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Cameron AB, Evans JL, Robb ND. A technical and clinical digital approach to the altered cast technique with an intraoral scanner and polyvinyl siloxane impression material. J Prosthet Dent 2024; 132:315-319. [PMID: 35850875 DOI: 10.1016/j.prosdent.2022.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/24/2022] [Accepted: 05/24/2022] [Indexed: 11/19/2022]
Abstract
This technique digitalizes the clinical and laboratory steps of fabricating removable partial dentures (RPDs) with the altered cast technique. An intraoral scanner was used to capture the mandibular Kennedy class II partially edentulous arch. An RPD framework was fabricated digitally and then combined with a custom tray with a wax occlusal rim. A conventional polyvinyl siloxane altered cast impression was made and then digitalized both intraorally and extraorally, followed by a digital interocclusal record. The resulting scan was modified to produce an additively manufactured cast. The teeth and gingival components were then designed and fabricated with a combination of additive and subtractive manufacturing, followed by the conventional acrylic resin pour technique. The definitive prosthesis was completed with minimal conventional techniques and without the use of gypsum, prefabricated teeth, or a physical articulator. The technique reduces the number of appointments and achieves the functional extension of the prosthesis through border molding, which is not possible with intraoral scanning.
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Affiliation(s)
- Andrew B Cameron
- Lecturer, School of Medicine and Dentistry, Griffith University, Gold Coast, Australia.
| | - Jane L Evans
- Professor, School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
| | - Nigel D Robb
- Professor, School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
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2
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Almufleh B, Arellanob A, Tamimi F. Patient-reported outcomes and framework fit accuracy of removable partial dentures fabricated using digital techniques: A systematic review and meta-analysis. J Prosthodont 2024; 33:626-636. [PMID: 37930081 DOI: 10.1111/jopr.13786] [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: 05/15/2023] [Revised: 09/26/2023] [Accepted: 10/20/2023] [Indexed: 11/07/2023] Open
Abstract
PURPOSE This review aimed to summarize the evidence on patient-reported outcomes and clinical performance of digitally fabricated removable partial dentures (RPDs) compared to traditionally fabricated dentures. METHODS Three databases were systematically searched (PubMed, CENTRAL, and Wiley online library) for clinical studies comparing digitally and conventionally fabricated RPDs regardless of data acquisition methods used for fabrication. The Cochrane Collaboration risk of bias assessment tool 2 and the Oxford Center for Evidence-based Medicine tool were used to assess risk of bias, and level of evidence, respectively. Descriptive narrative analysis was used to summarize data on patient-reported outcomes, as there were inadequate studies to pool data in a meta-analysis. A random-effects model was used to analyze the data of framework fit accuracy. RESULTS Ten randomized controlled trials were included in the systematic review, and 4 were included in the meta-analysis. Two studies showed that digitally fabricated RPDs are associated with higher patient satisfaction than conventionally fabricated RPDs (with a mean difference of 12.5 mm on a 100-satisfaction scale, p = .008). The pooled standardized mean difference for framework fit accuracy was 0.49 (p = 0.02) in favor of conventionally fabricated RPDs, which showed that conventionally fabricated RPDs have a quantitatively better fit compared to digitally fabricated RPDs. However, clinical evaluation studies showed that both frameworks have clinically acceptable fit. CONCLUSIONS Current evidence shows that digitally fabricated RPDs are associated with higher patient satisfaction compared to conventionally fabricated RPDs. However, the scarcity of literature here warrants the generalization of this conclusion. Both digitally and conventionally fabricated metal RPD frameworks showed acceptable fit clinically.
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Affiliation(s)
- Balqees Almufleh
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Alexia Arellanob
- College of Dental Medicine, QU Health, Qatar University, Doha, Qatar
| | - Faleh Tamimi
- College of Dental Medicine, QU Health, Qatar University, Doha, Qatar
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3
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Zhang L, Yi Y, Ding L, Meng J, Wu G. Effect of Reinforcement Bar on Trueness of Printed Titanium Kennedy I Removable Partial Denture Frameworks by Selective Laser Melting. Int Dent J 2024:S0020-6539(24)00167-9. [PMID: 39034209 DOI: 10.1016/j.identj.2024.06.016] [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: 03/04/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/23/2024] Open
Abstract
OBJECTIVE The addition of reinforcement bars is a commonly used method to improve the fabrication trueness of selective laser melting removable partial denture alloy frameworks. However, the effects of different reinforcement bar designs on the trueness of the entire framework remain unclear. This study investigated the trueness of removable partial denture frameworks of pure titanium fabricated by selective laser melting under different reinforcement bar settings. METHOD A virtual framework was designed based on the Kennedy Class I partially edentulous model using computer-aided design software. Frameworks with different reinforcement bar settings (Ti-A without reinforcement bar, Ti-B with a single horizontal bar joining the lingual bar, Ti-C with two more bars at the anterior region, Ti-D with another horizontal bar at the anterior region, and Ti-E with one more bar at the posterior region, n = 5) were printed using pure titanium powder using a direct metal laser melting machine. The fabricated frameworks were scanned, and their fabrication trueness was compared with the designed virtual framework using one-way ANOVA. RESULTS The overall mean discrepancies for Ti-A, Ti-B, Ti-C, Ti-D, and Ti-E were 0.111, 0.047, 0.073, 0.068, and 0.047 mm, respectively. For the group of Ti-A set with no reinforcement bars, larger discrepancies were observed compared with the other four groups (P < .05). Groups Ti-B and Ti-E showed better trueness of the RPI clasps, rests, and distal ends (P < .05). CONCLUSIONS Adding reinforcement bars improved the printing trueness of the pure titanium frameworks, and different settings resulted in various degrees of improvement. Setting a single reinforcement bar to join the lingual bar or an additional reinforcement bar at the distal end significantly enhanced the printing trueness of the RPI clasps, rests, and distal ends.
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Affiliation(s)
- Li Zhang
- Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China
| | - Yingjie Yi
- Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China
| | - Ling Ding
- Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China
| | - Jiali Meng
- Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China
| | - Guofeng Wu
- Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China.
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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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Pelletier S, Pelletier A, Al Dika G. Adaptation of removable partial denture rest seats in prostheses made with selective laser sintering or casting techniques: A randomized clinical trial. J Prosthet Dent 2024; 132:108-114. [PMID: 35786347 DOI: 10.1016/j.prosdent.2022.05.006] [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: 01/21/2021] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM New fabrication techniques have been developed for removable partial denture (RPD) frameworks although studies validating the clinical application of these techniques are scarce. PURPOSE The purpose of this clinical study was to compare the adaptation of RPD framework rests made with conventional casting or computer-aided design and computer-aided manufacturing (CAD-CAM) with selective laser sintering (SLS) at the clinical evaluation and 1 year after the delivery of the prostheses. MATERIAL AND METHODS This triple-blinded pilot study included 18 participants presenting with maxillary and/or mandibular partial edentulism, of which only 7 returned for the second measurement 1 year after prosthesis delivery. Participants were randomly assigned to 1 of 2 groups depending on whether the RPD framework was made with SLS or conventional lost-wax casting. The adaptation of the RPD at the rest seat area was evaluated by injecting a silicone material on the abutment tooth before seating. The silicone specimens were then sectioned transversely and measured with a scanning electron microscope. The statistical analysis was performed with a linear mixed-effect model with the intention to treat and with a 3-factor repeated measures ANOVA (α=.05). RESULTS At the metal framework evaluation (T0), the prostheses made with SLS showed a mean ±standard deviation adaptation of 398 ±45 μm, while those made with conventional casting presented a mean ±standard deviation adaptation of 176 ±41 μm (P=.009). One year after the delivery of the prostheses (T1), the adaptation of the frameworks made with conventional casting was still significantly better (88 ±6 μm versus 197 ±94 μm, P=.03). CONCLUSIONS Frameworks made with SLS showed worse clinical accuracy at the rest than frameworks produced with conventional casting.
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Affiliation(s)
- Samuel Pelletier
- Masters student in Dental Science, Department of General Dentistry, Faculty of Dental Medicine of Laval University, Québec, Canada; and Private practice, Montreal, Quebec, Canada.
| | - Annik Pelletier
- Professor, Department of Restorative Dentistry, Faculty of Dental Medicine of Laval University, Québec, Canada
| | - Ghassan Al Dika
- Professor, Department of Restorative Dentistry, Faculty of Dental Medicine of Laval University, Québec, Canada
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Kim S, Oh KC, Kim JH. Accuracy of Mandibular Removable Partial Denture Frameworks Fabricated by 3D Printing and Conventional Techniques. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3148. [PMID: 38998231 PMCID: PMC11242778 DOI: 10.3390/ma17133148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 06/21/2024] [Accepted: 06/25/2024] [Indexed: 07/14/2024]
Abstract
Herein, we used digital superimposition to evaluate the accuracy of metal frameworks for mandibular removable partial dentures fabricated using three techniques. Thirty master casts of a mandibular dentiform were categorized into three groups (n = 10) based on the framework manufacturing method: selective laser melting-based metal three-dimensional (3D) printing (SLM), digital light projection-based resin 3D printing and subsequent casting (RPC), and conventional casting (CON). The master casts were scanned twice, initially after preparation and subsequently after attaching silicone using the frameworks. These scan files were digitally superimposed to measure the silicone thickness. Statistical analysis was conducted using SPSS Statistics (Version 23.0, IBM Corp., Somers, NY, USA). One-way ANOVA and a post hoc Tukey's multiple comparison tests were performed to determine differences among the three groups (α = 0.05). The RPC group exhibited significantly higher overall and mean internal discrepancies at rest and tissue stops than the SLM and CON groups, which exhibited statistically insignificant differences. Thus, SLM fabrication resulted in comparable accuracy to that achieved by CON, whereas sequentially performing resin 3D printing and casting induced inferior accuracy. However, all frameworks across the three groups were clinically acceptable.
