Comparative evaluation of bondingbetween composite relined fibre post and Conventional fibre post: an in-vitrostudy

Background:Fiber posts are widely used aesthetic material in restorative dentistry. These materials were introduced to overcome the inherent shortcomings of cast posts.Aim: This study aimed to evaluate and compare the pull-out bond strengthof fibre posts with relining and without relining.Materials and methods:Twenty maxillary canines were extracted and underwent endodontic treatment, involving the removal of their crown portion. Post-space preparation was performed, and the appropriate post size was selected. In Group 1, ten samples were coated with a layer of composite, reinserted into the post space of the canal, and then light cured outside the canal. The other ten samples (Group 2) were without relining. The fibre posts from both groups were cemented with RMGIC. The samples were mounted in tensile fixtures ofthe universal testing machine and subjected to a tensile load until the posts were debonded. The debonded samples were analysed using a stereo microscope for bond failure analysis. The obtained results were subjected to statistical analysis.Results:The mean pull-out force in group 1 and group 2 was 72.2100±8.56420 and 61.3700±11.00611, respectively. One way ANOVA analysis showed a significant difference in the pull-out force among the groups (P=0.043). In Group 1, 30% of the samples reported adhesive-2failures and 70% adhesive-1&2 failures. But in Group 2, all samples were reported with adhesive-3 failures. Fisher’s Exact test displayed a significant difference in the type of bond failure between the groups (P=0.003).Conclusions:This study concluded that the coating of the fibre posts improves their tensile strength.