Er,Cr:YSGG激光照射对牙根尖封闭效果影响的实验研究

Experimental Research on the Effect of Apical Seal Achieved by the Irradiation of Er,Cr :YSGG Laser

目的:深入探讨在根尖倒充填术中Er,Cr:YSGG激光照射对牙根尖的封闭效果,为此激光在口腔临床上的应用与推广提供重要的理论与实验依据。方法:将56颗新拔除的单根牙随机分成7组,每组8颗牙。去除牙冠,常规进行根管预备、根管充填。将倒充填的牙根尖进行预备,然后银汞合金倒充填。预备方法:1手机切除根尖后,制备成烧瓶状洞形;2手机处理方法同1,然后Er,Cr:YSGG激光于不同能量(1W、2W)及不同方式(喷水或无水)下对洞内壁进行照射。结合微渗漏检测与扫描电镜观察对Er,Cr:YSGG激光照射后的牙根尖封闭效果进行评估。结果:Er,Cr:YSGG激光可有效去除根切面上的玷污层及碎屑;与手机加银汞倒充填组相比,激光照射后的根尖染料微渗漏深度有所减少;但只有1WEr,Cr:YSGG激光于无水条件下照射时,根尖染料微渗漏深度显著减少(P<0.05)。结论:Er,Cr:YSGG激光应用于根尖倒充填术中可减少微渗漏的发生;促进根尖封闭;在特定的能量参数下可获得优于常规银汞倒充填术的治疗效果。因此我们推荐临床上将Er,Cr:YSGG激光照射与常规银汞倒充填术结合使用,这将有助于提高根尖倒充填术治疗的成功率。

Objective: To discuss the effect of apical seal achieved by the irradiation of Er,Cr :YSGG laser in retrograde filling, and to provide the important experimental basis for the clinical application of Er,Cr :YSGG laser.Methods: 56 freshly single-rooted extracted human teeth were selected for the study, which were randomly divided into seven groups of eight each. The anatomical crowns were removed at the cementoenamel junction and the remaining roots were treated endodontically with conventional methods. Roots to receive retrofillings had their apies treated, either with bur preparation only, or with bur preparation plus the irradiation of Er,Cr :YSGG laser in different parameters and different patterns. Then they had amalgams placed. The effect of apical seal achieved by Er,Cr:YSGG laser was evaluated with microleakage measurements and scanning electron microscopy (SEM) observations.Results: Er,Cr :YSGG laser can abolish smear layer on the resected root surfaces effectively. Compared with the conventional retrograde amalgam, the amount of dye penetration from an apical stop with the irradiation of laser decreased; but only in 1W Er,Cr :YSGG laser without water flow, the amount of apical dye penetration was significantly lower (p<0.05).Conclusion: The utilization of Er,Cr :YSGG laser in retrograde filling can reduce the permeability of resected roots and promote the effect of apical seal. In some parameters, the effect of laser can be superior to the effect of the conventional method. Based on our results, it appears that the combinational application of Er,Cr :YSGG laser and conventional retrograde amalgam results in the improved healing of retrograde filling.