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AboElhassan RG, Watts DC, Alamoush RA, Elraggal A. Biomechanical behavior and Weibull survival of CAD-CAM endocrowns with different marginal designs: A 3D finite element analysis. Dent Mater 2024; 40:227-235. [PMID: 37977990 DOI: 10.1016/j.dental.2023.11.012] [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: 09/05/2023] [Revised: 11/04/2023] [Accepted: 11/06/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVES To evaluate and compare the effect of tooth preparation designs and different CADCAM. materials on stress distribution and Weibull survival probability of endocrowns. applied to root canal-treated lower first permanent molar using the 3D finite element. analysis method. METHODS A root canal-treated lower first permanent molar was prepared for endocrowns with a. butt joint or with a ferrule design by placing, circumferentially, a 1-mm wide shoulder. finish line. The prepared molar was scanned for the two designs and modeled on a 3D. Finite element model. Monolithic zirconia (IPS e.max ZirCAD MT, FCZ), lithium. disilicate (IPS e.max CAD, EX), and nano-ceramic resin composite (Lava Ultimate, LU). CAD-CAM materials were used for each preparation to design the virtual endocrown. A. total of six models were built according to the different tooth preparation designs and. endocrown materials. An occlusal load of 600 N and a transverse load of 20 N in. magnitude that simulates the average occlusal load was directed toward the occlusal. surfaces. von Mises and maximum principle values were evaluated Weibull risk-ofrupture. analysis was used to analyze the survival probability of the restorations and. tooth in the different models. RESULTS The highest von Mises were found in the butt joint design for FCZ, EX, and LU (45.3. MPa, 35.2 MPa, and 24.2 MPa, respectively) compared to the ferrule design for the. same materials (42.6 MPa, 31.2 MPa, and 23.6 MPa, respectively). For von Mises. stress distribution in the remaining part of tooth structure (dentin), the highest stresses. were found in LUFerrule which was closely similar to LUButt joint (135.4 MPa and. 134.7 MPa, respectively), followed by EXFerrule and FCZFerrule (132.2 MPa and. 131.7 MPa, respectively), while the lowest stresses were found in EXButt joint and. FCZButt joint (129.0 MPa and 128.4 MPa, respectively). Shear stresses within the. resin cement were the highest in FCZ and EX compared to LU. EX was found to be the. most reliable material with the highest survival probability, while FCZ showed the. lowest survival probability according to the Weibull risk-of-fracture results. SIGNIFICANCE Materials with high elastic modulus transfer more stresses to the endocrown and less. to the remaining tooth structure. Endocrown tooth preparation with ferrule design has. better stress distribution and magnitude compared to the butt joint design.
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Affiliation(s)
- Rewaa G AboElhassan
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - David C Watts
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - Rasha A Alamoush
- Department of Fixed and Removable Prosthodontics, School of Dentistry, the University of Jordan, Amman, Jordan
| | - Alaaeldin Elraggal
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt; Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
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Afshar K, Falahchai M, Ansarilari H, Tajziehchi G. Effect of CAD-CAM Framework Design Fabricated from Sintered Cobalt-Chromium Alloy on Fracture Resistance of Metal-Ceramic Restorations. Int J Dent 2023; 2023:3788590. [PMID: 39139497 PMCID: PMC11321897 DOI: 10.1155/2023/3788590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/29/2023] [Accepted: 04/27/2023] [Indexed: 08/15/2024] Open
Abstract
Introduction Porcelain fracture is a common problem of metal-ceramic restorations (MCRs). One suggested strategy to prevent it is to modify the metal framework design; however, the available information regarding the effect of framework design on porcelain fracture is scarce. Objective This study aimed to assess the effect of computer-aided design and computer-aided manufacturing (CAD-CAM) framework design fabricated from sintered cobalt-chromium (Co-Cr) alloy on fracture resistance of MCRs. Materials and Methods Twenty premolar metal dies were fabricated for this in vitro study. Ten standard frameworks were designed with 0.5 mm thickness, and 10 customized frameworks were designed with 1 mm thickness at the lingual margin and 0.5 mm thickness in all other areas. All specimens were fabricated from sintered Co-Cr alloy (Ceramill Sintron) using soft metal milling technology. After porcelain application, the specimens underwent thermocycling and cyclic loading for 3,000 cycles between 5 and 55°C. The fracture resistance was measured by a universal testing machine. The failure mode was also determined. Data were statistically analyzed by independent t-test (α = 0.05). Results The mean fracture resistance of porcelain was 2,379 ± 531 N in the standard and 2,557 ± 448 N in the customized group. No significant difference was found in fracture resistance of the two groups (P > 0.05). All specimens in both groups showed mixed failure. Conclusion The fracture resistance of porcelain and the failure mode were not affected by the framework design of MCRs fabricated from sintered Co-Cr alloy (Ceramill Sintron).
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Affiliation(s)
- Kourosh Afshar
- Department of Prosthodontics, Islamic Azad University Dental Branch, Tehran, Iran
| | - Mehran Falahchai
- Dental Sciences Research Center, Department of Prosthodontics, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
| | - Homeira Ansarilari
- Department of Prosthodontics, Islamic Azad University Dental Branch, Tehran, Iran
| | - Gelareh Tajziehchi
- Department of Restorative Dentistry, School of Dentistry, Guilan University of Medical Sciences, Rasht, Iran
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Nawafleh N, Elshiyab S, Öchsner A, George R. In Vitro Fatigue and Fracture Load of Monolithic Ceramic Crowns Supported by Hybrid Abutment. Open Dent J 2021. [DOI: 10.2174/1874210602115010664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Objective:
This study evaluated the performance of zirconia and lithium disilicate crowns supported by implants or cemented to epoxy resin dies.
Methods:
Eigthy zirconia and lithium disilicate crowns each were prepared and assigned in four groups according to the crown material and supporting structure combinations (implant-supported zirconia, die-supported zirconia, implant-supported lithium disilicate, and die-supported lithium disilicate). Ten crowns in each group acted as control while the rest (n=10) underwent thermocycling and fatigue with 100 N loading force for 1.5 million cycles. Specimens were then loaded to fracture in a universal testing machine. Data were analysed using one-way ANOVA and Tukey multiple comparison test with a 95% level of significance.
Results:
No implants or crown failure occurred during fatigue. The mean fracture load values (control, fatigued) in newton were as follows: (4054, 3344) for implant-supported zirconia, (3783, 3477) for die-supported zirconia, (2506, 2207) for implant-supported lithium disilicate, and (2159, 1806) for die-supported lithium disilicate. Comparing the control with the corresponding fatigued subgroup showed a significantly higher fracture load mean of the control group in all cases. Zirconia showed a significantly higher fracture load mean than lithium disilicate (P=0.001, P<0.001). However, comparing crowns made from the same material according to the supporting structure showed no significant difference (P=0.923, P=0.337).
Conclusion:
Zirconia and lithium disilicate posterior crowns have adequate fatigue and fracture resistance required for posterior crowns. However, when heavy fatigue forces are expected, zirconia material is preferable over lithium disilicate. Zirconia and lithium disilicate implant-supported crowns cemented to hybrid abutments should have satisfactory clinical performance.
