脉冲Nd:YAG激光联合羟基磷灰石对根尖切除的作用

目的评价脉冲Nd:YAG激光对应用羟基磷灰石的根尖切除术后的牙齿根部的作用.方法 70颗拔出的上颌中切齿,牙髓腔扩张后用马来乳胶封闭并覆以氧化锌. 随机分为7组,每组10颗,第1组为对照组;第2、3、4组为单纯激光照射组,以脉冲Nd:YAG 激光照射,脉宽150 μs,最高频率30Hz,波长1064nm,照射时间20s,功率分别为0.5、1.0、1.5W;第5、6、7组为羟基磷灰石加激光照射组,去除马来乳胶0.5mm,换以羟基磷灰石,激光照射方法同2、3、4组.7组牙齿标本均进行扫描电镜下观察.结果电镜观察可见单纯激光照射组牙本质表面出现很多孔状熔化及结晶;羟基磷灰石处理组,激光照射后羟基磷灰石未见明显改变,而在其周围的牙本质表面出现熔化及结晶,在二者之间有明显界限,说明二者没有相互融合.结论脉冲Nd:YAG激光对羟基磷灰石物质无明显作用,牙本质与羟基磷灰石之间也没有反应;在实验所用激光剂量范围内,激光照射可造成牙本质熔化及结晶 .

Effect of Pulsed Nd:YAG Laser on the Apical Root Dentin when Associated with Hydroxyapatite

Objective The purpose of this study was to evaluate the effects of the pulsed Nd: YAG laser on the apical root dentin of extracted human teeth, following apicoectomy when associated with hydroxyapatite.Methods Seventy sound, extracted maxillary central incisors were used in this study. The canals were enlarged and then obturated with laterally condensed gutta-percha and zinc oxide sealer. The seventy teeth were divided in seven groups of ten teeth each: one group was used as control group, three other groups were treated by the Nd:YAG laser only and the three remaining groups(teeth with the hydroxyapatite material) were treated in the name way. All seven groups were observed under the scanning electron microscope.Results The SEM study showed melted dentin on the apical surface but noevidence of hydr oxyapatite fusion to the dentin.Conclusions Some craters were observed at the surface of the dentin, investigation showed that this was most likely due to the preparation method for SEM observation.