Er:YAG激光激活下冲洗剂在根管内渗透效果的实验研究

Experimental study on the penetration effect of irrigating solution in root canals activated by Er:YAG laser

目的比较传统针头冲洗(conventional needle irrigation,CNI)、被动超声冲洗(passive ultrasonic irrigation,PUI)和铒钇铝石榴石(erbium:yttrium aluminium garnet,Er:YAG)激光的光子引导光声流技术(photon-induced photoacoustic streaming,PIPS)、Er:YAG的光波增强光声流技术(shock wave enhanced emission photoacoustic streaming,SWEEPS)四种冲洗方式将冲洗剂输送到牙本质小管及根尖区的效果。方法使用ProTaperNext系统对115颗离体前磨牙进行根管预备,预备过程中均使用3%NaClO进行冲洗,随机选取59颗离体牙在结晶紫溶液中浸泡72小时,随后将115例样本的根尖孔用复合树脂封闭。从染色的59颗离体牙中随机选取3颗不使用NaClO冲洗以确认牙本质染色充分,剩余染色牙根据冲洗方式(CNI、PUI、PIPS、SWEEPS)随机分为4组(n=14)进行根管冲洗。随后将所有染色标本的根管分为根上1/3、根中1/3和根尖1/3,在体视显微镜下观察。使用Image J图像处理软件测量漂白牙本质的平均宽度,从而确定NaClO在牙本质小管的渗透深度(μm)。将剩余的56颗离体牙同样分为上述4组。每组分别使用指定的冲洗系统配合1.5 mL阻射溶液碘海醇冲洗根管,使用平行投照技术拍摄数字X线片,借助Image J图像处理软件测量根尖孔与冲洗液渗透止点之间的距离(mm)。结果与CNI组相比,其他三种冲洗系统作用下冲洗剂在牙本质小管及根尖区的渗透深度显著增加,SWEEPS>PIPS>PUI>CNI。与CNI、PUI组相比,激光组(SWEEPS组和PIPS组)冲洗液在牙本质小管的渗透深度显著增加,冲洗液渗透止点距根尖孔的平均距离更短(P<0.05),而PIPS-Er:YAG组与SWEEPS-Er:YAG组相比差异无统计学意义。结论与CNI和PUI组相比,两激光组(PIPS、SWEEPS)能够增强冲洗液在牙本质小管的渗透,且能将冲洗剂输送到根尖区更接近根尖孔的区域,为实现充分根管消毒提供保障。

Objective To compare the effects of conventional needle irrigation(CNI),passive ultrasonic irrigation(PUI),photon-induced photoacoustic streaming(PIPS)and shock wave enhanced emission photoacoustic streaming(SWEEPS)on delivering irrigating solution to the dentinal tubules and apical regions.Methods115 isolated premolarswere collected and prepared by the Pro Taper Next system.During the preparation,the root canals were rinsed with3%NaClO.59 randomly selected isolated teeth were immersed in crystal violet solution for 72 hours,and theapical foramina of 115 samples were sealed with composite resin.Among the 59 stained teeth,3 teeth wererandomly selected without NaClO rinsing to confirm that the dentin was fully stained.The remaining stained teethwere randomly divided into 4 groups(n=14)according to irrigation methods(CNI,PUI,PIPS,SWEEPS).The rootcanals of all stained specimens were divided into coronal,middle and apical thirds and observed under thestereomicroscope.The average width of bleached dentin was measured using the Image J to determine thepenetration depth(μm)of NaClO in the dentinal tubules.The remaining 56 isolated teeth were similarly dividedinto the four groups described above.In each group,the root canals were flushed with the specified irrigationsystem and 1.5m L Iohexol.Then digital X-ray films were taken with parallel projection technique.The distance(mm)between the apical foramen and the penetration stop of irrigating solution was measured with the Image J.ResultsCompared with CNI group,the penetration depth of irrigating solution in the dentinal tubules and apical regionincreased significantly in the other three irrigation systems,SWEEPS>PIPS>PUI>CNI.Compared with the CNI and PUI groups,the laser groups(SWEEPS and PIPS)significantlyincreased the penetration depth of the irrigating solution inthe dentinal tubules,and the average distance between thepenetration stop of irrigating solution and the apicalforamen was shorter(P<0.05).There was no significantdifference between PIPS-Er:YAG and SWEEPS-Er:YAG.Conclusion Compared with the CNI and PUI groups,the two laser groups(PIPS and SWEEPS)can enhance thepenetration of irrigating solution in the dentinal tubules,and can deliver irrigating solution to the area closer to theapical foramen,providing guarantees for adequate root canal disinfection.