scholarly journals Influence of preparation design and ceramic thicknesses on fracture resistance and failure modes of premolar partial coverage restorations

2013 ◽  
Vol 110 (4) ◽  
pp. 264-273 ◽  
Author(s):  
Petra C. Guess ◽  
Stefan Schultheis ◽  
Martin Wolkewitz ◽  
Yu Zhang ◽  
Joerg R. Strub
2015 ◽  
Vol 16 (8) ◽  
pp. 613-618 ◽  
Author(s):  
Safoura Ghodsi ◽  
Reza Shabanpour ◽  
Niloufar Mousavi ◽  
Marzieh Alikhasi

ABSTRACT Aim The purpose of the current study was to compare the fracture resistance and mode of failure of zirconia and titanium abutments with different diameters. Materials and methods Fourteen groups of abutments including prefabricated zirconia, copy-milled zirconia and titanium abutments of an implant system (XiVE, Dentsply) were prepared in different diameters. An increasing vertical load was applied to each specimen until failure occurred. Fracture resistance was measured in each group using the universal testing machine. Moreover, the failure modes were studied and categorized as abutment screw fracture, connection area fracture, abutment body fracture, abutment body distortion, screw distortion and connection area distortion. Groups were statistically compared using univariate and post-hoc tests. The level of statistical significance was set at 5%. Results Fabrication method (p = 0.03) and diameter (p < 0.001) had significant effect on the fracture resistance of abutments. Fracture resistance of abutments with 5.5 mm diameter was higher than other diameters (p < 0.001). The observed modes of failure were dependent on the abutment material as well. All of the prefabricated titanium abutments fractured within the abutment screw. Abutment screw distortion, connection area fracture, and abutment body fracture were the common failure type in other groups. Conclusion Diameter had a significant effect on fracture resistance of implant abutments, as abutments with greater diameters were more resistant to static loads. Copy-milled abutments showed lower fracture resistance as compared to other experimental groups. Clinical significance Although zirconia abutments have received great popularity among clinicians and even patients selecting them for narrow implants should be with caution. How to cite this article Shabanpour R, Mousavi N, Ghodsi S, Alikhasi M. Comparative Evaluation of Fracture Resistance and Mode of Failure of Zirconia and Titanium Abutments with Different Diameters. J Contemp Dent Pract 2015;16(8):613-618.


F1000Research ◽  
2021 ◽  
Vol 8 ◽  
pp. 1020
Author(s):  
Omnia Nabil ◽  
Carl Hany Halim ◽  
Ashraf Hassan Mokhtar

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.


2020 ◽  
Vol 24 (8) ◽  
pp. 2745-2754 ◽  
Author(s):  
Uwe Blunck ◽  
Sabine Fischer ◽  
Jan Hajtó ◽  
Stefan Frei ◽  
Roland Frankenberger

2016 ◽  
Vol 20 (2) ◽  
pp. 99-103
Author(s):  
Katerina Zlatanovska ◽  
Ljuben Guguvcevski ◽  
Risto Popovski ◽  
Cena Dimova ◽  
Ana Minovska ◽  
...  

Summary Background: The aim of this in vitro study was to examine the fracture load of composite veneers using three different preparation designs. Material and methods: Fifteen extracted, intact, human maxillary central incisors were selected. Teeth were divided into three groups with different preparation design: 1) feather preparation, 2) bevel preparation, and 3) incisal overlap- palatal chamfer. Teeth were restored with composite veneers, and the specimens were loaded to failure. The localization of the fracture was recorded as incisal, gingival or combined. Results: Composite veneers with incisal overlap - palatal chamfer showed higher fracture resistance compared to feather preparation and bevel preparation. The mean (SD) fracture loads were: Group 1: 100.6±8.0 N, Group 2: 107.4±6.8 N, and Group 3: 122.0±8.8 N. The most common mode of failure was debonding for veneers with feather preparation and fracture when incisal edge is reduced. The most frequent localization of fracture was incisal. Conclusion: The type of preparation has a significant effect on fracture load for composite veneers. This study indicates that using an incisal overlap- palatal chamfer preparation design significantly increases the fracture resistance compared to feather and bevel preparation designs.


2015 ◽  
Vol 40 (2) ◽  
pp. 211-217 ◽  
Author(s):  
EM Bakeman ◽  
N Rego ◽  
Y Chaiyabutr ◽  
JC Kois

SUMMARY This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (p&lt;0.001); however, the thickness of ceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (p&lt;0.05). There was no significant difference in fracture resistance values between a lithium disilicate ceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.


2009 ◽  
Vol 21 (2) ◽  
Author(s):  
Rifki Kania Pramanik ◽  
Gantini Subrata ◽  
Erna Kurnikasari

Post-placement is one of the treatment plans supporting the success of a restoration. The design of root canal preparation is a factor in the success of post-use. The purpose of this study was to investigate the root fracture resistance of the root canal preparation for cast post with a seat and non-seat preparation. The study was a laboratory experimental study using 20 upper central incisors that met the criteria in the study. Ten incisors were prepared using seat design while the other ten were prepared using non-seat design. Then tested the compressive test by Universal Testing Machine with test speed 0,5 mm/min. The results of the fracture strength were analyzed using t student statistical test. The analysis showed a significant difference between the non-seat group and the seat group (α=0.05). The average force in the non-seat group was 852.27 N with a standard deviation of 112.6 N while the seat group showed a value of 495.78 N and 82.90 N, respectively. It was concluded therefore that the root fracture resistance in the non-seat root canal preparation design was higher than the seat preparation design.


2012 ◽  
Vol 40 (3) ◽  
pp. 202-209 ◽  
Author(s):  
Tai-Min Lin ◽  
Perng-Ru Liu ◽  
Lance C. Ramp ◽  
Milton E. Essig ◽  
Daniel A. Givan ◽  
...  

2008 ◽  
Vol 33 (5) ◽  
pp. 526-533 ◽  
Author(s):  
F. K. Cobankara ◽  
N. Unlu ◽  
A. R. Cetin ◽  
H. B. Ozkan

Clinical Relevance To restore endodontically-treated molars, the use of indirect hybrid inlay restorations may be recommended due to their more favorable fracture failure modes compared with amalgam, resin composite and fiber-reinforced resin composite restoration techniques and their greater fracture resistance compared with amalgam restorations.


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