An Experimental Study Of Apical Sealing Ability Of Obtura Ⅱ Technique With Different Root Canal Sealers

Objective: It is difficult for three-dimensional sealing of root canal because of the complexity of the root canal system. Presently, ObturaⅡthermoplasticized gutta - percha injection is regarded as an ideal root canal filling method, but the information about the sealing ability of this technique is still absent. The purpose of this study was to compare the apical leakage of different root canal sealers in combination with ObturaⅡthermoplasticized gutta-percha injection technique.Material and Methods: Fifty-eight freshly extracted human single-rooted teeth with fully formed apices were sectioned at the level of cemento-enamal junction. The root canals were instrumented with Tri Auto ZX and stainless steel K-file according to the crown down/step back technique. The root canal working length was 1mm short of the apical foramen with apical size 35 and 04 taper. Ten roots were selected and allocated randomly to five group as single sealer controls, positive and negative controls. The left forty-eight samples were divided randomly into A,B,C,D four experimental groups that each contained 12 teeth. All the root canal in the experimental groups were obturated with ObturaⅡthermoplasticized gutta - percha injection technique. The root canals in the group A, B, C were separately sealed with ZOE, Vitapex and AHplus paste, and the specimens in the group D were filled without any paste. Then the roots were stored in the condition of 37℃of temperature,100% of humidity for 1 week. Two specimens which had been randomly selected from each of the experimental group were split longitudinally and prepared for scanning electron microscope observation. After...