Under the conditions of these in vitro leakage studies , it is concluded that smear layer removal improves the fluid-tight seal of the root canal system whereas other factors such as the obturation technique or the sealer , did not produce significant effects
The purpose of this systematic review was to determine whether smear layer removal reduces leakage of obturated human teeth in vitro .
Bacterial penetration through canals of endodontically treated teeth in the presence or absence of the smear layer.
OBJECTIVES The goal of this study is to determine if the smear layer affects the passage of bacteria through or around obturating material as evidence d by penetration of bacteria through and out the canal . Specifically , this study focused on determining the effect of the smear layer on the magnitude of bacterial penetration through the apical foramen . METHODS Thirty extracted , maxillary central or lateral incisors were collected . Teeth were r and omly assigned ( 10 teeth per group ) to three groups : ( 1 ) smear layer removed , ( 2 ) smear layer present , and ( 3 ) negative control . Canal preparation and obturation using lateral condensation , gutta percha , and AH 26 sealer was performed on all of the teeth . Removal of the smear layer was accomplished by rinsing with 17 % EDTA . The model systems consisted of an upper chamber attached to the cemento-enamel junction and a lower chamber at the apices of the teeth . St and ardized bacterial suspensions containing Fusobacterium nucleatum , Campylobacter rectus , and Peptostreptococcus micros were inoculated into the upper chambers . Models were incubated anaerobically at 37 degrees C. At various times over a 60-day period , sample s were taken from the lower chamber and spiral-plated on selective-differential media to determine numbers and types of bacteria . RESULTS Leakage results were as follows : ( 1 ) smear layer present-6/10 leaked ; ( 2 ) smear layer removed-0/10 leaked ; ( 3 ) negative control-0/10 leaked . Profiles of bacterial leakage were similar among the groups . F. nucleatum was the predominant microorganism . CONCLUSIONS This study indicated that removal of the smear layer reduced the leakage of bacteria through the root canal system
Under the conditions of these in vitro leakage studies , it is concluded that smear layer removal improves the fluid-tight seal of the root canal system whereas other factors such as the obturation technique or the sealer , did not produce significant effects
The purpose of this systematic review was to determine whether smear layer removal reduces leakage of obturated human teeth in vitro .