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Affiliation(s)
- Soonam Kim
- Department of Dentistry, Graduate School, Yonsei University, Seoul 03722, Republic of Korea;
| | - Kyung Chul Oh
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul 03722, Republic of Korea;
| | - Jee-Hwan Kim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul 03722, Republic of Korea;
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Lan D, Luo Y, Qu Y, Man Y. The three-dimensional stability and accuracy of 3D printing surgical templates: An In Vitro study. J Dent 2024; 144:104936. [PMID: 38492806 DOI: 10.1016/j.jdent.2024.104936] [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: 08/15/2023] [Revised: 02/23/2024] [Accepted: 03/10/2024] [Indexed: 03/18/2024] Open
Abstract
OBJECTIVE To evaluate the three-dimensional (3D) stability and accuracy of additively manufactured surgical templates fabricated using two different 3D printers and materials. MATERIALS AND METHODS Forty surgical templates were designed and printed using two different 3D printers: the resin group (n = 20) used a digital light processing (DLP) 3D printer with photopolymer resin, and the metal group (n = 20) employed a selective laser melting (SLM) 3D printer with titanium alloy. All surgical templates were scanned immediately after production and re-digitalized after one month of storage. Similarly, the implant simulations were performed twice. Three-dimensional congruency between the original design and the manufactured surgical templates was quantified using the root mean square (RMS), and the definitive and planned implant positions were determined and compared. RESULTS At the postproduction stage, the metal templates exhibited higher accuracy than the resin templates (p < 0.001), and these differences persisted after one month of storage (p < 0.001). The resin templates demonstrated a significant decrease in three-dimensional stability after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). No significant differences in implant accuracy were found between the two groups. However, the resin templates showed a significant increase in apical and angular deviations after one month of storage (p < 0.001), whereas the metal templates were not affected (p > 0.05). CONCLUSION Printed metal templates showed higher fabrication accuracy than printed resin templates. The three-dimensional stability and implant accuracy of printed metal templates remained unaffected by one month of storage. CLINICAL SIGNIFICANCE With superior three-dimensional stability and acceptable implant accuracy, printed metal templates can be considered a viable alternative technique for guided surgery.
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Affiliation(s)
- Dongping Lan
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yilin Luo
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yili Qu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yi Man
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China.
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8
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Wang X, Ma D, Zhong S, Ye Q, Zhao Y, Ren N, Bai S. A digital workflow for designing and manufacturing metal frameworks and removable partial dentures: A novel dental technique. J Prosthodont 2024. [PMID: 38566576 DOI: 10.1111/jopr.13845] [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: 11/18/2023] [Accepted: 03/05/2024] [Indexed: 04/04/2024] Open
Abstract
The purpose of this technical report is to demonstrate a fully digital workflow for designing and fabricating metal frameworks and removable partial dentures. After obtaining a digital cast of the dental arch with bilateral distal extension defect, computer-aided design software and 3D printing technology are used for the design and fabrication of the removable partial denture frameworks, denture teeth, and denture bases, instead of the traditional workflow. The assembly of the three components is facilitated through a meticulously structured framework. The technology, which prints metal frameworks, denture bases, and denture teeth through different processes with different materials, achieves full 3D printing technology for making removable partial dentures.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Dan Ma
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Sheng Zhong
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Qingyuan Ye
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Yimin Zhao
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Nan Ren
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
| | - Shizhu Bai
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China
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Alavi SE, Alavi SZ, Gholami M, Sharma A, Sharma LA, Ebrahimi Shahmabadi H. Biocomposite-based strategies for dental bone regeneration. Oral Surg Oral Med Oral Pathol Oral Radiol 2023; 136:554-568. [PMID: 37612166 DOI: 10.1016/j.oooo.2023.04.015] [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: 03/22/2023] [Revised: 04/15/2023] [Accepted: 04/26/2023] [Indexed: 08/25/2023]
Abstract
OBJECTIVE Because of the anatomical complexity of the oral and maxillofacial sites, repairing bone defects in these regions is very difficult. This review article aims to consider the application of biocomposites-based strategies for dental bone regeneration. STUDY DESIGN Research papers related to the topic, published over the last 20 years, were selected using the Web of Science, Pubmed, Scopus, and Google Scholar databases. RESULTS The strategies of monophasic, biphasic/multiphasic scaffolds, and biopolymer-based nanocomposite scaffolds containing nanomaterials compared with traditional methods used for bone regeneration, such as autografts, allografts, xenografts, and alloplasts are found to be superior because of their ability to overcome the issues (e.g., limited bone sources, pain, immune responses, high cost) related to the applications of the traditional methods. CONCLUSIONS In addition, additive manufacturing technologies were found to be highly advantageous for improving the efficacy of biocomposite scaffolds for treating dental bone defects.
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Affiliation(s)
- Seyed Ebrahim Alavi
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
| | - Seyed Zeinab Alavi
- Immunology of Infectious Diseases Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Max Gholami
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
| | - Ajay Sharma
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia
| | - Lavanya A Sharma
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia.
| | - Hasan Ebrahimi Shahmabadi
- Immunology of Infectious Diseases Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
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Dolfini Alexandrino L, Martinez Antunes LH, Jardini Munhoz AL, Ricomini Filho AP, da Silva WJ. Mechanical and surface properties of Co-Cr alloy produced by additive manufacturing for removable partial denture frameworks. J Prosthet Dent 2023; 130:780-785. [PMID: 35184888 DOI: 10.1016/j.prosdent.2021.12.019] [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: 06/09/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 11/20/2022]
Abstract
STATEMENT OF PROBLEM Conventional analog methods have been replaced with digital methods for removable partial denture (RPD) frameworks. However, limited information is available regarding the build direction of RPD frameworks and its effect on properties. PURPOSE The purpose of this in vitro study was to evaluate the mechanical and surface properties of the cobalt chromium (Co-Cr) alloy produced at different build angles by the laser powder bed fusion additive manufacturing (AM) technology used for RPD framework fabrication. MATERIAL AND METHODS Plate-shaped Co-Cr specimens (n=6) were produced by the AM technology and divided into 3 groups depending on the build angle (0, 45, or 90 degrees). The elastic modulus and fracture properties were evaluated by flexural testing. Additionally, 15 disks were printed by using the same parameters of the plates (n=5) to analyze the surface hardness with microhardness testing, and surface properties were determined by surface free energy by using the contact angle and surface roughness measured by using a profilometer. Twelve Co-Cr cylindrical specimens were produced by using the same parameters (n=4), and their microstructure was examined by using an optical microscope. One-way ANOVA was used to evaluate the overall effects of the interaction between groups, and the Tukey test was applied when the interaction was statistically significant (α=.05). RESULTS The flexural strength showed a statistically significant difference (P<.05), with the peak value exhibited by the 0-degree group. A statistical difference was also observed between the angulation and modulus of elasticity; however, the highest value was exhibited by the 45-degree group. For the fracture topography, all groups observed a dimple-like fracture, although the 45-degree group showed wider cleavage planes of fractures than other angulations. For microhardness, the 0- and 45-degree groups exhibited a statistical difference in relation to the 90-degree group (P<.05). For surface properties, no statistically significant difference (P>.05) was found in any of the evaluated parameters. Dependence on the build angles was evidenced by the molten pool boundaries during observation of the microstructure. CONCLUSIONS The build angle influenced the flexural strength and microhardness of the Co-Cr alloy produced by AM; however, it does not affect surface free energy and surface roughness.
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Affiliation(s)
- Larissa Dolfini Alexandrino
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, SP, Brazil
| | | | - André Luiz Jardini Munhoz
- National Institute of Biofabrication, School of Chemical Engineering, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Antônio Pedro Ricomini Filho
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, SP, Brazil
| | - Wander José da Silva
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, SP, Brazil.
