von Fraunhofer J A, Allen D J
School of Dentistry, University of Louisville, Louisville 40292.
Angle Orthod. 1993 Winter;63(4):299-303. doi: 10.1043/0003-3219(1993)063<0299:TEAWTY>2.0.CO;2.
The heat produced at the dentinal pulpal wall opposite the irradiation site was measured during etching of dental enamel with an Nd:YAG laser in preparation for direct bonding of orthodontic appliances. Forty extracted human teeth were randomly divided into four groups of 10 teeth. Within each group, the buccal surfaces of 5 teeth and the lingual surfaces of the other 5 teeth were laser treated for 12 sec. Irradiation was performed with a commercial Nd:YAG laser at the power settings of 80mJ, 1W, 2W and 3W. Prior to irradiation, an occlusal access preparation was made into the pulp in order to facilitate the placement of a thermocouple for measurement of temperature changes at the dentinal pulpal wall opposite the irradiation site. The thermocouple was held against the dentinal pulpal wall and the resulting temperature changes were recorded. Heating effects at the dentinal pulpal wall on both buccal and lingual surfaces showed an increase in heat as a function of the increase in power output from the laser unit (p < 0.01). The temperatures measured at power levels 1-3W appeared to be of sufficient magnitude to cause at least localized pulpal inflammation and possible irreversible damage to the pulp tissue immediately opposite the site of laser irradiation.
在用Nd:YAG激光蚀刻牙釉质以准备直接粘结正畸矫治器的过程中，测量了照射部位相对的牙本质牙髓壁产生的热量。40颗拔除的人牙被随机分为四组，每组10颗牙。在每组中，5颗牙的颊面和另外5颗牙的舌面接受12秒的激光治疗。使用商用Nd:YAG激光，功率设置为80mJ、1W、2W和3W进行照射。在照射前，在牙髓上制作一个咬合通道，以便于放置热电偶，测量照射部位相对的牙本质牙髓壁的温度变化。将热电偶紧贴牙本质牙髓壁，并记录由此产生的温度变化。颊面和舌面牙本质牙髓壁的热效应显示，热量随着激光装置输出功率的增加而增加（p < 0.01）。在1-3W功率水平下测量的温度似乎足以引起至少局部牙髓炎症，并可能对激光照射部位正对面的牙髓组织造成不可逆的损伤。
