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Hennig CL, Stöcker A, Nitzsche A, Marquetand J, Jacobs C, Jahn F. Influence of Root Post Materials and Aging on Fracture Strength and Marginal Gap Quality of Ceramic Crowns-An In Vitro Study. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16113985. [PMID: 37297118 DOI: 10.3390/ma16113985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023]
Abstract
The design of and materials for prosthodontic abutments and posts have significant influences on the fracture resistance of restored teeth. This in vitro study compared the fracture strength and marginal quality of full-ceramic crowns as a function of the inserted root posts via simulation of a five-year period of use. Test specimens were prepared from 60 extracted maxillary incisors using titanium L9 (A), glass-fiber L9 (B), and glass-fiber L6 (C) root posts. The circular marginal gap behavior, linear loading capacity, and material fatigue after artificial aging were investigated. The marginal gap behavior and material fatigue were analyzed using electron microscopy. The linear loading capacity of the specimens was investigated using the Zwick Z005 universal testing machine. None of the tested root post materials showed statistically significant differences in marginal width values (p = 0.921), except in the case of marginal gap location. For Group A, there was a statistically significant difference from the labial to the distal (p = 0.012), mesial (p = 0.000), and palatinal (p = 0.005). Similarly, Group B showed a statistically significant difference from the labial to the distal (p = 0.003), mesial (p = 0.000), and palatinal (p = 0.003). Group C showed a statistically significant difference from the labial to the distal (p = 0.001) and mesial (p = 0.009). Linear load capacity reached mean values of 455.8-537.7 N, and micro-cracks occurred after artificial aging, predominantly in Groups B and C. Through the chosen experimental design, it was shown that the root post material and root post length had no influence on the fracture strength of the test teeth before or after artificial aging. However, the marginal gap location depends on the root post material and its length, which is wider mesially and distally and also tends to be greater palatinally than labially.
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Affiliation(s)
- Christoph-Ludwig Hennig
- Department of Orthodontics, Center of Dental Medicine, University Hospital Jena, An der alten Post 4, 07743 Jena, Germany
| | - André Stöcker
- Section of Geriodontics, Department of Conservative Dentistry and Periodontology, Center of Dental Medicine, University Hospital Jena, An der alten Post 4, 07743 Jena, Germany
| | - Ann Nitzsche
- Department of Orthodontics, Center of Dental Medicine, University Hospital Jena, An der alten Post 4, 07743 Jena, Germany
| | - Justus Marquetand
- Department of Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- Department of Neural Dynamics and Magnetoencephalography, Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- MEG-Center, University of Tübingen, 72076 Tübingen, Germany
| | - Collin Jacobs
- Department of Orthodontics, Center of Dental Medicine, University Hospital Jena, An der alten Post 4, 07743 Jena, Germany
| | - Florentine Jahn
- Section of Geriodontics, Department of Conservative Dentistry and Periodontology, Center of Dental Medicine, University Hospital Jena, An der alten Post 4, 07743 Jena, Germany
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Brezinsky S, Bowles W, McClanahan S, Fok A, Ordinola-Zapata R. In Vitro Comparison of Porcelain Fused to Metal Crown Retention after Endodontic Access and Subsequent Restoration: Composite, Amalgam, Amalgam with Composite Veneer, and Fiber Post with Composite. J Endod 2020; 46:1766-1770. [PMID: 32818565 DOI: 10.1016/j.joen.2020.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The aim of this study was to evaluate the effect of different access opening restorative materials on crown retention. METHODS Thirty-eight extracted molars were mounted in resin and prepared for porcelain fused to metal (PFM) crowns. The crowns were fabricated and cemented with zinc phosphate, and the force to displace it was measured with a tensile-testing machine before and after endodontic access preparations. The endodontic access area, crown preparation axial wall, and preparation surface area were measured for comparison. The crowns were then recemented, and access openings were restored with either amalgam or composite before displacement force was remeasured. The restorative material was removed from each access opening; access area was measured and restored again (amalgam with composite or fiber post with composite) for displacement force to be remeasured. Paired t test was used to compare the means of displacement between groups. One-way analysis of variance was used to compare the mean outcome measure within the groups. RESULTS Statistical analyses showed retention after unfilled access was significantly lower than intact crowns. Amalgam, composite, amalgam + composite, and fiber post + composite increased retention beyond the original value. There was no statistical difference among the different restorative protocols. Qualitative results indicate that the restorative material remains in the crown after displacement regardless of the material used to restore the access. CONCLUSIONS The results from this study suggest that an endodontic access cavity decreases retention of a PFM crown. However, subsequent restoration with amalgam, composite, amalgam + composite, or post + composite may increase the original retention of the crown.