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11
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Kassapidou M, Stenport VF, Johansson CB, Syverud M, Hammarström Johansson P, Börjesson J, Hjalmarsson L. Cobalt chromium alloys in fixed prosthodontics: Investigations of mechanical properties and microstructure. J Prosthet Dent 2023; 130:255.e1-255.e10. [PMID: 37355405 DOI: 10.1016/j.prosdent.2023.05.005] [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: 12/17/2022] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 06/26/2023]
Abstract
STATEMENT OF PROBLEM Cobalt chromium (Co-Cr) alloys possess beneficial mechanical properties because alloys, even in thin sections, can resist high mastication forces and exhibit an acceptable bond to the surface porcelain layer. Traditional manufacturing techniques of Co-Cr alloys such as casting have been replaced with newer fabrication techniques, such as milling, laser melting, and presintered milling. Despite scarce documentation, these new manufacturing techniques are being used to fabricate dental and implant constructions. PURPOSE This in vitro study investigates the hardness, yield strength, elastic modulus, and microstructure of the most commonly used Co-Cr alloys for fixed prosthodontics based on manufacturing technique. In addition, this study investigates the effect of heat treatment on the mechanical properties and microstructure of these materials. MATERIAL AND METHODS Five Co-Cr alloys were included (dumbbell and rectangular shaped) based on four manufacturing techniques: cast, milled, laser melted, and presintered milled. Commercially pure titanium grade 4 and titanium-6 aluminum-4 vanadium ELI (extra low interstitial) were included for comparison, and yield strength and elongation after fracture were evaluated. The specimens were tested for hardness using the Vickers test and for elastic modulus using a nondestructive impulse excitation technique. The microstructure of selected specimens was analyzed using focused ion beam-scanning electron microscopy (FIB-SEM) and energy dispersive X-ray spectroscopy (EDS). RESULTS The mechanical properties depend on the manufacturing technique used; the laser-melted and presintered Co-Cr specimens demonstrated the highest mechanical properties, followed by the milled and cast groups. Both the laser-melted and the presintered milled Co-Cr specimens showed smaller grain size compared with the cast and milled Co-Cr specimens. The titanium-6 aluminum-4 vanadium ELI demonstrated higher hardness and yield strength compared to commercially pure titanium grade 4. No major differences were observed for the selected materials regarding the mechanical properties and microstructural appearance after heat treatment. CONCLUSIONS The laser melting and presintered milling techniques produced higher mechanical properties compared with the cast and milled Co-Cr. These findings were confirmed through microstructural analysis with respect to the grain size, precipitation, and number of pores.
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Affiliation(s)
- Maria Kassapidou
- Researcher, Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden; Researcher, Department of Prosthetic Dentistry, Institute for Postgraduate Dental Education, Jönköping, Sweden.
| | - Victoria Franke Stenport
- Professor, Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Carina B Johansson
- Professor Emerita, Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Morten Syverud
- Researcher, NIOM, Nordic Institute of Dental Materials, Oslo, Norway
| | - Petra Hammarström Johansson
- Researcher, Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| | - Johan Börjesson
- Researcher, Department of Materials and Manufacturing, School of Engineering, Jönköping University, Jönköping, Sweden
| | - Lars Hjalmarsson
- Lecturer, Department of Prosthodontics/Dental Materials Science, Institute of Odontology, The Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden; Researcher, Centre for Clinical Research Sörmland, Uppsala University, Eskilstuna, Sweden
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12
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Okano H, Tasaka A, Matsunaga S, Kasahara M, Wadachi J, Hattori M, Abe S, Yamashita S. Effects of hollow structures added by selective laser sintering on the mechanical properties of Co-Cr alloy. J Prosthodont Res 2023; 67:460-467. [PMID: 36403960 DOI: 10.2186/jpr.jpr_d_22_00150] [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: 08/01/2023]
Abstract
PURPOSE This study investigates the effects of hollow structures, added by selective laser sintering (SLS), on the mechanical properties of a Co-Cr alloy for providing an optimal structural property to the framework components of removable partial dentures (RPDs). METHODS The specimens produced using the 3D data of the dumbbell-shaped cylinders were divided into four groups based on the manufacturing method: Cast, Mill, SLS-solid, and SLS-hollow. Tensile tests were performed to measure the mechanical properties of the specimens. The mechanical property values among the four groups were statistically compared using the Kruskal-Wallis test followed by the Steel-Dwass test (α = 0.05). RESULTS The median elastic modulus was the largest in the Cast, followed by SLS-solid, Mill, and SLS-hollow, with no significant differences observed between all conditions. The median ultimate tensile strength was the largest in the order of SLS-solid, Mill, SLS-hollow, and Cast. The median 0.2% proof stress was the largest in SLS-solid, followed by SLS-hollow, Cast, and Mill. The median elongation was the highest in the order of Mill, SLS-solid, SLS-hollow, and Cast. CONCLUSIONS With the addition of hollow structures, the elastic modulus decreased while the mechanical strength and proof stress remained high in SLS specimens. In addition, the ISO 22674 standard for dental metals was met, suggesting that SLS may be a possible method to design RPD frameworks with high strength and optimal structural properties.
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Affiliation(s)
- Haruna Okano
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Akinori Tasaka
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | | | - Masaaki Kasahara
- Department of Dental Materials Science, Tokyo Dental College, Tokyo, Japan
| | - Juro Wadachi
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Masayuki Hattori
- Department of Dental Materials Science, Tokyo Dental College, Tokyo, Japan
| | - Shinichi Abe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
| | - Shuichiro Yamashita
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
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Cai H, Xu X, Lu X, Zhao M, Jia Q, Jiang HB, Kwon JS. Dental Materials Applied to 3D and 4D Printing Technologies: A Review. Polymers (Basel) 2023; 15:2405. [PMID: 37242980 PMCID: PMC10224282 DOI: 10.3390/polym15102405] [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: 04/23/2023] [Revised: 05/09/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
As computer-aided design and computer-aided manufacturing (CAD/CAM) technologies have matured, three-dimensional (3D) printing materials suitable for dentistry have attracted considerable research interest, owing to their high efficiency and low cost for clinical treatment. Three-dimensional printing technology, also known as additive manufacturing, has developed rapidly over the last forty years, with gradual application in various fields from industry to dental sciences. Four-dimensional (4D) printing, defined as the fabrication of complex spontaneous structures that change over time in response to external stimuli in expected ways, includes the increasingly popular bioprinting. Existing 3D printing materials have varied characteristics and scopes of application; therefore, categorization is required. This review aims to classify, summarize, and discuss dental materials for 3D printing and 4D printing from a clinical perspective. Based on these, this review describes four major materials, i.e., polymers, metals, ceramics, and biomaterials. The manufacturing process of 3D printing and 4D printing materials, their characteristics, applicable printing technologies, and clinical application scope are described in detail. Furthermore, the development of composite materials for 3D printing is the main focus of future research, as combining multiple materials can improve the materials' properties. Updates in material sciences play important roles in dentistry; hence, the emergence of newer materials are expected to promote further innovations in dentistry.
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Affiliation(s)
- HongXin Cai
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Republic of Korea;
| | - Xiaotong Xu
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China; (X.X.); (X.L.); (M.Z.); (Q.J.)
| | - Xinyue Lu
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China; (X.X.); (X.L.); (M.Z.); (Q.J.)
| | - Menghua Zhao
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China; (X.X.); (X.L.); (M.Z.); (Q.J.)
| | - Qi Jia
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China; (X.X.); (X.L.); (M.Z.); (Q.J.)
| | - Heng-Bo Jiang
- The CONVERSATIONALIST Club, School of Stomatology, Shandong First Medical University, Jinan 250117, China; (X.X.); (X.L.); (M.Z.); (Q.J.)
| | - Jae-Sung Kwon
- Department and Research Institute of Dental Biomaterials and Bioengineering, Yonsei University College of Dentistry, Seoul 03722, Republic of Korea;
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14
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Souza Curinga MR, Claudino Ribeiro AK, de Moraes SLD, do Egito Vasconcelos BC, da Fonte Porto Carreiro A, Pellizzer EP. Mechanical properties and accuracy of removable partial denture frameworks fabricated by digital and conventional techniques: A systematic review. J Prosthet Dent 2023:S0022-3913(23)00075-6. [PMID: 36870892 DOI: 10.1016/j.prosdent.2023.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 03/06/2023]
Abstract
STATEMENT OF PROBLEM Providing a removable partial denture (RPD) can be a complex, time-consuming, and error-prone procedure. Computer-aided design and computer-aided manufacturing (CAD-CAM) techniques have shown promising clinical outcomes; however, the influence of manufacturing techniques on the properties of RPD components is unclear. PURPOSE The purpose of this systematic review was to determine the accuracy and mechanical properties of RPD components fabricated with conventional and digital methods. MATERIAL AND METHODS This study followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) and was registered on the international prospective register of systematic reviews (PROSPERO) database (CRD42022353993). An electronic search was conducted on PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library in August 2022. Only in vitro studies comparing the digital with the lost-wax casting technique were included. The quality of the studies was assessed by using the methodological index for nonrandomized studies (MINORS) scale. RESULTS Of the 17 selected studies, 5 evaluated the accuracy of RPD components as well as the mechanical properties, 5 studies evaluated only the component accuracy, and another 7 evaluated only the mechanical properties. The accuracy was similar regardless of the technique, with discrepancies within clinically acceptable values (50 to 426.3 μm). The surface roughness was higher for 3D-printed clasps and lower for milled clasps (P<.05). The metal alloy significantly influenced the porosity, with the highest number of pores obtained by casting for Ti clasps and by rapid prototyping for Co-Cr clasps. CONCLUSIONS In vitro studies showed that the digital technique provided similar accuracy to that of the conventional technique within a clinically acceptable range. The manufacturing technique influenced the mechanical properties of RPD components.
