The Sealing Ability Of Root Canal Obturation In Vitro

Objective:RCT is a mature treatment for dental pulp diseases and periapical diseases at present. Its purpose is to form good apical tight sealing. Its curative effect depends on many factors, among which choosing paste and obturation methods are crucial. In this study, the PreTaper nickel-titanium instruments, which possesses strong cutting capacity, elegant memory and super-elastic performance, was used on recently extracted teeth in vitro for canal preparation, with using this device hasa mechanical cutting function, high memory and super-elastic properties. Crown-Down technology with strong root canal shaping ability and slight post-operation complications. We use sodium hypochlorite thoroughly flushing root canals and EDTA lubricating canal wall in the whole process of preparation. This study is choosing different root canal filling paste and filling method to fill the root canal after unified root canal preparation in vitro. Measure the length of the root tip penetration through dye penetration method. To evaluate the apical sealing ability of different root canal obturation techniques and different paste formula through the determination of the apical sealing ability.Materials and Methods:60 extracted human Mandibular premolar with single root canal were selected, and randomly distributed into 5 groups. Each of these groups contains 12 teeth. These teeth root canal were prepared with ProTaper using crown down technique, and then choose different materials and techniques to complete the obturation of root canal. Group A, root canal were obturated with gutta-percha+AH plus sealer by using cold lateral condensation; group B, root canal were obturated with gutta-percha+Vitapex sealer by using cold lateral condensation; group C, root canal were obturated with gutta-percha+AH plus sealer by using warm vertical compaction; group D, root canal were obturated with gutta-percha+ Vitapex sealer by using warm vertical compaction; group E, received no obturation. After root canal obturation, all specimens under constant temperature box for a week, for root canal obturation material completely hard solid, afterward soak in India ink staining, and were decalcified with nitric acid, then underwent dehydration of gradient ethanol, at last under salicylic acid methyl ester in the solution to make transparent specimen processing production. Stereoscopic microscope measuring root penetration length, using SPSS 11.5 software package was carried out on the measurement data analysis of variance.Result:1. For the control group, the apical micro leakage liner length is significant longer than the warm vertical compaction and cold lateral condensation groups(P<0.05).2. The warm vertical compaction group’s leakage liner are obviously shorter than the cold lateral condensation group(P<0.05).3. For the cold lateral condensation group, the sealing ability of AH plus paste is better than Vitapex paste(P<0.05).4. For the warm vertical compaction group, there were no significant difference in using AH plus or Vitapex paste(P>0.05).Conclusion:1. Root canal obturation can significantly reduce the micro leakage occurred, at the same time, the choose of techniques and materials of root canal obturation is also very important.2. Using warm vertical compaction technique, the leakage liner are obviously shorter than the cold lateral condensation technique.3. About the cold lateral condensation technique, the sealing ability of AH plus paste is better than Vitapex paste.4. About the warm vertical compaction technique, there were no significant difference in using AH plus or Vitapex paste.