The effect of smear layer removal on internal apical baterial leakage along root canal fillings using three diferent obturation techniques

الملخص EN

Aim : This study was conducted to evaluate the influence of smear layer removal on internal apical bacterial leakage of infected root canals obturated with 3 techniques ; single cone, lateral compaction and vertical compaction with System-B.

Materials and Methods : A total of 140 human teeth were prepared using ProTaper rotary files.

The samples were classified into 2 equal groups according to whether the smear layer was removed or not.

The root canals were inoculated with Enterococcus faecalis suspension and incubated at 37°C for 1 week.

Each group of roots was then subdivided into 3 equal experimental subgroups according to the obturation technique.

Following obturation, the samples were suspended in Trypticase Soy Broth (TSB) and the broth was checked on daily basis for turbidity, as an evidence for internal apical bacterial leakage up to 3 months.

Results : All obturation techniques leaked more slowly in the absence of smear layer than in its presence, the difference was statistically significant for single cone technique, where-as for lateral compaction and vertical compaction techniques the difference was insignificant.

It was also observed that smear layer removal significantly minimized the counts of leaked bacteria through the apical foramen.

Conclusions : Smear layer removal minimizes the counts of leaked bacteria through the previously infected root canals and may enhance the sealability of the root canal obturation.