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Hlaing NHMM, Lee H, Jeong Y, Park JM, Lee SJ, Lee JH. Influence of crown shade, translucency, and scan powder application on the trueness of intraoral scanners. J Dent 2024; 144:104969. [PMID: 38537881 DOI: 10.1016/j.jdent.2024.104969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/10/2024] [Accepted: 03/24/2024] [Indexed: 04/26/2024] Open
Abstract
OBJECTIVES Natural teeth and dental restorations present with various shades and levels of translucency. This study aimed to determine whether these variations in ceramic crowns and scan powder application affect the trueness of intraoral scanners. METHODS Eight identical premade resin typodonts, each prepared for a crown on the maxillary right second molar, were used. Eight lithium disilicate crowns, distinguished by two levels of translucency (high and low) and four shades (BL1, A2, A3, and A4), were fabricated to an identical design and cemented onto each typodont, providing eight distinct experimental groups (2 levels of translucency × 4 shades). Reference scans were acquired using a desktop scanner. Test scans were performed ten times for each experimental group using two different intraoral scanners (Medit i700 and CEREC Primescan AC), with and without the application of scan powder (n = 10). Three-dimensional metrology software was used to assess the trueness of the intraoral scan datasets. Statistical analysis involved the Kruskal-Wallis H test, Mann-Whitney U test, and independent t-test (α=0.05). RESULTS For powder-free intraoral scan datasets, the crown shade did not significantly affect trueness within each translucency group (P = 1.000). For both intraoral scanners, compared with low translucency groups, higher marked deviations were exhibited by high translucency groups (P<.001). Scan powder use largely mitigated these differences (P>.05) and enhanced the trueness of the intraoral scan (P<.01). CONCLUSIONS Shade did not significantly influence the trueness of intraoral scans. High-translucency crowns were scanned with less accuracy than were low-translucency crowns. CLINICAL SIGNIFICANCE Unlike tooth shade, translucency significantly affected the accuracy of intraoral scans. Therefore, considering the use of scan powder when scanning objects with high translucency may be beneficial.
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Affiliation(s)
- Nan Hsu Myat Mon Hlaing
- Department of Prosthodontics, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Hyeonjong Lee
- Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Yuwon Jeong
- Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Ji-Man Park
- Department of Prosthodontics, Seoul National University School of Dentistry, Seoul, Republic of Korea; Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Sang J Lee
- Department of Restorative Dentistry and Biomaterial Sciences, Harvard School of Dental Medicine, Boston, Massachusetts, USA
| | - Jae-Hyun Lee
- Department of Prosthodontics, Seoul National University School of Dentistry, Seoul, Republic of Korea; Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
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Chang MC, Cheng LW, Chuang SF, Chen YC. The influence of pontic distribution on the marginal and internal gaps of CAD/CAM five-unit anterior zirconia framework. J Dent Sci 2024; 19:1105-1115. [PMID: 38618091 PMCID: PMC11010717 DOI: 10.1016/j.jds.2023.12.008] [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: 11/24/2023] [Revised: 12/12/2023] [Indexed: 04/16/2024] Open
Abstract
Background/purpose Nowadays, zirconia-based framework has been used for longspan or full-arch fixed dental prostheses (FDPs). This study aimed to evaluate the effect of pontic distribution on marginal and internal gaps of five-unit anterior zirconiabased DPs. Materials and methods Right maxillary central incisor and second premolar were selected as terminal abutments and three different edentulous conditions with one nonterminal abutment were simulated. Marginal and internal gaps in each zirconia-based samples(n = 10) were examined by computer-aided replica technique. Five regions, including marginal gaps at mesial or distal finishing line, internal gaps at the mesial or distal axial wall, and occlusal surface, were statistically analyzed (α = .05). Results Most of marginal gaps and internal gaps at axial wall were clinically acceptable, but larger at occlusal surface. For the three experimental groups, clinically accepted percentage with qualified gaps were less than 30%.There were statistical differences at axial wall over pontic side and marginal gaps over non-pontic side between groups (P<0.05). For sum of gaps of all abutments in each group, statistical differences were found at marginal and axial wall (P < 0.05). As for those on terminal and non-terminal abutments, statistical differences were found on second premolar (P < 0.05). Conclusion Except for occlusal surface, the overall marginal gaps and internal gaps at axial wall of five-unit anterior zirconia-based FDPs with different pontic distribution were clinically acceptable. However, the percentage with qualified gaps were low (<30%). Greater gaps were noted when adjacent pontic existed. Different pontic size and distribution with curvature had an influence on the gaps.
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Affiliation(s)
- Min-Chieh Chang
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
- Division of Prosthodontics, Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Lu-Wen Cheng
- School of Dentistry & Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Shu-Fen Chuang
- School of Dentistry & Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Division of Operative Dentistry, Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yung-Chung Chen
- Division of Prosthodontics, Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- School of Dentistry & Institute of Oral Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Chouksey P, Yadav NS, Hazari P, Saxena V, Mahajan H, Narwani S, Somkuwar K, Alzahrani AH, Alqahtani SM, Robaian A, Alamoudi A, Zidane B, Albar N, Baeshen HA, Patil S. In Vitro Evaluation of marginal adaptation of polyether ether ketone and zirconia copings. Niger J Clin Pract 2023; 26:701-708. [PMID: 37470642 DOI: 10.4103/njcp.njcp_701_22] [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: 07/21/2023]
Abstract
Background Polyether ether ketone (PEEK) has emerged as a new thermoplastic material with potential applications as a restorative material. Aim: This study aimed to evaluate the marginal adaptation of PEEK copings compared to zirconia copings using field emission scanning electron microscopy. Materials and Methods A freshly extracted maxillary central incisor was prepared for a full-coverage restoration following standard principles of tooth preparation. The tooth was sent to a laboratory for fabrication of samples using computer-aided design and manufacturing (CAD/CAM). Twenty samples of polyether ether ketone (PEEK) copings (group A) and 20 of zirconia copings were fabricated (group B). The copings were scanned under a field emission scanning electron microscope and measurements were taken at four distinct points. The marginal adaptation over the buccal, lingual, mesial, and distal margins for both groups was evaluated. One-way analysis of variance (ANOVA) and independent t test were applied. Results Our findings indicate that PEEK showed better marginal adaptation than zirconia at all measurement points. The mean marginal gap value of the PEEK group was 33.99 ± 8.81 μm and of the zirconia group was 56.21 ± 15.07 μm. On comparing marginal adaptation among the mesial, distal, buccal, and lingual aspects, PEEK showed better adaptation on all four margins, with the best adaptation on the buccal margin that had the lowest mean gap value of 29.27 ± 6.07 μm. The zirconia group adapted best at the distal margin, with a lowest mean gap value of 53.58 ± 15.25 μm (P ≤ 0.05). Conclusion PEEK copings had better marginal adaptation and fit compared to zirconia copings. It may have applications as a restorative material in fixed prostheses.
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Affiliation(s)
- P Chouksey
- Peoples Dental Academy, Bhopal, Madhya Pradesh, India
| | - N S Yadav
- Department of Prosthodontics Crown and Bridge and Implantology, Peoples Dental Academy, Peoples University, Bhopal, Madhya Pradesh, India
| | - P Hazari
- Department of Prosthodontics Crown and Bridge and Implantology, Peoples Dental Academy, Peoples University, Bhopal, Madhya Pradesh, India
| | - V Saxena
- Department of Public Health Dentistry, Government Dental College, Indore, Madhya Pradesh, India
| | - H Mahajan
- Department of Prosthodontics Crown and Bridge and Implantology, Peoples Dental Academy, Peoples University, Bhopal, Madhya Pradesh, India
| | - S Narwani
- Department of Prosthodontics Crown and Bridge and Implantology, Peoples Dental Academy, Peoples University, Bhopal, Madhya Pradesh, India
| | - K Somkuwar
- Department of Prosthodontics Crown and Bridge and Implantology, Peoples Dental Academy, Peoples University, Bhopal, Madhya Pradesh, India
| | - A H Alzahrani
- Department of Prosthodontics, Faculty of Dentistry, Taif University, Taif- 90813, Saudi Arabia
| | - S M Alqahtani
- Department of Prosthetic Dentistry, College of Dentistry, King Khalid University, Abha 62529, Saudi Arabia
| | - A Robaian
- Conservative Dental Sciences Department, College of Dentistry, Prince Sattam bin Abdulaziz University, Alkharj- 11942, Saudi Arabia
| | - Ahmed Alamoudi
- Oral Biology Department, King Abdulaziz University, Jeddah- 22252, Saudi Arabia
| | - B Zidane
- Restorative Dentistry Department, King Abdulaziz University, Jeddah- 22252, Saudi Arabia
| | - N Albar
- Restorative Dentistry Department, Faculty of Dentistry Jazan University, Jazan- 45412, Saudi Arabia
| | - H A Baeshen
- Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - S Patil
- College of Dental Medicine, Roseman University of Health Sciences, South Jordan, UTAH-84095, USA; Centre of Molecular Medicine and Diagnostics (COMManD), Department of Biochemistry, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India
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Alshamrani A, Alhotan A, Owais A, Ellakwa A. The Clinical Potential of 3D-Printed Crowns Reinforced with Zirconia and Glass Silica Microfillers. J Funct Biomater 2023; 14:jfb14050267. [PMID: 37233377 DOI: 10.3390/jfb14050267] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/27/2023] Open
Abstract
The development of 3D-printed crown resin materials with improved mechanical and physical properties is an area of growing interest in dentistry. This study aimed to develop a 3D-printed crown resin material modified with zirconia glass (ZG) and glass silica (GS) microfillers to enhance overall mechanical and physical properties. A total of 125 specimens were created and divided into five groups: control unmodified resin, 5% either ZG or GS reinforced 3D-printed resin, and 10% either ZG or GS reinforced 3D-printed resin. The fracture resistance, surface roughness, and translucency parameter were measured, and fractured crowns were studied under a scanning electron microscope. The results showed that 3D-printed parts that were strengthened with ZG and GS microfillers demonstrated comparable mechanical performance to unmodified crown resin but resulted in greater surface roughness, and only the group that contained 5% ZG showed an increase in translucency. However, it should be noted that increased surface roughness may impact the aesthetics of the crowns, and further optimisation of microfillers concentrations may be necessary. These findings suggest that the newly developed dental-based resins that incorporate microfillers could be suitable for clinical applications, but further studies are necessary to optimise the nanoparticle concentrations and investigate their long-term clinical outcomes.
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Affiliation(s)
- Abdullah Alshamrani
- Oral Rehabilitation & Dental Biomaterial and Bioengineering, The University of Sydney, Sydney, NSW 2006, Australia
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh P.O. Box 12372, Saudi Arabia
| | - Abdulaziz Alhotan
- Department of Dental Health, College of Applied Medical Sciences, King Saud University, Riyadh P.O. Box 12372, Saudi Arabia
| | - Ahmed Owais
- The X-ray Spectroscopy Node, Sydney Analytical, Core Research Facilities, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ayman Ellakwa
- Oral Rehabilitation & Dental Biomaterial and Bioengineering, The University of Sydney, Sydney, NSW 2006, Australia
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Chae YK, Lee H, Hyun HK, Lee HS, Choi SC, Nam OH. Three-dimensional evaluation of tooth preparation forms in paediatric zirconia crowns: An in vitro study. Int J Paediatr Dent 2022; 32:392-400. [PMID: 34608702 DOI: 10.1111/ipd.12918] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/13/2021] [Accepted: 09/21/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Though prefabricated zirconia crowns (PZCs) differ from stainless steel crowns and have different preparation guidelines for optimal crown adaptation, little is known about how clinicians prepare teeth for PZCs. AIM To investigate the prepared tooth forms for PZCs and identify the shared patterns of tooth preparation. DESIGN Twenty participants prepared primary maxillary first molars and mandibular second molars for PZCs. A model with ideally prepared tooth was digitally generated as a reference. The prepared teeth were digitally scanned and superimposed on the reference. Three-dimensional analysis software was used to evaluate the discrepancy between ideal and prepared surface for overall surface and subdivided area. RESULTS Half of the surfaces received excessive reduction, and 24% showed error within 0.2 mm (p < .001) in maxilla. 41.6% of surfaces showed error within 0.2 mm, and 20% were excessively prepared (p = .002) in mandible. The highest discrepancies were found at the mesiopalatal line angles (maxillary) and at the distobuccal line angles (mandibular). Significant discrepancies were observed on the occlusal surfaces, especially at the cusps. CONCLUSIONS Tooth preparations for PZCs showed wide variations related to depth among the participants.
