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Suksuphan P, Krajangta N, Didron PP, Wasanapiarnpong T, Rakmanee T. Marginal adaptation and fracture resistance of milled and 3D-printed CAD/CAM hybrid dental crown materials with various occlusal thicknesses. J Prosthodont Res 2024; 68:326-335. [PMID: 37438119 DOI: 10.2186/jpr.jpr_d_23_00089] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
PURPOSE To evaluate the marginal adaptation and fracture resistance of three computer-aided design/computer-assisted manufacturing hybrid dental materials with different occlusal thicknesses. METHODS Ninety single-molar crowns were digitally fabricated using a milled hybrid nanoceramic (Cerasmart, CE), polymer-infiltrated ceramic network (PICN, Vita Enamic, VE), and 3D-printed materials (Varseosmile, VS) with occlusal thicknesses of 0.8, 1, and 1.5 mm (10 specimens/group). Anatomical 3D-printed resin dies (Rigid 10K) were used as supporting materials. A CEREC MCX milling unit and a DLP-based 3D printer, Freeform Pro 2, were utilized to produce the crown samples. Before cementation, the marginal adaptation, absolute marginal discrepancy (AMD), and marginal gap (MG) were assessed using micro-CT scanning. After cementation with self-adhesive resin cement, fracture resistance was evaluated using a universal testing machine. The number of fractured crowns and the maximum fracture values (N) were recorded. Data were statistically analyzed using both one- and two-way ANOVA, followed by Tukey's honestly significant difference (HSD) test. RESULTS For all occlusal thicknesses, the VS crowns demonstrated the lowest AMD and MG distances, significantly different from those of the other two milling groups (P < 0.05), whereas CE and VE did not differ significantly (P > 0.05). All VS crowns were fractured using the lowest loading forces (1480.3±226.1 to 1747.2±108.7 N). No CE and 1 and 1.5 mm VE crowns fractured under a 2000 N maximum load. CONCLUSIONS All hybrid-material crowns demonstrated favorable marginal adaptation within a clinically acceptable range, with 3D printing yielding superior results to milling. All materials could withstand normal occlusal force even with a 0.8 mm occlusal thickness.
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Affiliation(s)
- Pisit Suksuphan
- Department of Restorative and Esthetic Dentistry, Faculty of Dentistry, Thammasat University, Pathumtani, Thailand
| | - Nantawan Krajangta
- Department of Restorative and Esthetic Dentistry, Faculty of Dentistry, Thammasat University, Pathumtani, Thailand
| | | | | | - Thanasak Rakmanee
- Department of Restorative and Esthetic Dentistry, Faculty of Dentistry, Thammasat University, Pathumtani, Thailand
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Wang J, Yang L. Clinical application principles and new developments of zirconia crown. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2024; 42:135-141. [PMID: 38597073 PMCID: PMC11034402 DOI: 10.7518/hxkq.2024.2023404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 01/09/2024] [Indexed: 04/11/2024]
Abstract
Zirconia crown has been widely used in the field of prosthodontics. Traditional zirconia exhibits excellent mechanical properties but lacks translucency. The introduction of transparent zirconia significantly enhances its aesthetic performance. In clinical applications, factors affecting the aesthetic results of full zirconia crown should be comprehensively considered, and the most suitable restoration should be chosen. Additionally, clinicians need to design appropriate tooth preparation dimensions and methods based on an individual patient's actual situation. During the clinical bonding process of zirconia, proper surface treatment of the tooth and restoration is essential. The selection of suitable adhesives is crucial for achieving optimal bonding strength and aesthetics.
