Fracture load of composite resin and feldspathic all-ceramic CAD/CAM crowns

SUMMARY Objectives The aim of this study was to investigate the restoration of broken-down endodontically treated molars without ferrule effect using glass ceramic crowns on different composite resin core buildups. Methods and Materials Forty-five decoronated endodontically treated teeth (no ferrule) were restored with a semidirect buildup using an experimental computer-aided design/computer-aided manufacturing (CAD/CAM) high-performance polymer (HPP group) or with light-curing composite core buildups of Tetric EvoCeram with (TECP group) or without (TEC group) a glass-fiber-reinforced post. All teeth were prepared to receive bonded glass ceramic crowns (Empress CAD luted with Variolink II) and were subjected to accelerated fatigue testing. Cyclic isometric loading was applied to the palatal cusp at an angle of 30° and a frequency of 5 Hz, beginning with a load of 200 N (×5000 cycles) and followed by stages of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. Specimens were loaded until failure or to a maximum of 185,000 cycles. Groups were compared using the life-table survival analysis (log rank test at p=0.05). Average fracture loads and number of survived cycles were compared with one-way analysis of variance (Scheffé post hoc at p=0.05). Results None of the tested specimen withstood all 185,000 load cycles. There was a significant difference in mean fracture load, survived cycles, and survival; the HPP group (fracture load 975.27N±182.74) was significantly higher than the TEC (716.87N±133.43; p=0.001) and TECP (745.67±156.34; p=0.001) groups, and the TEC and TECP groups showed no difference (p=0.884). Specimens in the TECP group were affected by an initial failure phenomenon (wide gap at the margin between the buildup/crown assembly and the root). Conclusions Semidirect core buildup made from high-performance polymer enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns compared with direct light-curing composite resin buildups. The use of a fiber-reinforced post system did not influence the fatigue strength of all-ceramic crowns.

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Computer-Aided Designed/Computer-Assisted Manufactured (CAD/CAM) All-Ceramic Crowns Appear to Perform Better than All-Composite Resin Crowns Following the First 3 Years of Placement

Journal of Evidence Based Dental Practice ◽

10.1016/j.jebdp.2011.09.015 ◽

2011 ◽

Vol 11 (4) ◽

pp. 203-205 ◽

Cited By ~ 4

Author(s):

J. Robert Kelly

Keyword(s):

Composite Resin ◽

Computer Assisted ◽

All Ceramic ◽

Computer Aided ◽

Cad Cam ◽

Ceramic Crowns ◽

Better Than

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Fracture load of nano-ceramic composite material for anterior endocrown restorations

Brazilian Dental Science ◽

10.14295/bds.2020.v23i1.1853 ◽

2020 ◽

Vol 23 (1) ◽

Author(s):

Salma Alghalayini ◽

Kamal Khaled Ebeid ◽

Ayman Aldahrab ◽

Marwa Wahsh

Keyword(s):

Ceramic Composite ◽

Fatigue Testing ◽

Testing Machine ◽

Cyclic Fatigue ◽

Fracture Load ◽

Endodontically Treated Teeth ◽

Ceramic Fracture ◽

Tooth Structure ◽

All Ceramic ◽

Cad Cam

Objective: To evaluate ability of Nano Ceramic Composite endocrown to withstand occlusal forces when used in the anterior region. Material and Methods: Eighty endodontically treated maxillary central incisors teeth were randomly divided into two main groups according to the restoration type. 40 of these teeth were post, core and crown restorations and 40 were endocrown restorations. Then they were divided by halves into two subgroups according to the material used 20 were made with Lava Ultimate and the other 20 with IPS e.max. Each subgroup was then further subdivided into two divisions according to the remaining tooth structure above the CEJ (n=10): 2 mm and 0.5 mm above the CEJ. After teeth preparation, the restorations were all made by CAD/CAM system (Cerec MCXL). All samples had undergone cyclic fatigue testing, and then loaded to fracture using a universal testing machine. The specimens were measured and statistically analyzed using Mann-Whitney test for comparing the mean changes between the groups. Results: Lava Ultimate showed higher mean fracture load values than IPS e.max specimens. Conclusion: Endocrowns were found to be more favorable when used on endodontically treated teeth than the conventional post, core and crown restorations.KEYWORDSEndocrowns; All-ceramic; Fracture; Cyclic loading.