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Affiliation(s)
- Yong Kwon Chae
- Department of Dentistry, Graduate School, Kyung Hee University, Seoul, Korea.,Department of Pediatric Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Hyeonjong Lee
- Department of Prosthodontics, Dental College, Yonsei University, Seoul, Korea
| | - Hong-Keun Hyun
- Department of Pediatric Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - Hyo-Seol Lee
- Department of Pediatric Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Sung Chul Choi
- Department of Pediatric Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Ok Hyung Nam
- Department of Pediatric Dentistry, School of Dentistry, Kyung Hee University, Seoul, Korea
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Hinz S, Bensel T, Bömicke W, Henningsen A, Rudolph J, Boeckler AF. Impact of the Veneering Technique and Framework Material on the Failure Loads of All-Ceramic Computer-Aided Design/Computer-Aided Manufacturing Fixed Partial Dentures. MATERIALS 2022; 15:ma15030756. [PMID: 35160701 PMCID: PMC8836578 DOI: 10.3390/ma15030756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/08/2022] [Accepted: 01/15/2022] [Indexed: 02/04/2023]
Abstract
Objectives: Zirconia (Y-TZP) ceramics are considered as posterior fixed partial denture (FPD) materials; however, their applications are limited due to chipping. The use of monolithic lithium disilicate (LiDi) glass ceramics in posterior FPDs can be advantageous. This in vitro study aims to compare the loads until failure of posterior Y-TZP-FPDs and LiDi-FPDs before and after aging.
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Affiliation(s)
- Sebastian Hinz
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Tobias Bensel
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
- Correspondence: (S.H.); (T.B.)
| | - Wolfgang Bömicke
- Department of Prosthetic Dentistry, University Hospital Heidelberg, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany;
| | - Anders Henningsen
- Department of Oral and Maxillofacial Surgery, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany;
| | - Judith Rudolph
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
| | - Arne F. Boeckler
- Department of Prosthodontics, Martin-Luther-University Halle-Wittenberg, Magdeburgerstraße 16, 06112 Halle, Germany; (J.R.); (A.F.B.)
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Faruqi S, Ganji KK, Bandela V, Nagarajappa AK, Mohamed RN, Ahmed MA, Farhan M, Alwakid WN, Al-Hammad KAS, Alam MK. Digital assessment of marginal accuracy in ceramic crowns fabricated with different marginal finish line configurations. J ESTHET RESTOR DENT 2021; 34:789-795. [PMID: 34668306 DOI: 10.1111/jerd.12822] [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: 02/23/2021] [Revised: 08/11/2021] [Accepted: 09/09/2021] [Indexed: 11/28/2022]
Abstract
AIM To digitally evaluate the marginal adaptation of different types of all-ceramic crowns on two different marginal configurations such as Shoulder and Chamfer of the prepared teeth. METHODS The marginal fit of the crown specimens on the model of the prepared teeth were assessed using the dual scan replica technique. Two plastic teeth were prepared; one having a Shoulder finishing line (A), while the other with a Chamfer finish line (B). Three types of different all-ceramic crowns, layered zirconia, monolithic zirconia, and pressed lithium disilicate, were fabricated for each prepared tooth (A) and (B). Measurements for assessing the marginal discrepancy were done on four designated points on the mesial, distal, buccal, and palatal surface of the superimposed image. RESULTS The average marginal gap was the largest in the layered zirconia group, followed by monolithic zirconia, while pressed lithium disilicate crowns showed the least marginal gaps. Crowns with Chamfer finish lines were better fitting (less marginal gap) than the shoulder finish lines across all the groups. CONCLUSIONS Chamfer finish lines produced better fitting restorations, and heat-pressed lithium disilicate crowns showed better adaptation at the margins than both layered zirconia and monolithic zirconia.
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Affiliation(s)
- Saif Faruqi
- Department of Prosthodontics, College of Dentistry, Jouf University, Saudi Arabia
| | - Kiran Kumar Ganji
- Department of Preventive Dentistry, College of Dentistry, Jouf University, Saudi Arabia.,Department of Periodontics, Sharad Pawar Dental College & Hospital, Datta Meghe Institute of Medical Sciences, Nagpur, Maharashtra, India
| | - Vinod Bandela
- Department of Prosthodontics, College of Dentistry, Jouf University, Saudi Arabia
| | - Anil Kumar Nagarajappa
- Department of Oral Maxillofacial Radiology, College of Dentistry, Jouf University, Saudi Arabia
| | - Roshan Noor Mohamed
- Department of Pediatric Dentistry, Faculty of Dentistry, Taif University, Taif, Saudi Arabia
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Jeong KW, Yoon HI, Lee JH, Yeo ISL, Kim DJ, Han JS. Clinical Feasibility of Fully Sintered (Y, Nb)-TZP for CAD-CAM Single-Unit Restoration: A Pilot Study. MATERIALS 2021; 14:ma14112762. [PMID: 34071077 PMCID: PMC8197114 DOI: 10.3390/ma14112762] [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: 03/26/2021] [Revised: 04/24/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022]
Abstract
Fifteen participants (9 male, 6 female) received a total of 15 monolithic single restorations made from fully sintered (Y, Nb)-TZP (tetragonal zirconia polycrystal) block. The restorations were clinically evaluated for survival, success rate, and periodontal probing depths 6 months after the insertion of the restorations. Esthetic, functional, and biological evaluations were also performed over a 6-month follow-up period. The survival and success rates of the single-unit restorations were 100%. The periodontal probing depth values ranged from 1 to 3 mm. No complications with regard to functional and biological properties were observed after 6 months. The postoperative sensitivity was only a transient phenomenon. The fully sintered (Y, Nb)-TZP single-unit restoration showed highly acceptable quality with successful clinical performance over 6 months.
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Affiliation(s)
- Ki-Won Jeong
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea; (K.-W.J.); (J.-H.L.); (I.-S.L.Y.); (J.-S.H.)
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea; (K.-W.J.); (J.-H.L.); (I.-S.L.Y.); (J.-S.H.)
- Correspondence: ; Tel.: +82-2-2072-4472
| | - Jae-Hyun Lee
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea; (K.-W.J.); (J.-H.L.); (I.-S.L.Y.); (J.-S.H.)
| | - In-Sung Luke Yeo
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea; (K.-W.J.); (J.-H.L.); (I.-S.L.Y.); (J.-S.H.)
| | - Dae-Joon Kim
- Department of Dentistry, VASIC Research Center, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea;
| | - Jung-Suk Han
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 03080, Korea; (K.-W.J.); (J.-H.L.); (I.-S.L.Y.); (J.-S.H.)
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Kilinc H, Sanal FA. Effect of sintering and aging processes on the mechanical and optical properties of translucent zirconia. J Prosthet Dent 2021; 126:129.e1-129.e7. [PMID: 33965239 DOI: 10.1016/j.prosdent.2021.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/24/2021] [Accepted: 03/24/2021] [Indexed: 02/04/2023]
Abstract
STATEMENT OF PROBLEM Sintering holding times and aging conditions may affect the optical, mechanical, and structural properties of polychromatic multitranslucent zirconia. However, a consensus on the ideal sintering condition for this material is lacking. PURPOSE The purpose of this in vitro study was to investigate the effect of different sintering holding and autoclave aging times on the flexural strength (FS), grain size, and translucency parameter (TP00) of a translucent zirconia. MATERIAL AND METHODS Sixty bar-shaped and 60 rectangular-shaped specimens were prepared from computer-aided design and computer-aided manufacturing (CAD-CAM) zirconia blocks and split into 2 groups to be sintered at 1550 °C for different holding times (regular: 2 hours, prolonged: 5 hours). The specimens were then divided into 3 subgroups and subjected to aging processes (control, aging for 60 minutes, aging for 120 minutes). FS values were obtained by using a 3-point bend test and Weibull analysis was conducted. Grain size evaluations were performed by using scanning electron microscope (SEM) observations. TP00 was measured with a spectrophotometer. Statistical evaluation included the Kolmogorov-Smirnov, 2-way ANOVA, and Tukey HSD tests (α=.05). RESULTS The sintering procedure, aging, and their interaction significantly influenced the TP00 (P<.05). FS values and grain sizes were affected by aging only (P<.001). Both aging times resulted in reduced FS and increased grain sizes. Prolonged sintering in combination with 120 minutes of aging negatively affect the TP00 scores (P<.05). CONCLUSIONS FS values were similar under regular and prolonged sintering. Prolonged sintering led to a decrease in translucency after 120 minutes of aging. Steam autoclave aging can affect the optical and mechanical properties of translucent zirconia.
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Affiliation(s)
- Hamiyet Kilinc
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Turkey.
| | - Fatma A Sanal
- Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Turkey
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Payaminia L, Moslemian N, Younespour S, Koulivand S, Alikhasi M. Evaluating the effect of repeated use of milling burs on surface roughness and adaptation of digitally fabricated ceramic veneers. Heliyon 2021; 7:e06896. [PMID: 33997414 PMCID: PMC8105639 DOI: 10.1016/j.heliyon.2021.e06896] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 02/18/2021] [Accepted: 04/20/2021] [Indexed: 11/15/2022] Open
Abstract
Objectives This study aimed to evaluate how repeated use of milling diamond burs with different coarseness affects surface roughness, and marginal and internal adaptation of CAD/CAM veneers. Methods Forty leucite-reinforced glass-ceramic veneers were milled in 2 groups based on the milling mode (with fine or extra-fine bur sets). In each group, every 10 veneers were milled with a new bur set. All veneers were cemented to bovine teeth and then polished. Labial surface roughness was measured before cementation, and after polishing. Marginal and internal discrepancies were measured using a field emission scanning electron microscope. Three-way and two-way mixed repeated measures ANOVA were applied to assess changes in surface roughness values of veneers and discrepancy values, respectively. The Bonferroni correction was applied for multiple comparisons. Results Repeated use of a milling diamond bur set had a significant effect on surface roughness of the veneers (P < .001). Mean surface roughness of the fine milling mode was significantly higher in comparison to that of extra-fine mode before (P = .002) and after (P = .01) polishing. After polishing a significant decrease in surface roughness occurred in fine (P = .02), but not in extra-fine milling mode (P = .99). Repeated use of milling burs significantly affected marginal and internal adaptation between some repeated uses. Conclusions Marginal and internal adaptation were significantly affected by repeated use of milling diamond burs up to 10 times between some repeated uses. However, no specific pattern could be established. Clinical significance Repeated use of milling burs could affect surface roughness, surface microcracks, critical defects, and adaptation of CAD/CAM restorations. Therefore, it plays a major role in clinical success of the restorations.
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Affiliation(s)
- Leila Payaminia
- Dental Research Center, Dental Implant Research Center, Dentistry Research Institute, Department of Prosthodontics, Tehran University of Medical Sciences, Tehran, Iran
| | - Naeime Moslemian
- Department of Prosthodontics, School of Dentistry, Hamedan University of Medical Sciences, Hamedan, Iran
| | - Shima Younespour
- Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Soudabeh Koulivand
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marzieh Alikhasi
- Dental Research Center, Dental Implant Research Center, Dentistry Research Institute, Department of Prosthodontics, Tehran University of Medical Sciences, Tehran, Iran
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Yang J, Li H, Xu L, Wang Y. Selective laser sintering versus conventional lost-wax casting for single metal copings: A systematic review and meta-analysis. J Prosthet Dent 2021; 128:897-904. [PMID: 33789799 DOI: 10.1016/j.prosdent.2021.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 10/21/2022]
Abstract
STATEMENT OF PROBLEM Evidence comparing the marginal and internal fit of single metal copings fabricated via selective laser sintering and conventional lost-wax casting is inadequate. PURPOSE The purpose of this systematic review was to compare the fit of single metal copings fabricated via selective laser sintering and lost-wax casting. Moreover, the effects of different variables on fit accuracy were determined. MATERIAL AND METHODS Google Scholar, ScienceDirect, SpringerLink, and Wiley databases were searched electronically as well as manually. The mean absolute marginal gap, marginal gap, internal gap, axial gap, and occlusal gap values of single metal copings fabricated via selective laser sintering and lost-wax casting were statistically analyzed to determine and evaluate the factors affecting the fit accuracy (α=.05). RESULTS Single metal copings fabricated via selective laser sintering had mean absolute marginal gaps and occlusal gaps similar to those of copings fabricated via lost-wax casting, based on a subgroup meta-analysis of gaps evaluated using stereomicroscopy (P>.05). The fit of single metal copings was not affected by the type of tooth (P>.05). The conventional impression, the indirect digital scan, and the direct digital scan led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via lost-wax casting (P>.05). The indirect and direct digital scans led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via selective laser sintering (P>.05). Printed wax patterns provided significantly smaller mean axial gap values than milled plastic or milled wax patterns for the copings fabricated via lost-wax casting (P<.05). Printed, milled, and conventional wax patterns had similar mean marginal gaps and internal gaps for the copings fabricated via lost-wax casting (P>.05). For single copings fabricated via lost-wax casting, Ni-Cr and Co-Cr had similar mean internal gaps (P>.05). CONCLUSIONS No statistically significant differences were found between single metal copings fabricated via selective laser sintering and lost-wax casting. Selective laser sintering can satisfy the clinical requirement for single metal copings.
