不同参数Er∶YAG激光照射牙体硬组织对结构的影响研究

Effect of different parameters Er： YAG laser irradiation on the structure of dental hard tissue

目的 探讨Er：YAG激光照射牙体硬组织对结构的影响.方法 牙釉质组26颗牙（104个样本）采用随机数字原则抽取2颗牙（8个样本）用于空白对照（C组）.剩余24颗牙（96个样本）随机分为A（照射10s）和B（照射20 s）两大组,每一大组再按功率随机分为1、2、3、4、5、6 W六个亚组,每个亚组8个样本.用Er：YAG激光在20 Hz频率下,按相应分组（不同功率和不同照射时间）分别对每个样本进行照射,牙本质分组同牙釉质组.观察不同能量与凹坑直径和深度的变化.结果 不同照射时间和功率各组牙釉质表面凹坑直径比较,同一照射时间组内不同功率间差异均有统计学意义（t=1.89、2.02、2.76、1.98、1.37、1.42,均P ＜0.05）,同一功率下B组与A组差异也有统计学意义（t=1.23、3.23、2.04、1.45、1.42、1.87,均P＜0.05）.不同照射时间和功率各组釉质表面凹坑深度比较,同一照射时间组内不同功率间差异有统计学意义（t=1.15、3.09、2.32、1.76、1.51、1.59,均P＜0.05）,同一功率下B组和A组差异也有统计学意义（t=1.15、3.09、2.32、1.76、1.51、1.59,均P＜0.05）.不同照射时间和功率各组牙本质表面凹坑直径比较,同一照射时间组内不同功率间差异有统计学意义（t=1.15、3.09、2.32、1.76、1.51、1.59,均P＜0.05）,同一功率下B组和A组差异也有统计学意义（t=1.15、3.09、2.32、1.76、1.51、1.59,均P＜0.05）.不同照射时间和功率各组牙本质表面凹坑深度比较,同一照射时间组内不同功率间差异有统计学意义（t =2.12、2.04、1.82、1.43、1.31、1.76,均P＜0.05）,同一功率下B组和A组差异也有统计学意义（=2.34、3.13、2.76、1.45、1.34、1.62,均P＜0.0S）.结论 随着激光能量和照射时间的增加,牙釉质产生的凹坑直径和深度也不断的增加；随着激光能量和照射时间的增加,牙本质产生的凹坑直径和深度也不断的增加.

Objective To investigate the effect of Er：YAG laser irradiation on the structure of dental hard tissue. Methods 2 teeth （8 samples） were randomly selected from 26 teeth enamel group（ 104 samples） for blank control（ group C）. The remaining 24 teeth （96 samples） were randomly divided into A group （irradiation 10 s） and B group （20 s irradiation）, each group according to power were randomly divided into 1,2,3,4,5,6W six subgroups, each subgroup had 8 samples. Using a Er： YAG laser at 20 Hz frequency, according to the corresponding packet （ with different power and different irradiation time） were irradiated for each sample. Dentin grouped with enamel group. To observe the changes of different energy and the pit diameter and depth. Results The enamel surface pit diameter was compared by different irradiation time and power, different power within the same irradiation time （t = 1.89,2. 02, 2. 76,1.98,1.37,1.42, all P 〈 0 05 ） ; compared between B group and the A group under the same power （ t = 1.23, 3.23,2.04,1.45,1.42,1.87, all P 〈 O. 05 ）. The enamel surface pit depth was compared by different irradiation time and power, different power within the same irradiation time （ t = 1.15,3.09,2.32,1.76,1.51,1.59, all P 〈 0.05 ） ; compared between B group and the A group under the same power（t = 1.15,3.09,2.32,1.76,1.51, I. 59, all P 〈 0. 05 ）. The dentin surface pit diameter was compared by different irradiation time and power, different power within the same irradiation time （ t = 1.15,3.09,2.32,1.76,1.51, I. 59, all P 〈 0.05 ） ; compared between B group and the A group under the same power（ t = 1.15,3.09,2.32 ,.1.76,1.51,1.59, all P 〈 0.05 ）. The dentin surface pit depth was compared by different irradiation time and power, different power within the same irradiation time（t = 2.12,2.04, 1.82,1.43,1.31,1.76, all P 〈 0.05 ） ; compared between B group and the A group under the same power（ t = 2.34, 3.13,2.76,1.45,1.34,1.62,all P〈0.05）. Conclusion With the increase in the laser energy and the irradiation time, the diameter and depth of enamel pits produced also continuously increase;With the increase in the laserenergy and the irradiation time, dentin diameter and depth of the pits produced constantly increased. The different pa- rameters of Er：YAG laser irradiation of dental hard tissues have different effects on the structure.