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Tekin YH, Hayran Y. Fracture resistance and marginal fit of the zirconia crowns with varied occlusal thickness. J Adv Prosthodont 2020; 12:283-290. [PMID: 33149849 PMCID: PMC7604235 DOI: 10.4047/jap.2020.12.5.283] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The present study aimed to evaluate the clinical applicability of monolithic zirconia (MZ) crowns of different thickness via determination of fracture resistance and marginal fit. MATERIALS AND METHODS MZ crowns with 0.5, 0.8, 1.0, and 1.5 mm thickness and porcelain fused to metal (PFM) crowns were prepared, ten crowns in each group. Marginal gaps of the crowns were measured. All crowns were aged with thermal cycling (5 - 55℃/10000 cycle) and chewing simulator (50 N/1 Hz/lateral movement: 2 mm, mouth opening: 2 mm/240000 cycles). After aging, fracture resistance of crowns was determined. Statistical analysis was performed with one-way ANOVA and Tukey's HDS post hoc test. RESULTS Fracture loads were higher in the PFM and 1 mm MZ crowns compared to 0.5 mm and 0.8 mm crowns. 1.5 mm MZ crowns were not broken even with the highest force applied (10 kN). All marginal gap values were below 86 µm even in the PFM crowns, and PFM crowns had a higher marginal gap than the MZ crowns. CONCLUSION The monolithic zirconia exhibited high fracture resistance and good marginal fit even with the 0.5 mm thickness, which might be used with reduced occlusal thickness and be beneficial in challengingly narrow interocclusal space.
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Affiliation(s)
- Yadel Hazır Tekin
- Department of Prosthodontic Dentistry, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, Turkey
| | - Yeliz Hayran
- Department of Prosthodontic Dentistry, Faculty of Dentistry, Tokat Gaziosmanpasa University, Tokat, Turkey
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Evaluation of the effects of finish line type and width on the fracture strength of provisional crowns. Odontology 2020; 109:76-81. [PMID: 32537671 DOI: 10.1007/s10266-020-00533-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 06/09/2020] [Indexed: 10/24/2022]
Abstract
This study aimed to investigate the impacts of finish line type and width on the fracture resistance of provisional crowns, and to determine the suitable type of crown material to use for that purpose. Chamfer and rounded shoulder preparations were done with stainless steel master models with a width of 0.6 mm and 1.0 mm and a total convergence angle of 6°. The provisional crowns were obtained using computer-aided design/computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA) material in the mandibular left first molar. From the obtained molar tooth, a silicon mold was used to obtain the provisional crowns from the CAD/CAM PMMA, bis-acrylic resin, and self-curing composite materials. The lowest fracture strength was found in the bis-acrylic resin group made using the rounded shoulder preparation with a width of 0.6 mm (699 N). The highest fracture strength was found in the CAD/CAM PMMA group made using the rounded shoulder preparation with a width of 1 mm (1339 N). The fracture strength is higher for CAD/CAM PMMA than the other provisional crown materials; thus, it is recommended that this material be used in provisional crown restorations due to its other advantages.
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Santos M, Coelho AS, Paula AB, Marto CM, Amaro I, Saraiva J, Marques Ferreira M, Antunes P, Carrilho E. Mechanical and Tribological Characterization of a Dental Ceromer. J Funct Biomater 2020; 11:jfb11010011. [PMID: 32098165 PMCID: PMC7151637 DOI: 10.3390/jfb11010011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/16/2020] [Accepted: 02/18/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Indirect restorations using composites with ceramic fillings can be an alternative to ceramic veneering and direct composite restorations for the treatment of posterior teeth. The aim of this study was the evaluation of the mechanical and tribological properties of a ceromer. MATERIALS AND METHODS Sixty specimens were produced and divided into two groups: one control group not submitted to thermocycling (n = 20) and one test group submitted to 5000 cycles of thermocycling (n = 40). The studied parameters were microhardness, surface roughness and the coefficient of friction (scratch test). RESULTS The ceromer exhibits a reduction of polymerization shrinkage, higher wear, and fracture resistance than the composite resins. The studied ceromer presented good mechanical properties, even after being submitted to thermocycling. Roughness was the property most affected, increasing 25.8%, microhardness decreased by 10.5% and the coefficient of friction increased by 4.2%. CONCLUSIONS In certain situations, ceromers can be an alternative to composite resins and ceramics, providing an aesthetic, conservative and longevity option.
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Affiliation(s)
- Mariana Santos
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
- Correspondence: ; Tel.: +351-934262687
| | - Ana Sofia Coelho
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
- Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal;
- CNC.IBILI Consortium, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Anabela Baptista Paula
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
- Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal;
- CNC.IBILI Consortium, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
| | - Carlos Miguel Marto
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
- Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal;
- CNC.IBILI Consortium, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute of Experimental Pathology, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Inês Amaro
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
| | - José Saraiva
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
| | - Manuel Marques Ferreira
- Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal;
- CNC.IBILI Consortium, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute of Endodontics, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal
| | - Pedro Antunes
- Department of Mechanical Engineering, Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), University of Coimbra, 3030-788 Coimbra, Portugal;
- Itecons—Institute of Research and Technological Development in Construction, Energy, Environment and Sustainability, Rua Pedro Hispano, 3030-289 Coimbra, Portugal
| | - Eunice Carrilho
- Institute of Integrated Clinical Practice, Faculty of Medicine, University of Coimbra, 3000-075 Coimbra, Portugal; (A.S.C.); (A.B.P.); (C.M.M.); (I.A.); (J.S.); (E.C.)
- Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal;
- CNC.IBILI Consortium, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
- Centre for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
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Kashkari A, Yilmaz B, Brantley WA, Schricker SR, Johnston WM. Fracture analysis of monolithic CAD‐CAM crowns. J ESTHET RESTOR DENT 2019; 31:346-352. [DOI: 10.1111/jerd.12462] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 01/19/2019] [Accepted: 02/13/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Afnan Kashkari
- Restorative and Esthetic DentistryJohns Hopkins Aramco Healthcare Dhahran Saudi Arabia
| | - Burak Yilmaz
- Division of Restorative and Prosthetic DentistryThe Ohio State University, College of Dentistry Columbus Ohio
| | - William A. Brantley
- College of Dentistry, Division of Restorative and Prosthetic DentistryThe Ohio State University Columbus Ohio
| | - Scott R. Schricker
- College of Dentistry, Division of Restorative and Prosthetic DentistryThe Ohio State University Columbus Ohio
| | - William M. Johnston
- College of Dentistry, Division of Restorative and Prosthetic DentistryThe Ohio State University Columbus Ohio
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Taha D, Spintzyk S, Sabet A, Wahsh M, Salah T. Assessment of marginal adaptation and fracture resistance of endocrown restorations utilizing different machinable blocks subjected to thermomechanical aging. J ESTHET RESTOR DENT 2018; 30:319-328. [PMID: 30113129 DOI: 10.1111/jerd.12396] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/22/2018] [Accepted: 05/13/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This in vitro study was conducted to assess the marginal adaptation and fracture resistance of computer aided design/computer aided manufacturer (CAD-CAM) fabricated endocrowns restoring endodontically treated molars using different machinable blocks with thermomechanical loading protocols. MATERIALS AND METHODS Devitalized mandibular molars were prepared in a standardized way and divided into 4 groups (n = 10) to receive CAD/CAM fabricated endocrowns using four materials (Lithium disilicate ceramics, polymer infiltrated ceramics, zirconia-reinforced lithium silicate ceramics and resin nanoceramics. Marginal gaps (µm) were measured using stereomicroscope before cementation and after cementation. After thermomechanical aging, marginal gap measurements were repeated, and then fracture resistance test was performed. Two-way analysis of variance (ANOVA) and Tukey HSD multiple comparisons were used to assess the effect of material on the marginal gap before, after cementation, and after thermomechanical aging. One Way ANOVA was used to assess the effect of material on the fracture resistance. RESULTS The difference between marginal gaps values of the tested materials was statistically insignificant but with significant increase after cementation and after thermomechanical aging. Cerasmart endocrowns showed the highest mean fracture load value (1508.5 ± 421.7N) with statistically significant difference than Vita Enamic endocrowns and Celtra Duo. CONCLUSION The tested materials showed marginal vertical gap readings within the limits of clinically acceptable standards. Resin nanoceramics and lithium disilicate showed the highest values of fracture resistance followed by polymer infiltrated ceramics favoring their use for endocrown restorations. CLINICAL SIGNIFICANCE The mechanical behavior of ceramic materials varies with the variation of their structure and mechanical properties. Accordingly, further investigation is always needed to explore the biomechanical behavior of recent materials when used as endocrowns before clinical trials.