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Affiliation(s)
- Jun Yang
- Lecturer, Department of Restorative Dentistry, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, PR China.
| | - Hainan Li
- Professor, School of Management Science and Engineering, Chongqing Technology and Business University, Chongqing, PR China
| | - Ling Xu
- Professor, Department of Restorative Dentistry, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, PR China
| | - Yuan Wang
- Assistant, Department of Restorative Dentistry, Stomatological Hospital of Chongqing Medical University, Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, PR China
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12
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Daou EE, Baba NZ. Fit Alteration of Presintered Co-Cr and Zirconia Multiple-Unit Prostheses After Ceramic Layering. J Prosthodont 2021; 30:789-794. [PMID: 33486845 DOI: 10.1111/jopr.13336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2021] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The fit alteration after ceramic layering of soft Cobalt-Chromium (Co-Cr) and zirconia is poorly documented. This study compared the marginal and internal fit of presintered Co-Cr and zirconia three-unit fixed dental prostheses before and after ceramic veneering. MATERIALS AND METHODS Co-Cr master model was prepared and duplicated 60 times to receive three-unit fixed dental prostheses (FDPs). Sixty dies were prepared, scanned and assigned to 3 groups (n = 20/group), to receive the FDPs made of presintered Co-Cr (CS), presintered zirconia (CZ) and cast Ni-Cr (Wi). Each framework was seated on its specific cast. A replica technique was used for marginal and internal discrepancy measurements in mesiodistal and buccolingual planes. Frameworks were ceramic veneered. Results were compared before and after ceramic layering within each group. Data were analyzed using the Levene, t test, and ANOVA (α = 0.05). RESULTS Significant difference was found when gaps were compared within groups for CS and CZ but not for Wi. At the abutments level, significant difference was found for both premolars and molars in the buccolingual planes (p < 0.001). A multiple comparison between materials tested showed significant differences between presintered and cast Ni-Cr. No significant difference was detected between CS and CZ (p = 1.000). CONCLUSIONS Although ceramic layering increased the discrepancy for presintered Co-Cr and zirconia, the marginal adaptation remained clinically acceptable.
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Affiliation(s)
- Elie E Daou
- Department of Prosthodontics Faculty of Dentistry, Faculty of Dental Medicine, Beirut, Lebanon
| | - Nadim Z Baba
- Advanced Specialty Education Program in Implant Dentistry, School of Dentistry, Loma Linda University, Loma Linda, CA
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13
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Jeon J, Chung SH, Um SH, Rhee SH. Effect of grain size of dental zirconia on shear bond strength of composite resin cement. J Appl Biomater Funct Mater 2020; 18:2280800020978138. [PMID: 33371771 DOI: 10.1177/2280800020978138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The effect of grain size of dental zirconia on the shear bond strength of composite resin cement was newly studied. Disc-shaped dental zirconia with small (sample S) and large (sample L) grains were made by sintering of pre-sintered dental zirconia at 1450°C for 0.5 h and 40 h, respectively. After the sintering, the average grain size of sample S was 1.37 ± 0.15 µm, while that of sample L was 3.74 ± 0.50 µm. The sintered discs were successively polished with different grades of diamond and alumina slurries. The interfacial free energies were 63.5 ± 4.2 dyne/cm for sample S and 52.1 ± 5.5 dyne/cm for sample L. Stainless steel cylinders, previously sandblasted with 50 µm alumina powder, were bonded to the zirconia discs using composite resin cement. Next, samples were kept in an oven for 7 d at 36.5°C. The shear bond strength of sample S was 23.0 ± 4.5 MPa while that of sample L was 17.5 ± 4.6 MPa. After the fracture, the areal % values of composite resin cement remaining on the zirconia surfaces were 89.7 ± 5.9% for sample S and 61.6 ± 5.5% for sample L. The results suggest that grain size reduction has a potential to enhance the degree of bonding between a composite resin cement and a dental zirconia due to the increase of interfacial free energy.
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Affiliation(s)
- JiHwan Jeon
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Shin Hye Chung
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Seung-Hoon Um
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Sang-Hoon Rhee
- Department of Dental Biomaterials Science, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
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14
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Feasibility of 3-Dimensional Visual Guides for Preparing Pediatric Zirconia Crowns: An In Vitro Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17165732. [PMID: 32784404 PMCID: PMC7459926 DOI: 10.3390/ijerph17165732] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/29/2020] [Accepted: 08/07/2020] [Indexed: 11/16/2022]
Abstract
This study evaluated the feasibility of a tooth preparation guide for prefabricated zirconia crowns (PZCs). Three-dimensional surface data for PZCs of the left maxillary primary first molar and left mandibular primary second molar were obtained using a model scanner. The tooth preparation data were digitally designed to harmonize with the adjacent teeth on the mixed dentition model and visualized using a color-coded map, which presents the required amount of tooth reduction. Twenty participants were recruited for preparing teeth with and without using the tooth preparation guide. The following three parameters were evaluated: tooth preparation time, harmony score, and amount of tooth reduction. The preparation time when using the guide was significantly reduced (p < 0.05), and a significant difference was observed in the harmony scores for the maxillary primary first molar preparation. Furthermore, the amount of tooth reduction was significantly different for both maxillary and mandibular primary molars (p < 0.05) in terms of the occlusal distal surface and buccal line angle in the maxillary primary first molars, and the smooth surfaces, proximal surfaces, and mesial line angles in the mandibular primary second molars. Thus, the results suggest that a tooth preparation guide could facilitate better tooth preparation for PZCs.
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15
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Hasanzade M, Koulivand S, Moslemian N, Alikhasi M. Comparison of three-dimensional digital technique with two-dimensional replica method for measuring marginal and internal fit of full coverage restorations. J Adv Prosthodont 2020; 12:173-180. [PMID: 32601537 PMCID: PMC7314633 DOI: 10.4047/jap.2020.12.3.173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/07/2020] [Accepted: 04/29/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This study compared digital (reference point matching) and replica methods for measuring marginal and internal fit of full coverage restorations. MATERIALS AND METHODS A maxillary left first molar typodent was fixed on to an aluminum base and prepared to receive all-ceramic full coverage restoration. The model was scanned with an intraoral scanner (CEREC Omnicam, Sirona, York, PA, USA). Twelve crowns were fabricated from lithium disilicate blocks (IPS emax CAD, Ivoclar Vivadent) and then crystalized. Marginal and internal fit of each restoration was measured by two examiners using replica and a new digital three-dimensional technique. Reliability between the two methods and two examiners was assessed by correlation and Cronbach's Alpha coefficient (P<.05). A Bland-Altman assessment for agreement was used to compare the two methods. RESULTS Bland-Altman assessment showed that the mean of difference for marginal, absolute marginal, and axial gap was respectively -1.04 µm, -41.9 µm, and -29.53 µm with limit of agreement (LOA) between -37.26 to 35.18 µm for marginal, -105.85 to 22.05 µm for absolute marginal and -80.52 to 22.02 µm for axial gap. Positive correlation for repeatability (P<.05) in determining marginal and internal gaps by the two examiners in both techniques was revealed. Reliability of both techniques in all sites of measurements was at least good (0.8 ≤ α < 0.9). CONCLUSION Both measuring techniques appeared highly reliable for evaluating fit of fixed dental restorations, while reference point matching provided higher values in axial and absolute marginal gap assessment.
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Affiliation(s)
- Mahya Hasanzade
- Dental Research Center, Dentistry Research Institute, Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Soudabeh Koulivand
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Naeime Moslemian
- Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Marzieh Alikhasi
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
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Freifrau von Maltzahn N, Bernhard F, Kohorst P. Fitting accuracy of ceramic veneered Co-Cr crowns produced by different manufacturing processes. J Adv Prosthodont 2020; 12:100-106. [PMID: 32377323 PMCID: PMC7183853 DOI: 10.4047/jap.2020.12.2.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/18/2020] [Accepted: 02/25/2020] [Indexed: 12/05/2022] Open
Abstract
PURPOSE The purpose of this in vitro study was to evaluate the fitting accuracy of single crowns made from a novel presintered Co-Cr alloy prepared with a computer-aided design and computer-aided manufacturing (CAD/CAM) technique, as compared with crowns manufactured by other digital and the conventional casting technique. Additionally, the influence of oxide layer on the fitting accuracy of specimens was tested. MATERIALS AND METHODS A total of 40 test specimens made from Co-Cr alloy were investigated according to the fitting accuracy using a replica technique. Four different methods processing different materials were used for the manufacture of the crown copings (milling of presintered (Ceramill Sintron-group_cer_sin) or rigid alloy (Tizian NEM-group_ti_nem), selective laser melting (Ceramill NPL-group_cer_npl), and casting (Girobond NB-group_gir_nb)). The specimens were adapted to a resin model and the outer surfaces were airborne-particle abraded with aluminum oxide. After the veneering process, the fitting accuracy (absolute marginal discrepancy and internal gap) was evaluated by the replica technique in 2 steps, before removing the oxide layer from the intaglio surface of the crowns, and after removing the layer with aluminum oxide airborne-particle abrasion. Statistical analysis was performed by multifactorial analysis of variance (ANOVA) (α=.05). RESULTS Mean absolute marginal discrepancy ranged between 20 µm (group_cer_npl for specimens of Ceramill NPL) and 43 µm (group_cer_sin for crowns of Ceramill Sintron) with the oxide layer and between 19 µm and 28 µm without the oxide layer. The internal gap varied between 33 µm (group_ti_nem for test samples of Tizian NEM) and 75 µm (group_gir_nb for the base material Girobond NB) with the oxide layer and between 30 µm and 76 µm without the oxide layer. The absolute marginal discrepancy and the internal gap were significantly influenced by the fabrication method used (P<.05). CONCLUSION Different manufacturing techniques had a significant influence on the fitting accuracy of single crowns made from Co-Cr alloys. However, all tested crowns showed a clinically acceptable absolute marginal discrepancy and internal gap with and without oxide layer and could be recommended under clinical considerations. Especially, the new system Ceramill Sintron showed acceptable values of fitting accuracy so it can be suggested in routine clinical work.
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17
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Comparison of crown fit and operator preferences between tooth preparation with electric and air-turbine handpieces. J Prosthet Dent 2020; 125:111-116. [PMID: 32037295 DOI: 10.1016/j.prosdent.2019.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 11/04/2019] [Accepted: 11/04/2019] [Indexed: 10/25/2022]
Abstract
STATEMENT OF PROBLEM Tooth preparations for ceramic crowns require precision and accuracy, which may be influenced by the choice of dental handpiece. However, comparisons of the accuracy of tooth preparations made with traditional air-turbine handpieces and electric handpieces are lacking. PURPOSE The purpose of this in vitro study was to evaluate operator preferences and tooth preparation performance by using electric and air-turbine handpieces with self-reported preferences, sound levels, surface roughness, and the fit of the crown produced. MATERIAL AND METHODS Twenty dentists were asked to use the air-turbine or the electric handpiece. Feedback on the noise, weight, feel of grip, flexibility, and tooth preparation in general was scored according to a visual analog scale (VAS). Additionally, the dentists were asked to complete a questionnaire on their handpiece preference. The noise of the 2 handpieces was measured by using a precision sound level meter. The surface roughness of 10 teeth was measured by using a profilometer. The other 18 teeth were prepared to measure the marginal and internal fit of ceramic crowns by the replica technique. The VAS scores of operator preferences were analyzed with the Wilcoxon signed ranks test. Decibel levels were analyzed with the Mann-Whitney U test. The McNemar test was used to compare the ratio of preferred handpiece. The surface roughness and marginal and internal fit were analyzed with the independent t test to determine significant differences (all α=.05). RESULTS The electric handpiece was heavier, had a poorer grip feel, was less flexible (P<.001), produced lower noise and better feeling of the tooth preparation in general (P<.001), and was preferred in the finishing stage for its greater smoothness (P<.05). The noise produced by the electric handpiece was lower during both idling and tooth preparation at 15-cm, 30-cm, and 45-cm distances (P<.01). The electric handpiece produced surface roughness values (Sa) similar to those of the air-turbine handpiece (P>.05). No significant differences were noted for the marginal and internal crown fit between the air-turbine handpiece and electric handpiece groups (P>.05). CONCLUSIONS Despite its heavier weight, poorer grip feel, and less flexibility, the electric handpiece emitted lower noise, produced better feeling of the tooth preparation in general, and was preferred in the finishing step of tooth preparation for its greater smoothness than the air-turbine handpiece. The surface roughness of the prepared teeth and the crown fit between the tooth and ceramic crown were not affected by the air-turbine or electric handpiece.
