022.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 01/07/2023]
Abstract
STATEMENT OF PROBLEM Support structures are essential for the quality of resin-based prostheses made by the digital light processing (DLP), but few studies have evaluated the effect of support structure on the accuracy of zirconia-based anatomic contour prostheses. PURPOSE The purpose of this in vitro study was to evaluate the effect of maximum support attachment angle (MSA) on the intaglio surface trueness of anatomic contour prostheses made by DLP and compare the trueness of 2-unit anatomic contour prostheses with that of those produced by milling. MATERIAL AND METHODS Anatomic contour single-unit prostheses were manufactured using DLP and a suspension with 3-mol% yttria-stabilized zirconia. Four different conditions of MSA values to the vertical axis of the object (50, 55, 60, and 65 degrees) were applied (n=10). After printing, postprocessing, and sintering, all successfully produced prostheses were evaluated for intaglio surface trueness by considering the root mean square (RMS). Using the MSA showing the highest trueness, the 2-unit prostheses made by DLP (DLP group) were compared with milled (MIL group) prostheses in terms of intaglio accuracy (n=10). One-way analysis of variance and a post hoc pairwise comparison or independent t test were used for trueness analysis (α=.05). RESULTS Three MSA groups (50, 55, and 60 degrees) were successfully produced with significant differences between the trueness of the single-unit prostheses for the groups with different MSA values (P<.05). The highest trueness was in the 50-degree MSA group. The 2-unit prostheses of the DLP group with 50-degree MSA showed significantly lower trueness than those of the MIL group (P<.05); however, the RMS values of both groups were lower than 50 μm. CONCLUSIONS The intaglio surface trueness of anatomic contour DLP-generated prostheses can be improved by changing the MSA. The 50-degree MSA was beneficial for the accuracy of both single-unit and 2-unit DLP-generated prostheses, produced within clinically acceptable limits.
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Affiliation(s)
- Jun-Ho Cho
- Research Associate, Department of Prosthodontics, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Republic of Korea
| | - Hyung-In Yoon
- Associate Professor, Department of Prosthodontics, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Republic of Korea.
| | - Jin-Ho Oh
- Principal Researcher, Research and Development Center, Mother-of-Pearl (M.O.P) Ltd, Seoul, Republic of Korea
| | - Do-Hyun Kim
- Principal Researcher, Research and Development Center, Mother-of-Pearl (M.O.P) Ltd, Seoul, Republic of Korea
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The Effect of a Digital Manufacturing Technique, Preparation Taper, and Finish Line Design on the Marginal Fit of Temporary Molar Crowns: An In-Vitro Study. Biomedicines 2023; 11:biomedicines11020570. [PMID: 36831106 PMCID: PMC9953521 DOI: 10.3390/biomedicines11020570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
The aim of this study is to investigate the combined effect of a digital manufacturing technique (subtractive vs. additive), preparation taper (10° vs. 20° TOC), and finish line (chamfer vs. shoulder) on the marginal adaptation of temporary crowns following cementation with a compatible temporary cement. Four mandibular first molar typodont teeth were prepared for full coverage crowns with standard 4 mm preparation height as follows: 10° TOC with the chamfer finish line, 10° TOC with the shoulder finish line, 20° TOC with the chamfer finish line and 20° TOC with the shoulder finish line. Each of the four preparation designs were subdivided into two subgroups to receive CAD/CAM milled and 3D-printed crowns (n = 10). A total of 80 temporary crowns (40 CAD/CAM milled and 40 3D-printed) were cemented to their respective die using clear temporary recement in the standard cementation technique. The samples were examined under a stereomicroscope at ×100 magnification following calibration. Linear measurements were performed at seven equidistant points on each axial surface and five equidistant points on each proximal surface. One-way ANOVA analysis and Tukey HSD (Honestly Significance Difference) were performed. The best marginal fit was seen in group 8, while the poorest fit was noted in group 2. Shoulder finish lines and 10° TOC resulted in higher marginal gaps, especially in CAD/CAM milled group. The selection of 3D-printed crowns may provide a better marginal fit within the range of clinical acceptability. Marginal gaps were within clinical acceptability (50 and 120 µm) in all groups except group 2.
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Jung JM, Kim GN, Koh YH, Kim HE. Manufacturing and Characterization of Dental Crowns Made of 5-mol% Yttria Stabilized Zirconia by Digital Light Processing. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1447. [PMID: 36837076 PMCID: PMC9963883 DOI: 10.3390/ma16041447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/05/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
We herein report manufacturing of dental crowns made of 5-mol% yttria partially stabilized zirconia (5Y-PSZ) with desired mechanical properties, optical translucency and dimensional accuracy using digital light processing (DLP). To this end, all processing parameters were carefully controlled and optimized. First, 5Y-PSZ particles with a bimodal distribution were prepared via calcination of as-received granules and subsequent ball-milling and then used to formulate 5Y-PSZ suspensions with a high solid loading of 50 vol% required for high densification after sintering. Dispersant content was also optimized. To provide high dimensional accuracy, initial dimensions of dental crowns for 3D printing were precisely determined by considering increase and decrease in dimensions during photopolymerization and sintering, respectively. Photopolymerization time was also optimized for a given layer thickness of 50 μm to ensure good bonding between layers. A multi-step debinding schedule with a slow heating rate was employed to avoid formation of any defects. After sintering at 1500 °C for 2 h, 5Y-PSZ could be almost fully densified without noticeable defects within layers and at interfaces between layers. They had high relative densities (99.03 ± 0.39%) with a high cubic phase content (59.1%). These characteristics allowed for achievement of reasonably high mechanical properties (flexural strength = 625.4 ± 75.5 MPa and Weibull modulus = 7.9) and % transmittance (31.4 ± 0.7%). In addition, 5Y-PSZ dental crowns showed excellent dimensional accuracy (root mean square (RMS) for marginal discrepancy = 44.4 ± 10.8 μm and RMS for internal gap = 22.8 ± 1.6 μm) evaluated by the 3D scanning technique.
