COMPARISON OF DENTINAL CRACK FORMATION DURING CANAL INSTRUMENTATION WITH NEW RECIPROCATION FILE SYSTEM AND CONVENTIONAL ROTARY SYSTEM BY OPTICAL COHERENCE TOMOGRAPHY (OCT) SCAN

Background/Purpose: Canal instrumentation with rotary nickel-titanium (NiTi) instruments might weaken the dentinal wall. This study aims to investigate the apical root cracks during canal instrumentation with new reciprocatory system and comparing it with the conventional rotary systems by using optical coherencetomography (OCT) scans. Materials and methods: Twenty mandibular incisors were selected and divided into two groups that are instrumented using S-One pro (S-one) and ProTaper Universal (PTU) systems. OCT scans were taken immediately after canal instrumentation with file #25, #30 and #40. Each cross-sectional reconstructed image of 1, 2 and 3 mm from the apex was examined, root cracks were scored, and dentin thickness was measured at 12 sites. Our null hypothesis was that there would be no difference in root cracks formation between different file systems used.