Department of Operative Dentistry, Faculty of Dentistry, School of Health Sciences, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
Department of Orthodontics, Faculty of Dentistry, School of Health Sciences, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
Lasers Med Sci. 2023 Sep 12;38(1):209. doi: 10.1007/s10103-023-03863-6.
The aim of this in vitro study was to investigate the safety of using blue diode laser (445 nm) for tooth bleaching with regard to intrapulpal temperature increase operating at different average power and time settings. Fifty human mandibular incisors (n = 10) were used for evaluating temperature rise inside the pulp chamber and in the bleaching gel during laser-assisted tooth bleaching. The change in temperature was recorded using K thermocouples for the five experimental groups (without laser, 0.5, 1, 1.5 and 2 W) at each point of time (0, 10, 20, 30, 40, 50 and 60 s). As the average power of the diode laser increases, the temperature inside the pulp chamber also increases and that of the bleaching gel was significantly higher in all the experimental groups (p < 0.05). However, the intrapulpal temperature rise was below the threshold for irreversible thermal damage of the pulp (5.6 °C). Average power of a diode laser (445 nm) ranging between 0.5-2 W and irradiation time between 10-60 s should be considered safe regarding the pulp health when a red-colored bleaching gel is used. Clinical studies should confirm the safety and effectiveness of such tooth bleaching treatments. The outcomes of the present study could be a useful guide for dental clinicians, who utilize diode lasers (445 nm) for in-office tooth bleaching treatments in order to select appropriate power parameters and duration of laser irradiation without jeopardizing the safety of the pulp.
本体外研究旨在探讨使用蓝色二极管激光（445nm）进行牙齿漂白的安全性，具体涉及不同平均功率和时间设置下对牙髓内温度升高的影响。本研究使用 50 个人类下颌切牙（n=10）来评估牙髓腔内和漂白凝胶在激光辅助牙齿漂白过程中的温度升高情况。使用 K 型热电偶记录五个实验组（无激光、0.5、1、1.5 和 2W）在每个时间点（0、10、20、30、40、50 和 60s）的温度变化。随着二极管激光的平均功率增加，牙髓腔内的温度也升高，所有实验组的漂白凝胶温度均显著升高（p<0.05）。然而，牙髓内的温度升高低于牙髓不可逆热损伤的阈值（5.6°C）。当使用红色漂白凝胶时，平均功率为 0.5-2W 的二极管激光和 10-60s 的辐照时间被认为对牙髓健康是安全的。临床研究应证实此类牙齿漂白治疗的安全性和有效性。本研究的结果可为牙科临床医生提供有用的指导，他们可以使用二极管激光（445nm）进行诊室牙齿漂白治疗，以选择合适的功率参数和激光照射时间，同时确保牙髓安全。
