In vitro evaluation of the strength of endodontically treated teeth after preservation of soffit and pericervical dentin

Aim: To evaluate the strength of an endodontically treated tooth after preservation of peri-cervical dentin and soffit. Methodology: 30 human molars having well developed cusps and morphology were extracted for periodontal reasons were included in this study. They were divided in two groups. In gp. A, ClarkKhademi access was made and endodontic treatment was carried out with 2% NiTi K-files and in gp. B, Straight line access was made and endodontic treatment was carried out with 2% NiTi K-files. Normal endodontic treatment was carried out with 2% flexible NiTi K-files with 17% EDTA as chelating agent and 5.25% Sodium Hypochlorite solution for irrigation. Obturation was carried out using the lateral condensation technique with guttapercha coated with sealer. After this, the pulp chamber was cleaned thoroughly with cotton and all-in-one bonding agent was applied and scrubbed with an applicator tip for 30 seconds. Next, Composite restoration was done as post-obturation restoration. Specimens were then tested with a universal testing machine, set to deliver an increasing load until failure. Failure was defined as a 25% drop in the applied load. The load was applied parallel to the long axis of the tooth. The variable of interest was the load at failure measured in Newtons. The data thus obtained was subjected to statistical analysis and was analysed using one way ANOVA test for significance with Bonferroni corrections. Result: The teeth with Clark-Khademi access preparation with 2% taper of the endodontic files were more efficient at resisting the fracture than the teeth with straight line access preparation with 2% taper of the endodontic files. Conclusion: The teeth after preservation of pericervical dentin and soffit were found to be structurally reinforced as compared to the teeth with straight line access. Clark-Khademi access preparation was found to be more effective at dentin preservation and strengthening the tooth when compared to straight line access.