Evaluation of cutting ability and plastic deformation of reciprocating files

Abstract This in vitro study evaluated the cutting ability of reciprocating files and the deformations caused by their multiple use. Five Reciproc® R25 files were divided into five groups for 10 simulated root canal preparations each. The resin blocks were weighed and photographed (12.5X and 20X) before and after preparation. The canals were prepared according to the manufacturer’s instructions. Enlargement of the root canals was evaluated by comparison of pre- and post-preparation images using a computer software. The preoperative and postoperative weight differences determined the cutting ability of repeatedly used instruments. The data were analyzed using Lilliefors and Friedman statistical tests. The cutting ability and enlargement of the canals gradually decreased after each use, with significant differences observed at the 8th and 9th repetitions, respectively. There was no evidence of file deformation. The cutting ability and enlargement of the simulated canals gradually decreased when a reciprocating file was used up to 10 times

Image-based study of marginal bone loss in teeth restored with cast endodontic posts

The aim of this study was to assess marginal bone loss in teeth restored with endodontic posts on all four aspects of the teeth using cone beam tomography. Bone loss was assessed via scores (0-5) in relation to root length and bone height. The results showed that the scores for the contralateral and restored sides, respectively, ranged from 0 to 3 and 0 to 5 buccally, 0 to 4 and 0 to 4 palatally, 0 to 3 and 0 and 4 mesially and 0 to 3 and 0 to 4 distally. A significant difference in bone loss was observed between the post-restored teeth and their contralaterals for the buccal, lingual/palatal and mesial aspects (p<0.05), with teeth bearing endodontic posts scoring highest. In conclusion, marginal bone loss was higher in teeth restored with intra-canal posts when compared to their sound contralaterals