A comparison between two current irrigation concepts for smear layer removal efficacy at the apical third of root canal system

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Thesis (MSD) --Boston University Institute for Dental Research and Education, Dubai, 2012 (Endodontics).Includes bibliographic references: leaves 71-87.INTRODUCTION: Multiple studies have suggested that bacteria and debris remain in the apical area within the root canal system even after meticulous chemo-mechanical debridement. However, some studies have suggested that agitation of the irrigation can increase efficacy of debris and smear layer removal in all areas of the canal system. PURPOSE: To compare between negative-pressure irrigation technique at two different exposure times to the passive ultrasonic irrigation technique for smear layer removal efficacy at the apical third of root canal system using EndoVac[R] (Discus Dental[R], Culver City, CA) versus ProUltra[R] PiezoFlow[TM] ultasonic irrigation needle (DENTSPLY Tulsa). METHODS AND MATERIALS: A total of eighty extracted human teeth or roots with fully developed apices with single canal will be assigned in this in vitro study. Canal was instrumented to a master apical file size#40/.04 taper. The samples was assigned into 2 main groups according to the final agitation of irrigation technique and then each main group was randomly divided into 2 different test subgroups with five teeth in each group according to the irrigation protocols. Two control groups of 2 teeth in each was included to confirm that the basic conditions of the experiment were able to produce a negative or positive result. Subsequently, the roots were split longitudinally in a buccolingual direction, resulting in 5 samples per subgroup. Each specimen was mounted on stubs, gold-sputtered, and was examined under scanning electron microscope the amount of remaining debris and smear layer at the apical region of each specimen was scored by three blinded expert observers with a 5-score system. RESULTS: For the apical aspect, there were significant differences in smear layer for the testing groups and the controls with significantly lower scores for EndoVac[R] and PiezoFlow[TM] among groups when one additional minute of EDTA was used. There was not a significant difference in debris scores among groups and none of the pairwise differences were significant. For the apical location of canal there was not a significant difference in debris scores among groups (p=0.8619), and none of the pairwise differences were significant. CONCLUSION: Additional application of activated 17% EDTA for 1 min was actively working upon the smear layer, which it partially removed, remaining only in some obliterated dentinal tubules