The Performance of Abutment Material and Finish Line Configuration on the Stress Distribution and Fracture Resistance of Implant-Supported Zirconia Fixed Partial Dentures When Loaded in a Bio-Faithful Model

2021 ◽  
Vol 41 (6) ◽  
pp. e265-e275
Author(s):  
Mohamed Radwan ◽  
A Shabban ◽  
Donia Elshafey ◽  
Aliaa Mahrous
Keyword(s):  
Stress Distribution ◽  
Fracture Resistance ◽  
Finish Line ◽  
Line Configuration

scholarly journals 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 ◽  
2021 ◽  
Vol 8 ◽  
pp. 1020
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.

scholarly journals Fracture Resistance and Strain Analysis of Zirconia Copings With Vertical Knife Edge and Three Horizontal Finish Line Designs; Chamfer, Deep Chamfer and Shoulder With Two Cementation Techniques

2021 ◽  
Vol 24 (4) ◽  
Author(s):  
Marwa Emam ◽  
Amr El-Etreby ◽  
Jihan Farouk Younis
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Tetragonal Zirconia ◽  
Resin Cement ◽  
Knife Edge ◽  
Glass Ionomer ◽  
Finish Line ◽  
Promising Alternative ◽  
Significant Difference ◽  
Mean Strain

Objective: The purpose of this in vitro study is to evaluate the effect of four finish line configurations and two cement types on the fracture resistance of zirconia copings. Material and Methods: Forty yttrium tetragonal zirconia polycrystals copings were manufactured on epoxy resin dies with four preparation designs: knife edge, chamfer, deep chamfer 0.5, 1 mm and shoulder 1 mm. The copings were cemented with two cement types (glass ionomer and resin cement); (n = 5). Two strain gauges were attached on each coping before they were vertically loaded till fracture with a universal testing machine. Data were analyzed by 2-way analysis of variance ANOVA (p < .05). Fractured specimens were examined for mode of failure with digital microscope. Results: Knife edge showed the highest mean fracture resistance (987.04 ± 94.18) followed by Chamfer (883.28 ± 205.42) followed by Shoulder (828.64 ± 227.79) and finally Deep chamfer finish line (767.66 ± 207.09) with no statistically significant difference. Resin cemented copings had higher mean Fracture resistance (911.76 ± 167.95) than glass ionomer cemented copings (821.55 ± 224.24) with no statistically significant difference. Knife edge had the highest strain mean values on the buccal (374.04 ± 195.43) and lingual (235.80 ± 103.46) surface. Shoulder finish line showed the lowest mean strain values on the buccal (127.47 ± 40.32) and lingual (68.35 ± 80.68) with no statistically significant difference. Resin cemented copings had higher buccal (295.05 ± 167.92) and lingual (197.38 ± 99.85) mean strain values  than glass ionomer copings (149.14 ± 60.94) and (90.27 ± 55.62) with no statistically significant difference. Conclusion: Vertical knife edge finish line is a promising alternative and either adhesive or conventional cementation can be used with zirconia copings.   KEYWORDS Cementation; Flexural strength; Prosthodontics; Tooth preparation; Zirconium.

scholarly journals Fracture Resistance of Monolithic Zirconia Crowns on Four Occlusal Convergent Abutments in Implant Prosthesis

2019 ◽  
Vol 9 (13) ◽  
pp. 2585 ◽  
Author(s):  
Ting-Hsun Lan ◽  
Chin-Yun Pan ◽  
Pao-Hsin Liu ◽  
Mitch M.C. Chou
Keyword(s):  
Cyclic Loading ◽  
Stress Distribution ◽  
Surface Area ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Hydraulic Testing ◽  
Occlusal Surface ◽  
Von Mises Stress ◽  
Implant Abutment ◽  
Von Mises

Adjusting implant abutment for crown delivery is a common practice during implant installation. The purpose of this study was to compare the fracture resistance and stress distribution of zirconia specimens on four occlusal surface areas of implant abutment. Four implant abutment designs [occlusal surface area (SA) SA100, SA75, SA50, and SA25] with 15 zirconia prostheses over the molar area per group were prepared for cyclic loading with 5 Hz, 300 N in a servo-hydraulic testing machine until fracture or automatic stoppage after 30,000 counts. The minimum occlusal thickness of all specimens was 0.5 mm. Four finite element models were simulated under vertical or oblique 10-degree loading to analyze the stress distribution and peak value of zirconia specimens. Data were statistically analyzed, and fracture patterns were observed under a scanning electron microscope. Cyclic loading tests revealed that specimen breakage had moderately strong correlation with the abutment occlusal area (r = 0.475). Specimen breakage differed significantly among the four groups (P = 0.001). The lowest von Mises stress value was measured for prosthesis with a smallest abutment occlusal surface area (SA25) and the thickest zirconia crown. Thicker zirconia specimens (SA25) had higher fracture resistance and lowest stress values under 300 N loading.

scholarly journals Examination of stress distribution and fracture resistance in five-unit tooth- and implant-supported partial fixed zirconia prosthesis

2015 ◽  
Vol 29 (6) ◽  
pp. 1176-1183 ◽  
Author(s):  
Sedat Guven ◽  
Suleyman Aguloglu ◽  
Koksal Beydemir ◽  
Serkan Dundar ◽  
Yusuf Atalay ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Fracture Resistance

scholarly journals Evaluation of fracture resistance of zirconia monolithic restorations: an in vitro study

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Ahmed Mohamed Arafa ◽  
Ahmad El-Kouedi ◽  
Tamer Hamza ◽  
Hisham Katamish
Keyword(s):  
Stainless Steel ◽  
Fracture Resistance ◽  
Artificial Aging ◽  
Testing Machine ◽  
Control Group ◽  
Hydrothermal Conditions ◽  
Finish Line ◽  
M Phase ◽  
Group A ◽  
Group B

Objective: The aim of the study was to evaluate fracture resistance of zirconia monolithic restorations after ageing procedures. Material and methods: The fracture resistance of zirconia-based restoration after ageing procedures was evaluated. Monolithic translucent zirconia 3-unit FDPs were fabricated using Cerec inLab CAD/CAM system on 2 stainless steel dies prepared from stainless steel with a uniform 120 degrees circumferential deep chamfer finish line of 1 mm width and were placed into a stainless steel holder. FDPs were divided into 2 groups, the first group (Group A) was subjected to aging procedures in an autoclave at hydrothermal conditions 134 °C /2 bars for 5 hours. The second group (Group B) was not subjected to any ageing procedures and was designed as control group. All specimens of group A (Aged TZI) and group B (non- aged TZI) were loaded compressively in a universal testing machine at cross head speed 0.5 mm/min until fracture occurred. The percentage of monoclinic (m) phase was detected by XRD device. Scanning electron microscope (SEM) was used to examine the fractured surfaces for Aged TZI (Group A) and Non-aged TZI (Group B). Student’s t-test was used to compare between fracture resistances of both groups. The significance level was set at P ? 0.05. Results: The fracture resistance mean (SD) values of non-aged TZI (Group B) was 2406.9±306.8 N which showed statistically significantly higher than that of aged group (Group A) which was 1964.5±234.5 N. The percentage of monoclinic (m) phase detected by XRD device software in non-aged TZI (Group B) was nearly 0 weight % and in aged TZI (Group A) was about 42 weight %. Conclusion: Accelerated artificial aging decreases the fracture resistance of monolithic TZI FDPs. Keywords Artificial aging; Fracture resistance; Monolithic zirconia.

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