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Effects of Endodontic Access Cavity Design and Thermocycling on Fracture Strength of Endodontically Treated Teeth

Authors Saberi EA, Pirhaji A, Zabetiyan F

Received 31 October 2019

Accepted for publication 16 April 2020

Published 23 April 2020 Volume 2020:12 Pages 149—156


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 5

Editor who approved publication: Professor Christopher E. Okunseri

Eshagh Ali Saberi,1 Arezoo Pirhaji,2 Fatemeh Zabetiyan3

1Department of Endodontics, Faculty of Dentistry, Oral and Dental Diseases Research Center, Zahedan University of Medical Sciences, Zahedan, Iran; 2Department of Endodontics, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran; 3General Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran

Correspondence: Eshagh Ali Saberi
Department of Endodontics, Faculty of Dentistry, Azadegan Street, Zahedan, Iran
Tel +98 9151416924

Introduction: This study aimed to assess the fracture strength of endodontically treated mandibular molars with traditional endodontic access cavity (TEC) and truss endodontic access cavity (TREC) designs that were restored with composite resin and underwent thermocycling.
Methods: Sixty mandibular first and second molars were randomly divided into 6 groups (n=10) of intact controls without thermocycling (group 1), intact controls with thermocycling (group 2), TEC without thermocycling (group 3), TEC with thermocycling (TEC-TC, group 4), TREC without thermocycling (group 5) and TREC with thermocycling (TREC-TC, group 6). The root canals were then instrumented to #25,7% using nickel-titanium files and were filled with gutta-percha and AH26 sealer with lateral compaction technique. Access cavity was restored with Gradia composite. All teeth were then thermocycled for 480 cycles between 5°C and  55°C for 30 seconds and their fracture strength was measured in a universal testing machine with a round-end piston with 6 mm diameter at a speed of 1 mm/min. Data were analyzed using two-way and one-way ANOVA.
Results: Without thermocycling, the fracture strength of endodontically treated teeth with TREC designs had no significant difference with the control group (P> 0.05). However, both TEC and TREC designs significantly decreased the fracture strength of endodontically treated teeth after thermocycling (P< 0.05), such that minimum fracture strength was noted in TEC-TC group.
Conclusion: Under the conditions of this ex vivo study, TREC enhances the fracture strength of endodontically treated teeth under thermal stresses.

Keywords: endodontic cavity, fracture strength, minimally invasive intervention

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