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Affiliation(s)
- Jian Wang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China Supported by: National Key R&D Program of China (2022YFC2410103)
| | - Linxin Yang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China Supported by: National Key R&D Program of China (2022YFC2410103)
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El-Ashkar A, Nabil O, Taymour M, El-Tannir A. Evaluation of zirconia crowns restoring endodontically treated posterior teeth with 2 finish line designs and 2 occlusal reduction schemes: A randomized clinical trial. J Prosthet Dent 2022:S0022-3913(22)00634-5. [PMID: 36396490 DOI: 10.1016/j.prosdent.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 11/17/2022]
Abstract
STATEMENT OF PROBLEM Preparation design has been linked to restoration survival, and the finish line geometry, such as a deep chamfer or shoulder, has been linked to marginal integrity. However, limited data are available for restoration success with the feather-edge finish line when used with monolithic zirconia crowns with different occlusal reduction schemes. PURPOSE The purpose of this randomized clinical trial was to evaluate the clinical performance of 2 finish line designs (feather-edge and rounded shoulder) in relation to 2 occlusal designs (flat and planar) in endodontically treated teeth restored with monolithic zirconia crowns. MATERIAL AND METHODS Sixty-six complete-coverage monolithic zirconia crowns were provided for posterior endodontically treated teeth. The participants were divided into 3 groups based on the preparation design: the control group (PS) had a planar occlusal scheme with a rounded shoulder finish line; the first intervention group (FF) had a flat occlusal scheme with a feather-edge finish line; and the second intervention group (FS) had a flat occlusal scheme with a rounded shoulder finish line. The crowns were designed with the exocad software program and milled with a 5-axis machine. After cementation, clinical performance in terms of marginal adaptation, marginal discoloration, fracture, and secondary caries was evaluated by using the modified United States Public Health Service (USPHS) criteria. The gingival index score system was used to evaluate the gingival response. The scores were recorded immediately after cementation and at 3 subsequent follow-up visits every 3 months for 1 year. The chi-square test was used in all comparisons of outcomes and follow-up durations (α=.05). RESULTS In terms of marginal adaptations, the control group (PS) demonstrated the best marginal adaptation scores during follow-up visits, followed by intervention 2 (FS), and lastly, intervention 1 (FF), which was scored mostly with Bravo. At the third follow-up visit, the intervention 1 (FF) group reported the most gingival responses of all groups. No significant difference among the groups was found in terms of marginal discoloration, fracture, or secondary caries at any of the follow-up visits. Each group received a perfect Alfa score of 100% on all 3 follow-up assessments. CONCLUSIONS In this 1-year randomized clinical trial, all evaluated preparation schemes and corresponding crowns were clinically successful. The clinical performance of monolithic zirconia crowns of the novel preparation design (FF) was successful in terms of marginal adaption, fracture, secondary caries, and marginal discoloration.
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Affiliation(s)
- Alaa El-Ashkar
- Lecturer, Fixed Prosthodontics Department, Faculty of Dentistry, Galala University, Suez, Egypt.
| | - Omnia Nabil
- Lecturer, Fixed Prosthodontics Department, Faculty of Dentistry, Cairo University, Cairo, Egypt
| | - Maha Taymour
- Professor, Fixed Prosthodontics Department, Faculty of Dentistry, Cairo University, Cairo, Egypt; Professor, Fixed Prosthodontics Department, School of Dentistry, New Giza University, Giza, Egypt
| | - Adel El-Tannir
- Professor, Fixed Prosthodontics Department, Faculty of Dentistry, Cairo University, Cairo, Egypt
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Assessment of Tooth Preparations Submitted to Dental Laboratories for Fabrication of Monolithic Zirconia Crowns. Dent J (Basel) 2021; 9:dj9100112. [PMID: 34677174 PMCID: PMC8534446 DOI: 10.3390/dj9100112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose: The objective of this study was to assess the quality of posterior teeth prepared for monolithic zirconia crowns. Materials and Methods: A total of 392 STL-files of posterior preparations for monolithic zirconia crowns were evaluated in this study. Three-dimensional (3D) images were evaluated using a software (3D Viewer; 3Shape A/S, Copenhagen, Denmark) for finish line design, finish line width, occluso-cervical dimension, total occlusal convergence (TOC), intercuspal angulation, finish line quality, line angle form, and presence or absence of undercut at the axial wall and unsupported lip of enamel. The assessment was performed by two calibrated evaluators. Then, data were descriptively analyzed. Data for occluso-cervical dimension and TOC were descriptively analyzed according to their location. Results: Thirty-nine percent of premolars, 77% of first molars, and 91% of second molars had an average occluso-cervical dimension of less than 3 mm (premolars) and 4 mm (molars), with most of the preparations having a TOC of more than 20 degrees. More than 50% of preparations had undercut, unsupported enamel and/or unacceptable finish line quality. Conclusions: The quality of tooth preparation including finish line quality, absence of unsupported enamel and undercut at the axial wall should be evaluated when preparing monolithic zirconia crowns.
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Torres C, Ávila D, Gonçalves LL, Meirelles L, Mailart MC, Di Nicoló R, Borges AB. Glass Ionomer Versus Self-adhesive Cement and the Clinical Performance of Zirconia Coping/Press-on Porcelain Crowns. Oper Dent 2021; 46:362-373. [PMID: 34491349 DOI: 10.2341/20-229-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVE This split-mouth clinical study investigated the effect of luting cement on the performance of veneered yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) zirconia crowns. METHODS AND MATERIALS A total of 60 crowns prepared with Y-TZP coping and press-on porcelain were made with a split-mouth design in 30 participants. The crowns were cemented either with glass ionomer cement (GIC) (Meron, Voco) or with self-adhesive resin cement (Bifix-SE, Voco). The restorations were assessed immediately after treatment and after 6, 12, 24, 36, and 48 months using the modified United States Public Health Service criteria. The parameters analyzed were retention, color stability, marginal discoloration, marginal adaptation, surface roughness, anatomic form, and secondary caries. The differences between the groups were analyzed by the Fisher exact test in each period of evaluation. The survival rate was analyzed with the Kaplan-Meier and log-rank test (α=0.05). RESULTS After 48 months, 20 participants attended the recall. During the period of evaluation, 1 crown cemented with glass ionomer cement and 1 crown cemented with resin cement lost retention. Color match, marginal discoloration and adaptation, surface roughness, and anatomic form did not change in any of the periods evaluated, and no secondary caries was observed. No significant differences were found between the 2 luting cements for any of the clinical parameters analyzed, nor for the survival rates during the study. CONCLUSIONS The type of cement did not influence the performance of the crowns after 48 months of clinical use. Both cements resulted in adequate retention rates, aesthetic and functional outcomes, and biological response.