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18
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Alikhasi M, Ameri N, Siadat H, Shamshiri AR, Nejati M. Dimensional Changes of 3-Unit Implant-Supported Zirconia Frameworks of Two CAD/CAM Systems from Scanning to Sintering. Front Dent 2019; 16:194-205. [PMID: 31858085 PMCID: PMC6911669 DOI: 10.18502/fid.v16i3.1591] [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: 09/06/2018] [Accepted: 11/03/2018] [Indexed: 11/26/2022] Open
Abstract
Objectives: Internal fit of implant frameworks is an important factor determining the long-term success of dental implant restorations. This in-vitro study aimed to evaluate dimensional changes of implant-supported zirconia frameworks fabricated by two computer-aided design/computer-aided manufacturing (CAD/CAM) systems from scanning to sintering. Materials and Methods: A master model of a three-unit fixed partial denture was fabricated with two implant abutments. In each CAD/CAM system (AmannGirrbach and Zirkonzahn), the master model was scanned 12 times, and data were saved as Standard Transformation Language files (scanning groups). Using semi-sintered zirconia, 12 real-size frameworks (milling groups) and 12 enlarged frameworks, were sintered (sintering groups) and made by each system. Dimensions of the master model and frameworks in each phase were measured. Dimensional changes (compared to the master model) were calculated. Data were analyzed using repeated measures analysis of variance, independent t-test, and paired sample t-test (α=0.05). Results: Comparison of the two systems revealed that although dimensional changes were greater in the milling phase of Zirkonzahn, they were larger in the sintering phase of the AmannGirrbach system. Evaluation of fabrication phases revealed greater dimensional changes in the milling phase compared to the other phases in the Zirkonzahn system (P<0.05). However, in the AmannGirrbach system, the values were not significantly different between milling and sintering phases (P>0.05). Conclusion: Within the limitations of this study, the results showed that fabrication phases, CAD/CAM system type and abutment size had significant effects on dimensional changes.
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Affiliation(s)
- Marzieh Alikhasi
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.,Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran
| | - Narges Ameri
- Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran
| | - Hakimeh Siadat
- Department of Prosthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.,Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Shamshiri
- Department of Epidemiology and Statistics, School of Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Nejati
- Nano Robotics Laboratory, Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
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Bousnaki M, Chatziparaskeva M, Bakopoulou A, Pissiotis A, Koidis P. Variables affecting the fit of zirconia fixed partial dentures: A systematic review. J Prosthet Dent 2019; 123:686-692.e8. [PMID: 31703922 DOI: 10.1016/j.prosdent.2019.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 06/02/2019] [Accepted: 06/03/2019] [Indexed: 10/25/2022]
Abstract
STATEMENT OF PROBLEM Different parameters affect the marginal and internal fit of zirconia fixed partial dentures (FPDs) on natural teeth. Determining a way to optimize these restorations is essential. PURPOSE The purpose of this systematic review was to determine the variables affecting the marginal fit and internal accuracy of zirconia FPDs on natural teeth. MATERIAL AND METHODS An electronic search was conducted by 2 independent reviewers by using the MEDLINE, Cochrane, Web of Science, and Scopus databases, as well as Google Scholar, for studies published up to July 2018, and a manual search was conducted from the reference lists of related articles. Eligibility criteria included articles in English published in peer-reviewed journals that assessed the marginal and/or internal adaptation of zirconia FPDs on teeth with 3 or more units, with at least 1 of the experimental groups being frameworks or FPDs fabricated from zirconia. Risk of bias was assessed with the aid of the Cochrane Handbook for Systematic Reviews of Interventions. RESULTS The search provided 418 records, with 41 fulfilling the inclusion criteria. The selected studies showed considerable heterogeneity regarding materials, state of sintering, manufacturer and computer-aided design and computer-aided manufacturing (CAD-CAM) system, experimental methodology, sample size, and span length. Of the included articles, 36 were in vitro studies and 5 were clinical studies, most of which exhibited high-performance and detection biases. CAD-CAM systems provided more precise marginal and internal fit than CAM systems. An increase of framework span length to 6 or more units decreased both marginal and internal fit. The reported marginal gap tended to increase after the veneering process. The introduction of a conventional impression into an otherwise digital workflow seems to have a negative effect on the marginal fit. CONCLUSIONS The accuracy of zirconia FPDs or frameworks is considerably influenced by the processing procedure used and the choice of CAD-CAM system.
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Affiliation(s)
- Maria Bousnaki
- Doctoral student, Department of Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Maria Chatziparaskeva
- Postgraduate student, Department of Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Athina Bakopoulou
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Argiris Pissiotis
- Professor, Department of Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Petros Koidis
- Professor and Chairman, Department of Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
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20
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Gedrimiene A, Adaskevicius R, Rutkunas V. Accuracy of digital and conventional dental implant impressions for fixed partial dentures: A comparative clinical study. J Adv Prosthodont 2019; 11:271-279. [PMID: 31754417 PMCID: PMC6856312 DOI: 10.4047/jap.2019.11.5.271] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 10/11/2019] [Accepted: 10/29/2019] [Indexed: 11/13/2022] Open
Abstract
PURPOSE The newest technologies for digital implant impression (DII) taking are developing rapidly and showing acceptable clinical results. However, scientific literature is lacking data from clinical studies about the accuracy of DII. The aim of this study was to compare digital and conventional dental implant impressions (CII) in a clinical environment. MATERIALS AND METHODS Twenty-four fixed zirconia restorations supported by 2 implants were fabricated using conventional open-tray impression technique with splinted transfers (CII group) and scan with Trios 3 IOS (3Shape) (DII group). After multiple verification procedures, master models were scanned using laboratory scanner D800 (3Shape). 3D models from conventional and digital workflow were imported to reverse engineering software and superimposed with high resolution 3D CAD models of scan bodies. Distance between center points, angulation, rotation, vertical shift, and surface mismatch of the scan bodies were measured and compared between conventional and digital impressions. RESULTS Statistically significant differences were found for: a) inter-implant distance, b) rotation, c) vertical shift, and d) surface mismatch differences, comparing DII and CII groups for mesial and dist al implant scan bodies (P≤.05). CONCLUSION Recorded linear differences between digital and conventional impressions were of limited clinical significance with two implant-supported restorations.
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Affiliation(s)
- Agne Gedrimiene
- Department of Prosthodontics, Institute of Odontology, Faculty of Medicine, Vilnius University, Lithuania
| | - Rimas Adaskevicius
- Department of Electrical Power Systems, Faculty of Electrical and Electronics Engineering, Kaunas University of Technology, Lithuania
| | - Vygandas Rutkunas
- Department of Prosthodontics, Institute of Odontology, Faculty of Medicine, Vilnius University, Lithuania
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21
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Ram SM, Ranadive NN, Nadgere JB. Microcomputed tomography a noninvasive method to evaluate the fit of a restoration as compared to conventional replica technique. J Indian Prosthodont Soc 2019; 19:233-239. [PMID: 31462862 PMCID: PMC6685334 DOI: 10.4103/jips.jips_71_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/19/2019] [Indexed: 11/04/2022] Open
Abstract
Aim The aim of the study was to compare the assessment methods used to evaluate the fit of Ni-Cr metal copings. Settings and Design Comparative- Invitro study design. Materials and Methods A stainless steel die simulating a prepared first maxillary premolar was used as a master die. Wax pattern copings were fabricated by the conventional dipping wax technique (n = 20) on the master die and were cast in Ni-Cr alloy. The finished copings were fitted on the master die and scanned by the micro-computed tomography (CT) scanner. Multiple projections of the sample were reconstructed to evaluate the marginal and internal fit at 5 predetermined locations. The same copings were used for the replica technique and were evaluated under a stereomicroscope in the same locations. Statistical Analysis Used Shapiro-Wilk's test and Unpaired t-test. Results The marginal fit values observed were 127.71 and 95.06 μm, chamfer area fit values were 151.97 and 132.7 μm, axial area fit values were 62.36 and 46.14 μm, axio-occlusal area fit values were 139.52 and 123.6 μm, occlusal area fit values were slightly higher with 217.91 and 193.1 μm, respectively, in replica and micro-CT technique. There was no statistically significant difference observed in the fit between the two assessment methods (α > 0.05). Conclusions There was no difference observed in the marginal and internal fit of Ni-Cr metal copings with the two methods of assessment. However, the micro-CT technique proved to be simpler, noninvasive, and time-saving assessment method.
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Affiliation(s)
- Sabita M Ram
- Department of Prosthodontics and Crown and Bridge, Mahatma Gandhi Mission's Dental College and Hospital, Navi Mumbai, Maharashtra, India
| | - Nishita Narendra Ranadive
- Department of Prosthodontics and Crown and Bridge, Mahatma Gandhi Mission's Dental College and Hospital, Navi Mumbai, Maharashtra, India
| | - Jyoti B Nadgere
- Department of Prosthodontics and Crown and Bridge, Mahatma Gandhi Mission's Dental College and Hospital, Navi Mumbai, Maharashtra, India
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Kim DY, Jeong ID, Kim JH, Kim HY, Kim WC. Reproducibility of different coping arrangements fabricated by dental micro-stereolithography: Evaluation of marginal and internal gaps in metal copings. J Dent Sci 2019; 13:220-225. [PMID: 30895124 PMCID: PMC6388866 DOI: 10.1016/j.jds.2017.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 06/14/2017] [Indexed: 11/23/2022] Open
Abstract
Background/purpose To evaluate the reproducibility of the marginal and internal gaps of metal copings fabricated using dental micro-stereolithography (μ-SLA), which is an additive manufacturing system. Materials and methods A study cast of abutment tooth 46 was made from type-IV dental stone and was scanned to create a standard triangulation language file. Arrays of one (ORM), three (TRM), and six (SRM) resin copings were then fabricated on the μ-SLA build platform using investment, burnout, and casting (n = 12). The marginal and internal gaps of these metal copings were measured using a silicone-replica technique with a digital microscope (×160). The data obtained were analyzed using a non-parametric Kruskal–Wallis H test, a post-hoc Mann–Whitney U test, and a Bonferroni correction. Results The mean and standard deviation of the marginal gap for each group were measured and found to be 81.1 and 53.2 μm, 68.3 and 44.8 μm, and 90.3 and 57.7 μm for ORM, TRM, and SRM, respectively. There were no statistical differences in the marginal gaps of the three groups (p > 0.05). Conclusion The marginal and internal gap of ORM, TRM and SRM groups were considered clinically acceptable.
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Affiliation(s)
- Dong-Yeon Kim
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Il-Do Jeong
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Ji-Hwan Kim
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Hae-Young Kim
- Department of Public Health Science, Graduate School & BK21 + Program in Public Health Sciences, Korea University, Seoul, Republic of Korea
| | - Woong-Chul Kim
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
- Corresponding author. Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea. Fax: +82 2 921 7361.
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Attachoo S, Juntavee N. Role of sintered temperature and sintering time on spectral translucence of nano-crystal monolithic zirconia. J Clin Exp Dent 2019; 11:e146-e153. [PMID: 30805119 PMCID: PMC6383898 DOI: 10.4317/jced.55497] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 01/14/2019] [Indexed: 02/04/2023] Open
Abstract
Background Sintering process is accountable for aesthetic appearance of zirconia restoration. This study appraised the effect of different sintering procedure via sintered temperatures and sintering times on spectral translucence of monolithic zirconia. Material and Methods One hundred and thirty five monolithic zirconia specimens (width, length, thickness = 10, 20, 1.5 mm) were prepared from yttrium-stabilized tetragonal zirconia polycrystalline (Y-TZP, Ceramill®) and unintentionally divided into nine groups to be sintered at different temperatures [decreasing- (SD, 1350°C), regular- (SR, 1450°C), and increasing- (SI, 1550°C) sintering temperature] and different sintering times [shortening- (HS, 60 min), regular- (HR, 120 min), and prolong- (HP, 180 min) sintering time]. Spectral translucence was determined by using spectrophotometer and calculated for translucency parameter (TP). The surface topography and grain size were evaluated by using a scanning electron microscope (SEM). Crystalline structures of monoclinic (m) and tetragonal (t) phases were determined by using the X-ray diffraction (XRD). An analysis of variance (ANOVA) was used to determine for significant differences of translucence upon different sintering processes (α=0.05). Results The mean, standard deviation of TP were 3.22±0.12 for SRHP, 3.14±0.18 for SIHS, 3.04±0.17 for SRHR, 2.94±0.18 for SRHS, 2.93±0.17 for SIHR, 2.67±0.15 for SIHP, 1.91±0.17 for SDHP, 1.34±0.21 for SDHR and 0.10±0.01 for SDHS. Spectral translucence was significantly affected by altering sintering temperatures and holding times (p<0.05). Enlargement of grain size and increasing t→m phase metamorphosis related with upraising sintered temperatures and extending sintered holding times were signified. Conclusions Altering sintering parameters affected spectral translucence of zirconia. Upraising sintered temperature to SR and prolonging sintering time to HP were advocated to enhance spectral translucence of nano-crystal monolithic zirconia, and advised to accomplished aesthetic appearance of restoration in clinical practice. Key words:CAD-CAM, sintering process, translucency, zirconia.