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Affiliation(s)
| | | | - Sandra Lúcia Dantas de Moraes
- Associate Professor, Division of Oral Rehabilitation, Faculty of Dentistry, University of Pernambuco (UPE), Recife, PE, Brazil
| | | | | | - Eduardo Piza Pellizzer
- Full Professor, Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Araçatuba, SP, Brazil
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15
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Alageel O, Alsadon O, Almansour H, Alshehri A, Alhabbad F, Alsarani M. Assessment of effect of accelerated aging on interim fixed dental materials using digital technologies. J Adv Prosthodont 2022; 14:360-368. [PMID: 36685789 PMCID: PMC9832148 DOI: 10.4047/jap.2022.14.6.360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/10/2022] [Accepted: 11/18/2022] [Indexed: 12/28/2022] Open
Abstract
PURPOSE This study assessed the physical and mechanical properties of interim crown materials fabricated using various digital techniques after accelerated aging. MATERIALS AND METHODS Three groups of interim dental restorative materials (N = 20) were tested. The first group (CO) was fabricated using a conventional manual method. The second group (ML) was prepared from prefabricated resin blocks for the milling method and cut into specimen sizes using a cutting disc. The third group (3D) was additively manufactured using a digital light-processing (DLP) 3D printer. Aging acceleration treatments using toothbrushing and thermocycling simulators were applied to half of the specimens corresponding to three years of usage in the oral environment (N = 10). Surface roughness (Ra), Vickers microhardness, 3-point bending, sorption, and solubility tests were performed. A 2-way analysis of variance (ANOVA) and Fisher's multiple comparison test were used to compare the results among the groups. RESULTS The mean surface roughness (Ra) of the resin after accelerated aging was significantly higher in the CO and ML groups than that before aging, but not in the 3D group. All groups showed reduced hardness after accelerated aging. The flexural strength values were highest in the 3D group, followed by the ML and CO groups after accelerated aging. Accelerated aging significantly reduced water sorption in the ML group. CONCLUSION According to the tested material and 3D printer type, both 3D-printed and milled interim restoration resins showed higher flexural strength and modulus, and lower surface roughness than those prepared by the conventional method after accelerated aging.
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Affiliation(s)
- Omar Alageel
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Omar Alsadon
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.,Engineer Abdullah Bugshan Research Chair for Dental and Oral Rehabilitation, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | - Haitham Almansour
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Abdullah Alshehri
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Fares Alhabbad
- Dental University Hospital, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Majed Alsarani
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
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16
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Zoabi A, Redenski I, Oren D, Kasem A, Zigron A, Daoud S, Moskovich L, Kablan F, Srouji S. 3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery. J Clin Med 2022; 11:jcm11092385. [PMID: 35566511 PMCID: PMC9104292 DOI: 10.3390/jcm11092385] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 02/01/2023] Open
Abstract
Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.
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Affiliation(s)
- Adeeb Zoabi
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Idan Redenski
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Daniel Oren
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Adi Kasem
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Asaf Zigron
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Shadi Daoud
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Liad Moskovich
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Fares Kablan
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
| | - Samer Srouji
- Department of Oral and Maxillofacial Surgery, Galilee College of Dental Sciences, Galilee Medical Center, Nahariya 2210001, Israel; (A.Z.); (I.R.); (D.O.); (A.K.); (A.Z.); (S.D.); (L.M.); (F.K.)
- The Azrieli Faculty of Medicine, Bar-Ilan University, Safed 1311502, Israel
- Correspondence:
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17
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Alabdullah SA, Hannam AG, Wyatt CC, McCullagh AP, Aleksejuniene J, Mostafa NZ. Comparison of digital and conventional methods of fit evaluation of partial removable dental prosthesis frameworks fabricated by selective laser melting. J Prosthet Dent 2022; 127:478.e1-478.e10. [DOI: 10.1016/j.prosdent.2021.09.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 09/25/2021] [Accepted: 09/27/2021] [Indexed: 11/30/2022]
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18
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Kobayashi H, Tasaka A, Higuchi S, Yamashita S. Influence of molding angle on the trueness and defects of removable partial denture frameworks fabricated by selective laser melting. J Prosthodont Res 2021; 66:589-599. [PMID: 34980787 DOI: 10.2186/jpr.jpr_d_21_00175] [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: 11/06/2022]
Abstract
PURPOSE To examine the effect of molding angle on the trueness and defects associated with removable partial denture (RPD) frameworks fabricated by selective laser melting (SLM). METHODS A plaster model of a partially edentulous mandibular arch classified as Kennedy class II modification 1 was used. After obtaining the 3D data of the model (design data), a framework was designed using CAD software. Based on the design data, three different molding angle conditions (0°, 45°, and -45°) were set in the CAM software. The frameworks were fabricated by SLM under each condition, and 3D data were captured (fabrication data). The design and fabrication data were superimposed using 3D inspection software to verify the shape errors. The number of support structures was then measured. To examine the internal defects, micro-computed tomography (µCT) was performed for void analysis. Surface roughness was measured using a laser microscope. RESULTS The overall shape errors of the RPD framework were smaller under the 0° condition compared with the others, and the largest number of support structures was observed at 0°. Many internal defects were observed in the large components of the framework at 45° and -45°. The surface roughness was the smallest at -45°. CONCLUSION The trueness and defects associated with the RPD frameworks were affected by the difference in the SLM molding angle.
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Affiliation(s)
- Hiro Kobayashi
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Akinori Tasaka
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - Shizuo Higuchi
- Department of Oral Health Engineering, Faculty of Health Sciences, Graduate School of Oral Health Sciences, Osaka Dental University, Osaka, Japan
| | - Shuichiro Yamashita
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
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19
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Influence of build angulation on the mechanical properties of a direct-metal laser-sintered cobalt-chromium used for removable partial denture frameworks. J Prosthet Dent 2021; 126:224-230. [DOI: 10.1016/j.prosdent.2020.06.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 06/06/2020] [Accepted: 06/08/2020] [Indexed: 11/20/2022]
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20
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Modern partial dentures - part 2: a review of novel metal-free materials and innovations in polymers. Br Dent J 2021; 230:813-818. [PMID: 34172865 DOI: 10.1038/s41415-021-3068-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/09/2020] [Indexed: 11/08/2022]
Abstract
New materials are continuously being developed and advanced for the provision of partial dentures. However, the rate at which they are developing makes it hard for the clinician to discern which would be worth adopting into their practice.This paper looks at some of those materials, including the earlier alternatives to conventional acrylic resins, polyamides and acetal resin, followed by a review of the newer novel polymers that are currently in use, including aryl-ketone-polymers and the polymer group polyaryletherketones.The newer polymers have many similarities, in both properties and aesthetics, such as increased elasticity that allows the dentures to engage deeper undercuts, while maintaining high strength. A significant benefit of the novel polymers is in their ability to fit into a digital workflow. Computer-aided design and manufacture confer a high degree of consistency, efficiency and accuracy in the prosthesis. The ability to use precise digital tools to create frameworks and clasps of accurate parameters limits the introduction of technical error that has the potential to be introduced in the construction of a conventional cobalt-chrome framework.The novel high-performance polymers show great promise. Research is needed on these materials investigating the effects on oral health, longevity and survival of the appliances, as well as studies looking at patient satisfaction and the impact on quality of life.
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21
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Modern partial dentures - part 1: novel manufacturing techniques. Br Dent J 2021; 230:651-657. [PMID: 34050296 DOI: 10.1038/s41415-021-3070-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 05/05/2021] [Indexed: 11/08/2022]
Abstract
While the conventional fabrication of removal partial dentures through the lost-wax technique is a time-tested technique, it is recognised as a 'complicated, error-prone, time-consuming and expensive process'. This has financial implications and can lead to increased chair time for the patient and dentist, resulting from low precision and ill-fitting frameworks. The use of computer-aided design and computer-aided manufacture brings removable prosthodontics into the digital era and opens up a host of benefits to the practitioner and laboratory technician. This paper introduces the benefits and downsides to adopting a digital workflow, and looks at the various alternative manufacturing techniques, which allow the clinician and technician to streamline their processes and make use of novel denture materials.