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Aktas G, Guncu MB, Akcin ET, Cakan U, Canay S. Effect of Anti-Rotational Abutment Features and Novel Computerized Fabrication Techniques on the Marginal Fit of Implant-Supported Metal Copings. J Prosthodont 2020; 30:252-256. [PMID: 32964601 DOI: 10.1111/jopr.13263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/11/2020] [Indexed: 11/29/2022] Open
Abstract
PURPOSE An in vitro study to compare the marginal fit of cobalt-chromium (Co-Cr) metal copings fabricated with selective laser melting (SLM), computer-aided design and computer-aided manufacturing (CAD/CAM) milling, and lost-wax (LW) techniques, on abutments with two different antirotational features. MATERIALS AND METHODS A total of 60 stainless steel abutments with the same length and convergence angles were fabricated using a numerical control machining. Half of the abutments had one flat plane, while the other half had three grooves as an antirotation feature. Thirty abutments of each kind were then divided into three subgroups, and metal copings were fabricated with SLM, CAD/CAM milling, or the LW technique (n = 10). The metal copings were cemented with polycarboxylate cement. Marginal gap measurements were performed using a stereomicroscope at a magnification of × 45 and data were analyzed with two-way analysis of variance (ANOVA) tests. RESULTS The LW (p = 0.002) and CAD/CAM (p < 0.001) techniques exhibited increased marginal gaps on the abutments with a three groove antirotational feature; however, no significant difference was detected with the SLM technique (p = 0.259). The copings fabricated with the SLM technique demonstrated significantly lower gap values in both abutment types (p < 0.001). CONCLUSION While all marginal gap values were within the clinically acceptable range (<120 µm), abutments with more antirotational grooves exhibited wider marginal gaps with the LW and CAD/CAM techniques.
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Affiliation(s)
- Guliz Aktas
- Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
| | - Mustafa Baris Guncu
- Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
| | - Elif Tuba Akcin
- Department of Prosthodontics, Faculty of Dentistry, Lokman Hekim University, Ankara, Turkey
| | - Umut Cakan
- Department of Prosthodontics, Faculty of Dentistry, Istanbul Medipol University, Istanbul, Turkey
| | - Senay Canay
- Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey
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Ahmed WM, Shariati B, Gazzaz AZ, Sayed ME, Carvalho RM. Fit of tooth-supported zirconia single crowns-A systematic review of the literature. Clin Exp Dent Res 2020; 6:700-716. [PMID: 32885613 PMCID: PMC7745068 DOI: 10.1002/cre2.323] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 07/07/2020] [Accepted: 07/22/2020] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this study is to systematically map all the factors that influence the fit and adaptation of zirconia crowns and/or copings. MATERIALS AND METHODS The investigational strategy involved carrying out an electronic search between December 1, 2009 and September 1, 2019 through the Embase and Medline databases using Boolean operators to locate appropriate articles. RESULTS A total of 637 articles were discovered after the removal of duplicates, and 46 of these were selected for evaluation. Further, a quality assessment was performed using GRADE evaluation criteria. CONCLUSIONS Shoulder finish line preparations had slightly better marginal fit compared to chamfer finish lines. Crowns obtained from digital impressions had comparable to superior marginal adaptation compared to conventional impressions. Increasing cement space showed to improve zirconia crown adaptation. Cementation and veneering zirconia frameworks found to increase the marginal and internal gaps. Limited information is available on the effect of the alteration of sintering time/Temperature and/or sintering techniques on the adaptation of zirconia crowns. Most of the selected studies had a moderate quality assessment evaluation. Future studies could investigate the chair-side, ultra-fast sintering effect on the marginal gap of zirconia crowns.