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Affiliation(s)
- Surawut Attachoo
- Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Niwut Juntavee
- Department of Prosthodontics, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Al-Imam H, Michou S, Benetti AR, Gotfredsen K. Evaluation of marginal and internal fit of acrylic bridges using optical coherence tomography. J Oral Rehabil 2018; 46:274-281. [PMID: 30387868 DOI: 10.1111/joor.12746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 10/25/2018] [Accepted: 10/31/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND The potential of non-invasive optical coherence tomography (OCT) as a tool for assessment of fit of indirect reconstructions is not fully explored. OBJECTIVES The objectives were to investigate the feasibility and validity of OCT, and to measure the internal and marginal fit of acrylic bridges fabricated using direct and indirect digitalisation. METHODS The accuracy of the employed swept source OCT (wavelength: 1310 nm) was assessed by comparing with an object with known dimensions. Validity was assessed by measuring an OCT measurements on replica, mimicking the cement film thickness, with stereomicroscopic measurements. The reconstructions were placed on the abutments without cementation. The internal and marginal fit of acrylic bridges from direct and indirect digitalisation techniques were then assessed by obtaining 5 OCT B-scans per abutment tooth at pre-defined positions located 250 μm apart. The marginal and internal cement gaps were measured using image-processing software (ImageJ). Mean and standard deviation were calculated for both groups and t test assuming unequal variances was carried out. The level of significance was defined at 0.05. RESULTS A strong linear correlation (r = 0.865) between OCT and stereomicroscopy was found. T test showed significantly (P < 0.01) better internal fit of bridges made from indirect digitalisation, but no difference in marginal fit. CONCLUSION OCT is a feasible and valid tool for investigating internal and marginal fit of acrylic dental reconstructions. Better internal fit was observed in bridges fabricated using the direct digitalisation technique. No difference in marginal fit was found between the two fabrication methods.
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Affiliation(s)
- Hiba Al-Imam
- Department of Odontology, Section of Oral Rehabilitation, Faculty of Health and Medical Sciences, University of Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Odontology, Section of Dental Materials, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stavroula Michou
- Department of Odontology, Section of Dental Materials, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ana R Benetti
- Department of Odontology, Section of Dental Materials, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Klaus Gotfredsen
- Department of Odontology, Section of Oral Rehabilitation, Faculty of Health and Medical Sciences, University of Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Al-Dwairi ZN, Alkhatatbeh RM, Baba NZ, Goodacre CJ. A comparison of the marginal and internal fit of porcelain laminate veneers fabricated by pressing and CAD-CAM milling and cemented with 2 different resin cements. J Prosthet Dent 2018; 121:470-476. [PMID: 30391059 DOI: 10.1016/j.prosdent.2018.04.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 04/17/2018] [Accepted: 04/18/2018] [Indexed: 10/28/2022]
Abstract
STATEMENT OF PROBLEM The marginal and internal adaptations of porcelain laminate veneers (PLVs) are key elements in their long-term success. However, the marginal and internal fit obtained with a pressable material compared with computer-aided design and computer-aided manufacturing (CAD-CAM) needs further investigation as does the choice of cement used. PURPOSE The purpose of this in vitro study was to evaluate the marginal and internal fit of PLVs fabricated using pressing and CAD-CAM milling and cemented using 2 types of composite resin cement. MATERIAL AND METHODS Twenty PLVs were fabricated from VITA PM9 pressable material, and 20 veneers were milled using VITA Blocs Mark II. Veneers were cemented to composite resin dies using either RelyX Veneer cement or Variolink-N cement. Specimens were embedded in clear resin and sectioned incisogingivally and mesiodistally. Marginal discrepancy at the incisal and cervical positions and the internal gap at 6 different locations were evaluated by using a scanning electron microscope. Two-way ANOVA followed by Tukey multiple comparisons were used to examine difference among groups (α=.05). RESULTS The cement and fabrication methods did not show any significant effect for absolute marginal gap (AMG) at the incisal edge, AMG at the cervical margin or marginal gap at the incisal edge. However, both had a significant effect on marginal gap at the cervical margin (P=.038 for the fabrication method and P=.050 for the cement used). Also, both cement and fabrication methods had a significant effect on internal gap average (P<.001). The lowest gap values were reported for veneers fabricated from VITA PM9 by using the press technique and cemented with RelyX Veneer cement. When the position of gap measurements was taken into consideration, it was the only significant factor (P<.001 for the effect of position on AMG and P<.001 for the effect of position on marginal gap). Gaps at the cervical position were significantly lower than gaps at the incisal position. CONCLUSIONS Smaller marginal and internal discrepancies were recorded for PLVs fabricated by using the pressing technique and cemented using RelyX Veneer cement compared with milled veneers and Variolink-N cement. Larger discrepancies were present incisally than cervically.
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Affiliation(s)
- Ziad N Al-Dwairi
- Professor, Department of Prosthodontics, Jordan University of Science and Technology (JUST), Irbid, Jordan.
| | - Rana M Alkhatatbeh
- Graduate student, Department of Prosthodontics, Jordan University of Science and Technology (JUST), Irbid, Jordan
| | - Nadim Z Baba
- Professor, Advanced Specialty Education Program in Prosthodontics, Loma Linda University, School of Dentistry, Loma Linda, Calif
| | - Charles J Goodacre
- Distinguished Professor, Advanced Specialty Education Program in Prosthodontics, Loma Linda University, School of Dentistry, Loma Linda, Calif
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Comparative Study of the Fit Accuracy of Full-Arch Bar Frameworks Fabricated with Different Presintered Cobalt-Chromium Alloys. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1962514. [PMID: 30175117 PMCID: PMC6098887 DOI: 10.1155/2018/1962514] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 06/06/2018] [Accepted: 07/08/2018] [Indexed: 11/17/2022]
Abstract
Purpose This study was to measure the geometric discrepancies that occur during the sintering contraction of presintered Co-Cr alloys in a full-arch bar framework and to compare the variations between alloys from different manufacturers. Materials and Methods Eighteen implant-supported full-arch bar frameworks were fabricated through a soft-machining process using presintered Co-Cr alloy blocks: Ceramill Sintron (CS), Soft Metal (SM), and Sintermetall (SML) (n=6 for each group). The sintered frameworks were digitized using a structured light scanner, and the scan images were superimposed on the reference design. The geometric discrepancies of the sintered frameworks were three-dimensionally analyzed for horizontal, angular, and internal discrepancies. Kruskal-Wallis and Mann-Whitney U tests were used to compare the discrepancies among the groups (α=.05). Results Significant differences were found in the geometric discrepancy measurements among the groups. The CS group showed larger horizontal and angular discrepancies, followed by the SM and SML groups (P<.001). The root mean square (RMS) values for internal discrepancy were not statistically different among the groups (P=.778). Conclusion The geometric discrepancies of full-arch bar frameworks fabricated using the soft-machining process were affected by accuracies in sintering contraction of presintered alloys.
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Bae EJ, Jeong ID, Kim WC, Kim JH. A study on the machining accuracy of dental digital method focusing on dental inlay. J Adv Prosthodont 2018; 10:321-327. [PMID: 30140400 PMCID: PMC6104499 DOI: 10.4047/jap.2018.10.4.321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/15/2018] [Accepted: 06/14/2018] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to compare the cutting method and the lamination method to investigate whether the CAD data of the proposed inlay shape are machined correctly. MATERIALS AND METHODS The Mesial-Occlusal shape of the inlay was modeled by changing the stereolithography (STL). Each group used SLS (metal powder) or SLA (photocurable resin) in the additive method, and wax or zirconia in the subtractive method (n=10 per group, total n=40). Three-dimensional (3D) analysis program (Geomagic Control X inspection software; 3D systems) was used for the alignment and analysis. The root mean square (RMS) in the 2D plane state was measured within 50 µm radius of eight comparison measuring points (CMP). Differences were analyzed using one-way analysis of variance and post-hoc Tukey's test were used (α=.05). RESULTS There was a significant difference in RMS only in SLA and SLS of 2D section (P<.05). In CMP mean, CMP 4 (−5.3±46.7 µm) had a value closest to 0, while CMP 6 (20.1±42.4 µm) and CMP 1 (−89.2±61.4 µm) had the greatest positive value and the greatest negative value, respectively. CONCLUSION Since the errors obtained from the study do not exceed the clinically acceptable values, the lamination method and the cutting method can be used clinically.
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Affiliation(s)
- Eun-Jeong Bae
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Il-Do Jeong
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Woong-Chul Kim
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
| | - Ji-Hwan Kim
- Department of Dental Laboratory Science and Engineering, College of Health Science, Korea University, Seoul, Republic of Korea
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Memari Y, Mohajerfar M, Armin A, Kamalian F, Rezayani V, Beyabanaki E. Marginal Adaptation of CAD/CAM All-Ceramic Crowns Made by Different Impression Methods: A Literature Review. J Prosthodont 2018; 28:e536-e544. [PMID: 29679423 DOI: 10.1111/jopr.12800] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2018] [Indexed: 11/28/2022] Open
Abstract
All-ceramic crowns for teeth are widely used for restoring teeth. Stone casts have been made from conventional impression methods; however, newer techniques have made this process easier and faster for both the patient and the practitioner. Laboratory CAD/CAM technology mainly involves scanning the die stone, while other systems permit impression or intraoral scanning; however, one major concern remaining is the marginal fit of the restorations made using different methods for recording the prepared teeth. This study aims to review studies evaluating the marginal fit of all-ceramic crowns manufactured by CAD/CAM systems using different extra- and intra-oral scanners compared to conventional impressions.
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Affiliation(s)
- Yeganeh Memari
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Mohajerfar
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | | | - Vida Rezayani
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elaheh Beyabanaki
- Department of Prosthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Torii M, Nakata T, Takahashi K, Kawamura N, Shimpo H, Ohkubo C. Fitness and retentive force of cobalt-chromium alloy clasps fabricated with repeated laser sintering and milling. J Prosthodont Res 2018; 62:342-346. [PMID: 29428170 DOI: 10.1016/j.jpor.2018.01.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 12/28/2017] [Accepted: 01/03/2018] [Indexed: 10/18/2022]
Abstract
PURPOSE With computer-aided design and computer-aided manufacturing (CAD/CAM), the study was conducted to create a removable partial denture (RPD) framework using repeated laser sintering rather than milling and casting techniques. This study experimentally evaluated the CAM clasp and compared it to a conventional cast clasp. METHODS After the tooth die was scanned, an Akers clasp was designed using CAD with and without 50μm of digital relief on the occlusal surface of the tooth die. Cobalt-chromium (Co-Cr) alloy clasps were fabricated using repeated laser sintering (RLS) and milling as one process simultaneously (hybrid manufacturing; HM). The surface roughness of the rest region, gap distances between clasp and tooth die, initial retentive forces, and changes of retentive forces up to 10,000 insertion/removal cycles were measured before and after heat treatment. The HM clasp was compared to the cast clasp and the clasp made by repeated laser sintering only without a milling process. RESULTS The HM clasp surface was smoother than those of cast and RLS clasps. With the digital relief, the fitness accuracy of the HM clasp improved. The retentive forces of the HM clasps with relief and after heat treatment were significantly greater than for the cast clasp. HM clasps demonstrated a constant or slight decrease of retention up to 10,000 cycles. CONCLUSIONS HM clasp exhibited better fitness accuracy and retentive forces. The possibility of clinically using HM clasps as well as conventional cast clasps can be suggested.
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Affiliation(s)
- Mana Torii
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan.
| | - Toyoki Nakata
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Kazuya Takahashi
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Noboru Kawamura
- Department of Technician Training Institute, Tsurumi University Dental Hospital, Yokohama, Japan
| | - Hidemasa Shimpo
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Chikahiro Ohkubo
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan
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Rudolph H, Ostertag S, Ostertag M, Walter MH, Luthardt RG, Kuhn K. Reliability of light microscopy and a computer-assisted replica measurement technique for evaluating the fit of dental copings. J Appl Oral Sci 2018; 26:e20160590. [PMID: 29412364 PMCID: PMC5777408 DOI: 10.1590/1678-7757-2016-0590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 05/19/2017] [Indexed: 11/22/2022] Open
Abstract
The aim of this in vitro study was to assess the reliability of two measurement systems for evaluating the marginal and internal fit of dental copings.