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22
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Richert R, Alsheghri AA, Alageel O, Caron E, Song J, Ducret M, Tamimi F. Analytical model of I-bar clasps for removable partial dentures. Dent Mater 2021; 37:1066-1072. [PMID: 33867171 DOI: 10.1016/j.dental.2021.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 02/26/2021] [Accepted: 03/29/2021] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Clasps of removable partial dentures (RPDs) often suffer from fatigue stress that leads to plastic deformation, loss of retention, and RPD failure. Recently, computer-based technologies were proposed to optimize clasp geometry design. The objective of this study was to create an analytic model of I-bar clasps for computer-aided design (CAD)-RPD. METHODS The analytical model based on mechanical laws was established to simulate I-bar clasp retention, and optimize its design. The model considered the lengths of the vertical (L1) and horizontal (L2) arms of the I-bar as well as the radius (r) of its half-round cross-section. The analytical model was validated with mechanical experiments evaluating the retention of cobalt-chromium (Co-Cr) clasps in vitro and compared with finite element analysis (FEA). RESULTS The analytical model was in good agreement with the mechanical experiments and FEA, and showed that I-bar clasp design could provide optimal mechanical performance as long as the length of arms (L1 and L2) do not exceed 6 mm. Clasps with L1 > 8 mm and L2 > 9 mm presented stress values exceeding the fatigue limit of Co-Cr. The proposed solution was to increase the radius of I-bar to conserve the initial mechanical performance of Co-Cr. SIGNIFICANCE Co-Cr I-bar clasps perform best on teeth with reduced mesiodistal dimensions (canine and premolar), and their designs could be optimized to prevent stress from reaching the yield strength and the fatigue failure limit.
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Affiliation(s)
- Raphaël Richert
- Hospices Civils de Lyon, PAM Odontologie, Lyon, France; Faculté d'Odontologie, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Laboratoire de Mécanique des Contacts et structures, UMR 5259 CNRS/INSA Lyon, Lyon, France
| | - Ammar A Alsheghri
- Department of Mining Materials Engineering, McGill University, Montreal, QC, Canada; Department of Software and Computer Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Omar Alageel
- Faculty of Dentistry, McGill University, Montreal, QC, Canada; King Saud University, Riyadh, Saudi Arabia
| | | | - Jun Song
- Department of Mining Materials Engineering, McGill University, Montreal, QC, Canada
| | - Maxime Ducret
- Hospices Civils de Lyon, PAM Odontologie, Lyon, France; Faculté d'Odontologie, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Faculty of Dentistry, McGill University, Montreal, QC, Canada
| | - Faleh Tamimi
- College of Dental Medicine, Qatar University, Doha, Qatar.
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23
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Krezel JD, Friel T, Waia S, Clark P, Taylor PD. Prosthetic Rehabilitation of a Repaired Cleft Palate with Use of a Two-Part Hinged Magnet Retained Removable Prosthesis. J Prosthodont 2021; 30:454-457. [PMID: 33660377 DOI: 10.1111/jopr.13353] [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: 02/26/2021] [Indexed: 11/28/2022] Open
Abstract
The presence of a cleft lip and palate is associated with a number of complications and the oral rehabilitation for the improvement of speech, function and esthetics can involve conventional and surgical orthodontics, distraction osteogenesis, fixed and removable prosthodontics, providing obturation of open defects if required. This clinical report describes the prosthodontic management of a patient with a repaired cleft lip and palate with significant maxillary hypoplasia and primary concern of aesthetics with the use of a two-part hinged magnet retained removable prosthesis.
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Affiliation(s)
- John Daniel Krezel
- Clinical Fellow/Clinical Lecturer in Prosthodontics, Department of Prosthodontics, University of Michigan, Ann Arbor, MI, United States
| | - Tim Friel
- Senior Clinical Lecturer in Prosthodontics, Department of Prosthodontics, Queen Mary University of London, London, UK
| | - Sarah Waia
- Clinical Lecturer in Prosthodontics, Department of Prosthodontics, Queen Mary University of London, London, UK
| | - Paul Clark
- Senior Dental Technologist, Dental Technician Laboratory, Cardiff University, Cardiff, UK
| | - Philip Duncan Taylor
- Dean of the RCSEd Faculty of Dental Surgery, Faculty of Dental Surgery, The Royal College of Surgeons of Edinburgh, Edinburgh, UK
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Khorsandi D, Fahimipour A, Abasian P, Saber SS, Seyedi M, Ghanavati S, Ahmad A, De Stephanis AA, Taghavinezhaddilami F, Leonova A, Mohammadinejad R, Shabani M, Mazzolai B, Mattoli V, Tay FR, Makvandi P. 3D and 4D printing in dentistry and maxillofacial surgery: Printing techniques, materials, and applications. Acta Biomater 2021; 122:26-49. [PMID: 33359299 DOI: 10.1016/j.actbio.2020.12.044] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022]
Abstract
3D and 4D printing are cutting-edge technologies for precise and expedited manufacturing of objects ranging from plastic to metal. Recent advances in 3D and 4D printing technologies in dentistry and maxillofacial surgery enable dentists to custom design and print surgical drill guides, temporary and permanent crowns and bridges, orthodontic appliances and orthotics, implants, mouthguards for drug delivery. In the present review, different 3D printing technologies available for use in dentistry are highlighted together with a critique on the materials available for printing. Recent reports of the application of these printed platformed are highlighted to enable readers appreciate the progress in 3D/4D printing in dentistry.
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Ziębowicz A, Sambok-Kiełbowicz A, Walke W, Mzyk A, Kosiel K, Kubacki J, Bączkowski B, Pawlyta M, Ziębowicz B. Evaluation of Bacterial Adhesion to the ZrO 2 Atomic Layer Deposited on the Surface of Cobalt-Chromium Dental Alloy Produced by DMLS Method. MATERIALS 2021; 14:ma14051079. [PMID: 33652601 PMCID: PMC7956347 DOI: 10.3390/ma14051079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/11/2021] [Accepted: 02/16/2021] [Indexed: 11/16/2022]
Abstract
The main purpose of the research was to analyze the influence of surface modification of the cobalt-based alloy used in dental prosthetics by applying zirconium oxide (ZrO2) layers using the ALD (Atomic Layer Deposition) method. The samples were made using the DMLS (Direct Metal Laser Sintering) technique, and their surfaces were prepared in accordance with the principles of removable partial dentures (RPDs). A 50 nm-thick zirconium oxide coating was applied to the prepared substrates. This paper deals with the issues of prosthetic stomatopathy, which is a complex of pathological changes occurring in approx. 40% of the Polish population using removable dentures. Often, these changes, occurring on the mucosa, are related to improper performance, allergic reactions or the multiplication of bacteria on the surface of partial dentures. An innovative method of surface modification was proposed, together with the analysis of its influence on the physicochemical properties of the alloy and the adhesion of bacteria to the surface.
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Affiliation(s)
- Anna Ziębowicz
- Department of Biomaterials and Medical Devices Engineering, Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta 40, 41-800 Zabrze, Poland; (A.Z.); (W.W.)
| | - Agata Sambok-Kiełbowicz
- Department of Biomaterials and Medical Devices Engineering, Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta 40, 41-800 Zabrze, Poland; (A.Z.); (W.W.)
- Correspondence:
| | - Witold Walke
- Department of Biomaterials and Medical Devices Engineering, Faculty of Biomedical Engineering, Silesian University of Technology, Roosevelta 40, 41-800 Zabrze, Poland; (A.Z.); (W.W.)
| | - Aldona Mzyk
- Department of Biomedical Engineering, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands;
| | - Kamil Kosiel
- Łukasiewicz Research Network—Institute of Microelectronics and Photonics, Department of Interdisciplinary Applications of Micro- and Nanotechnology, Al. Lotników 32/46, 02-668 Warsaw, Poland;
| | - Jerzy Kubacki
- August Chełkowski Institute of Physics, Silesian Centre for Education and Interdisciplinary Research, University of Silesia, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland;
| | - Bohdan Bączkowski
- Department of Prosthodontics, Institute of Dentistry, Medical University of Warsaw, Żwirki i Wigury 61, 02-091 Warsaw, Poland;
| | - Mirosława Pawlyta
- Department of Engineering Materials and Biomaterials, Faculty of Mechanical Engineering, Silesian University of Technology, Konarskiego 18A, 44-100 Gliwice, Poland; (M.P.); (B.Z.)
| | - Bogusław Ziębowicz
- Department of Engineering Materials and Biomaterials, Faculty of Mechanical Engineering, Silesian University of Technology, Konarskiego 18A, 44-100 Gliwice, Poland; (M.P.); (B.Z.)