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Affiliation(s)
- Scott Brezinsky
- Division of Endodontics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota
| | - Walter Bowles
- Division of Endodontics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota
| | - Scott McClanahan
- Division of Endodontics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota
| | - Alex Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota
| | - Ronald Ordinola-Zapata
- Division of Endodontics, School of Dentistry, University of Minnesota, Minneapolis, Minnesota.
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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: 39] [Impact Index Per Article: 6.5] [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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Longevity of composite build-ups without posts-10-year results of a practice-based study. Clin Oral Investig 2018; 23:1435-1442. [PMID: 30046906 DOI: 10.1007/s00784-018-2565-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/09/2018] [Indexed: 10/28/2022]
Abstract
AIM The aim of this prospective, non-interventional, multi-center, practice-based study was, firstly, to evaluate the longevity of composite build-ups in endodontically treated teeth (ETT) without post placement and, secondly, to analyze factors influencing the success of these composite build-ups. METHODOLOGY Each of seven general dental practitioners placed up to 50 composite build-ups without additional posts in ETT. Teeth were restricted to incisors, canines, and premolars. Several clinical data were recorded for 192 coronal restorations on ETT in 192 patients. Cox proportional hazard models were applied to analyze associations between clinical factors and time until failure. RESULTS Within a follow-up period of 10 years, 167 restorations were judged as successful [mean success time, 110 (105-115) months] and 180 teeth survived [mean survival time, 114 (110-119) months]. The main failure type was fracture of the restoration (n = 15). The annual failure rate was 2.4%. In bivariate Cox regression, both factors such as number of restored tooth surfaces and adhesive were significantly associated with the failure rate. In multivariate Cox proportional hazards regression, none of the investigated factors were significantly associated with the failure rate. CONCLUSION For composite build-ups in ETT without post placement, high success rates could be found after up to 10 years of observation time. Within the limitations of the present study, none of the analyzed factors such as "tooth type" or "number of restored tooth surfaces" was a significant predictor for the failure rate. CLINICAL RELEVANCE Endodontically treated teeth can be successfully directly restored with composite build-ups even when no additional post is inserted. TRIAL REGISTRATION The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00012882).
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Naumann M. Restorative procedures: effect on the mechanical integrity of root-filled teeth. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/etp.12086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Oyar P. The effects of post-core and crown material and luting agents on stress distribution in tooth restorations. J Prosthet Dent 2014; 112:211-9. [PMID: 24560984 DOI: 10.1016/j.prosdent.2013.10.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 10/02/2013] [Accepted: 10/02/2013] [Indexed: 11/15/2022]
Affiliation(s)
- Perihan Oyar
- Assistant Professor, Dental Prosthetics Technology Programme, School of Health Services, Hacettepe University, Ankara, Turkey.
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Akman S, Akman M, Eskitaşcıoğlu G, Belli S. The use of endodontically treated and/or fiber post-retained teeth as abutments for fixed partial dentures. Clin Oral Investig 2011; 16:1485-91. [DOI: 10.1007/s00784-011-0635-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Accepted: 10/25/2011] [Indexed: 10/15/2022]
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Dejak B, Młotkowski A. Finite element analysis of strength and adhesion of cast posts compared to glass fiber-reinforced composite resin posts in anterior teeth. J Prosthet Dent 2011; 105:115-26. [DOI: 10.1016/s0022-3913(11)60011-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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KIM MJ, JUNG WC, OH S, HATTORI M, YOSHINARI M, KAWADA E, ODA Y, BAE JM. Flexural properties of three kinds of experimental fiber-reinforced composite posts. Dent Mater J 2011; 30:38-44. [PMID: 21282890 DOI: 10.4012/dmj.2010-053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Evaluation of a one-piece milled zirconia post and core with different post-and-core systems: An in vitro study. J Prosthet Dent 2010; 103:369-79. [PMID: 20493326 DOI: 10.1016/s0022-3913(10)60080-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Successful endodontic treatment depends on the restorative treatment that follows. The connection between endodontic treatment and restorative dentistry is well accepted, but the best restorative approaches for endodontically treated teeth have always been somewhat controversial. A plethora of information from various sources contributes to the controversy and much of it is contradictory. With the emergence of implants in mainstream dentistry, there has been more emphasis on long-term outcomes and on evaluating the "restorability" of teeth prior to endodontic treatment. The long-term viability of endodontically treated teeth is no longer a "given" in the implant era. In consequence, some teeth that might have received endodontic treatment in the past are now extracted and replaced with implant-supported prostheses if they are marginally restorable or it makes more sense in the overall treatment plan. As it is not possible to review here all the literature on the restoration of endodontically treated teeth, this article focuses primarily on current concepts based on the literature from the past 10 years or so, and provides treatment guidelines based on that research.