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Affiliation(s)
- Heike Rudolph
- Universität Ulm, Zentrum für Zahn-, Mund- und Kieferheilkunde, Klinik für Zahnärztliche Prothetik, Ulm, Deutschland
| | - Silke Ostertag
- Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Poliklinik für Zahnärztliche Prothetik, Dresden, Deutschland.,Private practice, Esslingen, Deutschland
| | - Michael Ostertag
- Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Poliklinik für Zahnärztliche Prothetik, Dresden, Deutschland.,Private practice, Stuttgart, Deutschland
| | - Michael H Walter
- Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Poliklinik für Zahnärztliche Prothetik, Dresden, Deutschland
| | - Ralph Gunnar Luthardt
- Universität Ulm, Zentrum für Zahn-, Mund- und Kieferheilkunde, Klinik für Zahnärztliche Prothetik, Ulm, Deutschland
| | - Katharina Kuhn
- Universität Ulm, Zentrum für Zahn-, Mund- und Kieferheilkunde, Klinik für Zahnärztliche Prothetik, Ulm, Deutschland
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Boitelle P, Tapie L, Mawussi B, Fromentin O. Evaluation of the marginal fit of CAD-CAM zirconia copings: Comparison of 2D and 3D measurement methods. J Prosthet Dent 2018; 119:75-81. [DOI: 10.1016/j.prosdent.2017.01.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 01/26/2017] [Accepted: 01/26/2017] [Indexed: 10/19/2022]
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Carbajal Mejía JB, Yatani H, Wakabayashi K, Nakamura T. Marginal and Internal Fit of CAD/CAM Crowns Fabricated Over Reverse Tapered Preparations. J Prosthodont 2017; 28:e477-e484. [PMID: 29194841 DOI: 10.1111/jopr.12715] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2017] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Intraoral digital scanning can accurately record single abutment tooth preparations despite their geometry, and the algorithms of the CAD software can be set to manage different abutment forms. The purpose of this in vitro study was to evaluate the marginal and internal fit of CAD/CAM zirconia crowns fabricated over conventional and reverse-tapered preparations. MATERIALS AND METHODS Crown preparations with known total occlusal convergence (TOC) angles (-8°, -4°, 0°, 8°, 12°, 16°, and 22°) were digitally created from a maxillary left central incisor and printed in acrylic resin. Next, casts were scanned with a TRIOS intraoral scanner, and crowns were designed with KaVo multiCAD software using default parameters (50 μm cement space) on abutments with positive TOC angles, whereas reverse-tapered abutments (negative TOC angles) were digitally blocked out at 0° and had an extra mesiodistal gap set to 50 μm. Then, zirconia crowns were fabricated, and their marginal and internal discrepancies were recorded with the silicone replica technique. All replicas were examined under a stereomicroscope at 50× magnification. Collected data were analyzed with one-way ANOVA and post hoc Tukey test for marginal fit. For the axial and incisal fit, measured values did not follow a normal distribution; therefore, the Kruskal-Wallis and the Dunn/Bonferroni multiple comparison tests were applied (p = 0.05). RESULTS The mean marginal fit of -8° crowns (58.2 ± 6.0 μm) was statistically different (p < 0.0001) from all the remaining crowns (range 42.1-47.3 μm). Also, the internal fit was statistically significant when comparing crowns fabricated over abutments with positive and negative TOC angles (p < 0.0001). The largest median axial discrepancies were found in the -8° (165.5 μm) and -4° (130.8 μm) groups; however, when evaluating the incisal fit, they showed the smallest discrepancies (67.3 and 81.8 μm, respectively). CONCLUSIONS Under the conditions of this study, the marginal and internal fit of zirconia crowns fabricated over inverse-tapered preparations is within clinically accepted values.
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Affiliation(s)
- Jeison B Carbajal Mejía
- Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Hirofumi Yatani
- Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Kazumichi Wakabayashi
- Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Takashi Nakamura
- Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
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Azarbal A, Azarbal M, Engelmeier RL, Kunkel TC. Marginal Fit Comparison of CAD/CAM Crowns Milled from Two Different Materials. J Prosthodont 2017; 27:421-428. [PMID: 29143397 DOI: 10.1111/jopr.12683] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2017] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To evaluate the marginal fit of CAD/CAM copings milled from hybrid ceramic (Vita Enamic) blocks and lithium disilicate (IPS e.max CAD) blocks, and to evaluate the effect of crystallization firing on the marginal fit of lithium disilicate copings. MATERIALS AND METHODS A standardized metal die with a 1-mm-wide shoulder finish line was imaged using the CEREC AC Bluecam. The coping was designed using CEREC 3 software. The design was used to fabricate 15 lithium disilicate and 15 hybrid ceramic copings. Design and milling were accomplished by one operator. The copings were seated on the metal die using a pressure clamp with a uniform pressure of 5.5 lbs. A Macroview Microscope (14×) was used for direct viewing of the marginal gap. Four areas were imaged on each coping (buccal, distal, lingual, mesial). Image analysis software was used to measure the marginal gaps in μm at 15 randomly selected points on each of the four surfaces. A total of 60 measurements were made per specimen. For lithium disilicate copings the measurements for marginal gap were made before and after crystallization firing. Data were analyzed using paired t-test and Kruskal-Wallis test. RESULTS The overall mean difference in marginal gap between the hybrid ceramic and crystallized lithium disilicate copings was statistically significant (p < 0.01). Greater mean marginal gaps were measured for crystallized lithium disilicate copings. The overall mean difference in marginal gap before and after firing (precrystallized and crystallized lithium disilicate copings) showed an average of 62 μm increase in marginal gap after firing. This difference was also significant (p < 0.01). CONCLUSIONS A significant difference exists in the marginal gap discrepancy when comparing hybrid ceramic and lithium disilicate CAD/CAM crowns. Also crystallization firing can result in a significant increase in the marginal gap of lithium disilicate CAD/CAM crowns.
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Affiliation(s)
- Atousa Azarbal
- Department of Prosthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA
| | - Mohsen Azarbal
- Department of Prosthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA
| | - Robert L Engelmeier
- Department of Prosthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA
| | - Thomas C Kunkel
- Department of Prosthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA
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Edwards Rezende CE, Sanches Borges AF, Macedo RM, Rubo JH, Griggs JA. Dimensional changes from the sintering process and fit of Y-TZP copings: Micro-CT analysis. Dent Mater 2017; 33:e405-e413. [DOI: 10.1016/j.dental.2017.08.191] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/19/2017] [Accepted: 08/31/2017] [Indexed: 11/29/2022]
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Carbajal Mejía JB, Wakabayashi K, Nakamura T, Yatani H. Influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions. J Prosthet Dent 2017; 118:392-399. [PMID: 28222873 DOI: 10.1016/j.prosdent.2016.10.021] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 10/21/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
STATEMENT OF PROBLEM Direct (intraoral) and indirect (desktop) digital scanning can record abutment tooth preparations despite their geometry. However, little peer-reviewed information is available regarding the influence of abutment tooth geometry on the accuracy of digital methods of obtaining dental impressions. PURPOSE The purpose of this in vitro study was to evaluate the influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions in terms of trueness and precision. MATERIAL AND METHODS Crown preparations with known total occlusal convergence (TOC) angles (-8, -6, -4, 0, 4, 8, 12, 16, and 22 degrees) were digitally created from a maxillary left central incisor and printed in acrylic resin. Each of these 9 reference models was scanned with a highly accurate reference scanner and saved in standard tessellation language (STL) format. Then, 5 conventional polyvinyl siloxane (PVS) impressions were made from each reference model, which was poured with Type IV dental stone scanned using both the reference scanner (group PVS) and the desktop scanner and exported as STL files. Additionally, direct digital impressions (intraoral group) of the reference models were made, and the STL files were exported. The STL files from the impressions obtained were compared with the original geometry of the reference model (trueness) and within each test group (precision). Data were analyzed using 2-way ANOVA with the post hoc least significant difference test (α=.05). RESULTS Overall trueness values were 19.1 μm (intraoral scanner group), 23.5 μm (desktop group), and 26.2 μm (PVS group), whereas overall precision values were 11.9 μm (intraoral), 18.0 μm (PVS), and 20.7 μm (desktop). Simple main effects analysis showed that impressions made with the intraoral scanner were significantly more accurate than those of the PVS and desktop groups when the TOC angle was less than 8 degrees (P<.05). Also, a statistically significant interaction was found between the effects of the type of impression and the TOC angle on the precision of single-tooth dental impressions (F=2.43, P=.002). Visual analysis revealed that the intraoral scanner group showed a homogeneous deviation pattern across all TOC angles tested, whereas scans from the PVS and desktop scanner groups showed marked local deviations when undercuts (negative angles) were present. CONCLUSIONS Conventional dental impressions alone or those further digitized with an extraoral digital scanner cannot reliably reproduce abutment tooth preparations when the TOC angle is close to 0 degrees. In contrast, digital impressions made with intraoral scanning can accurately record abutment tooth preparations independently of their geometry.
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Affiliation(s)
- Jeison B Carbajal Mejía
- Doctoral student, Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan.
| | - Kazumichi Wakabayashi
- Associate Professor, Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Takashi Nakamura
- Associate Professor, Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Hirofumi Yatani
- Professor and Chairman, Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Osaka, Japan
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Marginal Accuracy and Internal Fit of 3-D Printing Laser-Sintered Co-Cr Alloy Copings. MATERIALS 2017; 10:ma10010093. [PMID: 28772451 PMCID: PMC5344574 DOI: 10.3390/ma10010093] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 12/04/2022]
Abstract
Laser sintered technology has been introduced for clinical use and can be utilized more widely, accompanied by the digitalization of dentistry and the development of direct oral scanning devices. This study was performed with the aim of comparing the marginal accuracy and internal fit of Co-Cr alloy copings fabricated by casting, CAD/CAM (Computer-aided design/Computer-assisted manufacture) milled, and 3-D laser sintered techniques. A total of 36 Co-Cr alloy crown-copings were fabricated from an implant abutment. The marginal and internal fit were evaluated by measuring the weight of the silicone material, the vertical marginal discrepancy using a microscope, and the internal gap in the sectioned specimens. The data were statistically analyzed by One-way ANOVA (analysis of variance), a Scheffe’s test, and Pearson’s correlation at the significance level of p = 0.05, using statistics software. The silicone weight was significantly low in the casting group. The 3-D laser sintered group showed the highest vertical discrepancy, and marginal-, occlusal-, and average- internal gaps (p < 0.05). The CAD/CAM milled group revealed a significantly high axial internal gap. There are moderate correlations between the vertical marginal discrepancy and the internal gap variables (r = 0.654), except for the silicone weight. In this study, the 3-D laser sintered group achieved clinically acceptable marginal accuracy and internal fit.
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Bae EJ, Jeong ID, Kim WC, Kim JH. A comparative study of additive and subtractive manufacturing for dental restorations. J Prosthet Dent 2017; 118:187-193. [PMID: 28089336 DOI: 10.1016/j.prosdent.2016.11.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 11/11/2016] [Accepted: 11/11/2016] [Indexed: 12/23/2022]
Abstract
STATEMENT OF PROBLEM Digital systems have recently found widespread application in the fabrication of dental restorations. For the clinical assessment of dental restorations fabricated digitally, it is necessary to evaluate their accuracy. However, studies of the accuracy of inlay restorations fabricated with additive manufacturing are lacking. PURPOSE The purpose of this in vitro study was to evaluate and compare the accuracy of inlay restorations fabricated by using recently introduced additive manufacturing with the accuracy of subtractive methods. MATERIAL AND METHODS The inlay (distal occlusal cavity) shape was fabricated using 3-dimensional image (reference data) software. Specimens were fabricated using 4 different methods (each n=10, total N=40), including 2 additive manufacturing methods, stereolithography apparatus and selective laser sintering; and 2 subtractive methods, wax and zirconia milling. Fabricated specimens were scanned using a dental scanner and then compared by overlapping reference data. The results were statistically analyzed using a 1-way analysis of variance (α=.05). Additionally, the surface morphology of 1 randomly (the first of each specimen) selected specimen from each group was evaluated using a digital microscope. RESULTS The results of the overlap analysis of the dental restorations indicated that the root mean square (RMS) deviation observed in the restorations fabricated using the additive manufacturing methods were significantly different from those fabricated using the subtractive methods (P<.05). However, no significant differences were found between restorations fabricated using stereolithography apparatus and selective laser sintering, the additive manufacturing methods (P=.466). Similarly, no significant differences were found between wax and zirconia, the subtractive methods (P=.986). The observed RMS values were 106 μm for stereolithography apparatus, 113 μm for selective laser sintering, 116 μm for wax, and 119 μm for zirconia. Microscopic evaluation of the surface revealed a fine linear gap between the layers of restorations fabricated using stereolithography apparatus and a grooved hole with inconsistent weak scratches when fabricated using selective laser sintering. In the wax and zirconia restorations, possible traces of milling bur passes were observed. CONCLUSIONS The results indicate that the accuracy of dental restorations fabricated using the additive manufacturing methods is higher than that of subtractive methods. Therefore, additive manufacturing methods are a viable alternative to subtractive methods.