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Takaichi A, Fueki K, Murakami N, Ueno T, Inamochi Y, Wada J, Arai Y, Wakabayashi N. A systematic review of digital removable partial dentures. Part II: CAD/CAM framework, artificial teeth, and denture base. J Prosthodont Res 2021; 66:53-67. [PMID: 33504722 DOI: 10.2186/jpr.jpr_d_20_00117] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE This study comprehensively reviewed the current status of the digital workflow of removable partial dentures (RPDs) and summarized information about the fabrication methods and material properties of the dental framework, artificial teeth, and denture base. STUDY SELECTION We performed a systematic review of the literature published in online databases from January 1980 to April 2020 regarding RPD fabrication and materials used in the related digital technology. We selected eligible articles, retrieved information regarding digital RPDs, and conducted qualitative/quantitative analyses. In this paper, the computer-aided design/computer-aided manufacturing (CAD/CAM) framework, artificial teeth, and denture base materials are reported. RESULTS A variety of materials, such as cobalt-chromium alloy, titanium, zirconia, and polyether ether ketone, are used for dental CAD/CAM frameworks. The mechanical strength of the metal materials used for the CAD/CAM framework was superior to that of the cast framework. However, the fitness and surface roughness of the framework and clasp fabricated using a selective laser melting (SLM) method were not superior to those obtained via cast fabrication. Most material properties and the surface roughness of poly methyl methacrylate (PMMA) discs used for digital RPDs were superior to those of heat-cured PMMA. CONCLUSIONS The use of a CAD/CAM framework and PMMA disc for digital RPDs offers numerous advantages over conventional RPDs. However, technical challenges regarding the accuracy and durability of adhesion between the framework and denture base remain to be solved. In digital fabrication, human technical factors influence the quality of the framework.
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Affiliation(s)
- Atsushi Takaichi
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Kenji Fueki
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Natsuko Murakami
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Takeshi Ueno
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Yuka Inamochi
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Junichiro Wada
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Yuki Arai
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
| | - Noriyuki Wakabayashi
- Department of Removable Partial Prosthodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo
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The use of selective laser melting in the fabrication of maxillary and mandibular metal base complete dentures for a patient with Ehlers-Danlos syndrome: A clinical report. J Prosthet Dent 2020; 124:509-513. [DOI: 10.1016/j.prosdent.2019.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 11/18/2022]
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Azpiazu-Flores FX, Lee DJ, Lang LA. Weighted mandibular complete denture fabricated by using selective laser melting: A clinical report. J Prosthet Dent 2020; 126:144-149. [PMID: 32893019 DOI: 10.1016/j.prosdent.2020.06.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 11/27/2022]
Abstract
The rehabilitation of patients with severely resorbed mandibular ridges can be a clinical challenge when rehabilitation with endosteal implants is not the elected treatment. Historically, weighted mandibular complete dentures have been used successfully to manage patients with severely resorbed ridges, and the weight of their cast metal has been calculated by using the weight of the wax and the density of the alloy. This clinical report presents the management of an 87-year-old woman with a severely resorbed mandibular ridge by using a weighted mandibular complete denture fabricated by using selective laser melting (SLM) technology in which the weight of the metal base was calculated by using the volume of the digital file used for manufacture.
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Affiliation(s)
- Francisco X Azpiazu-Flores
- Graduate student, Advanced Prosthodontics Program, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio.
| | - Damian J Lee
- Assistant Professor and Director of the Advanced Prosthodontics Program, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio
| | - Lisa A Lang
- Chair, Division of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus, Ohio
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Tasaka A, Shimizu T, Kato Y, Okano H, Ida Y, Higuchi S, Yamashita S. Accuracy of removable partial denture framework fabricated by casting with a 3D printed pattern and selective laser sintering. J Prosthodont Res 2020; 64:224-230. [DOI: 10.1016/j.jpor.2019.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 06/18/2019] [Accepted: 07/22/2019] [Indexed: 11/30/2022]
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The effect of build orientation on the microstructure and properties of selective laser melting Ti-6Al-4V for removable partial denture clasps. J Prosthet Dent 2020; 123:163-172. [DOI: 10.1016/j.prosdent.2018.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 12/05/2018] [Accepted: 12/05/2018] [Indexed: 11/17/2022]
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Evaluation of the design-driven prediction of removable partial denture retention. J Prosthet Dent 2019; 124:357-364. [PMID: 31810612 DOI: 10.1016/j.prosdent.2019.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 10/02/2019] [Accepted: 10/02/2019] [Indexed: 11/27/2022]
Abstract
STATEMENT OF PROBLEM Removable partial dentures (RPDs) are a cost-effective treatment designed to replace missing teeth for partially edentulous patients. However, RPDs often have insufficient retention, which results in treatment failure and patient dissatisfaction. PURPOSE The purpose of this clinical study was to investigate the factors related to RPD retention that affect patient satisfaction, to clinically validate a newly published model for predicting RPD retention based on the number and position of missing teeth and clasps, and to identify the predictions of patient satisfaction to improve the guidelines for RPD design. MATERIAL AND METHODS Seventy-five patients treated with 107 RPDs delivered at the McGill University Dental Clinic (Montreal, Canada) and Estaing University Hospital (Clermont-Ferrand, France) participated in this study. Data on the RPD design were collected from the clinical records, and the retention of each RPD was tested with the mathematical model designed for predicting RPD retention. Data on patient satisfaction with their RPDs were collected by using a standardized questionnaire (McGill Denture Satisfaction Instrument). Statistical analysis of factors related to RPD retention and patient satisfaction was performed by using the chi-square test and Mann-Whitney test, while the developed model for predicting RPD retention was evaluated by using sensitivity and specificity analysis. RESULTS The average satisfaction score for all RPDs was 8.2 ±1.7 out of 10. Patients were more satisfied with RPDs in the maxillary arch, tooth-supported, or retained by ≥3 clasps than with RPDs in the mandibular arch, with distal extension bases, or retained by <3 clasps. The materials used for RPD fabrication (metal-based or acrylic resin-based), the number of missing teeth, and the presence of indirect retention were not associated with patient satisfaction. Participants were significantly more satisfied with RPD designs predicted by the developed mathematical model to have enough retention than with RPD designs predicted to have insufficient retention. The mathematical model for predicting the RPD retention showed a clinical specificity of 83% in predicting patient satisfaction. CONCLUSIONS RPD retention predicted from the number and position of clasps and missing teeth might help to determine patient satisfaction. In addition, patient satisfaction with RPDs was influenced by the arch type, the presence of a distal extension base, and the number of clasps.
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Tasaka A, Uekubo Y, Mitsui T, Kasahara T, Takanashi T, Homma S, Matsunaga S, Abe S, Yoshinari M, Yajima Y, Sakurai K, Yamashita S. Applying intraoral scanner to residual ridge in edentulous regions: in vitro evaluation of inter-operator validity to confirm trueness. BMC Oral Health 2019; 19:264. [PMID: 31791324 PMCID: PMC6889518 DOI: 10.1186/s12903-019-0918-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 09/20/2019] [Indexed: 11/17/2022] Open
Abstract
Background The purpose of this study was to investigate the trueness of intraoral scanning of residual ridge in edentulous regions during in vitro evaluation of inter-operator validity. Methods Both edentulous maxillary and partially edentulous mandibular models were selected as a simulation model. As reference data, scanning of two models was performed using a dental laboratory scanner (D900, 3Shape A/S). Five dentists used an intraoral scanner (TRIOS 2, 3Shape A/S) five times to capture intraoral scanner data, and the “zig-zag” scanning technique was used. They did not have experience with using intraoral scanners in clinical treatment. The intraoral scanner data was overlapped with the reference data (Dental System, 3Shape A/S). Regarding differences that occurred between the reference and intraoral scanner data, the vertical maximum distance of the difference and the integral value obtained by integrating the total distance were analyzed. Results In terms of the maximum distances of the difference on the maxillary model, the means of five operators were as follows: premolar region, 0.30 mm; molar region, 0.18 mm; and midline region, 0.18 mm. The integral values were as follows: premolar region, 4.17 mm2; molar region, 6.82 mm2; and midline region, 4.70 mm2. Significant inter-operator differences were observed with regard to the integral values of the distance in the premolar and midline regions and with regard to the maximum distance in the premolar region, respectively. The maximum distances of the difference in the free end saddles on mandibular model were as follows: right side, 0.05 mm; and left side, 0.08 mm. The areas were as follows: right side, 0.78 mm2; and left side, 1.60 mm2. No significant inter-operator differences were observed in either region. Conclusions The present study demonstrated satisfactory trueness of intraoral scanning of the residual ridge in edentulous regions during in vitro evaluation of inter-operator validity.