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Affiliation(s)
- Marga Ree
- University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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Nam SH, Chang HS, Min KS, Lee Y, Cho HW, Bae JM. Effect of the Number of Residual Walls on Fracture Resistances, Failure Patterns, and Photoelasticity of Simulated Premolars Restored with or without Fiber-reinforced Composite Posts. J Endod 2010; 36:297-301. [DOI: 10.1016/j.joen.2009.10.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 09/30/2009] [Accepted: 10/18/2009] [Indexed: 10/20/2022]
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Mohammadi N, Kahnamoii MA, Yeganeh PK, Navimipour EJ. Effect of Fiber Post and Cusp Coverage on Fracture Resistance of Endodontically Treated Maxillary Premolars Directly Restored with Composite Resin. J Endod 2009; 35:1428-32. [DOI: 10.1016/j.joen.2009.07.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 07/01/2009] [Accepted: 07/03/2009] [Indexed: 11/16/2022]
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Bitter K, Noetzel J, Stamm O, Vaudt J, Meyer-Lueckel H, Neumann K, Kielbassa AM. Randomized clinical trial comparing the effects of post placement on failure rate of postendodontic restorations: preliminary results of a mean period of 32 months. J Endod 2009; 35:1477-82. [PMID: 19840634 DOI: 10.1016/j.joen.2009.07.026] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/21/2009] [Accepted: 07/27/2009] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The aim of this randomized clinical trial was to assess whether the placement of a fiber post (DT Light Post) (DT) and the amount of residual coronal dentin affect the time to failure of single-unit postendodontic restorations. METHODS Ninety patients providing 120 teeth were selected. Three groups (n = 40) were defined on the basis of the amount of residual coronal dentin: 2-walls group, 2 or more coronal walls; 1-wall group, 1 coronal wall; no-wall group, no wall exceeding 2 mm above the gingival level. Within each group teeth were randomized and allocated to 2 intervention groups (n = 20), including subgroups no post (no root canal retention) and subgroups post (placement of DT). RESULTS After a mean observation period of 32.4 (13.7) months in subgroups no post, the failure rates were 10%, whereas in subgroups post, failure rates of 7% were observed (P = .318). In no-wall group post placement significantly affected the time to failure of total restorations (P = .029, log-rank test). Teeth without post retention revealed a significantly higher failure rate (31%) compared with teeth restored with post retention (7%). CONCLUSIONS Within the observation time of the present study, fiber post placement was efficacious to reduce failures of postendodontic restorations only with teeth that exhibited no coronal walls. Post insertion for teeth showing a minor substance loss should be critically reconsidered.