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Affiliation(s)
- Eun-Jeong Bae
- Research Professor, Department of Dental Laboratory Science and Engineering, Korea University, Seoul, Republic of Korea
| | - Il-Do Jeong
- Doctoral student, Department of Dental Laboratory Science and Engineering, Korea University, Seoul, Republic of Korea
| | - Woong-Chul Kim
- Professor, Department of Dental Laboratory Science and Engineering, Korea University, Seoul, Republic of Korea
| | - Ji-Hwan Kim
- Professor, Department of Dental Laboratory Science and Engineering, Korea University, Seoul, Republic of Korea.
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Jianming Y, Ying T, Feng P, Weixing X. [Comparative evaluation of the marginal accuracy of single crowns fabricated computer using aided design/computer aided manufacturing methods, self-curing resin and Luxatemp]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2016; 34:575-578. [PMID: 28318156 DOI: 10.7518/hxkq.2016.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE This study aims to compare the marginal accuracy of single crowns fabricated using self-curing resin, Luxatemp, and computer aided design/computer aided manufacturing (CAD/CAM) methods in clinical application. METHODS A total of 30 working dies, which were obtained from 30 clinical teeth prepared with full crown as standard, were created and made into 30 self-curing resin, Luxatemp, and CAD/CAM single crowns. The restorations were seated on the working dies, and stereomicroscope was used to observe and measure the thickness of reference points. One-way analysis of variance, which was performed using SPSS 19.0 software package, compared the marginal gap widths of self-curing resin, Luxatemp, and CAD/CAM provisional crowns. RESULTS The mean marginal gap widths of the fabricated self-curing resin, Luxatemp, and CAD/CAM were (179.06±33.24), (88.83±9.56), and (43.61±7.27) μm, respectively. A significant difference was observed among the three provisional crowns (P<0.05). CONCLUSIONS The marginal gap width of CAD/CAM provisional crown was lower than that of the self-curing resin and Luxatemp. Thus, the CAD/CAM provisional crown offers a better remediation effect in clinical application.
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Affiliation(s)
- Yuan Jianming
- Dept. of Prosthodontics, The Second Stomatological Disease Institution of Huangpu District in Shanghai, Shanghai 200020, China
| | - Tang Ying
- Dept. of Prosthodontics, The Second Stomatological Disease Institution of Huangpu District in Shanghai, Shanghai 200020, China
| | - Pan Feng
- Dept. of Prosthodontics, The Second Stomatological Disease Institution of Huangpu District in Shanghai, Shanghai 200020, China
| | - Xu Weixing
- Dept. of Prosthodontics, The Second Stomatological Disease Institution of Huangpu District in Shanghai, Shanghai 200020, China
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Kale E, Seker E, Yilmaz B, Özcelik TB. Effect of cement space on the marginal fit of CAD-CAM-fabricated monolithic zirconia crowns. J Prosthet Dent 2016; 116:890-895. [DOI: 10.1016/j.prosdent.2016.05.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 10/21/2022]
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Alghazzawi TF, Al-Samadani KH, Lemons J, Liu PR, Essig ME, Bartolucci AA, Janowski GM. Effect of imaging powder and CAD/CAM stone types on the marginal gap of zirconia crowns. J Am Dent Assoc 2016; 146:111-20. [PMID: 25637209 DOI: 10.1016/j.adaj.2014.10.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To compare the marginal gap using different types of die stones and titanium dies with and without powders for imaging. METHODS A melamine tooth was prepared and scanned using a laboratory 3-shape scanner to mill a polyurethane die, which was duplicated into different stones (Jade, Lean, CEREC) and titanium. Each die was sprayed with imaging powders (NP, IPS, Optispray, Vita) to form 15 groups. Ten of each combination of stone/titanium and imaging powders were used to mill crowns. A light-bodied impression material was injected into the intaglio surface of each crown and placed on the corresponding die. Each crown was removed, and the monophase material was injected to form a monophase die, which was cut into 8 sections. Digital images were captured using a stereomicroscope to measure marginal gap. Scanning electron microscopy was used to determine the particle size and shape of imaging powders and stones. RESULTS Marginal gaps ranged from mean (standard deviation) 49.32 to 1.20 micrometers (3.97-42.41 μm). There was no statistical difference (P > .05) in the marginal gap by any combination of stone/titanium and imaging powders. All of the imaging powders had a similar size and rounded shape, whereas the surface of the stones showed different structures. CONCLUSIONS When a laboratory 3-shape scanner is used, all imaging powders performed the same for scanning titanium abutments. However, there was no added value related to the use of imaging powder on die stone. It is recommended that the selection of stone for a master cast be based on the hysical properties. PRACTICAL IMPLICATIONS When a laboratory 3-shape scanner is used, the imaging powder is not required for scanning die stone. Whenever scanning titanium implant abutments, select the least expensive imaging powder.
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Clasp fabrication using one-process molding by repeated laser sintering and high-speed milling. J Prosthodont Res 2016; 61:276-282. [PMID: 27825561 DOI: 10.1016/j.jpor.2016.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/03/2016] [Accepted: 10/14/2016] [Indexed: 11/22/2022]
Abstract
PURPOSE A single machine platform that integrates repeated laser sintering and high-speed milling for one-process molding has been developed. METHODS The Akers clasp was designed using the CAD system (DWOS Partial Frameworks, Dental Wings) and fabricated using repeated laser sintering and a high-speed milling machine (LUMEX Advance-25, Matsuura) with 50-μm Co-Cr particles (CAM clasp). As controls, cast clasps of the same forms were also prepared using conventional casting methods with a Co-Cr alloy and CP titanium Grade 3. After the surface roughness was measured, the gap distance between the clasps and the tooth die was assessed using the silicone film method. The initial retentive force and changes in retention up to 10,000 cycles were also measured. The data were analyzed using two-way ANOVA and Tukey's multiple comparison test (α=0.05). RESULTS CAM clasps exhibited significantly smoother surfaces than those of cast Co-Cr and CP Ti clasps (p<0.05). However, the gap distances of the CAM clasps were significantly greater than those of the cast clasps (p<0.05). The retentive forces of both CAM and cast Co-Cr clasps were significantly higher than those of CP Ti clasps. (p<0.05). The retention of CAM clasps demonstrated a constant or slight decrease from 1000 up to 10,000 cycles. CONCLUSIONS The CAM clasp made by repeated laser sintering and high-speed milling can be used effectively as an RPD component.
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Kim EH, Lee DH, Kwon SM, Kwon TY. A microcomputed tomography evaluation of the marginal fit of cobalt-chromium alloy copings fabricated by new manufacturing techniques and alloy systems. J Prosthet Dent 2016; 117:393-399. [PMID: 27677219 DOI: 10.1016/j.prosdent.2016.08.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 08/01/2016] [Accepted: 08/01/2016] [Indexed: 11/18/2022]
Abstract
STATEMENT OF PROBLEM Although new digital manufacturing techniques are attracting interest in dentistry, few studies have comprehensively investigated the marginal fit of fixed dental prostheses fabricated with such techniques. PURPOSE The purpose of this in vitro microcomputed tomography (μCT) study was to evaluate the marginal fit of cobalt-chromium (Co-Cr) alloy copings fabricated by casting and 3 different computer-aided design and computer-aided manufacturing (CAD-CAM)-based processing techniques and alloy systems. MATERIAL AND METHODS Single Co-Cr metal crowns were fabricated using 4 different manufacturing techniques: casting (control), milling, selective laser melting, and milling/sintering. Two different commercial alloy systems were used for each fabrication technique (a total of 8 groups; n=10 for each group). The marginal discrepancy and absolute marginal discrepancy of the crowns were determined with μCT. For each specimen, the values were determined from 4 different regions (sagittal buccal, sagittal lingual, coronal mesial, and coronal distal) by using imaging software and recorded as the average of the 4 readings. For each parameter, the results were statistically compared with 2-way analysis of variance and appropriate post hoc analysis (using Tukey or Student t test) (α=.05). RESULTS The milling and selective laser melting groups showed significantly larger marginal discrepancies than the control groups (70.4 ±12.0 and 65.3 ±10.1 μm, respectively; P<.001), whereas the milling/sintering groups exhibited significantly smaller values than the controls (P=.004). The milling groups showed significantly larger absolute marginal discrepancy than the control groups (137.4 ±29.0 and 139.2 ±18.9 μm, respectively; P<.05). In the selective laser melting and milling/sintering groups, the absolute marginal discrepancy values were material-specific (P<.05). Nonetheless, the milling/sintering groups yielded statistically comparable (P=.935) or smaller (P<.001) absolute marginal discrepancies to the control groups. CONCLUSIONS The findings of this in vitro μCT study showed that the marginal fit values of the Co-Cr alloy greatly depended on the fabrication methods and, occasionally, the alloy systems. Fixed dental prostheses produced by using the milling/sintering technique can be considered clinically acceptable in terms of marginal fit.
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Affiliation(s)
- Eun-Ha Kim
- Graduate student, Department of Medical and Biological Engineering, Graduate School, Kyungpook National University, Daegu, Republic of Korea
| | - Du-Hyeong Lee
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Sung-Min Kwon
- Graduate student, Department of Dental Science, Graduate School, Kyungpook National University, Daegu, Republic of Korea
| | - Tae-Yub Kwon
- Associate Professor, Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
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Kirsch C, Ender A, Attin T, Mehl A. Trueness of four different milling procedures used in dental CAD/CAM systems. Clin Oral Investig 2016; 21:551-558. [PMID: 27469100 DOI: 10.1007/s00784-016-1916-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 07/18/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Milling is a crucial step in producing restorations using computer-aided design and computer-aided manufacturing (CAD/CAM) systems. In this study the trueness of currently available milling devices was evaluated. MATERIALS AND METHODS Thirty clinical cases (ten inlays, ten crowns, ten onlays) were milled from ceramic blocks using four different milling approaches: five axis with IMES CORiTEC 450i, four axis with CEREC MCXL, four axis with CEREC MCXL-EF and five axis with inLab MCX5. The milled restorations were scanned and the occlusal and inner surfaces compared to the originally calculated 3D surface using difference analysis software. The (90-10 %) / 2 percentile of the distances were calculated and analysed using one-way ANOVA with the post hoc Scheffé test (α = 0.05). Chipping of marginal areas were visually examined and analysed using one-way ANOVA with a post hoc Tamhane test (α = 0.05). RESULTS At inner surfaces, the milling trueness of IMES (33.9 ± 16.3 μm), X5 (32.3 ± 9.7 μm) and MCXL-EF (34.4 ± 7.5 μm) was significantly better (p < 0.001) than that of MCXL (62.1 ± 17.1 μm). At occlusal surfaces, MCXL-EF (25.7 ± 9.3 μm) showed significant higher accuracy (p < 0.001) than MCXL (48.7 ± 23.3 μm) and X5 (40.9 ± 20.4 μm). IMES produced the most chipping (p < 0.001). CONCLUSIONS Five-axis milling devices yield high trueness. MCXL-EF is competitive and may allow chairside fabrication with good milling results. CLINICAL RELEVANCE Accurate milling is required for well-fitting restorations and thereby requires fewer manual finishing steps, yields smaller marginal gaps, resistance to secondary caries and longevity of restorations.