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Influence of the fabrication method on the fracture behavior of all-ceramic prosthesis

Cerâmica ◽

10.1590/0366-69132018643702371 ◽

2018 ◽

Vol 64 (370) ◽

pp. 284-287

Author(s):

A. C. Piccoli ◽

M. Borba

Keyword(s):

Fracture Behavior ◽

Testing Machine ◽

Slip Casting ◽

Fracture Load ◽

Resin Cement ◽

Fabrication Method ◽

All Ceramic ◽

Cad Cam ◽

Ceramic Crowns ◽

Student’S T

Abstract Different methods are available to produce all-ceramic dental prosthesis. Each processing step may introduce flaws to the material, which compromises its properties and reliability. The objective of this study was to evaluate the effect of fabrication method on the fracture behavior of prosthetic crowns produced with an alumina-based glass-infiltrated zirconia-reinforced ceramic. Two groups of all-ceramic crowns were produced according to the fabrication method of the infrastructure (IS) (n=30): IZC - IS produced by CAD-CAM; IZS - IS produced by slip-casting. The IS were veneered with porcelain and cemented to fiber-reinforced composite dies with resin cement. Crowns were loaded in compression to failure using a universal testing machine, at 1 mm/min crosshead speed and 37 ºC distilled water. Fractography was performed using stereomicroscope and SEM. Data were statistically analyzed with Student’s t test (α=0.05) and Weibull analysis. There were no significant differences among the experimental groups for fracture load (p=0.481) and Weibull modulus. For both groups, the failure mode was catastrophic failure involving IS and porcelain. It was concluded that the fabrication methods evaluated resulted in all-ceramic crowns with similar fracture behavior and reliability.

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Fracture Load of Metal, Zirconia and Polyetheretherketone Posterior CAD-CAM Milled Fixed Partial Denture Frameworks

Materials ◽

10.3390/ma14040959 ◽

2021 ◽

Vol 14 (4) ◽

pp. 959

Author(s):

Verónica Rodríguez ◽

Celia Tobar ◽

Carlos López-Suárez ◽

Jesús Peláez ◽

María J. Suárez

Keyword(s):

Computer Aided Design ◽

Testing Machine ◽

Fracture Load ◽

Fracture Pattern ◽

Bending Test ◽

Weibull Statistics ◽

Promising Alternative ◽

Computer Aided ◽

Cad Cam ◽

Group 2

The aim of this study was to investigate the load to fracture and fracture pattern of prosthetic frameworks for tooth-supported fixed partial dentures (FPDs) fabricated with different subtractive computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Thirty standardized specimens with two abutments were fabricated to receive three-unit posterior FDP frameworks with an intermediate pontic. Specimens were randomly divided into three groups (n = 10 each) according to the material: group 1 (MM)—milled metal; group 2 (L)—zirconia; and group 3 (P)—Polyetheretherketone (PEEK). The specimens were thermo-cycled and subjected to a three-point bending test until fracture using a universal testing machine (cross-head speed: 1 mm/min). Axial compressive loads were applied at the central fossa of the pontics. Data analysis was made using one-way analysis of variance, Tamhane post hoc test, and Weibull statistics (α = 0.05). Results: Significant differences were observed among the groups for the fracture load (p < 0.0001). MM frameworks showed the highest fracture load values. The PEEK group registered higher fracture load values than zirconia samples. The Weibull statistics corroborated these results. The fracture pattern was different among the groups. Conclusions: Milled metal provided the highest fracture load values, followed by PEEK, and zirconia. However, all tested groups demonstrated clinically acceptable fracture load values higher than 1000 N. PEEK might be considered a promising alternative for posterior FPDs.

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