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Affiliation(s)
- Kerstin Bitter
- Department of Operative Dentistry and Periodontology, University School of Dental Medicine, CharitéCentrum 3, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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Meira JBC, Espósito COM, Quitero MFZ, Poiate IAVP, Pfeifer CSC, Tanaka CB, Ballester RY. Elastic modulus of posts and the risk of root fracture. Dent Traumatol 2009; 25:394-8. [DOI: 10.1111/j.1600-9657.2009.00772.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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NAUMANN M, METZDORF G, FOKKINGA W, WATZKE R, STERZENBACH G, BAYNE S, ROSENTRITT M. Influence of test parameters onin vitrofracture resistance of post-endodontic restorations: a structured review. J Oral Rehabil 2009; 36:299-312. [DOI: 10.1111/j.1365-2842.2009.01940.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hahnel S, Rosentritt M, Handel G, Bürgers R. In vitro evaluation of artificial ageing on surface properties and early Candida albicans adhesion to prosthetic resins. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:249-255. [PMID: 18758916 DOI: 10.1007/s10856-008-3570-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Accepted: 08/18/2008] [Indexed: 05/26/2023]
Abstract
OBJECTIVE The aim of this in vitro study was to examine potential changes and influences of prosthetic resin surface properties on Candida albicans adhesion after surface treatment or artificial ageing. MATERIALS AND METHODS Standardized specimens of a denture base resin and a veneering composite were prepared, polished, and randomly subjected to different surface roughness treatments or artificial ageing protocols (storage in ethanol or artificial saliva for 7/90 d, thermocycling). Surface roughness (Ra) and surface free energy were determined prior and after each treatment. Specimens were incubated with phosphate buffered saline or whole saliva for 2 h at 37 degrees C, and later with Candida albicans suspension (2.5 h, 37 degrees C). Adherent viable fungi were quantified using a bioluminescence assay. RESULTS Artifical ageing did not affect substratum surface roughness, yet slight increases in substratum surface free energy and significant increases in Candida albicans adhesion were observed. Saliva coating marginally influenced Candida albicans adherence to reference and surface treated specimens, yet more pronounced differences in Candida albicans adhesion between the various artificially aged specimens were found. CONCLUSION No correlation between substratum surface roughness or surface free energy and Candida albicans adhesion could be established.
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Affiliation(s)
- Sebastian Hahnel
- Department of Prosthetic Dentistry, Regensburg University Medical Center, Regensburg, 93042, Germany.
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AL-Wahadni AM, Hamdan S, Al-Omiri M, Hammad MM, Hatamleh MM. Fracture resistance of teeth restored with different post systems: in vitro study. ACTA ACUST UNITED AC 2008; 106:e77-83. [DOI: 10.1016/j.tripleo.2008.03.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 02/29/2008] [Accepted: 03/31/2008] [Indexed: 10/21/2022]
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Reill MI, Rosentritt M, Naumann M, Handel G. Influence of core material on fracture resistance and marginal adaptation of restored root filled teeth. Int Endod J 2008; 41:424-30. [DOI: 10.1111/j.1365-2591.2008.01385.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Meira JBC, Quitero MFZ, Braga RR, Placido E, Rodrigues FP, Lima RG, Ballester RY. The suitability of different FEA models for studying root fractures caused by wedge effect. J Biomed Mater Res A 2007; 84:442-6. [PMID: 17618491 DOI: 10.1002/jbm.a.31353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Finite element analysis (FEA) utilizing models with different levels of complexity are found in the literature to study the tendency to vertical root fracture caused by post intrusion ("wedge effect"). The objective of this investigation was to verify if some simplifications used in bi-dimensional FEA models are acceptable regarding the analysis of stresses caused by wedge effect. Three plane strain (PS) and two axisymmetric (Axi) models were studied. One PS model represented the apical third of the root entirely in dentin (PS-nG). The other models included gutta-percha in the apical third, and differed regarding dentin-post relationship: bonded (PS-B and Axi-B) or nonbonded (PS-nB and Axi-nB). Mesh discretization and material properties were similar for all cases. Maximum principal stress (sigma max) was analyzed as a response to a 165 N longitudinal load. Stress magnitude and orientation varied widely (PS-nG: 10.3 MPa; PS-B: 0.8 MPa; PS-nB: 10.4 MPa; Axi-B: 0.2 MPa; Axi-nB: 10.8 MPa). Axi-nB was the only model where all sigma max vectors at the apical third were perpendicular to the model plane. Therefore, it is adequate to demonstrate the tendency to vertical root fractures caused by wedge effect. Axi-B showed only part of the sigma max perpendicular to the model plane while PS models showed sigma max on the model plane. In these models, sigma max)orientation did not represent a situation where vertical root fracture would occur due to wedge effect. Adhesion between post and dentin significantly reduced sigma max.
