不同热牙胶充填及根管预备方法对根尖封闭性的影响

Effect of different warm gutta-percha root canal filling and root canal preparation on apical sealing

目的比较在两种根管预备理念下两种热牙胶充填技术的根尖封闭性。方法收集离体恒前磨牙108颗,随机分为A、B、C、D 4个实验组(n=21),阳性、阴性对照组(n=12)。A组与C组根管预备至主尖锉50#02、B组与D组根管预备至主尖锉25#08,随后A组与B组传统式热牙胶充填、C组与D组改良式热牙胶充填。各实验组随机抽6颗在1、3、5 mm处制备切片,观察充填物与牙本质壁界面间隙。余牙在体视显微镜下用染料渗透法及透明牙技术观察根尖微渗漏。结果改良式较传统式热牙胶充填渗漏值小且差异有统计学意义(P<0.05),主尖锉为25#08预备时较50#02预备渗漏值小且差异有统计学意义(P<0.05),其中B组<C组<D组<A组,A组与各组、B组与D组差异有统计学意义(P<0.05),其余各组间差异无统计学意义;在分别统计单根管和双根管时,发现染料渗漏平均值仍为B组<C组<D组<A组且A组与各实验组差异均有统计学意义,但B组与D组差异无统计学意义;各实验组界面间隙在组内及组间差异均无统计学意义,但在3 mm处间隙最小,在C、D组见较大间隙。结论以25#08为主尖锉预备时采用传统式热牙胶充填较好,以50#02为主尖锉预备时采用改良式热牙胶充填可与以25#08为主尖锉预备一样产生较好结果。界面观察,在改良式热牙胶充填时易产生较大间隙。

Objective To compare the apical sealing of two kinds of warm gutta-percha filling techniques under two root canal preparation concepts.Methods One hundred and eight extracted permanent premolars were collected and stochastically divided into six groups,two control groups(n=12)and four experimental groups(A,B,C and D groups,n=21).Groups A and C were prepared to 50#02 as the master apical file;groups B and D were prepared to 25#08 as the master apical file.Then groups A and B were obturated with the traditional warm gutta-percha filling technique;groups C and D were obturated with modified warm gutta-percha filling technique.Six samples were randomly selected from each experimental group to prepare sections at 1,3,and 5 mm,and the interfacial gap between the filling material and the dentin wall was observed.The apical microleakage of the rest of the teeth was observed with dye penetration and transparent teeth technique under a stereomicroscope.Results The microleakage value of the modified type was smaller than that of the traditional warm gutta-percha filling,and the difference was statistically significant(P<0.05).The microleakage value of preparation with 25#08 as the master apical file was smaller than that of preparation with 50#02,and the difference was statistically significant(P<0.05).The average value of dye leakage was group B<group C<group D<group A,and the differences were statistically significant between group A and each group,group B and group D(P<0.05),while the differences among remaining groups were not statistically significant.In the statistics of single and double root canals,the average value of dye leakage was still group B<group C<group D<group A,and the difference was statistically significant between group A and each experimental group,while the difference was not statistically significant between group B and group D.There was no statistically significant difference in the interfacial gap between groups and within groups,but a relatively small gap was found at 3 mm,and a large gap was found in groups C and D.Conclusion The traditional warm gutta-percha filling with 25#08 as the master apical file is better,which is as good as the modified warm gutta-percha filling with 50#02 as the master apical file.In the interface observation,it is easy to produce a large gap when using the modified warm gutta-percha filling.