Er:YAG激光PIPS技术对乳牙根充糊剂渗透牙本质小管影响的体外研究

Effect of Er:YAG laser by photon-initiated photoacoustic streaming on penetration of root filling paste into dentinal tubules of primary teeth in vitro

目的 使用激光扫描共聚焦显微镜(confocal laser scanning microscope, CLSM)评估掺铒钇铝石榴石铒激光(erbium:yttrium-aluminium-garnet laser, Er:YAG)光子引发的光声流技术(photon-initiated photoacoustic streaming, PIPS)荡洗乳牙根管后根充糊剂渗透牙本质小管的效果。方法 收集20颗乳切牙和20颗乳磨牙,按不同根管冲洗方法及牙位随机分为4组(n=10),分别是乳切牙注射器冲洗组(A组)、乳切牙PIPS-Er:YAG激光组(B组)、乳磨牙注射器冲洗组(C组)、乳磨牙PIPS-Er:YAG激光组(D组)。体外行常规根管预备和不同方式的根管冲洗,使用混有罗丹明荧光剂的Vitapex根充糊剂进行根管充填,并用CLSM观察距根尖3 mm(根尖1/3)和5 mm(根中1/3)处的横剖面,测量根充糊剂渗入牙本质小管的长度,比较不同冲洗方法对乳牙根充糊剂渗透深度的影响。结果 B组、D组根充糊剂在乳牙根管内的渗透深度分别大于A组、C组,A组、B组根充糊剂在乳牙根管内的渗透深度分别大于C组、D组,各组在距根尖5 mm处根充糊剂在乳牙根管内的渗透深度均大于距根尖3 mm处,差异有统计学意义(P<0.05)。结论 PIPS-Er:YAG激光荡洗比传统单独使用注射器冲洗效果好,可以明显增加乳牙根充糊剂的渗透深度,但是根管形态会影响冲洗效果。

Objective To evaluate the effect of root filling paste penetrating into dentinal tubules after erbiumytrium aluminium garnet laser(Er:YAG) photon-initiated photoacoustic streaming(PIPS) irrigating primary teeth root canals by confocal laser scanning microscope(CLSM).Methods Twenty primary incisors and 20 primary molars were randomly divided into four groups according to final irrigation techniques and tooth positions:They were primary incisors through needle irrigation(Group A,n=10),primary incisors through Er:YAG-PIPS(Group B,n=10),primary molars through needle irrigation(Group C,n=10) and primary molars through Er:YAG-PIPS(Group D,n=10).After the conventional root canal preparation and different methods of root canal irrigation in vitro,Vitapex root canal filling paste mixed with rhodamine(fluorescent agent) was used for root canal filling.The cross sections of 3 mm(1/3 of the apex) and 5 mm(1/3 of the middle of the root) from the apex were observed by CLSM.The length of root canal filling paste penetrating into dentin tubules was measured to compare the effects of different irrigation methods on the penetration depth of root canal filling paste for primary teeth.Results The penetration depth of root filling paste in Group B and Group D was greater than that in Group A and Group C,and the penetration depth of root filling paste in Group A and Group B was greater than that in Group C and Group D,respectively.The penetration depth of root filling paste in the root canal of primary teeth at 5 mm of the root apex was greater than that at 3 mm of the root apex in each group,and the difference was statistically significant(P<0.05).Conclusion The Er:YAG laser by PIPS-activated irrigation is more effective than traditional needle irrigation alone,which can significantly increase the penetration depth of root canal filling paste of primary teeth.However,the root canal morphology would have an impact on the effect of irrigation.