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Affiliation(s)
- Josete B C Meira
- Department of Dental Materials, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Stricker EJ, Göhring TN. Influence of different posts and cores on marginal adaptation, fracture resistance, and fracture mode of composite resin crowns on human mandibular premolars. An in vitro study. J Dent 2006; 34:326-35. [PMID: 16202498 DOI: 10.1016/j.jdent.2005.07.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 07/27/2005] [Accepted: 07/29/2005] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE To evaluate marginal adaptation, fracture modes, and loads to failure of composite crowns with different substructures on root-canal-treated premolars. METHODS Forty-eight mandibular teeth with single root canals were selected and assigned to six equal groups: group I, untreated; group II, root-canal-treated (RCT), access cavity restored with composite resin; group III, RCT, ferrule (2 mm), no post, standardized composite resin crown (SRCC); group IV, RCT, ferrule, glass fiber post, SRCC; group V, RCT, ferrule, zirconium post, SRCC; group VI, RCT, ferrule, cast gold post, SRCC. All teeth were subjected to thermocycling and mechanical loading (TCML) in a computer-controlled masticator (1,200,000 loads, 49N, 1.7Hz, 3000 temperature cycles of 5-50-5 degrees C). Marginal adaptation was evaluated before and after TCML with scanning electron microscopy at x200 at the tooth-to-luting-composite (IF1) and the luting-composite-to-crown (IF2) interfaces. After TCML, all specimens were loaded to failure in a universal testing machine at 0.5mm/min. RESULTS A significant decrease in marginal adaptation was found in groups III and IV after TCML at IF1. A significant decrease was observed at IF2 in group V. Mean loads to failure did not differ significantly between the groups with SRCCs. Those of groups II, III, and IV did not differ from that of unrestored teeth. Half the specimens exhibited partial root fractures, independent of the substructures used. No deep or vertical root fractures were observed in any group. CONCLUSION All studied posts had a positive effect on marginal adaptation at IF1, but not on failure modes or loads to failure of composite resin crowns.
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Affiliation(s)
- Elisabeth J Stricker
- Clinic for Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zurich, Plattenstrasse 11, 8032 Zurich, Switzerland
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Naumann M, Preuss A, Rosentritt M. Effect of incomplete crown ferrules on load capacity of endodontically treated maxillary incisors restored with fiber posts, composite build-ups, and all-ceramic crowns: an in vitro evaluation after chewing simulation. Acta Odontol Scand 2006; 64:31-6. [PMID: 16428180 DOI: 10.1080/00016350500331120] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The aim of this study was to compare the fracture resistance of endodontically treated maxillary central incisors with incomplete crown ferrules after chewing simulation. MATERIAL AND METHODS Forty caries-free maxillary central incisors were divided into 4 groups (n = 10). Endodontic treatment was performed. Teeth were decoronated 2 mm above the cemento-enamel junction (CEJ). Group I (control) provided a 360 degrees circumferential 2-mm ferrule. In group II, a 2-mm ferrule was present on the palatal aspect (status after occlusal overload), and in group III on the facial aspect (status after traumatic injury). In group IV, the ferrule was interrupted by bi-proximal cavitations (simulating caries treatment). The teeth received glass fiber reinforced posts and composite core restorations. All-ceramic crowns were adhesively cemented. Specimens were simultaneously exposed to thermal cycling and mechanical loading (1.2 million cycles; 6,000 cycles 5 degrees/55 degrees C) and finally statically loaded until failure in a universal testing machine (crosshead speed = 1 mm/min). For statistical analysis, the Kruskal-Wallis test was applied followed by the Mann-Whitney U-test as post hoc testing. RESULTS The median fracture load values (min./max.) were: group I = 502 (326/561), group II = 658 (280/827), group III = 899 (396/1176), and group IV = 360 (279/646). Analysis revealed statistically significant differences between test groups, except between groups I and IV and groups II and IV. CONCLUSIONS The fracture resistance of endodontically and post/core restored teeth is dependent on the degree of tooth conservation. An incomplete crown ferrule is associated with greater variation in load capacity and, despite high fracture values, inclines to fracture.
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Affiliation(s)
- Michael Naumann
- Department of Prosthodontics and Geriatric Dentistry, Charité, Humboldt University, Berlin, Germany.
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