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Affiliation(s)
- Jae-Min Jung
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul 02841, Republic of Korea
- School of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Gyu-Nam Kim
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul 02841, Republic of Korea
- School of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Young-Hag Koh
- Interdisciplinary Program in Precision Public Health, Korea University, Seoul 02841, Republic of Korea
- School of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Hyoun-Ee Kim
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
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Accuracy of marginal fit of an implant-supported framework fabricated by 3D printing versus subtractive manufacturing technique: A systematic review and meta-analysis. J Prosthet Dent 2023; 129:301-309. [PMID: 34147238 DOI: 10.1016/j.prosdent.2021.05.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM Evidence comparing additive 3-dimensional printing (3DP) with subtractive milling for implant-supported frameworks is lacking. PURPOSE The purpose of this systematic review and meta-analysis was to compare the marginal fit and accuracy of complete arch implant-supported frameworks (CA), implant-retained fixed partial dentures (IRFPDs), single implant crowns (SICs), and interim implant-retained restorations (IIRRs) by using additive manufacturing (AM) and subtractive manufacturing (SM) methods. MATERIAL AND METHODS An electronic search was performed in PubMed, ScienceDirect, Google Scholar, and the Cochrane Library for articles published up to August 2020. The authors acquired the data and evaluated the articles, and the final selection of articles was made according to the inclusion and exclusion criteria. The Methodological Index for Non-Randomized Studies (MINORS) scale was used to evaluate the quality of the included studies. Heterogeneity was evaluated, and meta-analyses with subgroup analyses were performed in the selected studies. RESULTS The database search resulted in 960 articles. After removing duplicate articles (410 studies), the titles and abstracts were screened in detail, and 10 in vitro studies were selected for qualitative analysis and 9 for quantitative analysis according to the eligibility criteria. Subgroup analyses were performed to compare the 3DP versus the SM technique for different types of implant-supported frameworks (IRFPDs, SICs, IIRRs, and CA). In the IRFPDs analysis, the marginal fit accuracy of the 3DP systems was higher than that with the subtractive manufacturing method (P<.001). In the subgroup analysis of SIC frameworks (P=.55) and CA (P=.67) frameworks, no significant difference was observed in the assessed techniques. CONCLUSIONS The marginal fit of implant-supported frameworks manufactured by AM or SM methods is in the clinically acceptable range.
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Lee HB, Bea EJ, Lee WS, Kim JH. Trueness of stereolithography ZrO 2 crowns with different build directions. Dent Mater J 2023; 42:42-48. [PMID: 36288942 DOI: 10.4012/dmj.2022-041] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This study aims to measure the trueness of zirconia crowns with different build directions of materials fabricated using the stereolithography (SLA) method. The anatomic contour crown of prepped maxillary right first molar was designed using CAD software to obtain the standard tessellation language (STL) file. Two different build directions were set for the crowns using Materialize Magics software. One group was built with a margin base platform, while the other group was built in the direction opposite to the occlusal surface base platform. The 20 crown-shaped parts were printed. The STL files of scanned printing zirconia crowns were superimposed each segment by the 3D analysis software. The two groups were statistically analyzed using t-tests. Significant differences were found in the marginal and internal discrepancies between the groups. The build direction had a significant influence on the accuracy of the zirconia crown. The results indicate the most effective build direction for manufacturing SLA 3D-printed crowns.
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Affiliation(s)
- Ha-Bin Lee
- Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University
| | | | - Wan-Sun Lee
- Department Of Dental Technology, Bucheon University
| | - Ji-Hwan Kim
- Transdisciplinary Major in Learning Health Systems, Department of Healthcare Sciences, Graduate School, Korea University
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Mogan J, Harun WSW, Kadirgama K, Ramasamy D, Foudzi FM, Sulong AB, Tarlochan F, Ahmad F. Fused Deposition Modelling of Polymer Composite: A Progress. Polymers (Basel) 2022; 15:polym15010028. [PMID: 36616377 PMCID: PMC9823360 DOI: 10.3390/polym15010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/04/2022] [Accepted: 11/10/2022] [Indexed: 12/24/2022] Open
Abstract
Additive manufacturing (AM) highlights developing complex and efficient parts for various uses. Fused deposition modelling (FDM) is the most frequent fabrication procedure used to make polymer products. Although it is widely used, due to its low characteristics, such as weak mechanical properties and poor surface, the types of polymer material that may be produced are limited, affecting the structural applications of FDM. Therefore, the FDM process utilises the polymer composition to produce a better physical product. The review's objective is to systematically document all critical information on FDMed-polymer composite processing, specifically for part fabrication. The review covers the published works on the FDMed-polymer composite from 2011 to 2021 based on our systematic literature review of more than 150 high-impact related research articles. The base and filler material used, and the process parameters including layer height, nozzle temperature, bed temperature, and screw type are also discussed in this review. FDM is utilised in various biomedical, automotive, and other manufacturing industries. This study is expected to be one of the essential pit-stops for future related works in the FDMed-polymeric composite study.