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Affiliation(s)
- Doaa Taha
- Section Medical Materials science & technology, University Hospital Tübingen, Tübingen, Germany.,Department of Fixed Prosthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Sebastian Spintzyk
- Section Medical Materials Science & Technology, University Hospital Tübingen, Germany
| | - Ahmed Sabet
- Department of Fixed Prosthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Marwa Wahsh
- Department of Fixed Prosthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
| | - Tarek Salah
- Department of Fixed Prosthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt
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Jalalian E, Darvish N, Saberi S. Investigating the effect of G-Bond and Z-PRIME Plus on the bond strength between prefabricated zirconia posts and the root canal wall in vitro. J Dent Res Dent Clin Dent Prospects 2018; 12:128-134. [PMID: 30087764 PMCID: PMC6076877 DOI: 10.15171/joddd.2018.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 05/18/2018] [Indexed: 11/17/2022] Open
Abstract
Background. The aim of this study was to analyze the effect of G-Bond and Z-PRIME Plus on the bond strength between prefabricated zirconia posts and the root canal wall.
Methods. The study was carried out on 21 premolar teeth with similar conditions. The samples were cut at the CEJ. After root canal treatment of the roots, the post space was prepared up to a length of 10mm. The samples were randomly assigned to two groups of 10. G-Bond was used in one group and Z-PRIME Plus in the other to prepare the posts’ surfaces. After cementation and mounting the samples in polyester, the post was cut from the apical area into three equal sections. The bond strength of the samples was tested using the push-out test on a universal testing machine. Data wereanalyzed using t-test.
Results. The meanpush-out bond strengths in the control,G-Bond and Z-PRIME Plus groups were 14.3, 27.6±11.8 and 27.4±13.4N, respectively. There was no statistically significant difference between the two groups (P<0.9). Both methods of surface treatment increased bond strength. The bond strengths were different in different sections such as coronal, middle and apical in each group.
Conclusion. There was no significant differencebetween the G-Bond and Z-PRIME Plus groups and both products in-creased the bond strength of prefabricated zirconia posts.
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Affiliation(s)
- Ezzatollah Jalalian
- Department of Fixed Prosthodontics, Member of Dental Materials Research Center, Dental Branch of Islamic Azad University, Tehran, Iran
| | | | - Sogol Saberi
- Dentist, Laser Research Center of Dentistry, Dentistry Research Institute, University of Medical Sciences, Tehran, Iran
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Peroz I, Mitsas T, Erdelt K, Kopsahilis N. Marginal adaptation of lithium disilicate ceramic crowns cemented with three different resin cements. Clin Oral Investig 2018; 23:315-320. [PMID: 29663086 DOI: 10.1007/s00784-018-2438-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/09/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVES The cementation process and cementation materials have an influence on the marginal adaptation of restorations. The gap could be affected by thermal and mechanical loading (TCML). The computerized x-ray microtomography (μCT) method offers the possibility of measuring the marginal gap without destruction of the restoration. The aim of this study was to evaluate the marginal gap (MG) and the absolute marginal discrepancy (AMD) before and after TCML. MATERIALS AND METHODS Thirty-nine human premolars were prepared for full ceramic crowns made of lithium disilicate. The crowns were cemented by three different resins-Panavia F 2.0, Variolink II, and Relyx Unicem. The MG and AMD were evaluated by μCT before and after TCML. RESULTS Panavia F 2.0 had the lowest MG (before 118 μm-after TMCL 124 μm) and AMD (before 145 μm-after TMCL 154 μm), followed by Relyx Unicem (MG: before 164 μm-after TCML 155 μm; AMD: before 213 μm-after TMCL 209 μm) and Variolink II (MG: before 317 μm-after TMCL 320 μm; AMD: before 412 μm-after TMCL 406 μm). The differences were statistically significant before and after TCML. Rather than TCML, it appeared the resin cement was responsible for differences between the MG and AMD before and after TCML. CONCLUSIONS μCT is an accurate technique for assessing cemented restorations. Panavia F 2.0 has the lowest MG and AMD before and after TCML. CLINICAL RELEVANCE The resin material that features a three-step protocol (Variolink II) produced higher MG and AMG values than the Panavia or Relyx Unicem varieties with less or no intermediate steps at all.
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Affiliation(s)
- Ingrid Peroz
- Department of Prosthodontics, Gerodontology and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Aßmannshauserstraße 4-6, 14197, Berlin, Germany.
| | | | - Kurt Erdelt
- Department of Prosthodontics, Dental School of the Ludwig-Maximilians University, Munich, Germany
| | - Niko Kopsahilis
- Department of Prosthodontics, Gerodontology and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, CC3, Berlin, Germany
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Miura S, Kasahara S, Yamauchi S, Egusa H. Effect of finish line design on stress distribution in bilayer and monolithic zirconia crowns: a three-dimensional finite element analysis study. Eur J Oral Sci 2018; 126:159-165. [DOI: 10.1111/eos.12402] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Shoko Miura
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan
| | - Shin Kasahara
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan
| | - Shinobu Yamauchi
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan
| | - Hiroshi Egusa
- Division of Molecular and Regenerative Prosthodontics; Tohoku University Graduate School of Dentistry; Sendai Miyagi Japan
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12
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Choi JW, Kim SY, Bae JH, Bae EB, Huh JB. In vitro study of the fracture resistance of monolithic lithium disilicate, monolithic zirconia, and lithium disilicate pressed on zirconia for three-unit fixed dental prostheses. J Adv Prosthodont 2017; 9:244-251. [PMID: 28874990 PMCID: PMC5582089 DOI: 10.4047/jap.2017.9.4.244] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 02/17/2017] [Accepted: 03/15/2017] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The purpose of this study was to determine fracture resistance and failure modes of three-unit fixed dental prostheses (FDPs) made of lithium disilicate pressed on zirconia (LZ), monolithic lithium disilicate (ML), and monolithic zirconia (MZ). MATERIALS AND METHODS Co-Cr alloy three-unit metal FDPs model with maxillary first premolar and first molar abutments was fabricated. Three different FDPs groups, LZ, ML, and MZ, were prepared (n = 5 per group). The three-unit FDPs designs were identical for all specimens and cemented with resin cement on the prepared metal model. The region of pontic in FDPs was given 50,000 times of cyclic preloading at 2 Hz via dental chewing simulator and received a static load until fracture with universal testing machine fixed at 10°. The fracture resistance and mode of failure were recorded. Statistical analyses were performed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni's correction (α=0.05/3=0.017). RESULTS A significant difference in fracture resistance was found between LZ (4943.87 ± 1243.70 N) and ML (2872.61 ± 658.78 N) groups, as well as between ML and MZ (4948.02 ± 974.51 N) groups (P<.05), but no significant difference was found between LZ and MZ groups (P>.05). With regard to fracture pattern, there were three cases of veneer chipping and two interfacial fractures in LZ group, and complete fracture was observed in all the specimens of ML and MZ groups. CONCLUSION Compared to monolithic lithium disilicate FDPs, monolithic zirconia FDPs and lithium disilicate glass ceramics pressed on zirconia-based FDPs showed superior fracture resistance while they manifested comparable fracture resistances.
