Zhu L, Tolba M, Arola D, Salloum M, Meza F
Department of Mechanical Engineering, University of Maryland, Baltimore, MD 21250, USA.
J Biomech Eng. 2009 Jul;131(7):071004. doi: 10.1115/1.3147801.
Erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) lasers are currently being investigated for disinfecting the root canal system. 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, a theoretical simulation using the Pennes bioheat equation is conducted to evaluate how heat spreads from the canal surface using an Er,Cr:YSGG laser. Results of the investigation show that some of the proposed treatment protocols for killing bacteria in the deep dentin are ineffective, even for long heating durations. Based on the simulation, an alternative treatment protocol is identified that has improved effectiveness and is less likely to introduce collateral damage to the surrounding tissue. The alternative protocol uses 350 mW laser power with repeating laser tip movement to achieve bacterial disinfection in the deep dentin (800 microm lateral from the canal surface), while avoiding thermal damage to the surrounding tissue (T<47 degrees C). The alternative treatment protocol has the potential to not only achieve bacterial disinfection of deep dentin but also shorten the treatment time, thereby minimizing potential patient discomfort during laser procedures.
钇钪镓石榴石（Er,Cr:YSGG）激光目前正被用于研究根管系统的消毒。在使用激光治疗之前，了解温度分布并评估对周围组织的热损伤非常重要。在本研究中，使用彭尼斯生物热方程进行理论模拟，以评估使用Er,Cr:YSGG激光时热量如何从根管表面扩散。研究结果表明，一些提议的用于杀死深层牙本质中细菌的治疗方案无效，即使加热时间很长。基于模拟，确定了一种替代治疗方案，该方案具有更高的有效性，并且不太可能对周围组织造成附带损伤。替代方案使用350毫瓦的激光功率并重复激光头移动，以在深层牙本质（距根管表面横向800微米处）实现细菌消毒，同时避免对周围组织造成热损伤（T<47摄氏度）。该替代治疗方案不仅有可能实现深层牙本质的细菌消毒，还能缩短治疗时间，从而将激光治疗过程中患者的潜在不适感降至最低。
