Structural and functional changes in root dentin following exposure to KTP/532 laser

Area of Science:

• Endodontics
• Dental Materials Science
• Laser Dentistry

Background:

• The smear layer in root canals can impede treatment efficacy.
• Understanding laser-tissue interactions is crucial for endodontic procedures.
• Nd:YAG lasers have been explored for endodontic applications.

Purpose of the Study:

• To evaluate the KTP/532 laser's effect on root canal dentin permeability.
• To assess the impact of KTP/532 laser irradiation on the scanning electron microscopic (SEM) appearance of canal dentin.
• To investigate these effects under conditions with and without smear layer removal.

Main Methods:

• KTP/532 laser application within root canals at controlled energy levels and exposure times (1 W x 1 s to 5 W x 0.5 s) to maintain periodontal temperature below 5°C.
• Root canals were prepared with either intact smear layer or treated with EDTA/NaOCI for smear layer removal.
• Dentin permeability was measured, and canal dentin surfaces were examined using SEM.

Main Results:

• The KTP/532 laser did not alter the permeability of smear layer-covered dentin.
• SEM revealed surface modifications to the smear layer after laser treatment.
• Lasing of etched dentin resulted in modest increases in root permeability.
• These permeability increases were linked to the enlargement and cracking of dentinal tubule orifices.

Conclusions:

• The KTP/532 laser, under the tested parameters, does not increase dentin permeability when the smear layer is present.
• Laser irradiation of etched dentin can enhance root permeability by affecting dentinal tubules.
• Further research is needed to fully understand the clinical implications of these findings in endodontics.