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Affiliation(s)
- Jae-Won Choi
- Department of Prosthodontics, Dental Research Institute, Institute of Translation Dental Science, School of Dentistry, Pusan National University, Yangsan, Republic of Korea.,BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - So-Yeun Kim
- Department of Prosthodontics, Pusan National University Hospital, Pusan, Republic of Korea
| | - Ji-Hyeon Bae
- Department of Prosthodontics, Dental Research Institute, Institute of Translation Dental Science, School of Dentistry, Pusan National University, Yangsan, Republic of Korea.,BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Eun-Bin Bae
- Department of Prosthodontics, Dental Research Institute, Institute of Translation Dental Science, School of Dentistry, Pusan National University, Yangsan, Republic of Korea.,BK21 PLUS Project, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
| | - Jung-Bo Huh
- Department of Prosthodontics, Dental Research Institute, Institute of Translation Dental Science, School of Dentistry, Pusan National University, Yangsan, Republic of Korea
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Mohammadzadeh Z, Parisay I, Mehrabkhani M, Madani AS, Mazhari F. Clinical evaluation of fiber-reinforced composite crowns in pulp-treated primary molars: 12-month results. Eur J Dent 2017; 10:522-528. [PMID: 28042269 PMCID: PMC5166310 DOI: 10.4103/1305-7456.195177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Objective: The aim of this study was to evaluate the clinical performance of tooth-colored fiber-reinforced composite (FRC) crowns in pulp-treated second primary mandibular teeth. Materials and Methods: This split-mouth randomized, clinical trial performed on 67 children between 3 and 6 years with two primary mandibular second molars requiring pulp treatment. After pulp therapy, the teeth were randomly assigned to stainless steel crown (SSC) or FRC crown groups. Modified United States Public Health Service criteria were used to evaluate marginal integrity, marginal discoloration, and secondary caries in FRC crowns at intervals of 3, 6, and 12 months. Retention rate and gingival health were also compared between the two groups. The data were analyzed using Friedman, Cochran, and McNemar's tests at a significance level of 0.05. Results: Intact marginal integrity in FRC crowns at 3, 6, and 12 months were 93.2%, 94.8%, and 94.2%, respectively. Marginal discoloration and secondary caries were not found at any of the FRC crowns. The retention rates of the FRC crowns were 100%, 98.3%, and 89.7% at 3, 6 and 12 months, respectively, whereas all the SSCs were found to be present and intact after 12 months (P = 0.016). There was no statistically significant difference between the two groups in gingival health. Conclusion: According to the results of this study, it seems that when esthetics is a concern, in cooperative patients with good oral hygiene, FRC crowns can be considered as a valuable procedure.
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Affiliation(s)
- Zahra Mohammadzadeh
- Dental Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Iman Parisay
- Dental Material Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Maryam Mehrabkhani
- Oral and Maxillofacial Diseases Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Azam Sadat Madani
- Dental Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Mazhari
- Dental Material Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
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Duarte S, Sartori N, Phark JH. Ceramic-Reinforced Polymers: CAD/CAM Hybrid Restorative Materials. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40496-016-0102-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nawafleh N, Hatamleh M, Elshiyab S, Mack F. Lithium Disilicate Restorations Fatigue Testing Parameters: A Systematic Review. J Prosthodont 2015; 25:116-26. [PMID: 26505638 DOI: 10.1111/jopr.12376] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2015] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To review laboratory studies that investigated fatigue resistance of lithium disilicate (LD) crowns and fixed dental prostheses (FDPs) to elucidate study designs and testing parameters. METHODS An electronic search was performed in PubMed, Scopus, and Ovid to identify in vitro studies that investigated fatigue resistance of LD crowns and FDPs. The search included all studies published in English in peer-reviewed journals in the period from 1998 to June 2014. The search followed a specific strategy that included combination of the following keywords: lithium disilicate, e.max, empress, all-ceramic, all ceramic, glass ceramic, fatigue, cyclic loading, dynamic loading, chewing simulator, fracture resistance, thermocycling, laboratory simulation, aging, crown, FDPs, FPDs, fixed partial denture, fixed dental prosthesis, and bridge. Studies were selected if mechanical and thermal loading parameters were clearly identified. Search results with abstracts were transferred into Endnote reference system, and duplicates were deleted. The remaining studies were then reviewed at three levels (title, abstract, full text) to further refine the articles. RESULTS The initial search retrieved 1044 eligible studies. After deduplication, 864 records were examined by titles and then abstracts; 826 were excluded, and 38 were assessed by full-text reading. In total, 19 articles met inclusion criteria and were included in this study. CONCLUSION The studies reviewed showed a level of heterogeneity, as testing parameters were considered through different setups. The current study demonstrated that various setting of the testing parameters and having a lack of testing standardization has likely led to inconsistency in the reported results. The obvious heterogeneity in the setting of testing variables-especially the magnitude of load and number of cycles applied-made it impractical to run direct comparisons between the reviewed studies. Therefore, specific international standardization of fatigue testing of dental restorations is urgently needed to ensure the delivery of consistent, indicative, and comparable data.
