Laser sterilization technique for root canal treatment: Investigating the use of thulium fiber laser

Abstract

Conventional endodontic treatment uses a chemomechanical protocol to eliminate all infected debris and take the bacteria out from the root canal in order to prevent the development of persisting apical periodontal inflamation. The inadequate penetration depth of irrigants and anatomical irregularities of root canal negatively affect the success of the treatment. Laser assisted endodontic treatment is a new and effective adjunctive method in root canal to enhance the quality of the conventional treatment. The aim of this study is to evaluate a new wavelength, 1940-nm thulium fiber laser, in endodontic studies and finding optimum parameter ranges for an antibacterial efficiency while protecting the health of root canal and paradontal tissues. This thesis study consists of preliminary and main experiment parts. Initiatory experiments were done in order to learn and practice in oral microbiology and laboratory protocols. Main part of this study has preliminary analyses for determining the optimum irradiation parameters with regard to the temperature increase and identifying the effective laser power and irradiation time ranges for a sufficient antibacterial effect in vitro. With the parameters obtained from the pre-studies, optimum parameters range for 1940-nm Thulium Fiber Laser assisted endodontic therapy was considered within the safest conditions. After definining 1 W for the maximum safe laser power in root canal therapy, antibacterial efficiencies of four different laser powers were compared. After obtaining an sterilization up to log kill of 3, optimum laser power was examined in three different irradiation times: 15s, 30s, and 60s. The results of colony forming unit (CFU) values concluded that 1 W with application for 30 seconds for 1940-nm Thulium fiber laser was the optimal dose to perform the maximum antibacterial efficiency preserve the healthy condition.|Keywords : Sterilization, Endodontics, Bacteria, Laser.