Effect of incorporation of Nanoparticles on setting time, bond strength and fracture resistance of two endodontic sealers: an In-Vitro study

Abstract

The aim of the study was to evaluate the effect of incorporation of Silver nanoparticles (AgNPs) into two types of endodontic sealers; epoxy-resin based sealer (AH Plus) and bioceramic sealer (Sure-Seal Root). On push-out bond strength, fracture resistance and setting time. For bond strength and fracture resistance, a total of eighty-four human single-rooted teeth of upper incisors were used in this study. Eighty Teeth were decoronated, cleaned and shaped using crown-down technique. Samples were divided into two main groups (40 each) according to the type of sealer used; Group1 (AH Plus sealer) and Group2 (Sure-Seal Root sealer). Each group was divided into two subgroups (20 each); Subgroup A (with AgNPs) and Subgroup B (without AgNPs). Each subgroup was further subdivided into two subdivision (10 each); Subdivision 1 (subjected to push-out bond strength test) and Subdivision 2 (subjected to fracture resistance test). The remaining four teeth were used for fracture resistance test and classified into two control groups (2 each); positive control group (instrumented teeth) and negative control group (no shaping or filling). The teeth were obturated using one of the tested sealers (AH Plus / Sure-Seal Root) with and without incorporation of AgNPs by lateral condensation technique. The bond strength was evaluated using the push-out test, and the failure mode was analyzed using digital microscope for all the tested samples. While the fracture resistance was measured by using a vertical load with zero angle subjected on each sample until fracture occurred. Both push-out bond strength & fracture resistance tests were performed using the Universal testing machine.