Laser applications in smear layer removal from posterior root canals: A comparative study

Area of Science:

• Endodontics
• Dental Laser Technology
• Biomaterials Science

Background:

• Smear layer removal is crucial for endodontic treatment success.
• Conventional methods for smear layer removal can be challenging in complex root canal anatomy.
• Erbium lasers offer a potential alternative for root canal cleaning.

Purpose of the Study:

• To evaluate the efficacy of erbium lasers in removing smear layer from mesial roots of mandibular first molars.
• To compare the performance of two types of erbium lasers (Er, Cr: YSGG and erbium-doped YAG) at various settings.
• To assess the influence of irrigation protocols and laser power on smear layer removal.

Main Methods:

• One hundred mandibular first molars were used, with 96 mesial roots divided into experimental groups.
• Two laser wavelengths (Er, Cr: YSGG and erbium-doped YAG) were applied with different irrigation protocols and power settings.
• Samples were examined using scanning electron microscopy (SEM) for smear layer evaluation.

Main Results:

• No significant difference in smear layer removal was found between the two erbium laser types.
• Significant differences were observed between subgroups with different irrigation protocols (A vs. B) for both laser types.
• While groups IIA and IIB showed better outcomes in all root thirds, the difference was not statistically significant. No significant differences were found among varying laser power subcategories.

Conclusions:

• The tested erbium laser parameters were insufficient for complete smear layer removal from root canals.
• Chelating agents may play a supportive role in enhancing laser-assisted smear layer removal, particularly in the apical portions of narrow and curved canals.