Evaluation of Effectiveness of Er,Cr:YSGG Laser for Root Canal Disinfection: Theoretical Simulation of Temperature Elevations in Root Dentin

Lasers have been used in dentistry for removing hard tooth tissue for more than twenty years. Erbium, chromium: yttrium, scandium, gallium, garnet (Er, Cr: YSGG) lasers are currently being investigated for disinfecting the root canal system, since bacteria can spread from the root canal surface to the deep dentin via the dentin tubules [1]. It is expected that temperature elevation in the deep dentin is sufficient to eradicate bacteria there. Prior to using laser therapy, it is important to understand the temperature distribution and to assess thermal damage to the surrounding tissue. In this study, we develop a heat transfer model to estimate the temperature elevations in both the tooth root and surrounding tissue during Er,Cr:YSGG laser disinfection of the root canal surface. The laser power level, pulse setting, as well as laser duration are incorporated into the Pennes bioheat equation for the theoretical study. We propose a treatment protocol that achieves better heat penetration with shorter treatment time than the existing protocols used in dentistry [2].