Evaluation of Fracture Resistance of Mandibular Premolar Canals Filled with Four Different Obturation Techniques- An In vitro Study

Abstract

Introduction: To prevent the ingress of microorganisms and their byproducts into root canal space is the primary goal of obturation. Endodontically treated teeth are weak and more susceptible to fracture than vital teeth. Therefore, to increase the strength of the root canal and increase root fracture resistance by adhesion and mechanically interlocking root canal filling material with radicular dentin is also one of the goal of obturation. Aim: To evaluate and compare the fracture resistance of mandibular premolar canals filled with four different obturation techniques. Materials and Methods: The in vitro study was conducted in Department of Conservative Dentistry and Endodontics, Krishna Institute of Medical Sciences (Deemed To Be University), Karad, Maharshtra, India, from August 2020 to December 2020. A total of 100 extracted human mandibular premolars with single canals were collected for the study and sectioned horizontally to obtain a standardised length of 14 mm. With the help of 15 K-file (Dentsply) working length was determined and root canals were prepared to an International Organisation for Standardisation (ISO) size 45 file at the apex and flared using a #4 Gates-Glidden drill (Mani, Japan). The teeth were then randomly divided into four experimental groups, Group I-Lateral condensation, Group II-ROEKO GuttaFlow® bioseal, Group III- Guttacore, Group IV-Thermoplasticised gutta percha (System B) and two control groups, they were Group V-(Negative control), instrumentation was done, but no obturation, Group VI-(Positive control), teeth were neither instrumented nor obturated. All the experimental teeth were filled as per the obturation technique. A universal testing machine was used for evaluating fracture resistance. The results were analysed using the One-way ANOVA test. The significance between the groups was tested with Scheffe’s post hoc test. Results: There were statistically significant difference among six group for mean fracture load (N) with p-value <0.001. furthermore, pair wise comparison of fracture load (N) showed that the mean difference is significant at p-value <0.05. The mean difference between Group IV and V was not significant (p-value=0.935) Conclusion: Under the limitation of this study, it was concluded that the resistance of the root to vertical fracture amongst the experimental group was maximum in Group III (Guttacore) and minimum in Group IV (Thermoplasticised gutta-percha, System B).