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Affiliation(s)
- Walaa Magdy Ahmed
- Faculty of Dentistry, The University of British Columbia, Vancouver, British Columbia, Canada.,Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Batoul Shariati
- Faculty of Dentistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Arwa Z Gazzaz
- Faculty of Dentistry, The University of British Columbia, Vancouver, British Columbia, Canada.,College of Dentistry, King Saud University, Riyadh, Saudi Arabia
| | | | - Ricardo M Carvalho
- Faculty of Dentistry, The University of British Columbia, Vancouver, British Columbia, Canada
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Huang X, Zou L, Yao R, Wu S, Li Y. Effect of preparation design on the fracture behavior of ceramic occlusal veneers in maxillary premolars. J Dent 2020; 97:103346. [PMID: 32325176 DOI: 10.1016/j.jdent.2020.103346] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/27/2020] [Accepted: 04/15/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES The fracture strengths of four types of occlusal veneers and a traditional full crown ceramic restoration and the influence of preparation design on the stress of restorations were examined. METHODS Forty intact maxillary premolars randomly divided into five groups were prepared based on the demands of type O (occlusal surface coverage), OF (occlusal and lingual surface coverage), POF (occlusal, lingual, and mesial surface coverage), and POFP (occlusal, lingual, mesial, and distal surface coverage) veneers and full crown, and then restored by glass ceramic. Specimens were subjected to fracture resistance tests after cyclic loading. The fracture strengths and modes were analyzed statistically. The level of significance was set at α = 0.05. One maxillary premolar was prepared for type O, OF, POF, POFP veneer and full crown, and then scanned to establish finite element models. The mean fracture load was applied vertically to calculate the maximum principal stress on the ceramic. RESULTS Type O veneer showed higher fracture strength than type POF and POFP veneers (P < 0.05). Both type O and OF veneers exhibited higher fracture strength than full crown (P < 0.05). No significant difference in failure mode was observed. The maximum principal stress for type O, OF, POF, POFP veneers, and full crown increased progressively and concentrated at the bonding surface directly beneath the loading area. CONCLUSIONS Four types of occlusal veneer showed fracture strengths that considerably exceeded normal biting forces. They represent conservative alternatives to full crowns and present a viable treatment for severely worn teeth. CLINICAL SIGNIFICANCE The occlusal veneers with different preparation designs, including type O, OF, POF and POFP veneers, show higher fracture resistances than traditional full coverage crowns that considerably exceed the normal biting forces. Therefore, these represent conservative alternatives to crown restorations and present a viable treatment for restoring severely worn teeth.
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Affiliation(s)
- Xiaoqiong Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.
| | - Leiyan Zou
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.
| | - Run Yao
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Shuyi Wu
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.
| | - Yan Li
- Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, People's Republic of China.
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Sadid-Zadeh R, DeLuca JT, Arany H, Li R. Assessment of Teeth Prepared by Senior Dental Students for CAD/CAM Restorations. J Dent Educ 2020; 84:358-366. [PMID: 32176344 DOI: 10.21815/jde.019.178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 10/15/2019] [Indexed: 09/01/2023]
Abstract
The aim of this study was to evaluate teeth prepared for computer-aided design/computer-aided manufacturing (CAD/CAM) restorations by senior dental students using recently developed rubrics. The rubrics used evaluation criteria based on four factors: retention or resistance form; marginal or internal adaption or manufacturing process; biology, esthetics, or durability of restorative material; and intraoral scanner impression. In academic year 2018-19, four faculty members used the rubrics to assess 111 first maxillary right premolars (tooth no. 4) prepared for lithium disilicate crowns and 223 second maxillary right premolars (tooth no. 5) and first maxillary right molars (tooth no. 3) prepared for monolithic zirconia partial fixed dental prostheses. The preparations had been performed on typodont teeth. The most common errors identified for tooth preparations were in the finish line quality (136 errors in 223 prostheses), a criterion that is crucial for quality CAD/CAM restorations. To prevent poorly fit CAD/CAM restoration preparations that result from an unacceptable finish line quality, students need to understand the rationale used to develop detailed rubrics and adhere to the defined critera.
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Affiliation(s)
| | | | - Hema Arany
- University at Buffalo School of Dental Medicine
| | - Rui Li
- University at Buffalo School of Dental Medicine
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Al-Haj Ali SN. In vitro comparison of marginal and internal fit between stainless steel crowns and esthetic crowns of primary molars using different luting cements. Dent Res J (Isfahan) 2019; 16:366-371. [PMID: 31803381 PMCID: PMC6873236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND This study was to assess and compare the marginal and internal fit of stainless steel crowns (SSCs) with those of preveneered SSCs and zirconia crowns using different luting cements. MATERIALS AND METHODS In this in vitro study, 36 primary first molars were divided into three groups (n = 12) each prepared to receive different crowns (SSCs, preveneered SSCs, or zirconia crowns). Each group was further subgrouped (n = 4) according to the luting cement (resin cement, glass ionomer cement [GIC], or resin-modified GIC [RMGIC]). After cementation, the teeth were sectioned in the buccolingual direction to assess the marginal and internal fit. The results were analyzed using ANOVA and Bonferroni statistical tests. The level of significance was set at P < 0.05. RESULTS Zirconia crowns, especially those cemented with resin cement, were associated with the lowest marginal and internal gap width. Regardless of the luting cement, no significant difference was observed between all three crowns tested in terms of marginal gap (P > 0.05); however, zirconia crowns cemented with resin cement had significantly lower internal gap than preveneered SSCs and SSCs cemented with resin cement. In addition, those cemented with RMGIC had significantly lower internal gap than preveneered SSCs cemented with that cement (P < 0.05). CONCLUSION Zirconia crowns cemented with resin cement were the most accurately fitted internally, while marginally, they were not significantly different from the rest of crown-luting cement combinations tested.