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Affiliation(s)
- Akinori Tasaka
- Department of Removable Partial Prosthodontics, Tokyo Dental College, 2-9-18 Kandamisakicho Chiyoda-ku, Tokyo, 101-0061, Japan. .,Oral Health Science Center, Tokyo Dental College, Tokyo, Japan.
| | - Yuuki Uekubo
- Department of Removable Partial Prosthodontics, Tokyo Dental College, 2-9-18 Kandamisakicho Chiyoda-ku, Tokyo, 101-0061, Japan
| | - Tomoharu Mitsui
- Department of Removable Partial Prosthodontics, Tokyo Dental College, 2-9-18 Kandamisakicho Chiyoda-ku, Tokyo, 101-0061, Japan
| | - Takao Kasahara
- Department of Prosthodontics, Matsumoto Dental University, Shiojiri, Japan
| | - Takuya Takanashi
- Department of Oral and Maxillofacial Implantology, Tokyo Dental College, Tokyo, Japan
| | - Shinya Homma
- Department of Oral and Maxillofacial Implantology, Tokyo Dental College, Tokyo, Japan
| | - Satoru Matsunaga
- Oral Health Science Center, Tokyo Dental College, Tokyo, Japan.,Department of Anatomy, Tokyo Dental College, Tokyo, Japan
| | - Shinichi Abe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
| | - Masao Yoshinari
- Oral Health Science Center, Tokyo Dental College, Tokyo, Japan
| | - Yasutomo Yajima
- Department of Oral and Maxillofacial Implantology, Tokyo Dental College, Tokyo, Japan
| | - Kaoru Sakurai
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Tokyo, Japan
| | - Shuichiro Yamashita
- Department of Removable Partial Prosthodontics, Tokyo Dental College, 2-9-18 Kandamisakicho Chiyoda-ku, Tokyo, 101-0061, Japan
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Schweiger J, Güth JF, Erdelt KJ, Edelhoff D, Schubert O. Internal porosities, retentive force, and survival of cobalt-chromium alloy clasps fabricated by selective laser-sintering. J Prosthodont Res 2019; 64:210-216. [PMID: 31680054 DOI: 10.1016/j.jpor.2019.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE The purpose of this study was to evaluate internal porosities, retentive force values and survival of cobalt-chromium (Co-Cr) alloy clasps fabricated by direct metal laser-sintering (DMLS) and compare them to conventionally cast clasps. METHODS Embrasure clasps were digitally designed fitting teeth 35 and 36 on identical metal models (N = 32). Sixteen clasps were fabricated using DMLS (group DMLS) and another sixteen clasps were additively manufactured from wax and then cast from a Co-Cr alloy (group CAST). Internal porosities were examined using micro-focus X-ray (micro-CT) and analyzed applying Kolmogorov-Smirnov test, Mann-Whitney test, and T test (significance level: p < 0.050). A universal testing machine was used to determine the retentive force values at baseline and after 1095, 5475, 10,950 and 65,000 cycles of simulated aging. Data were analyzed employing Kolmogorov-Smirnov test, one-way ANOVA, and Scheffé's post-hoc test (significance level: p < 0.050). Survival was estimated for 65,000 cycles of artificial aging using Kaplan-Meier analysis. RESULTS Micro-CT analysis revealed a higher prevalence (p < 0.001), but a more homogeneous size and a significantly smaller mean (p = 0.009) and total volume (p < 0.001) of internal porosities for group DMLS. The groups showed mean initial retentive force values of 13.57 N (CAST) and 15.74 N (DMLS), which significantly declined over aging for group CAST (p = 0.003), but not for group DMLS (p = 0.107). Survival was considerably higher for group DMLS (93.8%) than for group CAST (43.8%) after 65,000 cycles of aging. CONCLUSIONS Clasps made by laser-sintering could be an alternative to conventional cast clasps for the fabrication of removable partial denture frameworks.
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Affiliation(s)
- Josef Schweiger
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Germany.
| | - Jan-Frederik Güth
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Germany
| | - Kurt-Jürgen Erdelt
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Germany
| | - Daniel Edelhoff
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Germany
| | - Oliver Schubert
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, Germany
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Alageel O, Alsheghri AA, Algezani S, Caron E, Tamimi F. Determining the retention of removable partial dentures. J Prosthet Dent 2019; 122:55-62.e3. [DOI: 10.1016/j.prosdent.2018.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 12/14/2022]
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Chen L, Lin WS, Polido WD, Eckert GJ, Morton D. Accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates. J Prosthet Dent 2019; 122:309-314. [PMID: 30948293 DOI: 10.1016/j.prosdent.2019.02.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 02/12/2019] [Accepted: 02/13/2019] [Indexed: 11/28/2022]
Abstract
STATEMENT OF PROBLEM Additively manufactured surgical templates are commonly used for computer-guided implant placement. However, their accuracy, reproducibility, and dimensional stability have not been thoroughly investigated with the different 3D printers and materials used for their fabrication. PURPOSE The purpose of this in vitro study was to evaluate the accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates fabricated by using different 3D printers. MATERIAL AND METHODS Thirty surgical templates were designed and additively manufactured from 3 different 3D printers as follows: group SLA (n=10) was fabricated by using a desktop stereolithography (SLA) 3D printer and photopolymerizing resin; group PolyJet (n=10) was fabricated by using a PolyJet 3D printer and photopolymerizing resins; and group DMP (n=10) was fabricated by using a direct metal printing (DMP) system and Co-Cr metal alloy. All surgical templates were scanned by using a laser scanner within 36 hours of production and digitalized again 1 month later. All scanned files were compared with the corresponding designed files in a surface matching software program. The mean deviation root mean square (RMS, measured in mm, representing accuracy), percentage of measurement data points within 1 standard deviation of mean RMS (in %, representing reproducibility), and dimensional changes were determined and compared. RESULTS At the postproduction stage, group PolyJet was most accurate with the lowest RMS value of 0.10 ±0.02 mm and highest reproducibility with 93.07 ±1.54% of measurement data points within 1 standard deviation of mean RMS. After 1-month storage, group PolyJet(1month) remained the most accurate with the lowest RMS value of 0.14 ±0.03 mm and the highest reproducibility value of 92.46 ±1.50%. For dimensional stability, group SLA versus group SLA(1month) comparison showed a significant decrease in accuracy (RMS values of 0.20 ±0.08 mm versus 0.25 ±0.08 mm, P<.001) and reproducibility (88.16 ±3.66% versus 86.10 ±4.16%, P=.012). Group PolyJet versus group PolyJet(1month) comparison only showed significant changes in accuracy (RMS values of 0.10 ±0.02 mm versus 0.14 ±0.03 mm, P=.011). Group DMP versus group DMP(1month) comparison showed no significant changes in accuracy (RMS values of 0.19 ±0.03 mm versus 0.20 ±0.04 mm, P=.981) or reproducibility (89.77 ±1.61% versus 89.74 ±2.24%, P=1.000). CONCLUSIONS Printed resin surgical templates produced by using the PolyJet 3D printer showed higher accuracy and reproducibility than those produced by using the desktop SLA 3D printer and printed Co-Cr surgical templates at both the postproduction stage and after 1-month storage. The level of accuracy and reproducibility in printed Co-Cr surgical templates was not affected by 1-month storage.
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Affiliation(s)
- Li Chen
- Attending Faculty, Department of Prosthodontics, Peking University School and Hospital of Stomatology; National Clinical Research Center for Oral Diseases; National Engineering Laboratory for Digital and Material Technology of Stomatology; and Beijing Key Laboratory of Digital Stomatology, Beijing, PR China; and Former Scholar, Division of Prosthodontics, Department of Oral Health and Rehabilitation, School of Dentistry, University of Louisville, Louisville, Ky
| | - Wei-Shao Lin
- Associate Professor, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Ind.
| | - Waldemar D Polido
- Professor, Department of Oral Surgery and Hospital Dentistry, Indiana University School of Dentistry, Indianapolis, Ind
| | - George J Eckert
- Biostatistician Supervisor, Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Ind
| | - Dean Morton
- Professor and Chair, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, Ind
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Soltanzadeh P, Su JM, Habibabadi SR, Kattadiyil MT. Obturator fabrication incorporating computer-aided design and 3-dimensional printing technology: A clinical report. J Prosthet Dent 2019; 121:694-697. [PMID: 30711293 DOI: 10.1016/j.prosdent.2018.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 12/15/2022]
Abstract
This article reports an approach to fabricating a maxillary obturator using the computer-aided design and computer-aided manufacturing (CAD-CAM) process. The maxillary definitive cast and the trial tooth arrangement were separately scanned and superimposed. The virtual cast created from the scan data was surveyed, and the framework was designed using specific software. The definitive cobalt-chromium framework was fabricated by using 3-dimensional (3D) selective laser sintering (SLS) technology. After framework trial placement, the definitive obturator prosthesis was processed using conventional heat-polymerizing resin with the lost-wax processing technique. Using CAD technology and 3D metal printing resulted in improved fit, function, and esthetics for the definitive obturator prosthesis.