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Affiliation(s)
- J Mogan
- Institute of Postgraduate Studies, Universiti Malaysia Pahang, Gambang, Kuantan 26300, Pahang, Malaysia
| | - W. S. W. Harun
- Department of Mechanical Engineering, College of Engineering, Universiti Malaysia Pahang, Gambang, Kuantan 26300, Pahang, Malaysia
- Correspondence:
| | - K. Kadirgama
- Faculty of Mechanical and Automotive Engineering Technology, Universiti Malaysia Pahang, Gambang, Kuantan 26300, Pahang, Malaysia
| | - D. Ramasamy
- Department of Mechanical Engineering, College of Engineering, Universiti Malaysia Pahang, Gambang, Kuantan 26300, Pahang, Malaysia
| | - F. M. Foudzi
- Department of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| | - A. B. Sulong
- Department of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| | - F. Tarlochan
- Department of Mechanical and Industrial Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar
| | - F. Ahmad
- Department of Mechanical Engineering, Universiti Teknologi Petronas, Seri Iskandar 32610, Perak, Malaysia
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Revilla-León M, Al-Haj Husain N, Barmak AB, Pérez-López J, Raigrodski AJ, Özcan M. Chemical Composition and Flexural Strength Discrepancies Between Milled and Lithography-Based Additively Manufactured Zirconia. J Prosthodont 2022; 31:778-783. [PMID: 35068002 DOI: 10.1111/jopr.13482] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/13/2022] [Indexed: 01/04/2023] Open
Abstract
PURPOSE To evaluate the chemical composition, flexural strength, and Weibull characteristics of milled and lithography-based additively manufactured (AM) zirconia. MATERIALS AND METHODS A virtual design of a bar (25×4×2 mm) was completed using a software program. The standard tessellation language file was used to manufacture all the specimens: 3Y-TZP zirconia (Priti multidisc ZrO2 monochrome) milled (M group) and 3Y-TZP zirconia (LithaCon 3Y 210) lithography-based AM (CeraFab System S65 Medical) (AM group) bar specimens (n = 20). The chemical composition of the specimens was determined by using energy dispersive X-ray (EDAX) elemental analysis in a scanning electron microscope. Flexural strength was measured in all specimens using 3-point bend test according to ISO/CD 6872.2 with a universal testing machine (Instron Model 8501). Two-parameter Weibull distribution values were calculated. The Shapiro-Wilk test revealed that the data were normally distributed (p < 0.05). Flexural strength values were analyzed using independent Student's t-test (α = 0.05). RESULTS There were no major chemical composition differences observed between M and AM groups. The AM specimens (1518.9 ± 253.9 MPa) exhibited a significantly higher flexural strength mean value compared to the milled (980.5 ± 130.3 MPa) specimens (DF = 13, T-value = -5.97, p < 0.001). The Weibull distribution presented the highest shape for M specimens (11.49) compared to those of AM specimens (6.95). CONCLUSIONS There was no significant difference in the chemical composition of milled and AM zirconia material tested. AM zirconia tested exhibited significantly higher flexural strength compared with the milled zirconia evaluated.
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Affiliation(s)
- Marta Revilla-León
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Kois Center, Seattle, WA.,Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, MA
| | - Nadin Al-Haj Husain
- University of Zurich, Clinic for Reconstructive Dentistry, Division of Dental Biomaterials, Center of Dental Medicine, Zurich, Switzerland.,Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland
| | - Abdul B Barmak
- Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, NY
| | | | - Ariel J Raigrodski
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.,Private Practice, Lynnwood, WA
| | - Mutlu Özcan
- University of Zurich, Clinic for Reconstructive Dentistry, Division of Dental Biomaterials, Center of Dental Medicine, Zurich, Switzerland
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Abualsaud R, Alalawi H. Fit, Precision, and Trueness of 3D-Printed Zirconia Crowns Compared to Milled Counterparts. Dent J (Basel) 2022; 10:dj10110215. [PMID: 36421402 PMCID: PMC9689223 DOI: 10.3390/dj10110215] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022] Open
Abstract
Precise fit of a crown and accurate reproduction of the digital design are paramount for successful treatment outcomes and preservation of clinician and technician time. The study aimed to compare the internal fit, marginal adaptation, precision, and trueness of 3D-printed zirconia crowns compared to their milled counterpart. A total of 20 monolithic 3 mol% yttria stabilized-zirconia crowns (n = 10) were made using computer-assisted design (CAD) followed by additive (3D-printed) and subtractive (milled) manufacturing. Digital scanning of the master die with and without a fit checker followed by image superimposition, and analysis was performed to evaluate internal and marginal adaptation in four areas (occlusal, axial, marginal, and overall). ISO 12836:2015 standard was followed for precision and trueness evaluation. Statistical analysis was achieved using a t-test at α = 0.05. Internal fit and marginal adaptation revealed no significant difference between the two test groups (p > 0.05). The significant difference in trueness (p < 0.05) was found between the two groups in three areas (occlusal, axial, and internal). The best and worst trueness values were seen with 3D-printed crowns at occlusal (8.77 ± 0.89 µm) and Intaglio (23.90 ± 1.60 µm), respectively. The overall precision was statistically better (p < 0.05) in the 3D-printed crowns (9.59 ± 0.75 µm) than the milled (17.31 ± 3.39 µm). 3D-printed and milled zirconia crowns were comparable to each other in terms of internal fit and marginal adaptation. The trueness of the occlusal and axial surfaces of 3D-printed crowns was better, whereas the trueness of fitting surface of milled crowns was better. 3D-printed crowns provided a higher level of precision than milled crowns. Although the internal and marginal fit of both production techniques were comparable, 3D printing of zirconia produced more precise crowns.