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Affiliation(s)
- Sanaa Najeh Al-Haj Ali
- Department of Orthodontics and Pediatric Dentistry, College of Dentistry, Qassim University, Qassim, Kingdom of Saudi Arabia,Address for correspondence: Dr. Sanaa Najeh Al-Haj Ali, Department of Orthodontics and Pediatric Dentistry, College of Dentistry, Qassim University, Postal Code 51452, P.O. Box 6700, Qassim, Kingdom of Saudi Arabia. E-mail:
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Habib SR. Digital microscopic evaluation of vertical marginal discrepancies of CAD/CAM fabricated zirconia cores. ACTA ACUST UNITED AC 2019; 64:207-214. [PMID: 29775437 DOI: 10.1515/bmt-2017-0234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/16/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE The aim of this in vitro research study was to evaluate the vertical marginal discrepancies of zirconia (Zr) cores fabricated by five different computer-aided design and manufacturing (CAD/CAM) systems using a digital microscope. MATERIALS AND METHODS A total of 60 specimens were prepared and randomly divided into five groups (n=12 each) using the following systems: Ceramill Motion 2 (CM, Amanngirrbach, Germany); Weiland (WI, Ivoclar Vivadent, USA); Cerec (CS, Sirona Dental, USA); Zirkonzahn (ZZ, Gmbh Bruneck, Italy) and Cad4dent (CD, Canada). The specimens were numbered and the vertical marginal discrepancies were evaluated with a digital microscope at 50× magnification. RESULTS A one-way analysis of variance showed a statistically significant difference (p=0.002) between the groups. The CM group exhibited the lowest values for the marginal gaps (31.30±15.12 μm), while the ZZ group exhibited the highest values for the marginal gaps (44.83±28.76 μm) compared to other groups. A post hoc Tukey's test for multiple comparisons between the experimental groups showed a statistically significant difference (p<0.05) between the group CM and group CD with group ZZ. The rest of the groups showed no significant differences between them. Variations in the values were observed for the four sites measured with the highest and the least mean marginal gap value of 43.19±23.84 μm and 32.49±12.21 μm for buccal and lingual sites, respectively. CONCLUSION Variations existed in the marginal discrepancy values for the CAD/CAM systems investigated in the study. Vertical marginal discrepancy values observed for various systems investigated in the study were well within the clinically acceptable range.
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Affiliation(s)
- Syed Rashid Habib
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, King Abdullah Road, Riyadh, 11545, Saudi Arabia
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Habib SR, Ali M, Al Hossan A, Majeed-Saidan A, Al Qahtani M. Effect of cementation, cement type and vent holes on fit of zirconia copings. Saudi Dent J 2019; 31:45-51. [PMID: 30705568 PMCID: PMC6349892 DOI: 10.1016/j.sdentj.2018.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/29/2018] [Accepted: 09/11/2018] [Indexed: 10/28/2022] Open
Abstract
Objectives To investigate the effect of cementation, cement type and vent-holes on the marginal and internal fit of Zirconia (Zr) Copings. Materials and methods Extracted premolars (N = 100) were mounted in resin and prepared for Zr crowns. Samples were randomly divided into 5 groups (n = 20); A: No Cementation; B: Cementation with Glass-Ionomer (GI); C: GI + Vent-Holes; D: Cementation with Resin Cement (RC); E: RC + Vent-Holes. The copings were fabricated using semi sintered Zr Blocks with a standardized cement space of 20 µm. Groups C & E were designed to have 0.5 mm of Vent-Holes on the Buccal and Lingual Cusp Tips. The copings were tried, cemented, thermocycled, re-embedded in resin and cross sectioned into two halves. The copings were examined with 3D-Digital Microscope (HIROX, KH-7700, Tokyo, Japan) at 50-200X. The gaps were recorded at 9 predetermined points. Results The non-cemented groups showed statistically better fit compared to the cemented groups P < 0.05 except vs Group E (RC plus vent holes). No significance was found between the cemented groups P > 0.05. Copings with vent-holes showed statistically better fit than copings without holes P < 0.05. Conclusion Marginal and Internal gap values designed in the software programs differed than the actual values measured for the non-cemented copings. Cementation process also influenced the fit of the Zr copings, the resin cement being the more accurate. The addition of vent-holes on the occlusal surface improved the fit.