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Affiliation(s)
- Noor Nawafleh
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| | - Muhanad Hatamleh
- Cranio-Maxillofacial Prosthetics Unit, King's College Hospital NHS Foundation Trust, London, UK
| | - Shareen Elshiyab
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
| | - Florian Mack
- School of Dentistry and Oral Health, Griffith University, Queensland, Australia
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Vigolo P, Mutinelli S, Biscaro L, Stellini E. An In Vivo Evaluation of the Fit of Zirconium-Oxide Based, Ceramic Single Crowns with Vertical and Horizontal Finish Line Preparations. J Prosthodont 2015; 24:603-9. [DOI: 10.1111/jopr.12340] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Paolo Vigolo
- Department of Clinical Odontostomatology; University of Padova; Padova Italy
| | | | | | - Edoardo Stellini
- Department of Clinical Odontostomatology; University of Padova; Padova Italy
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Gwinner FP, Bottino MA, Nogueira-Junior L, Della Bona A. Effect of finish line on marginal fit of sintered gold copings. Braz Dent J 2013; 24:322-5. [PMID: 24173248 DOI: 10.1590/0103-6440201301575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 02/02/2012] [Indexed: 05/27/2023] Open
Abstract
The aim of this study was to evaluate the vertical marginal gap of sintered gold copings and metal-ceramic crowns with different finish line preparations: a beveled round shoulder (BRS) and a beveled long chamfer (BLC), testing the null hypotheses that there are no differences in marginal gap regardless of finish line and phase of restoration (coping or crown). Stainless steel master models were fabricated to simulate tooth preparation for metal-ceramic crowns with different finish lines (BRS and BLC). Ten dies were obtained from each model. Preparations were coated with 2 layers of spacer to 1 mm from the margin. Sintercast gold copings were prepared, sintered and adjusted to the dies. The copings (n=10) were placed onto the master model and the marginal gap was measured in 24 equidistant points using optical microscopy (X230). An opaque and two body ceramic layers were subsequently applied to the copings and the same measuring procedure was performed for the crowns. The data were analyzed statistically using paired and unpaired Student's t-test (α=0.05). Mean marginal gap values (µm) for the copings and crowns were, respectively: 113.6 and 117.1 for the BRS; and 58.2 and 74.3 for the BLC preparation. Significantly greater marginal gaps (p=0.0307) were found for restorations with BRS than with BLC finish line, which also showed statistically significant differences in the gap size between coping and crown (p=0.001). In conclusion, marginal gap is influenced by ceramic application on copings fabricated on BLC preparation, and greater marginal gaps were found for restorations with BRS finish line, rejecting the experimental null hypotheses.
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Affiliation(s)
- Fernanda Pelogia Gwinner
- Department of Biomaterials and Biomechanics, Oregon Health and Science University, PortlandOregon, USA
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Corazza PH, Feitosa SA, Borges ALS, Della Bona A. Influence of convergence angle of tooth preparation on the fracture resistance of Y-TZP-based all-ceramic restorations. Dent Mater 2013; 29:339-47. [DOI: 10.1016/j.dental.2012.12.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 11/12/2012] [Accepted: 12/29/2012] [Indexed: 11/28/2022]
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Nawafleh NA, Mack F, Evans J, Mackay J, Hatamleh MM. Accuracy and Reliability of Methods to Measure Marginal Adaptation of Crowns and FDPs: A Literature Review. J Prosthodont 2013; 22:419-28. [DOI: 10.1111/jopr.12006] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- Noor A. Nawafleh
- Griffith University, School of Dentistry and Oral Health; Gold Coast Australia
- Jordan University of Science and Technology; Faculty of Applied Medical Science; Irbid Jordan
| | - Florian Mack
- Griffith University, School of Dentistry and Oral Health; Gold Coast Australia
| | - Jane Evans
- Griffith University, School of Dentistry and Oral Health; Gold Coast Australia
| | - John Mackay
- Griffith University, School of Dentistry and Oral Health; Gold Coast Australia
| | - Muhanad M. Hatamleh
- University of Manchester, School of Dentistry; Manchester UK
- Jordan University of Science and Technology; Faculty of Applied Medical Science; Irbid Jordan
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Biscaro L, Bonfiglioli R, Soattin M, Vigolo P. An in vivo evaluation of fit of zirconium-oxide based ceramic single crowns, generated with two CAD/CAM systems, in comparison to metal ceramic single crowns. J Prosthodont 2012; 22:36-41. [PMID: 22946875 DOI: 10.1111/j.1532-849x.2012.00907.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PURPOSE The purpose of this study was to assess in vivo the marginal fit of single crowns produced using two CAD/CAM all-ceramic systems, in comparison to more traditional metal ceramic crowns. MATERIALS AND METHODS Thirty vital, caries-free, and previously untreated teeth were chosen in five patients who needed extraction for implant placement and therefore were included in this study. In the control group (C), 10 regular metal ceramic crowns with porcelain occlusal surfaces were fabricated. In the other two groups (Z and E), CAD/CAM technology was used for the fabrication of 20 zirconium-oxide-based ceramic single crowns with two systems. All zirconia crowns were cemented with glass-ionomer cement, always following the manufacturer's instructions. The same dentist carried out all clinical phases. The teeth were extracted 1 month later. Marginal gaps along vertical planes were measured for each crown, using a total of four landmarks for each tooth by means of a microscope at a magnification of 50×. On completion of microscopic evaluation, representative specimens from each group were prepared for ESEM evaluation. Mean and standard deviations of the four landmarks (mesial, distal, buccal, palatal) at each single crown were calculated for each group. Multivariate analysis of variance (MANOVA) was performed to determine whether the four landmarks, taken into consideration together, differed between groups. Two-way ANOVA was performed to study in detail, for each landmark, how the three systems used to produce the FPDs affected the gap measurements. Differences were considered to be significant at p < 0.05. RESULTS MANOVA revealed no quantitative differences of the four landmarks, when taken into consideration together, between the three groups (p < 0.0001). Two-way ANOVA, performed at each landmark, revealed no quantitative differences between the three groups (p < 0.0001 for each landmark). CONCLUSIONS Within the limitations of this study, it was concluded that the two zirconium-oxide-based ceramic CAD/CAM systems demonstrated a similar and acceptable marginal fit when compared to more traditional metal ceramic crowns.
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Affiliation(s)
- Leonello Biscaro
- Department of Clinical Odontostomatology, University of Padova, Institute of Clinical Dentistry, Padova, Italy
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Saridag S, Ozyesil AG, Pekkan G. Fracture strength and bending of all-ceramic and fiber-reinforced composites in inlay-retained fixed partial dentures. J Dent Sci 2012. [DOI: 10.1016/j.jds.2012.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Angerame D, Sorrentino R, Cettolin D, Zarone F. The effects of scaling and root planing on the marginal gap and microleakage of indirect composite crowns prepared with different finish lines: an in vitro study. Oper Dent 2012; 37:650-9. [PMID: 22616926 DOI: 10.2341/11-347-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The present in vitro study aimed to assess the effects of root surface mechanical instrumentation on the marginal integrity and adaptation of resin composite crowns. The following null hypotheses were tested: no differences exist between finish line and 1) marginal gap or 2) marginal microleakage before and after manual mechanical periodontal maintenance. A total of 56 intact human mandibular molars were randomly distributed into four groups and subjected to standardized tooth preparations for indirect composite crowns with different marginal finish lines (90° shoulder, beveled 90° shoulder, feather edge, chamfer). One-half of the specimens was used as a control and remained untreated, and the remaining half was subjected to root surface procedures simulating five years of semestral mechanical supportive periodontal treatment. The marginal gap and microleakage were evaluated and statistically analyzed. The specimens used as controls showed lower mean marginal gaps than those subjected to the simulated periodontal treatment, whereas the latter showed lower microleakage than the control crowns. Statistically significant differences were recorded for both the experimental variables. The root surface procedures resulted in altered surfaces of the composite crowns. The marginal gap increased after the treatment, whereas the marginal microleakage was reduced. The 90° shoulder and the chamfer preparation could be considered a viable option to fabricate composite crowns, but the beveled 90° shoulder and the feather edge should not be recommended.
