Effect of cavity preparation design and ceramic type on the stress distribution, strain and fracture resistance of CAD/CAM onlays in molars

Background: The flat occlusal preparation design (FOD) of posterior teeth offers promising results of fracture resistance and stress distribution, but its application in vital teeth is limited as there may be a danger of pulp injury. Although this danger is omitted in endodontically treated teeth, there is no research work assessing the impact of FOD on the fracture resistance and distribution of stresses among these teeth. The aim of this study was to assess the impact of FOD of endodontically treated molars on the fracture resistance and distribution of stresses among a ceramic crown-molar structure when compared to the two planes occlusal preparation design (TOD). Methods: 20 human mandibular molars were endodontically treated and distributed equally to two groups: Group I (TOD) and Group II (FOD). Ceramic CAD/CAM milled lithium disilicate (IPS e.max CAD) crowns were produced for all preparations and adhered using self-adhesive resin cement. Using a universal testing machine, the fracture resistance test was performed. The fractured samples were examined using a stereomicroscope and scanning electron microscope to determine modes of failure. Stress distribution was evaluated by 3D finite element analysis, which was performed on digital models of endodontically treated mandibular molars (one model for each design). Results: Group II recorded statistically non-significant higher fracture resistance mean values (3107.2± 604.9 N) than Group I mean values (2962.6 ±524.27 N) as indicated by Student’s t-test (t=0.55, p= 0.57). Also, Group II resulted in more favorable failure mode as compared to Group I. Both preparation designs yielded low von-Mises stresses within the factor of safety. However, the stress distribution among different layers of the model differed. Conclusions: FOD having comparable fracture strength to TOD and a more favorable fracture behavior can be used for the preparation of endodontically treated molars.

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Fracture Resistance of CAD/CAM-Fabricated Lithium Disilicate MOD Inlays and Onlays with Various Cavity Preparation Designs

Journal of Prosthodontics ◽

10.1111/jopr.12787 ◽

2018 ◽

Vol 28 (2) ◽

pp. e524-e529 ◽

Cited By ~ 3

Author(s):

Hyung-In Yoon ◽

Paul J. Sohn ◽

Sharon Jin ◽

Hawazin Elani ◽

Sang J. Lee

Keyword(s):

Fracture Resistance ◽

Lithium Disilicate ◽

Cavity Preparation ◽

Cad Cam

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Influence of cavity preparation design on fracture resistance of posterior Leucite-reinforced ceramic restorations

Journal of Prosthetic Dentistry ◽

10.1016/j.prosdent.2006.03.022 ◽

2006 ◽

Vol 95 (6) ◽

pp. 421-429 ◽

Cited By ~ 77

Author(s):

Carlos Jose Soares ◽

Luis Roberto Marcondes Martins ◽

Rodrigo Borges Fonseca ◽

Lourenco Correr-Sobrinho ◽

Alfredo Julio Fernandes Neto

Keyword(s):

Fracture Resistance ◽

Cavity Preparation ◽

Ceramic Restorations ◽

Preparation Design

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Fracture resistance and 3D finite element analysis of machined ceramic crowns bonded to endodontically treated molars with two planes versus flat occlusal preparation designs: an in vitro study

F1000Research ◽

10.12688/f1000research.19455.1 ◽

2019 ◽

Vol 8 ◽

pp. 1020 ◽

Cited By ~ 1

Author(s):

Omnia Nabil ◽

Carl Hany Halim ◽

Ashraf Hassan Mokhtar

Keyword(s):

Stress Distribution ◽

Fracture Resistance ◽

Element Analysis ◽

3D Finite Element ◽

Mean Values ◽

Group I ◽

Group Ii ◽

The Impact ◽

Preparation Design ◽

Distribution Of Stresses

Background:The flat occlusal preparation design (FOD) of posterior teeth offers promising results of fracture resistance and stress distribution, but its application in vital teeth is limited as there may be a danger of pulp injury. Although this danger is omitted in endodontically treated teeth, there is no research work assessing the impact of FOD on the fracture resistance and distribution of stresses among these teeth. The aim of this study was to assess the impact of FOD of endodontically treated molars on the fracture resistance and distribution of stresses among a ceramic crown-molar structure when compared to the two planes occlusal preparation design (TOD).Methods:20 human mandibular molars were endodontically treated and distributed equally to two groups: Group I (TOD) and Group II (FOD). Ceramic CAD/CAM milled lithium disilicate (IPS e.max CAD) crowns were produced for all preparations and adhered using self-adhesive resin cement. Using a universal testing machine, the fracture resistance test was performed. The fractured samples were examined using a stereomicroscope and scanning electron microscope to determine modes of failure. Stress distribution was evaluated by 3D finite element analysis, which was performed on digital models of endodontically treated mandibular molars (one model for each design).Results:Group II recorded statistically non-significant higher fracture resistance mean values (3107.2± 604.9 N) than Group I mean values (2962.6 ±524.27 N) as indicated by Student’s t-test (t=0.55, p= 0.57). Also, Group II resulted in more favorable failure mode as compared to Group I. Both preparation designs yielded low von-Mises stresses within the factor of safety. However, the stress distribution among different layers of the model differed.Conclusions:FOD having comparable fracture strength to TOD and a more favorable fracture behavior can be used for the preparation of endodontically treated molars.