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Kao CT, Liu SH, Kao CY, Huang TH. Clinical evaluation of 3D-printed zirconia crowns fabricated by selective laser melting (SLM) for posterior teeth restorations: Short-term pilot study. J Dent Sci 2022; 18:715-721. [PMID: 37021225 PMCID: PMC10068370 DOI: 10.1016/j.jds.2022.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/14/2022] [Indexed: 11/28/2022] Open
Abstract
Background/purpose Zirconia crowns (ZrC) without veneering porcelain have become an effective alternative in clinical practice. Monolithic zirconia restorations fabricated by the dry milling method do not have acceptable clinical properties. This study evaluated the periodontal qualities of three-dimensional printed ZrC using the modified United States Public Health Service (USPHS) criteria. Materials and methods A total of 15 patients who required dental crowns were recruited, and all 15 teeth were restored with digital 3D-printed ZrC. All crowns were assessed at the time of crown placement and 2, 6, and 24 weeks post-placement. Clinical parameters, including plaque index, gingival index, probing depth, crown marginal integrity, and attrition of the antagonist's teeth, were evaluated and recorded. Results According to the Modified California Dental Association quality evaluation system, 100% of the crowns received satisfactory grades. Despite the significant increase in plaque index and gingival index at two weeks post-ZrC placement, there was no deterioration in probing depth. Moreover, there was discard usage of ZrC on the antagonist's teeth at 24 weeks posttreatment. Of the 15 crowns, one tooth had to be extracted due to a vertical root fracture. Overall, the digital 3D-printed crowns showed no adverse effects on periodontal tissues after 24 weeks of follow-up. Conclusion The 3D-printed ZrC showed no periodontal problems. It can serve as an alternative for patients, particularly those with high esthetic expectations.
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Camargo B, Willems E, Jacobs W, Van Landuyt K, Peumans M, Zhang F, Vleugels J, Van Meerbeek B. 3D printing and milling accuracy influence full-contour zirconia crown adaptation. Dent Mater 2022; 38:1963-1976. [DOI: 10.1016/j.dental.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 09/26/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022]
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Abualsaud R, Abussaud M, Assudmi Y, Aljoaib G, Khaled A, Alalawi H, Akhtar S, Matin A, Gad MM. Physiomechanical and Surface Characteristics of 3D-Printed Zirconia: An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6988. [PMID: 36234329 PMCID: PMC9572578 DOI: 10.3390/ma15196988] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The objective of this study is to examine the physiomechanical and surface properties of 3D-printed zirconia in comparison to milled zirconia. A total of 80 disc-shaped (14 × 1.5 ± 0.2 mm) specimens (20 milled and 60 3D-printed (at three different orientations; horizontal, vertical, and tilted)) were manufactured from 3-mol% yttria-stabilized tetragonal zirconia. Five specimens per group were evaluated for crystalline phase, grain size, density, porosity, surface roughness, wettability, microhardness, and SEM analysis of the surface. Biaxial flexural strength (BFS) was measured (n = 15) followed by Weibull analysis and SEM of fractured surfaces. Statistical analysis was performed using one-way ANOVA and Tukey’s post hoc test at α = 0.05. All groups showed a predominant tetragonal phase, with a 450 nm average grain size. There was no significant difference between groups with regards to density, porosity, and microhardness (p > 0.05). The tilted group had the highest surface roughness (0.688 ± 0.080 µm), significantly different from the milled (p = 0.012). The horizontal group presented the highest contact angle (89.11 ± 5.22°), significantly different from the milled and tilted (p > 0.05). The BFS of the milled group (1507.27 ± 340.10 MPa) was significantly higher than all other groups (p < 0.01), while vertical and tilted had a similar BFS that was significantly lower than horizontal (p < 0.005). The highest and lowest Weibull modulus were seen with tilted and milled, respectively. Physical properties of all groups were comparable. The surface roughness of the tilted group was higher than milled. The horizontal group had the highest hydrophobicity. Printing orientations influenced the flexural strength of 3D-printed zirconia. Clinical implications: This study demonstrates how the printing orientation affects the physiomechanical characteristics of printed zirconia.
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Affiliation(s)
- Reem Abualsaud
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Maissan Abussaud
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Yara Assudmi
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Ghadah Aljoaib
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Abrar Khaled
- Intern, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Haidar Alalawi
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Sultan Akhtar
- Department of Biophysics, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Asif Matin
- IRC Membranes & Water Security, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Mohammed M. Gad
- Substitutive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
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Abstract
The purpose of this study is to present current dental ceramic materials and processing methods. The clinical indication was emphasized on basis of the material's microstructure and composition. Studies of ceramic characterization were also discussed, as they impact the clinical indication and serve as a parameter for the development of new materials. The novel strategies were mostly found aiming to mimic the natural dental structures, provide mechanical reliability, and develop predictable restorations in terms of adaptation and design.
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Affiliation(s)
- Atais Bacchi
- Post-Graduate Program in Dentistry, Paulo Picanço School of Dentistry, Rua Joaquim Sá 900, Fortaleza, Ceará 60325-218, Brazil.