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Affiliation(s)
- Corinna Kirsch
- Division for Computerized Restorative Dentistry, Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, 11 Plattenstrasse, 8032, Zurich, Switzerland.
| | - Andreas Ender
- Division for Computerized Restorative Dentistry, Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, 11 Plattenstrasse, 8032, Zurich, Switzerland
| | - Thomas Attin
- Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, 11 Plattenstrasse, 8032, Zurich, Switzerland
| | - Albert Mehl
- Division for Computerized Restorative Dentistry, Clinic for Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, 11 Plattenstrasse, 8032, Zurich, Switzerland
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Farjood E, Vojdani M, Torabi K, Khaledi AAR. Marginal and internal fit of metal copings fabricated with rapid prototyping and conventional waxing. J Prosthet Dent 2016; 117:164-170. [PMID: 27460320 DOI: 10.1016/j.prosdent.2016.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 04/05/2016] [Accepted: 04/07/2016] [Indexed: 10/21/2022]
Abstract
STATEMENT OF PROBLEM Given the limitations of conventional waxing, computer-aided design and computer-aided manufacturing (CAD-CAM) technologies have been developed as alternative methods of making patterns. PURPOSE The purpose of this in vitro study was to compare the marginal and internal fit of metal copings derived from wax patterns fabricated by rapid prototyping (RP) to those created by the conventional handmade technique. MATERIAL AND METHODS Twenty-four standardized brass dies were milled and divided into 2 groups (n=12) according to the wax pattern fabrication method. The CAD-RP group was assigned to the experimental group, and the conventional group to the control group. The cross-sectional technique was used to assess the marginal and internal discrepancies at 15 points on the master die by using a digital microscope. An independent t test was used for statistical analysis (α=.01). RESULTS The CAD-RP group had a total mean (±SD) for absolute marginal discrepancy of 117.1 (±11.5) μm and a mean marginal discrepancy of 89.8 (±8.3) μm. The conventional group had an absolute marginal discrepancy 88.1 (±10.7) μm and a mean marginal discrepancy of 69.5 (±15.6) μm. The overall mean (±SD) of the total internal discrepancy, separately calculated as the axial internal discrepancy and occlusal internal discrepancy, was 95.9 (±8.0) μm for the CAD-RP group and 76.9 (±10.2) μm for the conventional group. The independent t test results showed significant differences between the 2 groups. The CAD-RP group had larger discrepancies at all measured areas than the conventional group, which was statistically significant (P<.01). CONCLUSIONS Within the limitations of this in vitro study, the conventional method of wax pattern fabrication produced copings with better marginal and internal fit than the CAD-RP method. However, the marginal and internal fit for both groups were within clinically acceptable ranges.
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Affiliation(s)
- Ehsan Farjood
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Hormozgan University of Medical Sciences, Bandarabbas, Iran
| | - Mahroo Vojdani
- Professor, Dental Biomaterial Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Kiyanoosh Torabi
- Associate Professor, Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Ali Reza Khaledi
- Assistant Professor, Department of Prosthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
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Dai N, Zhong Y, Liu H, Yuan F, Sun Y. Digital modeling technology for full dental crown tooth preparation. Comput Biol Med 2016; 71:190-7. [PMID: 26945598 DOI: 10.1016/j.compbiomed.2016.02.008] [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: 11/29/2015] [Revised: 02/11/2016] [Accepted: 02/12/2016] [Indexed: 11/24/2022]
Abstract
A dental defect is one of the most common oral diseases, and it often requires a full crown restoration. In this clinical operation, the dentist must manually prepare the affected tooth for the full crown so that it has a convergence angle between 4° and 10°, no undercuts, and uniform and even shoulder widths and depths using a high speed diamond bur in the patient׳s mouth within one hour, which is a difficult task that requires visual-manual operation. The quality of the tooth preparation has an important effect on the success rate of the subsequent prosthodontic treatment. This study involved research into digital modeling technology for full dental crown tooth preparation. First, the margin line of the tooth preparation was designed using a semi-automatic interactive process. Second, the inserting direction was automatically computed. Then, the characteristic parameters and the constraints on the tooth preparation were defined for the model. Next, the shoulder and axial surface of the tooth preparation were formed using parametric modeling. Finally, the implicit surface of a radial basis function was used to construct the tooth preparation׳s occlusal surface. The experimental results verified that the method of digital modeling for full crown preparation proposed in this study can quickly and accurately implement personalized designs of various parameters, such as the shoulder width and the convergence angle; it provides a digital design tool for full crown preparation.
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Affiliation(s)
- Ning Dai
- College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics & Astronautics, 210016 Nanjing, PR China.
| | - Yicheng Zhong
- College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics & Astronautics, 210016 Nanjing, PR China.
| | - Hao Liu
- College of Mechanical & Electrical Engineering, Nanjing University of Aeronautics & Astronautics, 210016 Nanjing, PR China.
| | - Fusong Yuan
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, 100081 Beijing, PR China.
| | - Yuchun Sun
- Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, 100081 Beijing, PR China.
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Berrendero S, Salido MP, Valverde A, Ferreiroa A, Pradíes G. Influence of conventional and digital intraoral impressions on the fit of CAD/CAM-fabricated all-ceramic crowns. Clin Oral Investig 2016; 20:2403-2410. [PMID: 26800669 DOI: 10.1007/s00784-016-1714-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 01/10/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To compare the fit of all-ceramic crowns fabricated from conventional silicone impressions with the fit of all-ceramic crowns fabricated from intraoral digital impressions. METHODS Thirty patients with 30 posterior teeth with a prosthetic demand were selected. Zirconia-based ceramic crowns were made using an intraoral digital impression system (Ultrafast Optical Sectioning technology) (digital group, D) and 2-step silicone impression technique (conventional group, C). To replicate the interface between the crown and the preparation, each crown was cemented on its corresponding clinical preparation using ultra-flow silicone. Each crown was embedded in resin to stabilize the registered interface. Specimens were sectioned in buccolingual orientation, and internal misfit was measured at different areas using stereomicroscopy (×40). Data was analysed using Student's t test and Mann-Whitney test (α = 0.05). RESULTS No statistically significant differences were found (P > 0.05) between two groups. The mean internal misfit and mean marginal misfit were 170.9 μm (SD = 119.4)/106.6 μm (SD = 69.6) for group D and 185.4 μm (SD = 112.1)/119.9 μm (SD = 59.9) for group C. CONCLUSION Ceramic crowns fabricated using an intraoral scanner are comparable to elastomer conventional impressions in terms of their marginal and internal fits. The mean marginal fit in both groups was within the limits of clinical acceptability. CLINICAL SIGNIFICANCE Impressions based on Ultrafast Optical Sectioning technology can be used for manufacturing ceramic crowns in a normal workflow, with the same results as silicone conventional impressions.
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Affiliation(s)
- S Berrendero
- Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, S/N Ciudad Universitaria, 28040, Madrid, Spain.
| | - M P Salido
- Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, S/N Ciudad Universitaria, 28040, Madrid, Spain
| | - A Valverde
- Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, S/N Ciudad Universitaria, 28040, Madrid, Spain
| | - A Ferreiroa
- Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, S/N Ciudad Universitaria, 28040, Madrid, Spain
| | - G Pradíes
- Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid, Plaza Ramón y Cajal, S/N Ciudad Universitaria, 28040, Madrid, Spain
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Effects of Computer-Aided Manufacturing Technology on Precision of Clinical Metal-Free Restorations. BIOMED RESEARCH INTERNATIONAL 2015; 2015:619027. [PMID: 26557681 PMCID: PMC4628743 DOI: 10.1155/2015/619027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/12/2015] [Indexed: 11/17/2022]
Abstract
PURPOSE The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM) systems. MATERIALS AND METHODS The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG) crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan's post hoc test were used for data analysis at the significance level of 0.05. RESULTS The mean (standard deviation) marginal gaps were 70.5 (34.4) μm for the MCG crowns, 87.2 (22.8) μm for Lava, 58.5 (17.6) μm for Cercon, and 72.3 (30.8) μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns (P < 0.001). CONCLUSIONS Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy.
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Renne W, Wolf B, Kessler R, McPherson K, Mennito AS. Evaluation of the Marginal Fit of CAD/CAM Crowns Fabricated Using Two Different Chairside CAD/CAM Systems on Preparations of Varying Quality. J ESTHET RESTOR DENT 2015; 27:194-202. [PMID: 26177118 PMCID: PMC7179725 DOI: 10.1111/jerd.12148] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE This study evaluated the marginal gap of crowns fabricated using two new chairside computer-aided design/computer-aided manufacturing systems on preparations completed by clinicians with varying levels of expertise to identify whether common preparation errors affect marginal fit. The null hypothesis is that there is no difference in the mean marginal gaps of restorations of varying qualities and no difference in the mean marginal gap size between restorations fabricated using the PlanScan (D4D, Richardson, TX, USA) and the CEREC Omnicam (Sirona, Bensheim, Germany). MATERIAL AND METHODS The fit of 80 lithium disilicate crowns fabricated with the E4D PlanScan or CEREC Omnicam systems on preparations of varying quality were examined for marginal fit by using the replica technique. These same preparations were then visually examined against common criteria for anterior all-ceramic restorations and placed in one of four categories: excellent, good, fair, and poor. Linear mixed modeling was used to evaluate associations between marginal gap, tooth preparation rating, and fabrication machine. RESULTS The fit was not significantly different between both systems across all qualities of preparation. The average fit was 104 μm for poor-quality preparations, 87.6 μm for fair preparations, 67.2 μm for good preparations, and 36.6 μm for excellent preparations. CONCLUSION The null hypothesis is rejected. It can be concluded that preparation quality has a significant impact on marginal gap regardless of which system is used. However, no significant difference was found when comparing the systems to each other. CLINICAL SIGNIFICANCE Within the limitations of this in vitro study, it can be concluded that crown preparation quality has a significant effect on marginal gap of the restoration when the clinician uses either CEREC Omnicam or E4D PlansScan.
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Affiliation(s)
- Walter Renne
- Department of Oral Rehabilitation, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Bethany Wolf
- Department of Biostatistics and Epidemiology, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Raymond Kessler
- Department of Oral Rehabilitation, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Karen McPherson
- Department of Oral Rehabilitation, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Anthony S Mennito
- Department of Oral Rehabilitation, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
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Ueda K, Beuer F, Stimmelmayr M, Erdelt K, Keul C, Güth JF. Fit of 4-unit FDPs from CoCr and zirconia after conventional and digital impressions. Clin Oral Investig 2015; 20:283-9. [PMID: 26121970 DOI: 10.1007/s00784-015-1513-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To evaluate the marginal and internal fit of CAD/CAM-generated frameworks for 4-unit, fixed dental prostheses (FDPs) from zirconia (Z) and cobalt-chromium alloy (C) made with conventional (CI) and digital impressions (DI). MATERIALS AND METHODS A titanium model was digitized with an intraoral scanner (DI, LAVA™ C.O.S.; 3M ESPE; Seefeld, Germany; n = 12). Additionally, 12 conventional impressions were taken, and referring plaster casts were digitized by a laboratory-scanner (CI, LAVA™ Scan ST; 3M ESPE; n = 12). Frameworks were fabricated (3M ESPE) from cobalt-chromium (DI-C, n = 12; CI-C, n = 12) and zirconia (DI-Z, n = 12; CI-Z, n = 12) from the same datasets. A replica technique was applied to measure the accuracy. The Mann-Whitney U statistical test was applied to detect statistical differences between each material and methodology groups in terms of fit. RESULTS Frameworks from DI-C (median 19.07 μm) showed significantly better marginal fit than CI-C (median 64.64 μm, p < 0.001). Frameworks from DI-Z (median 52.50 μm) showed significantly better marginal fit than CI-Z (median 72.94 μm, p = 0.001). Additionally, frameworks from DI-C showed a significantly better marginal fit than DI-Z (p < 0.001). CONCLUSIONS CI and DI led to a clinically acceptable marginal fit of 4-unit FDPs from cobalt-chromium and zirconia. DI leads to better marginal fit of the cobalt-chromium frameworks; however, no effect on zirconia was found. CLINICAL RELEVANCE The results indicate that DI is suitable for fabricating 4-unit, cobalt-chromium and zirconia frameworks with regard to fit requirements.
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Affiliation(s)
- Kazuhiko Ueda
- Comprehensive Dental Care, Oral Implant Center, Niigata Hospital, The Nippon Dental University, 1-8, Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.,Department of Prosthodontics, Dental School of the Ludwig-Maximilian University of Munich, Goethestrasse 70, 80336, München, Germany
| | - Florian Beuer
- Department of Prosthodontics, Charité UniversityMedicine Berlin, Assmanshauser Str. 4-6, 14197, Berlin, Germany
| | - Michael Stimmelmayr
- Department of Prosthodontics, Dental School of the Ludwig-Maximilian University of Munich, Goethestrasse 70, 80336, München, Germany
| | - Kurt Erdelt
- Department of Prosthodontics, Dental School of the Ludwig-Maximilian University of Munich, Goethestrasse 70, 80336, München, Germany
| | - Christine Keul
- Department of Prosthodontics, Dental School of the Ludwig-Maximilian University of Munich, Goethestrasse 70, 80336, München, Germany
| | - Jan-Frederik Güth
- Department of Prosthodontics, Dental School of the Ludwig-Maximilian University of Munich, Goethestrasse 70, 80336, München, Germany.
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El-Dessouky R, Salama M, Shakal M, Korsel A. Marginal adaptation of CAD/CAM zirconia-based crown during fabrication steps. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.tdj.2014.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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