Comparative study of root canals instrumented manually and mechanically, with and without Er:YAG laser.

Objective: The aim of this study was to compare the scanning electron microscopic (SEM) morphology of root canal walls instrumented manually and mechanically with and without the application of Er:YAG laser.
Methods: Single-rooted, human, extracted teeth were cut at the cementoenamel junction. The teeth were divided into four groups: teeth that were simply instrumented manually, those that were instrumented manually and laser treated, a group that was mechanically instrumented, and a fourth in which the teeth were mechanically instrumented and laser treated. After instrumentation, the teeth were split longitudinally to facilitate their evaluation by SEM.
Results: The results show that the use of the Er:YAG laser is effective in removing the smear layer from root canal walls.
Conclusions: The removal of the smear layer is essential to the success of endodontic treatment; the use of the Er:YAG laser combined with rotary and manual techniques improves the cleanliness of root canals.