| | - Paulo Francisco Cesar
- Department of Biomaterials and Oral Biology, University of São Paulo - USP. Av Prof Lineu Prestes, 2227. Cidade Universitária, São Paulo, São Paulo 05508-000, Brazil
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Zenthöfer A, Schwindling FS, Schmitt C, Ilani A, Zehender N, Rammelsberg P, Rues S. Strength and reliability of zirconia fabricated by additive manufacturing technology. Dent Mater 2022; 38:1565-1574. [PMID: 35933222 DOI: 10.1016/j.dental.2022.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/29/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To test strength and reliability of 3D printed compared to milled zirconia. METHODS Cylindrical specimens were fabricated from milled (group G1; e.max ZirCAD LT) and from 3D printed (group G2; LithaCon 3Y 230) 3-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP). While G1 and G2 were sintered in one step, a further series (G3) of 3D printed 3Y-TZP was sintered in two steps including intermediate color infiltration. In each group, two different conditioning strategies were applied (n ≥ 20 samples/subgroup): (1) final polishing with #1200 diamond discs according to ISO 6872, and (2) final polishing with #220 diamond discs resulting in imperfectly polished surfaces. All samples were tested to fracture with a universal testing device (cross-head speed: 1 mm/min). Characteristic strengths and Weibull moduli were calculated. Effects were analyzed by means of either ANOVA (homocedastic data) or Welch ANOVA (heterocedastic data). RESULTS For samples conditioned according to ISO 6872, mean flexural strengths were 1462 ± 105 MPa (G1), 1369 ± 280 MPa (G2), and 1197 ± 317 MPa (G3). For the imperfectly polished subgroups, strength values were 1461 ± 121 MPa (G1), 1349 ± 332 MPa (G2), and 1271 ± 272 MPa (G3). Although all groups showed high mean strength values, the reliability of milled zirconia (Weibull moduli 14 < m <16) outperformed that of the 3D-printed material (3 < m <6). SIGNIFICANCE Even after color infiltration in a partially sintered state, the tested 3D printed zirconia exceeded the ISO flexural strength criteria for all types of fixed ceramic restorations by far (800 MPa for class 6, ISO 6872), indicating its high potential for clinical use. Further optimization of the internal material structure after sintering might improve the reliability of 3D printed zirconia which is currently inferior to that of milled zirconia.
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Affiliation(s)
- Andreas Zenthöfer
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
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Donmez MB, Okutan Y. Marginal gap and fracture resistance of implant-supported 3D-printed definitive composite crowns: An in vitro study. J Dent 2022; 124:104216. [PMID: 35803388 DOI: 10.1016/j.jdent.2022.104216] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 06/20/2022] [Accepted: 07/04/2022] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES To compare the marginal gap and fracture resistance of implant-supported 3-dimensional (3D) printed definitive composite crowns with those fabricated by using 3 different millable materials. MATERIAL AND METHODS A prefabricated abutment was digitized by using a laboratory scanner (E4 Lab Scanner) and a complete-coverage maxillary first premolar crown was designed (Dental Designer). Forty crowns were fabricated either by 3D printing (Saremco Print Crowntec, SP) or milling (Brilliant Crios, BC; Vita Enamic, VE; Cerasmart 270, CS) (n = 10). Baseline marginal gap values were evaluated by measuring 60 predetermined points on an abutment (15 points for each side) with a stereomicroscope at ×40 magnification. Marginal gap values were reevaluated after adhesive cementation. Load-to-fracture test was performed by using a universal testing machine. Two-way analysis of variance (ANOVA) was used to evaluate the effect of material type and cementation on marginal gap values. While Tukey HSD tests were used to compare the materials' marginal gap values before and after cementation, the effect of cementation on marginal gap values within each material was analyzed by using paired samples t-tests. Fracture resistance data were analyzed by using 1-way ANOVA (α=0.05). RESULTS Material type and cementation significantly affected marginal gap values (P < .001). Regardless of cementation, SP had the lowest marginal gap values (P < .001), while the differences among milled crowns were nonsignificant (P ≥ .14). Cementation significantly increased the marginal gap values (P < .001). Material type did not affect fracture resistance values (F = 1.589, P = .209). CONCLUSION Implant-supported 3D-printed composite crowns showed higher marginal adaptation compared with the milled crowns before and after cementation. In addition, all crowns endured similar forces before fracture.
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Affiliation(s)
- Mustafa Borga Donmez
- Department of Prosthodontics, Faculty of Dentistry, Istinye University, Istanbul, Turkey; Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
| | - Yener Okutan
- Department of Prosthodontics, Aydin Adnan Menderes University Faculty of Dentistry, Aydin, Turkey.
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Lüchtenborg J, Willems E, Zhang F, Wesemann C, Weiss F, Nold J, Sun J, Sandra F, Bai J, Reveron H, Chevalier J, Spies BC. Accuracy of additively manufactured zirconia four-unit fixed dental prostheses fabricated by stereolithography, digital light processing and material jetting compared with subtractive manufacturing. Dent Mater 2022; 38:1459-1469. [DOI: 10.1016/j.dental.2022.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/08/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022]
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44
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Al Hamad KQ, Al-Rashdan BA, Ayyad JQ, Al Omrani LM, Sharoh AM, Al Nimri AM, Al-Kaff FT. Additive Manufacturing of Dental Ceramics: A Systematic Review and Meta-Analysis. J Prosthodont 2022; 31:e67-e86. [PMID: 35675133 DOI: 10.1111/jopr.13553] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/29/2022] [Indexed: 12/25/2022] Open
Abstract
PURPOSE The purpose of this systematic review and meta-analysis was to evaluate the effect of using additive manufacturing (AM) for dental ceramic fabrication in comparison with subtractive manufacturing (SM), and to evaluate the effect of the type of AM technology on dental ceramic fabrication. MATERIALS AND METHODS A search was conducted electronically in MEDLINE (via PubMed), EBSCOhost, Scopus, and Cochran Library databases, and also by other methods (table of contents screening, backward and forward citations, and grey literature search) up to February 12, 2022, to identify records evaluating additive manufacturing of ceramics for dental purposes in comparison with subtractive manufacturing. A minimum of 2 review authors conducted tstudy selection, quality assessment, and data extraction. Quality assessment was performed with Joanna Briggs Institute tool, and the quantitative synthesis was performed with the Comprehensive Meta-Analysis program (CMA, Biostat Inc). Hedges's g for effect size was calculated, with 0.2 as small, 0.5 as medium, and 0.8 as large. Heterogeneity was assessed with I2 and prediction interval (PI) statistics. Publication bias was investigated with funnel plots and