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Affiliation(s)
- Syed Rashid Habib
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Saudi Arabia
| | - Mohsin Ali
- Department of Comprehensive Dental Sciences, Case Western University, OH, USA
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Ahmed WM, Abdallah MN, McCullagh AP, Wyatt CCL, Troczynski T, Carvalho RM. Marginal Discrepancies of Monolithic Zirconia Crowns: The Influence of Preparation Designs and Sintering Techniques. J Prosthodont 2019; 28:288-298. [PMID: 30656786 DOI: 10.1111/jopr.13021] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2019] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The marginal fit is an essential component for the clinical success of prosthodontic restorations. The aim of this study was to investigate the influence of different abutment finish line widths and crown thicknesses on the marginal fit of zirconia crowns fabricated using either standard or fast sintering protocols. MATERIALS AND METHODS Six titanium abutments were fabricated for receiving zirconia molar crowns. Crowns were designed virtually and milled from partially sintered zirconia blanks and divided into 12 groups (n = 10/group). Crowns in groups 1 to 6 were sintered by standard sintering, while those in groups 7 to 12 were sintered by fast sintering. Groups were further categorized according to abutment finish line and crown thickness: G1/G7 (0.5 mm chamfer, 0.8 mm thick); G2/G8 (0.5 mm chamfer, 1.5 mm thick); G3/G9 (1.0 mm chamfer, 0.8 mm thick); G4/10 (1.0 mm chamfer, 1.5 mm thick); G5/G11 (1.2 mm chamfer, 0.8 mm thick); G6/G12 (1.2 mm chamfer, 1.5 mm thick). The marginal gaps were assessed at 8 locations using digital microscopy. The linear mixed effect model analysis was performed at a significance level of 0.05. RESULTS All vertical marginal gaps were within the clinically acceptable range (∼11-52 μm). G8 (FS, 0.5 mm chamfer, 1.5 mm thick) demonstrated the largest gaps (47.95 μm, 95% CI: 44.57-51.23), whereas G3 (SS, 1.0 mm chamfer, 0.8 thick) had the smallest marginal gap (14.43 μm, 95% CI: 11.15-17.71). A linear mixed effect models showed significant differences for the interaction between finish line × crown thickness × sintering (F = 18.96, p < 0.001). The lingual surfaces showed the largest gaps in both sintering protocols, while the mesial and mesiobuccal surfaces demonstrated the smallest gaps. CONCLUSIONS There was a significant interaction between finish line widths, crown thickness, and sintering protocol on the marginal gaps in both sintering protocols; 1.0 mm finish line preparations with either 0.8 mm or 1.5 mm occlusal reduction had better marginal fit in both sintering protocols compared to 0.5 mm or 1.2 mm finish lines. Smaller marginal discrepancies were observed for standard sintering crowns with a 0.5 mm finish line and 1.5 mm occlusal reduction. Conservative occlusal reduction should be accompanied with a 1.2 mm finish line to obtain better marginal fit for full-contoured zirconia crowns.
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Affiliation(s)
- Walaa Magdy Ahmed
- Faculty of Dentistry, The University of British Columbia, Vancouver, BC, Canada.,Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Anthony P McCullagh
- Faculty of Dentistry, The University of British Columbia, Vancouver, BC, Canada
| | - Chris C L Wyatt
- Faculty of Dentistry, The University of British Columbia, Vancouver, BC, Canada
| | - Tom Troczynski
- Faculty of Applied Science, The University of British Columbia, Vancouver, BC, Canada
| | - Ricardo M Carvalho
- Faculty of Dentistry, The University of British Columbia, Vancouver, BC, Canada
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Sadid-Zadeh R, Li R, Patel R, Makowka S, Miller LM. Impact of Occlusal Intercuspal Angulation on the Quality of CAD/CAM Lithium Disilicate Crowns. J Prosthodont 2019; 29:219-225. [PMID: 30636017 DOI: 10.1111/jopr.13016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2019] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Modification of intercuspal angulation (ICA) influences the amount of tooth structure removal, which may impact the retention and resistance form of the preparation. This study evaluated the impact of ICA on the marginal gap of CAD/CAM crowns and the influence that tooth structure removal, caused by variation of ICA, has on the resistance and retention form of the preparation. MATERIALS AND METHODS Sixty ivorine molars were manufactured with various ICAs (100°, 110°, 120°, 140°, 160°, and 180°; 10 per group). The preparations were digitized using an intraoral scanner, and the crowns were designed using a design software. The designed crowns were then manufactured from lithium disilicate using a 3-axis milling machine, with the "detailed mode" selected for the manufacturing. The marginal gap of each crown was evaluated using a stereomicroscope at 20× magnification. Then, the marginal integrity and the resistance form of the preparation were assessed by tactile-visual evaluation, and they were given a categorical score. Crowns were then secured on their associated preparations using a temporary luting agent, and retention force was measured on a universal testing machine under tension with a 0.5 mm/min crosshead speed. Wilcoxon test followed by post-hoc tests (α = 0.05) were used to evaluate the impact of the ICA on the marginal gap and the retention form of the preparation. Fisher's exact test followed by post-hoc tests (α = 0.05) were used to assess the impact of the occlusal preparation design on the marginal integrity and the resistance form of the preparation. RESULTS The marginal gap was significantly larger for ICA-180 preparations (72 μm), compared to the other groups (ICA-180 vs ICA-100, ICA-110, ICA-120, and ICA-160 p = 0.0001; ICA-180 vs. ICA-140 p = 0.0017). None of the crowns for ICA-180 preparations had clinically acceptable resistance form. Preparations with ICAs of 100°, 110°, and 120° had a significantly higher value of retention than the other groups (ICA-100 vs. ICA-120 p = 0.0119; ICA-100 vs. ICA-140, ICA-160, and ICA-180 p < 0.0001; ICA-110 vs. ICA-140, ICA-160, and ICA-180 p = 0.0001; ICA-120 vs. ICA-180 p = 0.0017). CONCLUSIONS Crowns fabricated for preparations with various ICAs had clinically acceptable marginal adaptation. Variation in ICA impacts the loss of tooth structure. This loss of tooth structure may influence the resistance and retention form of the preparation.