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Affiliation(s)
- D Angerame
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
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Kara HB, Aykent F, Ozturk B. The Effect of Bleaching Agents on the Color Stability of Ceromer and Porcelain Restorative Materials In Vitro. Oper Dent 2012; 38:E1-8. [DOI: 10.2341/11-436-l] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Purpose
The aim of this in vitro study was to determine the color changes of five different restorative materials after exposing these materials to two different home bleaching agents.
Methods
This study applied bleaching agents to an ultralow-fusing porcelain, a low-fusing porcelain, two types of heat-pressed glass ceramics, and a ceromer. A total of 24 disc-shaped specimens were fabricated (with a diameter of 10 mm and a thickness of 2 mm) from each material (n=12). The initial color measurements were taken with a spectrophotometer. The first set of specimens were bleached with 10% hydrogen peroxide (HP) for one hour daily for 10 days. The other set of specimens were bleached with 10% carbamide peroxide (CP) bleaching gel for eight hours daily for 14 days. Data were analyzed with the one-way analysis of variance and Kruskal-Wallis statistical test. The difference in the prebleaching and postbleaching color of each material was considered to be statistically significant at p < 0.05.
Results
The study found a statistically significant difference among the color changes of the test groups after exposing them to both bleaching agents (p<0.05). Appreciable color change was observed in the Estenia (ΔE=3.99) specimens that were bleached with the HP, and noticeable color changes were observed in the Estenia (ΔE=1.89) and IPS Empress 2 (ΔE=1.66) groups when they were treated with the CP.
Conclusions
Restorations (especially polymer-containing restorative materials) should be protected before any bleaching procedure due to the high risk of color change.
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Affiliation(s)
- HB Kara
- Haluk Baris Kara, Faculty of Dentistry, Medipol University, Istanbul, Turkey
| | - F Aykent
- Filiz Aykent, Faculty of Dentistry, Selcuk University, Konya, Turkey
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Alghazzawi TF, Liu PR, Essig ME. The Effect of Different Fabrication Steps on the Marginal Adaptation of Two Types of Glass-Infiltrated Ceramic Crown Copings Fabricated by CAD/CAM Technology. J Prosthodont 2012; 21:167-72. [DOI: 10.1111/j.1532-849x.2011.00803.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Yucel MT, Yondem I, Aykent F, Eraslan O. Influence of the supporting die structures on the fracture strength of all-ceramic materials. Clin Oral Investig 2011; 16:1105-10. [PMID: 21845404 DOI: 10.1007/s00784-011-0606-z] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 08/05/2011] [Indexed: 11/24/2022]
Abstract
This study investigated the influence of the elastic modulus of supporting dies on the fracture strengths of all-ceramic materials used in dental crowns. Four different types of supporting die materials (dentin, epoxy resin, brass, and stainless steel) (24 per group) were prepared using a milling machine to simulate a mandibular molar all-ceramic core preparation. A total number of 96 zirconia cores were fabricated using a CAD/CAM system. The specimens were divided into two groups. In the first group, cores were cemented to substructures using a dual-cure resin cement. In the second group, cores were not cemented to the supporting dies. The specimens were loaded using a universal testing machine at a crosshead speed of 0.5 mm/min until fracture occurred. Data were statistically analyzed using two-way analysis of variance and Tukey HSD tests (α = 0.05). The geometric models of cores and supporting die materials were developed using finite element method to obtain the stress distribution of the forces. Cemented groups showed statistically higher fracture strength values than non-cemented groups. While ceramic cores on stainless steel dies showed the highest fracture strength values, ceramic cores on dentin dies showed the lowest fracture strength values among the groups. The elastic modulus of the supporting die structure is a significant factor in determining the fracture resistance of all-ceramic crowns. Using supporting die structures that have a low elastic modulus may be suitable for fracture strength tests, in order to accurately reflect clinical conditions.
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Affiliation(s)
- Munir Tolga Yucel
- Department of Prosthodontics, Faculty of Dentistry, University of Selcuk, 42079 Kampus Konya, Turkey.
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Maghrabi AA, Ayad MF, Garcia-Godoy F. Relationship of Margin Design for Fiber-Reinforced Composite Crowns to Compressive Fracture Resistance. J Prosthodont 2011; 20:355-60. [DOI: 10.1111/j.1532-849x.2011.00713.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Vigolo P, Fonzi F. An In Vitro Evaluation of Fit of Zirconium-Oxide-Based Ceramic Four-Unit Fixed Partial Dentures, Generated with Three Different CAD/CAM Systems, before and after Porcelain Firing Cycles and after Glaze Cycles. J Prosthodont 2008; 17:621-6. [DOI: 10.1111/j.1532-849x.2008.00366.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Ohlmann B, Gruber R, Eickemeyer G, Rammelsberg P. Optimizing preparation design for metal-free composite resin crowns. J Prosthet Dent 2008; 100:211-9. [DOI: 10.1016/s0022-3913(08)60180-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Soares CJ, Fonseca RB, Gomide HA, Correr-Sobrinho L. Cavity preparation machine for the standardization of in vitro preparations. Braz Oral Res 2008; 22:281-7. [DOI: 10.1590/s1806-83242008000300016] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Accepted: 05/03/2007] [Indexed: 11/22/2022] Open
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Fonseca RB, Fernandes-Neto AJ, Correr-Sobrinho L, Soares CJ. The influence of cavity preparation design on fracture strength and mode of fracture of laboratory-processed composite resin restorations. J Prosthet Dent 2007; 98:277-84. [PMID: 17936127 DOI: 10.1016/s0022-3913(07)60101-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
STATEMENT OF PROBLEM Removal of large amounts of sound tooth structure may result in a weakened restored tooth. Nevertheless, removal of tooth structure for cuspal coverage has been recommended to protect teeth restored with laboratory-processed composite resin (LPCR) from fracture. PURPOSE The purpose of this study was to evaluate the influence of different cavity preparation designs on fracture strength and modes of fracture of teeth restored with LPCR. MATERIAL AND METHODS Ninety anatomically similar human third mandibular molars were selected. There were 2 experimental factors, occlusal isthmus width (narrow versus wide) and cuspal coverage (inlay, 1-cusp onlay, 2-cusp onlay, and all-cusp onlay), and 1 control group that received no treatment, resulting in 9 groups (n=10). Indirect composite resin (SR Adoro) restorations were manufactured and adhesively cemented with Adper Single Bond 2 and Rely-X ARC. A compressive loading test (0.5 mm/min) was performed. The modes of fracture were classified according to 4 categories. One-way and 2-way ANOVA followed by Tukey-HSD test were used to statistically analyze the fracture load data (alpha =.05). RESULTS The statistical analysis failed to show significant differences among restored groups but showed differences between these groups and the control group (P = .001). Two-way ANOVA failed to show any difference when considering the occlusal isthmus width alone (P = .98), cuspal coverage (P = .273), or the interaction between these factors (P = .972). Several teeth had fractures affecting a great amount of both restoration and tooth structure. CONCLUSIONS This in vitro study showed restored teeth having similar fracture strength and fracture modes, suggesting that with the tested preparation designs, there is no advantage of cuspal coverage to protect LPCR restored teeth from fracture.