grey literature search. Certainty of evidence was assessed with the Grading of Recommendations: Assessment, Development, and Evaluation (GRADE) tool. RESULTS A total of 28 studies were included for the qualitative and quantitative synthesis; 11 in vitro studies on accuracy, 1 in vivo study on color, and 16 in vitro studies on physical and mechanical properties. Meta-analysis showed overall higher accuracy for SM compared with AM, with medium effect size (0.679, CI: 0.173 to 1.185, p = 0.009) and also for marginal (g = 1.05, CI: 0.344 to 1.760, p = 0.004), occlusal (g = 2.24, CI: 0.718 to 3.766, p = 0.004), and total (g = 4.544, CI: -0.234 to 9.323, p = 0.062) with large effect size; whereas AM had higher accuracy than SM with small effect size for the external (g = -0.238, CI: -1.215 to 0.739), p = 0.633), and internal (g = -0.403, CI: -1.273 to 0.467, p = 0.364) surfaces. For technology, self-glazed zirconia protocol had the smallest effect size (g = -0.049, CI: -0.878 to 0.78, p = 0.907), followed by stereolithography (g = 0.305, CI: -0.289 to 0.9, p = 0.314), and digital light processing (g = 1.819, CI: 0.662 to 2.976, p = 0.002) technologies. Flexural strength was higher for ceramics made by SM in comparison to AM with large effect size (g = -2.868, CI: -4.371 to -1.365, p < 0.001). Only 1 study reported on color, favoring ceramics made through combined AM and SM. CONCLUSIONS Subtractive manufacturing had better overall accuracy, particularly for the marginal and occlusal areas, higher flexural strength, and more favorable hardness, fracture toughness, porosity, fatigue, and volumetric shrinkage; whereas AM had more favorable elastic modulus and wettability. Both methods had favorable biocompatibility. All studies on accuracy and mechanical properties were in vitro, with high heterogeneity and low to very low certainty of evidence. There is a lack of studies on color match and esthetics.
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Affiliation(s)
- Khaled Q Al Hamad
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | | | - Jad Q Ayyad
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Leen M Al Omrani
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Ayat M Sharoh
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Adnan M Al Nimri
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
| | - Fatma T Al-Kaff
- Department of Prosthodontics, Jordan University of Science & Technology, Irbid, Jordan
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45
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Kim YK, Han JS, Yoon HI. Evaluation of intaglio surface trueness, wear, and fracture resistance of zirconia crown under simulated mastication: a comparative analysis between subtractive and additive manufacturing. J Adv Prosthodont 2022; 14:122-132. [PMID: 35601347 PMCID: PMC9095451 DOI: 10.4047/jap.2022.14.2.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This in-vitro analysis aimed to compare the intaglio trueness, the antagonist's wear volume loss, and fracture load of various single-unit zirconia prostheses fabricated by different manufacturing techniques. MATERIALS AND METHODS Zirconia crowns were prepared into four different groups (n = 14 per group) according to the manufacturing techniques and generations of the materials. The intaglio surface trueness (root-mean-square estimates, RMS) of the crown was measured at the marginal, axial, occlusal, and inner surface areas. Half of the specimens were artificially aged in the chewing simulator with 120,000 cycles, and the antagonist's volume loss after aging was calculated. The fracture load for each crown group was measured before and after hydrothermal aging. The intaglio trueness was evaluated with Welch's ANOVA and the antagonist's volume loss was assessed by the Kruskal-Wallis tests. The effects of manufacturing and aging on the fracture resistance of the tested zirconia crowns were determined by two-way ANOVA. RESULTS The trueness analysis of the crown intaglio surfaces showed surface deviation (RMS) within 50 µm, regardless of the manufacturing methods (P = .053). After simulated mastication, no significant differences in the volume loss of the antagonists were observed among the zirconia groups (P = .946). The manufacturing methods and simulated chewing had statistically significant effects on the fracture resistance (P < .001). CONCLUSION The intaglio surface trueness, fracture resistance, and antagonist's wear volume of the additively manufactured 3Y-TZP crown were clinically acceptable, as compared with those of the 4Y- or 5Y-PSZ crowns produced by subtractive milling.
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Affiliation(s)
- Yong-Kyu Kim
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Jung-Suk Han
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
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46
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Zandinejad A, Khanlar LN, Barmak AB, Tagami J, Revilla-León M. Surface Roughness and Bond Strength of Resin Composite to Additively Manufactured Zirconia with Different Porosities. J Prosthodont 2022; 31:97-104. [PMID: 35313023 DOI: 10.1111/jopr.13434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2021] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To investigate the bond strength of resin cement to additively manufactured (AM) zirconia with different porosities when compared to milled zirconia. MATERIALS AND METHODS A 12 × 5 mm disk virtual design file was used to fabricate a total of 48 disks divided into 4 groups: 3 groups were AM with different porosities including 0%-porosity (AMZ0 group), 20%-porosity (AMZ20 group), and 40%-porosity (AMZ40 group), and 1 milled zirconia (control or CNCZ group). The dimensions of all specimens were measured using a digital caliper. A 3D- confocal laser scanner was used to analyze surface morphology and measure the surface roughness (Sa), followed by SEM analysis. Tensile bond strength of composite resin cement to specimens was measured before and after aging procedures using a universal testing machine (n = 10). Failure modes were evaluated under a light microscope. Volumetric change data was analyzed using one-way ANOVA, and two-way ANOVA was used to compare bond strength values (α = 0.05). RESULTS There was a significant difference in volumetric changes among the groups. The CNCZ group showed the least changes in diameter 0.027 ± 0.029 mm and thickness 0.030 ± 0.012 mm and AM zirconia with 40% porosity showed the most volumetric changes in diameter 5.237 ± 0.023 mm. ANOVA test indicated an overall significant difference in surface roughness across all groups (F = 242.6, p < 0.001). The CNCZ group showed the highest mean Sa of 1.649 ± 0.240 µm, followed by AMZ40 group with Sa of 0.830 ± 0.063 µm, AMZ20 group with Sa of 0.780 ± 0.070 µm, and the AMZ0 group with Sa of 0.612 ± 0.063 µm. Two-way ANOVA showed significant difference in bond strength between the CNCZ group 12.109 ± 3.223 MPa and the AMZ0 group 8.629 ± 0.914 MPa, with significant pretest failures in specimens with porosities. Thermal cycling methods reduced the bond strength non-significantly in CNCZ group with no effect in the AMZ0 group. CONCLUSION Milled zirconia had a higher surface roughness and bond strength to composite resin cement than AM zirconia, and porosities in AM zirconia decreased the bond strength with significant pretest failures.
