OR40 - A Microscopic Comparison of Dentinal Cracks After in Vitro Root-end Resection: Comparison Between a Surgical Piezoelectric Device and High-speed Bur Root Resections

Abstract: Piezoelectric ultrasonic devices for use in endodontic microsurgery (EMS) have gained popularity in recent years. Their surgical use is purported to decrease post-operative pain, intraoperative bleeding, and need for analgesics. Iatrogenic damage to soft tissues such as neurovascular structures or the sinus membrane is also minimized. Piezoelectric saws are powerful enough to perform root resection, but the effect on radicular dentin following resection has not been reported. Do micro-cracks form during root resection with a piezoelectric saw? A pilot study was performed ahead of an invitro study designed to compare micro-crack formation after root end resection with a piezoelectric saw vs. a conventional high-speed carbide surgical bur. Extracted teeth scheduled for disposal were resected and root ends observed for crack formation. Crack observation using high-magnification video microscopy (20-220x magnification) and scanning electron microscopy was compared. High-power video microscopy was found to be sufficient for crack identification. Root-end resections are currently underway on 30 bilaterally-matched-pairs of single-rooted teeth, 15 with a piezoelectric saw and 15 with a high-speed carbide bur. Time for root resection is recorded. Root tips are inspected under high-power video magnification with transillumination, and methylene blue staining for the presence, location, and number of micro-cracks. Preliminary analysis of data shows no significant difference in frequency of crack formation (p=0.005). The piezoelectric saw requires 2-3 times more time for resection compared to the high-speed carbide bur. Upon our preliminary findings it is suspected that the use of piezoelectric saws will not produce more micro-cracks than high speed carbide burs.