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Fonseca RB, Correr-Sobrinho L, Fernandes-Neto AJ, Quagliatto PS, Soares CJ. The influence of the cavity preparation design on marginal accuracy of laboratory-processed resin composite restorations. Clin Oral Investig 2007; 12:53-9. [PMID: 17690921 DOI: 10.1007/s00784-007-0145-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 07/19/2007] [Indexed: 11/26/2022]
Abstract
The aim of this study was to evaluate the influence of different cavity preparation designs on marginal accuracy of laboratory-processed resin composite restored teeth. Eighty mandibular human third molars were selected. There were two experimental factors, occlusal isthmus width (narrow vs wide) and cuspal coverage (inlay, one-cusp onlay, two-cusp onlay, and all-cusp onlay), resulting on eight groups (N = 10). Indirect composite restorations (SR Adoro, Ivoclar-Vivadent) were manufactured and positioned over each respective preparation. Marginal accuracy evaluation was accomplished using a stereomicroscope at three points on buccal, lingual, mesial, and distal regions with 40x magnification. The results showed significant differences (P = 0.00) with wide inlay showing the best overall marginal accuracy and narrow inlay the worst one. Two-way analysis of variance (ANOVA) showed significant differences when considering the factor occlusal isthmus width (P = 0.00). In general, preparations with wide occlusal isthmus presented better results than narrow ones, except for wide all-cusp onlays; however, the test failed to show differences when considering the cuspal coverage (P = 0.42) or the interaction between both factors (P = 0.30). The effect of occlusal width extension on marginal accuracy of indirect composite resin restorations is significant, with lower values of gaps width in wide preparations, but since in a clinical situation this would mean greater removal of sound tooth structure, less-aggressive preparations combined with other restorative procedures seem to be more feasible.
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Affiliation(s)
- Rodrigo Borges Fonseca
- Department of Dental Materials, Piracicaba Dental School, University of Campinas, Campinas, Brazil
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Xie Q, Lassila LVJ, Vallittu PK. Comparison of load-bearing capacity of direct resin-bonded fiber-reinforced composite FPDs with four framework designs. J Dent 2007; 35:578-82. [PMID: 17513033 DOI: 10.1016/j.jdent.2007.04.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 03/27/2007] [Accepted: 04/02/2007] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES This in vitro study was aimed to compare the fracture resistance of directly fabricated inlay-retained fiber-reinforced composite (FRC) fixed partial dentures (FPDs) with four types of framework designs. METHODS Forty-eight directly fabricated inlay retained FPDs were made of FRC and particulate resin composite (everStick/Tetric flow and Ceram). Extracted human mandibular first premolars and first molars were as abutments. The following framework designs were tested: in the Group A (control group), the framework was made of two prepregs of unidirectional glass FRC; the Group B, two prepregs in pontic portion were covered with one layer of multidirectional fiber veil FRC; the Group C, the FRC prepregs were covered in pontic portion with four short unidirectional FRC pieces along the main prepregs; in Group D, one short unidirectional FRC prepregs were placed on the main prepregs in 90 degrees angle to the main framework. After thermal cycling, FPDs of each group (n=12) were randomly divided into two subgroups (n=6). Fracture test was performed at the universal testing machine (1mm/min) where FPDs were loaded from the occlusal direction to the occlusal fossa or to the buccal cusp. Failure patterns were observed with stereomicroscope. Median and 25%/75% percentile values were calculated and nonparametric analysis was performed. RESULTS Compared with three other framework designs, the FPDs in Group D showed the highest resistance when loading to the occlusal fossa, with maximum load of 2,353.8N (25%/75%: 2,155.5/2,500.0) (p=0.000, 0.000, and 0.005 for compared with Group A, B, and C). The same group showed also higher resistance when loaded to the buccal cusp (1,416.3N (1,409.2/1,480.8)) if compared to the FPDs of the Group A and Group C (p=0.044, 0.010). In general the FPDs showed higher resistant to loading at the occlusal fossa (p<0.05). CONCLUSIONS This in vitro study showed that inlay-retained FRC FPD constructed with direct technique provided high fracture resistance. The framework design that provided support for the veneering composite of the pontic contributed to the highest load-bearing capacity even when loaded to the buccal cusp.
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Affiliation(s)
- Qiufei Xie
- Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Haidian District, Beijing, China.
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Ohlmann B, Dreyhaupt J, Schmitter M, Gabbert O, Hassel A, Rammelsberg P. Clinical performance of posterior metal-free polymer crowns with and without fiber reinforcement: one-year results of a randomised clinical trial. J Dent 2006; 34:757-62. [PMID: 16567032 DOI: 10.1016/j.jdent.2006.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Revised: 02/12/2006] [Accepted: 02/15/2006] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the clinical performance of posterior, metal-free polymer crowns with and without a glass-fiber framework, in comparison to metal-ceramic crowns. METHODS After randomisation, 80 single crowns, manufactured from a newly designed polymer composite, were set in posterior teeth. Half of these received a glass-fiber framework, while half were prepared without any framework stabilisation. All polymer crowns were adhesively luted with resin cement. As the control group, 40 conventional metal-ceramic crowns were inserted with hybrid cement. Documentation included failures and other complications, as well as gingival/plaque status and aesthetic performance. RESULTS During the 12-month observation period, eight polymer crowns and three metal-ceramic crowns showed clinically relevant complications. The most frequent complications were root canal treatments (n=4) and decementation (n=4) of the crowns. A total of two crowns (one polymer crown with fiber network and one crown of the control group) had to be replaced. After 12 months, polymer crowns with glass-fiber framework exhibited significantly higher plaque accumulation (p=0.005) and gingival index (p=0.04) than metal-ceramic crowns, while no significant differences could be demonstrated for polymer crowns without fiber reinforcement. Postoperative sensibility and aesthetic performance did not differ significantly between the groups. CONCLUSIONS Within a 12-month observation period, posterior polymer crowns with and without glass-fiber framework demonstrated acceptable stability and aesthetic performance. Polymer crowns with fiber framework showed significant higher plaque accumulation and gingival index than metal-ceramic crowns.
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Affiliation(s)
- Brigitte Ohlmann
- Department of Prosthodontics, University of Heidelberg, Im Neuenheimer Feld 400, Heidelberg, Germany.