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Affiliation(s)
- Amirali Zandinejad
- Department of comprehensive dentistry, College of Dentistry, Texas A&M University, Dallas, TX
| | - Leila Nasiry Khanlar
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Abdul Basir Barmak
- Department of comprehensive dentistry, EIOH Medical Center, University of Rochester, Rochester, NY
| | - Junji Tagami
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Marta Revilla-León
- Department of comprehensive dentistry, School of Dentistry, University of Washington, Seattle, WA.,Department of comprehensive dentistry, Revilla Research Center, Madrid, Spain
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47
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Rutkūnas V, Gedrimienė A, Auškalnis L, Admakin O, Mangano F. Accuracy of Fixed Implant-Supported Dental Prostheses Additively Manufactured by Metal, Ceramic, or Polymer: A Systematic Review. J Prosthodont 2022; 31:70-87. [PMID: 35313029 DOI: 10.1111/jopr.13449] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2021] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Additive manufacturing (AM) in prosthodontics is used as an alternative to casting or milling. Various techniques and materials are available for the additive manufacturing of the fixed and removable tooth-supported restorations, but there is a lack of evidence on the accuracy of AM fixed implant-supported prostheses. Recent studies investigated the accuracy of ceramic AM prostheses. Therefore, the aim of this systematic review was to evaluate the accuracy of additively manufactured metal, ceramic or polymers, and screw- or cement-retained fixed implant-supported prostheses. MATERIALS AND METHODS Two calibrated investigators performed an electronic search of relevant publications in the English language following selected PICOS criteria and using a well-defined search strategy (latest search date-1st of June, 2021). Based on the exclusion criteria (no control group, less than five samples per group, 3D printing of the implant abutment part, only subjective evaluation of accuracy, etc.) studies were not included in the review. Quantitative data of accuracy evaluation such as marginal gap, strain analysis, and linear measurements was extracted and interpreted. QUADAS-2 tool was used to assess the risk of methodological bias of all included studies. RESULTS Sixteen in vitro studies were selected for the final analysis. Six of the selected studies evaluated screw-retained restorations and 10 cement-retained implant-supported restorations. Only 4 publications concluded that AM restorations were more accurate than conventionally made (cast or milled) ones. The most common finding was that AM restorations were more accurate than cast and demonstrated less or similar accuracy compared to milled ones (n = 10 studies). Detected marginal discrepancies mean values of the AM prosthesis varied from 23 to more than 200 µm, but most of them were categorized as clinically acceptable. CONCLUSIONS AM implant-supported fixed prostheses demonstrate similar accuracy compared to conventional and computer-aided design and computer-aided manufacturing techniques in vitro. Detected inaccuracies of AM restorations do not exceed clinically acceptable limits. Clinical studies with longer follow-up periods are needed to show the reliability of AM prostheses.
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Affiliation(s)
- Vygandas Rutkūnas
- Department of Prosthodontics, Institute of Odontology, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | - Agnė Gedrimienė
- Department of Prosthodontics, Institute of Odontology, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | | | - Oleg Admakin
- Department of Prevention and Communal Dentistry, Sechenov First State Medical University, Moscow, Russian Federation
| | - Francesco Mangano
- Department of Prevention and Communal Dentistry, Sechenov First State Medical University, Moscow, Russian Federation
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48
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Dyakonenko EE, Parunov VA, Sakhabieva DA, Lebedenko IY. [Manufacturing of zirconia restorations by means of additive fabrication. Part I]. STOMATOLOGIIA 2022; 101:91-97. [PMID: 36562374 DOI: 10.17116/stomat202210106191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Additive fabrication or layer-by-layer synthesis technologies is one of the most dynamically developing areas of digital production. Modern additive technologies can be used to fabricate zirconia-based restorations. The first part of this article will present the fabrication of zirconia restorations using additive technologies such as stereolithography, digital light processing, selective laser sintering, selective laser melting and inkjet printing, as well as the advantages and disadvantages of the mentioned technologies.
