半导体激光根管内照射与牙根表面温度变化的关系

Study of the effects of diode laser irradiation in root canals on the temperatures of root surfaces

目的采用不同功率半导体激光根管内连续照射或间隔照射,观察3种照射模式对根管外壁温度升高的影响。方法实验一:60颗离体单根管牙分A组(功率1.5 W)与B组(功率3 W),每组又分为3亚组(A1、A2、A3),每组10颗,采用三种不同照射模式:A1:照射5s 4次,A2:照射10 s 2次,单次照射间均间隔5 s;A3:连续照射20 s,同时测定根管外壁平均温度的变化。实验二:30颗离体单根管牙,采用功率1.5 W,连续照射20 s的模式,测定牙根外三点:G1(根尖点)、G2(根尖1/3)、G3(根中1/3)温度变化值。结果 A组中,A1、A2、A3照射模式下根管外壁温度升高均值分别为4.78℃,5.21℃,5.97℃,3组间无明显统计学差异。B组于相同照射模式下温升均值均大于A组,且B3模式下根管外壁温度升高最高可达10.3℃。相同照射条件下,根尖(G1点)温度升高明显低于根尖1/3(G2点)及根中1/3(G3点)的温度(P<0.05),G2、G3间无显著统计学差异。结论照射模式及激光功率对根管外壁温度改变均有显著影响,且不同部位升温幅度也不相同。功率1.5 W条件下,本实验设计的3种不同照射模式,均是临床较为安全的使用参数。

Objective To evaluate the effects of continued or intermittent irradiation from the diode laser to the root canals in differ- ent power, observe temperature changes on the root surfaces in three different irradiation modes. Methods Part 1 ： a total of 60 sin- gle-root human teeth were divided into tow groups, A（ power is 1.5w） and B（ power is 3 W ）. Every group was divided into three sub- groups（A1/A2/A3） with 10 teeth in each. Use three different irradiation modes, A1 ： irradiating for 5 s for 4 times with time interval of 5s, A2： irradiating for lOs for 2 times with time interval of 5s, A3 ： irradiating continuously for 20s. The temperatures of root sur- faces were recorded. Part 2 ： a total of 30 single-root human teeth were divided into three Groups. Continued irradiation for 20 s was made in power of 1.5 W. Temperatures on three spots of the root surfaces were recorded, GI （ apical spot） , G2 （ apical third spot） , G3 （ middle third spot）. Results In group A, A1 ,A2, and A3 were dealt in different modes, and temperatures increased averagely by 4. 78℃, 5.21 ℃ ,5.97 ℃. No significant difference was shown among the three groups. Group B was dealt under the same irradiation condition. The average temperature increase was higher in B than that in group A. The highest temperature reached 10.3 ℃ in A3. Under the same irradiation condition, the temperature was obviously lower on apical spot（ G1 ） than on apical third spot（G2） and on middle third spot（G3） （P 〈 0.05）. No significant difference was found between G2 and G3. Conclusions The modes of irradiation and power of irradiation both have significant effects on temperature changes on the root surfaces. Changes are different on different spots. The three irradiation modes in power of 1.5 W are all the safe parameters in clinical use.