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Affiliation(s)
- Ramtin Sadid-Zadeh
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, NY
| | - Rui Li
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, NY
| | - Reena Patel
- University at Buffalo School of Dental Medicine, Buffalo, NY
| | - Steven Makowka
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, NY
| | - Lorin M Miller
- Department of Biostatistics, The State University of New York, University at Buffalo, Buffalo, NY
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15
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Al-Haj Ali S. In vitro comparison of marginal and internal fit between stainless steel crowns and esthetic crowns of primary molars using different luting cements. Dent Res J (Isfahan) 2019. [DOI: 10.4103/1735-3327.270783] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Micro-CT Analysis of Y-TZP Copings Made by Different CAD/CAM Systems: Marginal and Internal Fit. Int J Dent 2018; 2018:5189767. [PMID: 30254675 PMCID: PMC6145157 DOI: 10.1155/2018/5189767] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/05/2018] [Accepted: 08/01/2018] [Indexed: 11/17/2022] Open
Abstract
Purpose The aim of the study was to measure the marginal and internal adaptation (MIA) of zirconia copings, made of 4 ceramic systems for CAD/CAM, using microcomputed tomography (micro-CT) technology. Material and Methods Two identical stainless steel models were used, representing a preparation for full ceramic crown on a lower molar. The master models were then scanned for the production of copings from specific yttrium oxide partially stabilized tetragonal zirconia polycrystal ceramic blocks of each system (n=10): Cerec/inCoris Zi, Sirona; Cercon/Cercon base, Dentsply; Ceramill/Ceramill Zi, Amann Girrbach; and Lava/Lava Frame Zirconia, 3M ESPE. MIA was evaluated measuring 4 points as follows: marginal gap (MG), axial wall gap (AW), axio-occlusal angle gap (AO), and central occlusal area gap (CO). The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05). Results The ceramic system Lava showed greater internal desadaptation (80.75 ± 22.69 µm) while CEREC presented the lowest values (49.92 ± 11.77 µm). There were significant differences between the measurement points evaluated. CO demonstrated the greater values (77.03 ± 22.61 µm). All marginal and internal adaptation values were considered clinically acceptable. Conclusion It was concluded that there was an influence of the type of ceramic system in marginal and internal adaptation of copings in zirconia.
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Sadid-Zadeh R, Farsaii A, Goodarzi A, Davis EL. Loss of tooth structure associated with preparation for two monolithic CAD-CAM complete coverage restorations. J Prosthet Dent 2018; 120:403-408. [PMID: 29724561 DOI: 10.1016/j.prosdent.2017.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/10/2017] [Accepted: 12/12/2017] [Indexed: 10/17/2022]
Abstract
STATEMENT OF PROBLEM Different techniques are used to fabricate complete coverage restorations. Each fabrication technique requires a specific preparation design that may violate a principle of tooth preparation, that is, conservation of tooth structure. PURPOSE The purpose of this in vitro study was to compare the volume of loss of mandibular first molar structure associated with a preparation for computer-aided design and computer-aided manufacturing (CAD-CAM) versus conventionally fabricated complete coverage restorations. MATERIALS AND METHODS Fifty artificial mandibular right first molars were weighed before and after preparation for complete coverage restorations of the following types: complete cast, monolithic zirconia, monolithic pressed lithium disilicate, monolithic milled lithium disilicate, and metal-ceramic crowns (n=10 per method). Tooth mass loss was measured by subtracting the mass after preparation from the mass before the preparation, and tooth volume loss was calculated by dividing the mass by the density of the material. A robust analysis of variance (ANOVA), followed by a post hoc test, was used to compare the volume of tooth loss (α=.01). RESULTS Mean tooth volume losses were 255.6 mm3, 270.0 mm3, 312.7 mm3, 331.7 mm3, and 309.9 mm3 for complete cast, monolithic zirconia, monolithic pressed lithium disilicate, monolithic milled lithium disilicate, and metal-ceramic crowns, respectively. Teeth prepared for monolithic CAD-CAM zirconia and lithium disilicate crowns did not exhibit a significantly lower (P>.01) decrease in volume loss than with complete cast and monolithic pressed lithium crowns. CONCLUSIONS Preparation of teeth for monolithic CAD-CAM complete coverage restorations is not associated with a significantly higher volume of tooth loss than their conventionally fabricated counterpart preparations.