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Affiliation(s)
- E E Dyakonenko
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia
| | - V A Parunov
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia.,Peoples' Friendship University of Russia, Moscow, Russia
| | - D A Sakhabieva
- Peoples' Friendship University of Russia, Moscow, Russia
| | - I Yu Lebedenko
- Central Research Institute of Dentistry and Maxillofacial Surgery, Moscow, Russia.,Peoples' Friendship University of Russia, Moscow, Russia
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49
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Gatto ML, Groppo R, Furlani M, Giuliani A, Mangano C, Mangano F. Lithography-based Ceramic Manufacturing (LCM) versus Milled Zirconia Blocks under uniaxial compressive loading: An in vitro comparative study. J Dent 2021; 116:103886. [PMID: 34762988 DOI: 10.1016/j.jdent.2021.103886] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/21/2021] [Accepted: 10/28/2021] [Indexed: 10/19/2022] Open
Abstract
AIM This in vitro study aimed to compare the mechanical performance of 3D printed versus milled zirconia blocks, when subjected to uniaxial compression load, and to investigate the microstructural characteristics of the 3D printed samples, before and after the application of the load. METHODS Twenty zirconia blocks (5 × 5 × 5mm3) were prepared: 10 (tests) were 3D printed with a Lithography-based Ceramic Manufacturing (LCM) printer (Cerafab S65®, Lithoz, Vienna, Austria), and 10 (controls) were milled with a 5-axis milling machine (DWX-52D®, DGShape, a Roland Company, Hamamatsu, Japan). Compression tests were carried out on all samples, using a load cell of 30 kN and crosshead speed of 0.5 mm/min, in according to the ASTM C1424-15. The elastic modulus of the material was calculated from stress/strain curve by taking compressive stress values between 50 MPa and 100 MPa. Compression data obtained were plotted as stress-strain curves. Finally, the 3D printed test samples were also observed by VEGA3 Tescan scanning electron microscope (SEM) to detect the presence of eventual defects on surface before and after compression. A statistical analysis was performed to compare the elastic modulus and the deformation in compression at maximum load of the test samples that did not break and the control samples. RESULTS Under mechanical compression, four of the test samples reached failure, whereas all the control samples did not reach failure at the limit of the load cell. However, the 3D printed samples that did not break revealed interesting properties, such as a better modulus of elasticity (p = 0.15) and a lower tendency to deformation under compression (p<0.001), when compared to the milled ones. CONCLUSIONS Within the limits of this study (experimental setting, in vitro design, only one type of force applied) milled zirconia blocks were found more resistant to compression forces than 3D printed ones.
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Affiliation(s)
- Maria Laura Gatto
- Department SIMAU, Università Politecnica delle Marche, Ancona, Italy
| | - Riccardo Groppo
- Department of Engineering "Enzo Ferrari", Università di Modena e Reggio Emilia, Italy
| | - Michele Furlani
- Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Alessandra Giuliani
- Department of Clinical Sciences, Università Politecnica delle Marche, Ancona, Italy
| | - Carlo Mangano
- Department of Dental Sciences, San Raffaele University, Milan, Italy
| | - Francesco Mangano
- Department of Pediatric, Preventive Dentistry and Orthodontics, Sechenov First State Medical University, Moscow, Russia.
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50
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Zandinejad A, Das O, Barmak AB, Kuttolamadom M, Revilla-León M. The Flexural Strength and Flexural Modulus of Stereolithography Additively Manufactured Zirconia with Different Porosities. J Prosthodont 2021; 31:434-440. [PMID: 34580962 DOI: 10.1111/jopr.13430] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Additive manufacturing (AM) technologies are capable of fabricating complex geometries with different porosities. However, the effect of such porosities on mechanical properties of stereolithography (SLA) AM zirconia with different porosities is unclear. The purpose of this in vitro study was to investigate the mechanical properties namely flexural strength, and flexural modulus of AM zirconia with different porosities. MATERIALS AND METHODS A bar (25 × 4 × 3 mm) for flexural strength test (ISO standard 6872/2015) was designed by CAD software program and standard tessellation language (STL) file was obtained. The STL file was used to fabricate a total of 80 bars in four groups. Three experimental groups each containing 20 samples were manufactured using an SLA ceramic printer (CeraMaker 900; 3DCeram Co) and zirconia material (3DMix ZrO2 paste; 3DCeram Co) with different sintering post processing to achieve different porosities including 0%-porosity (AMZ0), 20%-porosity (AMZ20), and 40%-porosity (AMZ40). The same STL file was used for subtractive manufacturing or milling of 20 zirconia bars as control group (CNCZ) with the same dimensions using a commercial zirconia. Three-point bending tests were performed for all groups following ISO standard 6872/2015 specification using a universal testing machine. Outcomes measured included load at fracture, mean flexural strength, and flexural modulus and they were compared across the experimental groups using a one-way ANOVA. Post hoc pair wise comparison between each pair of the groups were performed using Tukey test. RESULTS There was a significant difference between the four groups, in terms of fracture load, flexural strength and flexural modulus using one-way ANOVA. AM zirconia with 0% porosity (AMZ0) showed the highest value for fracture load (1132.7 ± 220.6 N), flexural strength (755.1 ± 147.1 MPa) and flexural modulus (41,273 ± 2193 MPa) and AM zirconia with 40% porosity (AMZ40) showed the lowest fracture load (72.13 ± 13.42 N), flexural strength (48.09 ± 8.95 MPa) and flexural modulus (7177 ± 506 MPa). Tukey's pairwise comparisons detected a significant difference between all the possible pairs for all variables except flexural modulus between AMZ0 and CNCZ. The Weibull moduli presented the lowest value for AMZ20 (4.4) followed by AMZ40 (6.1), AMZ0 (6.1), and the highest value was for CNCZ (8.1). CONCLUSION AM zirconia with 0% porosity showed significantly higher flexural strength and flexural modulus when compared to milled and AM zirconia with 20% and 40% porosities.
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Affiliation(s)
| | - Omprakash Das
- College of Engineering, Texas A&M University, College Station, TX
| | | | | | - Marta Revilla-León
- College of Dentistry, Texas A&M University, Dallas, TX.,School of Dentistry, University of Washington, Seattle, WA.,Revilla Research Center, Madrid, Spain
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