scholarly journals Influence of the type of post and core on in vitro marginal continuity, fracture resistance, and fracture mode of lithia disilicate-based all-ceramic crowns

2008 ◽  
Vol 100 (4) ◽  
pp. 264-273 ◽  
Author(s):  
Nicole Forberger ◽  
Till N. Göhring
2008 ◽  
Vol 9 (4) ◽  
pp. 17-25 ◽  
Author(s):  
Ilser Turkyilmaz ◽  
Suat Gokce ◽  
Emine Celik-Bagci

Abstract Aim The aim of this study was to investigate the influence of three different thicknesses of In-Ceram core on the load at fracture of all-ceramic crowns. Methods and Materials Thirty standardized crown-shaped nickel-chromium alloy dies were fabricated using a milling machine. Twenty dies were prepared with a 1 mm shoulder for Groups A and B. The only difference in the ten dies used for Group C was a smaller 0.5 mm lingual shoulder. The thicknesses of In-Ceram were 0.5 mm, 1.5 mm, and 0.75 mm for Groups A, B, and C. All all-ceramic crowns were fabricated in accordance with the manufacturer's instructions. After cementation of the crowns, their fracture resistance was tested with a universal testing machine. The load was directed to a point located 3 mm from the lingual aspect of the incisal edge at 30 degrees to the long axis of each specimen until catastrophic failure occurred. Results The mean loads at fracture for Groups A, B, and C were 1117±388 N, 2083±385 N, and 1439±368 N, respectively. No statistically significant difference in load at fracture between Groups A and C was found (p>0.05). However, the differences were statistically significant between Groups A and B (p<0.001) and Groups B and C (p<0.001). Conclusion Under the guidelines of this study, increasing the thickness of the In-Ceram core increased the fracture resistance of the all-ceramic crowns. Clinical Significance The sufficient thickness of the In-Ceram core of all-ceramic crowns is an important factor in fracture resistance. Therefore, dental practitioners should be careful in patient selection; if the horizontal overlap of a tooth to be restored is too limited, then all-ceramic crowns may not be a feasible option. Citation Gokce S, Celik-Bagci E, Turkyilmaz I. A Comparative in vitro Study of the Load at Fracture of Allceramic Crowns with Various Thicknesses of In-Ceram Core. J Contemp Dent Pract 2008 May; (9)4:017-025.


2012 ◽  
Vol 3 (1) ◽  
pp. 33-38
Author(s):  
Tariq Abduljabbar ◽  
Haneef Sherfudhin ◽  
S.A. AlSaleh ◽  
Abdulaziz A. Al-Helal ◽  
Saleh S. Al-Orini ◽  
...  

2020 ◽  
Vol 12 (5) ◽  
pp. 517
Author(s):  
Tharammal Fayaz ◽  
SanathK Shetty ◽  
Mohammed Zahid ◽  
KarkalaS Suhaim ◽  
Mallikarjun Ragher ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Carolina Clausson ◽  
Cristiano Clausson Schroeder ◽  
Paulo Vicenti Goloni ◽  
Flavio Artur Rego Farias ◽  
Leandro Passos ◽  
...  

The aim of this study was to evaluate the fracture resistance of 2 different types of all-ceramic crown using immediate dentin sealing (IDS), obtained using a CAD/CAM system on molars with different preparations. Forty extracted lower molars were endodontically treated and divided into four groups (n = 10) according to the dental preparation. Group 1 (SP0) was prepared without filling the pulp chamber and crown-root junction was located at the cementoenamel junction (CEJ). Group 2 (SP1) was prepared without filling the pulp chamber and crown-root junction was located 1-mm above the CEJ. Groups 3 and 4 contained a flat preparation surface with no axial wall height. Group 3 (CP0) was made IDS with complete filling of the pulp chamber with composite resin and crown-root junction was located at the CEJ. Group 4 (CP1) was prepared with complete filling of the pulp chamber and crown-root junction was located 1-mm above the CEJ. All groups were restored with CAD/CAM lithium disilicate ceramic crowns. Specimens were subjected to the fracture test and statistically analyzed using analysis of variance (ANOVA). Fracture mode was determined using a stereoscopic microscope, classified as repairable or nonrepairable, and analyzed using Fischer’s exact test. Results indicated that there were no significant differences between the groups in terms of fracture resistance or fracture pattern (p >0.05). Fracture resistance was the lowest in the SP0 group, followed by the SP1 group (1634.38 N) of CP0 (1821.50 N), and it was the highest in the CP1 group. There was a predominance of nonrepairable fractures and there were no significant differences in the fracture resistance and fracture mode of CAD/CAM lithium disilicate molar all-ceramic crowns. Endodontically treated molars teeth might be restored with endocrowns or all-ceramic crowns on flat preparation; however tooth fracture failures that affect reliability of these types of restorations should be considered.


2017 ◽  
Vol 7 (2) ◽  
pp. 97-102
Author(s):  
Sabita M Ram ◽  
Naisargi Shah ◽  
Amit M Gaikwad

ABSTRACT Aim To comparatively evaluate the fracture resistance of endodontically treated teeth restored with light-cured composite resin core using two different designs of prefabricated metal posts. Materials and methods A total of 30 single-rooted anterior teeth were selected for the study and endodontically treated. Teeth were sectioned 2 mm above the cementoenamel junction and were randomly divided into two groups (n = 15). Teeth in group I were restored with Parallel post—EG post and group II with parallel post with coronal flare—i post. Light-cured composite core buildup was done in all samples using a customized core former. Compressive load was applied at a 135° angle to the long axis of the tooth at a cross-head speed of 1 mm/minute until visible signs of fracture were observed. Levene's test and t-test were used to determine the difference of the failure loads between the groups (α = 0.05). Results The mean values (standard deviation [SD]) for fracture resistance were 295.55 N and 469.59 N for parallel post—EG post and parallel post with coronal flare—i post respectively. Since the p-value for the t-test is less than 0.05, it indicates that we should reject null hypothesis and conclude that the mean fracture load of parallel post with coronal flare—i post is significantly more than that of mean fracture load of parallel post—EG post. Conclusion The study conducted evaluated that the fracture resistance of endodontically treated teeth with parallel post with coronal flare—i post and core buildup had better strength as compared with parallel post—EG post and core buildup. Clinical significance The present study will help the clinician to select the appropriate prefabricated metal post that will fit exactly into the coronal flare of the canal improving clinical performance, thus increasing the longevity of the restoration. How to cite this article Gaikwad AM, Shah N, Ram SM. A Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth restored with Composite Resin Core using Two Different Designs of Prefabricated Metal Posts: An in vitro Study. J Contemp Dent 2017;7(2):97-102.


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