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 .
Effect of removal of the smear layer on apical microleakage.
It has been shown previously that the smear layer created during instrumentation of the root canal promotes apical microleakage . The purpose of the present study was to investigate the effect of removal of the smear layer on apical microleakage , using the fluid filtration method . Thirty-six single-rooted human premolar teeth were used . Six of the teeth were selected r and omly as controls , and the remaining 30 teeth were r and omly divided into two groups of 15 teeth each . For the first group ( group 1 ) teeth were irrigated with NaOCl only ( smear layer not removed ) . In the second group ( group 2 ) the teeth were irrigated with 15 % EDTA , followed by NaOCl to remove the smear layer . Both groups were filled with thermoplasticized gutta-percha ( Obtura II ) using glass-ionomer cement as sealer . All teeth were stored at 37 degrees C and 100 % humidity for 2 days . Apical microleakage of the filled root canal was measured by the fluid filtration technique . Hydraulic conductance was measured by the movement of an air bubble in a capillary tube after a pressure of 200 mm Hg was applied to the system . The mean microleakage rate of group 1 and group 2 were 13.0 ( SD + /- 5.1 ) and 16.9 ( SD + /- 15.3 ) nl/s , respectively . Removal of the smear layer caused significantly more apical microleakage ( p < 0.05 , Student 's t test ) than when the smear layer was left intact
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 .