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Affiliation(s)
- Pooya Soltanzadeh
- Assistant Professor, Division of General Dentistry, School of Dentistry, Loma Linda University, Loma Linda, Calif.
| | - Jui-Min Su
- Assistant Professor, Advanced Specialty Education Program in Prosthodontics, School of Dentistry, Loma Linda University, Loma Linda, Calif
| | | | - Mathew T Kattadiyil
- Professor and Director, Advanced Specialty Education Program in Prosthodontics, School of Dentistry, Loma Linda University, Loma Linda, Calif
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Soltanzadeh P, Suprono MS, Kattadiyil MT, Goodacre C, Gregorius W. An In Vitro Investigation of Accuracy and Fit of Conventional and CAD/CAM Removable Partial Denture Frameworks. J Prosthodont 2018; 28:547-555. [PMID: 30407685 DOI: 10.1111/jopr.12997] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2018] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To evaluate the overall accuracy and fit of conventional versus computer-aided design/computer-aided manufactured (CAD/CAM) removable partial denture (RPD) frameworks based on standard tessellation language (STL) data analysis, and to evaluate the accuracy and fit of each component of the RPD framework. MATERIALS AND METHODS A maxillary metal framework was designed for a Kennedy class III Modification I arch. The master model was scanned and used to compare the fit and accuracy of RPD frameworks. Forty impressions (conventional and digital) of the master cast were made and divided into 4 groups based on fabrication method: group I, lost-wax technique (conventional technique), group II, CAD-printing, group III, CAD-printing from stone cast, and group IV, lost-wax technique from resin-printed model. RPD frameworks were fabricated in cobalt-chromium alloy. All frameworks were scanned, and the gap distance between the framework and scanned master model was measured at 8 locations. Color mapping was conducted using comprehensive metrology software. Data were statistically analyzed using the Kruskall-Wallis test, followed by the Bonferroni method for pairwise comparisons (α = 0.05). RESULTS Color mapping revealed distinct discrepancies in major connectors among the groups. When compared to 3D-printed frameworks, conventional cast frameworks fabricated using dental stone or printed resin models revealed significantly better fit (p < 0.05) particularly in the major connectors and guide plates. The biggest gap (0.33 mm ± 0.20 mm) was observed with the anterior strap of the major connector with the printed frameworks (groups II and III). The method of fabrication did not affect the adaptation of the rests or reciprocation plates. CONCLUSIONS Although both conventional and 3D-printing methods of framework fabrication revealed clinically acceptable adaptation, the conventional cast RPD groups revealed better overall fit and accuracy.
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Affiliation(s)
- Pooya Soltanzadeh
- Division of General Dentistry, Loma Linda University School of Dentistry, Loma Linda, CA
| | - Montry S Suprono
- Advanced Education Program in Prosthodontics, and Center for Dental Research, Loma Linda University School of Dentistry, Loma Linda, CA
| | - Mathew T Kattadiyil
- Advanced Education Program in Prosthodontics, Loma Linda University School of Dentistry, Loma Linda, CA
| | - Charles Goodacre
- Advanced Education Program in Prosthodontics, Loma Linda University School of Dentistry, Loma Linda, CA
| | - Wendy Gregorius
- Division of General Dentistry, Loma Linda University School of Dentistry, Loma Linda, CA
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Abduo J, Curtis M, Budhwar V, Palamara J. Influence of novel implant selective laser melting framework design on mechanical durability of acrylic veneer. Clin Implant Dent Relat Res 2018; 20:969-975. [PMID: 30338898 DOI: 10.1111/cid.12685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 09/18/2018] [Accepted: 09/20/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND A novel implant framework design is proposed to improve the mechanical durability of acrylic veneer. PURPOSES Comparing the mechanical durability of acrylic veneer on implant frameworks fabricated from selective laser melting (SLM) with novel design against conventional computer numeric controlled (CNC) milled frameworks. MATERIALS AND METHODS Implant titanium frameworks with distal cantilever were fabricated by SLM (n = 10) and CNC milling (n = 10). The CNC frameworks had multiple vertical pins, while the SLM frameworks had 3D metal networks of horizontal beams connected by vertical struts. All the frameworks were veneered with acrylic teeth and resin material and were subjected to a static load-to-failure test at the cantilever region. The load-to-failure readings and the pattern of prosthesis damage were recorded for each prosthesis. RESULTS The CNC and SLM prostheses failed at statistically similar loads. The acrylic veneer around the CNC frameworks tend to initially crack around the distal implant followed by acrylic chipping. Six SLM prostheses failed at the framework connector on the mesial implant by separation of the screw seat. After reloading these prostheses, they failed by acrylic veneer chipping. The SLM prostheses had significantly less incidence of acrylic flexure and severity of acrylic veneer chipping than CNC prostheses. CONCLUSIONS The SLM framework with novel design is efficient in reinforcing acrylic veneering. However, the SLM frameworks appeared weak in thin sections, such as the screw seat.
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Affiliation(s)
- Jaafar Abduo
- Melbourne Dental School, Melbourne University, Melbourne, Victoria, Australia
| | - Michael Curtis
- Melbourne Dental School, Melbourne University, Melbourne, Victoria, Australia
| | - Vandana Budhwar
- Melbourne Dental School, Melbourne University, Melbourne, Victoria, Australia
| | - Joseph Palamara
- Melbourne Dental School, Melbourne University, Melbourne, Victoria, Australia
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Alsheghri AA, Alageel O, Amine Mezour M, Sun B, Yue S, Tamimi F, Song J. Bio-inspired and optimized interlocking features for strengthening metal/polymer interfaces in additively manufactured prostheses. Acta Biomater 2018; 80:425-434. [PMID: 30244027 DOI: 10.1016/j.actbio.2018.09.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/28/2018] [Accepted: 09/13/2018] [Indexed: 01/02/2023]
Abstract
Biomedical and dental prostheses combining polymers with metals often suffer failure at the interface. The weak chemical bond between these two dissimilar materials can cause debonding and mechanical failure. This manuscript introduces a new mechanical interlocking technique to strengthen metal/polymer interfaces through optimized additively manufactured features on the metal surface. To reach an optimized design of interlocking features, we started with the bio-mimetic stress-induced material transformation (SMT) optimization method. The considered polymer and metal materials were cold-cured Poly(methyl methacrylate) (PMMA) and laser-sintered Cobalt-Chromium (Co-Cr), respectively. Optimal dimensions of the bio-inspired interlocking features were then determined by mesh adaptive direct search (MADS) algorithm combined with finite element analysis (FEA) and tensile experiments such that they provide the maximum interfacial tensile strength and stiffness while minimizing the stress in PMMA and the displacement of PMMA at the Co-Cr/PMMA interface. The SMT optimization process suggested a Y-shape as a more favorable design, which was similar to mangrove tree roots. Experiments confirmed that our optimized interlocking features increased the strength of the Co-Cr/PMMA interface from 2.3 MPa (flat interface) to 34.4 ± 1 MPa, which constitutes 85% of the tensile failure strength of PMMA (40.2 ± 1 MPa). STATEMENT OF SIGNIFICANCE: The objective of this study was to improve metal/polymer interfacial strength in dental and orthopedic prostheses. This was achieved by additive manufacturing of optimized interlocking features on metallic surfaces using laser-sintering. The interlocking design of the features, which was a Y-shape similar to the roots of mangrove trees, was inspired by a bio-memetic optimization algorithm. This interlocking design lowered the PMMA displacement at the Co-Cr/PMMA interface by 70%, enhanced the interfacial strength by more than 12%, and increased the stiffness by 18% compared with a conventional bead design, meanwhile no significant difference was found in the toughness of both designs.
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Alsheghri AA, Alageel O, Caron E, Ciobanu O, Tamimi F, Song J. An analytical model to design circumferential clasps for laser-sintered removable partial dentures. Dent Mater 2018; 34:1474-1482. [PMID: 29937332 DOI: 10.1016/j.dental.2018.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 04/05/2018] [Accepted: 06/07/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Clasps of removable partial dentures (RPDs) often suffer from plastic deformation and failure by fatigue; a common complication of RPDs. A new technology for processing metal frameworks for dental prostheses based on laser-sintering, which allows for precise fabrication of clasp geometry, has been recently developed. This study sought to propose a novel method for designing circumferential clasps for laser-sintered RPDs to avoid plastic deformation or fatigue failure. METHODS An analytical model for designing clasps with semicircular cross-sections was derived based on mechanics. The Euler-Bernoulli elastic curved beam theory and Castigliano's energy method were used to relate the stress and undercut with the clasp length, cross-sectional radius, alloy properties, tooth type, and retention force. Finite element analysis (FEA) was conducted on a case study and the resultant tensile stress and undercut were compared with the analytical model predictions. Pull-out experiments were conducted on laser-sintered cobalt-chromium (Co-Cr) dental prostheses to validate the analytical model results. RESULTS The proposed circumferential clasp design model yields results in good agreement with FEA and experiments. The results indicate that Co-Cr circumferential clasps in molars that are 13mm long engaging undercuts of 0.25mm should have a cross-section radius of 1.2mm to provide a retention of 10N and to avoid plastic deformation or fatigue failure. However, shorter circumferential clasps such as those in premolars present high stresses and cannot avoid plastic deformation or fatigue failure. SIGNIFICANCE Laser-sintered Co-Cr circumferential clasps in molars are safe, whereas they are susceptible to failure in premolars.
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Affiliation(s)
- Ammar A Alsheghri
- Department of Mining Materials Engineering, McGill University, Montreal, QC, Canada.
| | - Omar Alageel
- Faculty of Dentistry, McGill University, Montreal, QC, Canada; College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
| | | | - Ovidiu Ciobanu
- Faculty of Dentistry, McGill University, Montreal, QC, Canada.
| | - Faleh Tamimi
- Faculty of Dentistry, McGill University, Montreal, QC, Canada.
| | - Jun Song
- Department of Mining Materials Engineering, McGill University, Montreal, QC, Canada.
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