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 .
Apical sealing ability of a new glass ionomer root canal sealer.
This study compared the sealing ability of Ketac Endo with and without smear layer and Tubli Seal .  Thirty upper central incisors and canines with straight canals were instrumented and r and omly divided into three equal groups of 10 . All teeth were obturated with laterally condensed gutta-percha . An additional group of five teeth with unobturated++ root canals served as positive controls . The sealers were Tubli Seal ( group A ) , Ketac Endo ( group B ) , and Ketac Endo preceded by the removal of the smear layer ( group C ) . The teeth were immersed in India ink for 7 days , centrifuged for 5 min at 3000 rpm , cleared , and then examined under a light microscope at X 50 magnification . The mean value of ink penetration for group A was 0.14 mm , for group B 0.24 mm , and for group C 0.48 mm . No statistically significant differences were observed among groups ( p > 0.05 )
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 .