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Effect of deep marginal elevation on marginal adaptation and fracture resistance in endodontically treated teeth restored with endocrowns constructed by two different CAD/CAM ceramics: an in-vitro study

Egyptian Dental Journal ◽

10.21608/edj.2020.79129 ◽

2020 ◽

Vol 66 (1) ◽

pp. 541-556

Author(s):

Shams Ali ◽

Dalia Moukarab

Keyword(s):

Fracture Resistance ◽

In Vitro Study ◽

Vitro Study ◽

Marginal Adaptation ◽

Endodontically Treated Teeth ◽

Cad Cam

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Fracture Resistance of Molar Teeth Restored by Endocrown and Onlay CAD/CAM Monolithic Ceramic Materials. An In-vitro Study

Al-Azhar Journal of Dental Science ◽

10.21608/ajdsm.2020.120665 ◽

2020 ◽

Vol 23 (2) ◽

pp. 95-102

Keyword(s):

Fracture Resistance ◽

In Vitro Study ◽

Ceramic Materials ◽

Vitro Study ◽

Cad Cam ◽

Molar Teeth

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Fracture Resistance in Non-Vital Teeth: Absence of Interproximal Ferrule and Influence of Preparation Depth in CAD/CAM Endocrown Overlays—An In Vitro Study

Materials ◽

10.3390/ma15020436 ◽

2022 ◽

Vol 15 (2) ◽

pp. 436

Author(s):

Lucía Barallat ◽

María Arregui ◽

Sandra Fernandez-Villar ◽

Blanca Paniagua ◽

Andrés Pascual-La Rocca

Keyword(s):

Fracture Strength ◽

Fracture Resistance ◽

Testing Machine ◽

Compressive Force ◽

Ample Evidence ◽

Alveolar Crest ◽

Cad Cam ◽

Group A ◽

Group B ◽

Group D

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.

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Review of Marginal Adaptation and Fracture Resistance of Computer Aided Design/Computer Aided Manufacturer (CAD‐CAM) Fabricated Endo-crowns

Journal of Pharmaceutical Research International ◽

10.9734/jpri/2021/v33i55a33823 ◽

2021 ◽

pp. 196-208

Author(s):

Abdulrahman Alhaddad ◽

Samar Abuzinadah ◽

Abdullah Al-Otaibi ◽

Abrar Alotaibi ◽

Mohsen Alfkih ◽

...

Keyword(s):

Computer Aided Design ◽

Fracture Resistance ◽

Systemic Review ◽

Marginal Adaptation ◽

Marginal Gap ◽

Computer Aided ◽

Cad Cam ◽

Electronic Database Search ◽

Cause Of Failure

Background: Zirconia-based restorations have become more popular in dentistry during the last two decades. Patients choose metal-free restorations, preferring materials with similar attributes to natural teeth and similar light scattering characteristics, resulting in a nice esthetic appearance. Restoring a root canal treated teeth is one of the hot topics today. endo crown materials can be either; feldspathic, glass-ceramic, monolithic hybrid ceramic or composite material. Considering the marginal gap of endocrown, an important cause of failure of treatment, the current study evaluated the marginal gap of CAD‐CAM concocted endo-crowns. Materials and Methods: This research is an analysis systemic review study was conducted between January 2020 and October 2021. We followed the PRISMA principles and recorded this systematic review using the PROSPERO database to find and identify published literature related to the marginal adaptation of CAD-CAM-fabricated endocrown. The search will include all relevant articles through the end of 2021. Finally, 24 papers on marginal clearance and fracture resistance in coronary arteries were reviewed. Results: The electronic database search yielded 98 studies that were relevant. After cross-referencing, further seven studies were added. After a full-text analysis and duplicate reduction, 74 of the 98 articles were eliminated. 5 clinical (prospective) studies, 19 in vitro studies were found. Conclusion: This analysis of the recent literature on the marginal seating integrity and fracture resistance of CAD/CAM made-up endo-crowns showed that the endo-crown had superior marginal seating integrity than classical full crown. CAM/CAM showed statistically significant higher mean fracture resistance than MAD/MAM.

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