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Affiliation(s)
- Ramtin Sadid-Zadeh
- Assistant Professor, Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, NY.
| | - Adrian Farsaii
- Predoctoral student, University at Buffalo School of Dental Medicine, Buffalo, NY
| | - Athena Goodarzi
- Resident, Department of General Dentistry, Harlem Hospital Center, New York, NY
| | - Elaine L Davis
- Professor, Department of Oral Diagnostic Sciences, University at Buffalo School of Dental Medicine, Buffalo, NY
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Habib SR, Al Ajmi MG, Al Dhafyan M, Jomah A, Abualsaud H, Almashali M. Effect of Margin Designs on the Marginal Adaptation of Zirconia Copings. Acta Stomatol Croat 2017; 51:179-187. [PMID: 29225358 PMCID: PMC5708331 DOI: 10.15644/asc51/3/1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Objective The aim of this in vitro study was to investigate the effect of Shoulder versus Chamfer margin design on the marginal adaptation of zirconia (Zr) copings. Materials and Methods 40 extracted molar teeth were mounted in resin and prepared for zirconia crowns with two margin preparation designs (20=Shoulder and 20=Chamfer). The copings were manufactured by Cercon® (DeguDent GmbH, Germany) using the CAD/CAM system for each tooth. They were tried on each tooth, cemented, thermocycled, re-embedded in resin and were subsequently cross sectioned centrally into two equal mesial and distal halves. They were examined under electron microscope at 200 X magnification and the measurements were recorded at 5 predetermined points in micrometers (µm). Results The overall mean marginal gap for the two groups was found to be 206.98+42.78µm with Shoulder margin design (Marginal Gap=199.50+40.72µm) having better adaptation compared to Chamfer (Marginal Gap=214.46+44.85µm). The independent-samples t-test showed a statistically non-significant difference (p=.113) between the means of marginal gap for Shoulder and Chamfer margin designs and the measurements were recorded at 5 predetermined points for the two groups. Conclusions The Chamfer margin design appeared to offer the same adaptation results as the Shoulder margin design.
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Miura S, Kasahara S, Yamauchi S, Okuyama Y, Izumida A, Aida J, Egusa H. Clinical evaluation of zirconia-based all-ceramic single crowns: an up to 12-year retrospective cohort study. Clin Oral Investig 2017; 22:697-706. [DOI: 10.1007/s00784-017-2142-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/29/2017] [Indexed: 12/21/2022]
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Accuracy of Digital Impressions and Fitness of Single Crowns Based on Digital Impressions. MATERIALS 2015; 8:3945-3957. [PMID: 28793417 PMCID: PMC5455646 DOI: 10.3390/ma8073945] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/23/2015] [Accepted: 06/19/2015] [Indexed: 11/17/2022]
Abstract
In this study, the accuracy (precision and trueness) of digital impressions and the fitness of single crowns manufactured based on digital impressions were evaluated. #14-17 epoxy resin dentitions were made, while full-crown preparations of extracted natural teeth were embedded at #16. (1) To assess precision, deviations among repeated scan models made by intraoral scanner TRIOS and MHT and model scanner D700 and inEos were calculated through best-fit algorithm and three-dimensional (3D) comparison. Root mean square (RMS) and color-coded difference images were offered. (2) To assess trueness, micro computed tomography (micro-CT) was used to get the reference model (REF). Deviations between REF and repeated scan models (from (1)) were calculated. (3) To assess fitness, single crowns were manufactured based on TRIOS, MHT, D700 and inEos scan models. The adhesive gaps were evaluated under stereomicroscope after cross-sectioned. Digital impressions showed lower precision and better trueness. Except for MHT, the means of RMS for precision were lower than 10 μm. Digital impressions showed better internal fitness. Fitness of single crowns based on digital impressions was up to clinical standard. Digital impressions could be an alternative method for single crowns manufacturing.
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