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Ozcan M, Breuklander MH, Vallittu PK. The effect of box preparation on the strength of glass fiber–reinforced composite inlay-retained fixed partial dentures. J Prosthet Dent 2005; 93:337-45. [PMID: 15798684 DOI: 10.1016/j.prosdent.2005.01.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM Nonstandardized box dimensions for inlay-retained fixed partial dentures (FPDs) may result in uneven distribution of the forces on the connector region of such restorations. PURPOSE The objective of this in vitro study was to evaluate the effect of box dimensions on the initial and final failure strength of inlay-retained fiber-reinforced composite (FRC) FPDs. MATERIAL AND METHODS Twenty-one inlay-retained FPDs were prepared using FRC (everStick) frameworks with unidirectional fiber reinforcement between mandibular first premolars and first molars. Boxes were prepared using conventional inlay burs (Cerinlay), and small and large ultrasonic tips (SONICSYS approx). Box dimensions were measured after preparation with a digital micrometer. All restorations were subjected to thermal cycling (6000 cycles, 5 degrees C-55 degrees C). Fracture testing was performed in a universal testing machine (1 mm/min). Acoustic emission signals were monitored during loading of the specimens. Initial and final fracture strength values (2-way ANOVA, Bonferroni post hoc tests, alpha =.05) and failure types (Fisher exact test) were statistically compared for each group. RESULTS Significant differences (P =.0146 and P =.0086) were observed between the groups in the dimensions of the boxes prepared using conventional burs buccolingually (2.8-3.0 mm in molars, 3.1-4.3 mm in premolars) and the small size (2.5-2.9, 2.9-3.8 mm) or large size (2.6-3.8, 3.2-4.9 mm) ultrasonic tips for the premolars and the molars, respectively. No significant differences were found at the initial and final failures between the conventionally prepared group (842 +/- 267 N, 1161 +/- 428 N) and those prepared with either small (1088 +/- 381 N, 1320 +/- 380 N) or large ultrasonic tips (1070 +/- 280 N, 1557 +/- 321 N), respectively. The failure analysis demonstrated no significant difference in failure types but predominant delamination of the veneering resin (85%) in all experimental groups. According to acoustic emission tests, a higher energy level was required for final failure of the FRC FPDs with boxes finished using small ultrasonic tips. CONCLUSION Standardized box dimensions showed no significant effect on fracture strength at either initial or final failure of the fiber-reinforced FPDs. The FRC FPDs with boxes refined with small ultrasonic burs required a greater energy level before failure. The type of failure observed after the fracture tests was primarily delamination of the veneering resin.
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Affiliation(s)
- Mutlu Ozcan
- Department of Dentistry and Dental Hygiene, University of Groningen, The Netherlands.
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Balkaya MC, Cinar A, Pamuk S. Influence of firing cycles on the margin distortion of 3 all-ceramic crown systems. J Prosthet Dent 2005; 93:346-55. [PMID: 15798685 DOI: 10.1016/j.prosdent.2005.02.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM Although all-ceramic restorations are widely used, there is a lack of information about how the fit is affected by fabrication procedures. The adequacy of the fit of all-ceramic restorations has been questioned. PURPOSE This study examined the effect of porcelain and glaze firing cycles on the fit of 3 types of all-ceramic crowns. MATERIAL AND METHODS Ten standardized all-ceramic crowns were fabricated on a metal die from each of 3 systems: conventional In-Ceram, copy-milled In-Ceram, and copy-milled feldspathic crowns. Copings of the conventional and copy-milled In-Ceram crowns and nonglazed copy-milled feldspathic crowns served as the control. A device was used to apply a uniform load on specimens during measurement and to reposition the specimens on the measurement device after each manufacturing process. The specimens were not cemented and were measured on the metal die using a profile projector. Measurements were recorded at 18 points selected along horizontal and vertical planes. The crown systems were compared by use of the Student t test and 1-way analysis of variance (ANOVA). Data of measurements repeated at identical locations were analyzed with a multivariate repeated-measures ANOVA. The Bonferroni post hoc test was used for multiple comparisons (alpha=.05). RESULTS The conventional In-Ceram (57 +/- 24 microm) and copy-milled In-Ceram (57 +/- 32 microm) crowns demonstrated nearly identical marginal discrepancy values, followed by the copy-milled feldspathic crowns with a mean of 17 +/- 12 microm in the vertical plane. The copy-milled In-Ceram crowns had a mean horizontal discrepancy value of -12 +/- 4 microm, followed by the copy-milled feldspathic crowns with a mean of -4 +/- 5 microm and the conventional In-Ceram crowns with a mean of -6 +/- 4 microm. Statistical analyses demonstrated no significant differences in the marginal discrepancy values among the 3 all-ceramic crown systems, except for the horizontal discrepancy values between the conventional and copy-milled In-Ceram crowns after the porcelain firing cycle. Results indicated that the addition of porcelain to the copings caused a significant change ( P <.05) in the marginal fit of the crowns, except for the fit in the horizontal plane of the conventional In-Ceram crowns. However, no significant changes occurred in the fit of the 3 all-ceramic crowns after the glaze firing cycle. There were significant differences in the marginal discrepancy values among the measurement locations ( P <.05), and the discrepancy value at each location was independent of the mean of the entire crown. CONCLUSIONS Within the limitations of this study, it was concluded that the 3 all-ceramic crown systems demonstrated a comparable and acceptable marginal fit. The porcelain firing cycle affected the marginal fit of the all-ceramic crowns. However, the glaze firing cycle had no significant effect on fit. The conventional and copy-milled In-Ceram crowns demonstrated medial deformations at the labial and palatal surfaces that might result in occlusal displacement of the crown.
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Cho L, Choi J, Yi YJ, Park CJ. Effect of finish line variants on marginal accuracy and fracture strength of ceramic optimized polymer/fiber-reinforced composite crowns. J Prosthet Dent 2004; 91:554-60. [PMID: 15211298 DOI: 10.1016/j.prosdent.2004.03.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM Ceramic optimized polymer (Ceromer)/fiber-reinforced composite (FRC) crowns have been promoted as alternatives to conventional crowns. However, little is known regarding the ideal tooth preparation for this type of crown. PURPOSE This in vitro study evaluated the marginal adaptation and fracture strength of ceromer/FRC crowns with respect to the various types of finish lines. MATERIAL AND METHODS Four metal dies with different finish lines (0.9-mm chamfer, 1.2-mm chamfer, 1.2-mm rounded shoulder, and 1.2-mm shoulder) were prepared. Forty (10 for each finish line) Targis/Vectris crowns were fabricated on duplicated base metal alloy dies. The restorations were stereoscopically evaluated at 56 points along the entire circumferential margin for measuring the margin adaptation before and after cementation with a resin luting agent. The specimens were then compressively loaded to failure using a universal testing machine. The marginal adaptation (microm) was analyzed with the Kruskal-Wallis test and post-hoc Dunnett test (alpha=.05). The fracture load (N) was analyzed with a 1-way analysis of the variance and the Scheffe adjustment (alpha=.05). The fractured surfaces of the crowns were examined with a scanning electron microscope to determine the mode of fracture. RESULTS The marginal adaptation of crowns with a shoulder finish line was significantly better than crowns with a chamfer finish line before and after cementation (P<.001). The increased marginal gap after cementation was the lowest in the 1.2-mm rounded shoulder group. The fracture strength of the crowns with the 0.9-mm chamfer and crowns with 1.2-mm chamfer was significantly greater than those of the crowns with the 1.2-mm shoulder or rounded shoulder (P=.011, P=.049, respectively). The mean fracture load of all crowns, regardless of the finish line design, was 1646 N. The fractured surface of the crown revealed adhesive failure and 3 types of cohesive failure (fracture of the Targis and Vectris, Targis fracture with a crack in the Vectris layer, and crushing without fracture). CONCLUSION The marginal gaps were greater for the chamfer finish line specimens than in the shoulder finish line specimens. However, the fracture strength of the chamfer finish line specimens was greater than that of the shoulder finish line specimens.
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Affiliation(s)
- LeeRa Cho
- Department of Prosthodontics and Research Institute of Oral Science, College of Dentistry, Kangnung National University, Gangneung, Korea.
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