Comparative Study Of The Apical Sealing Ability Of Three Root Canal Obturation Methods

ObjectiveRoot canal therapy is the most commonly used and most effective way to treat pulp and periapical diseases. Among all the processes of root canal therapy, root canal filling is the key step process.The Purpose of root canal filling is tightly fill the root canal system to the three-dimensional filling,to prevent microleakage from coronal and root side to avoid root canal system of re-infection. By the extracted teeth in vitro experiments, Using dye penetration assay method of leakage to compare and evaluate the sealing ability of three canal obturation methods of the cold lateral condensation technique, the ultrasonic lateral condensation technique and the continuous wave of vertical condensation technique. So as to choose the suitable clinical root canal obturation method providing a theoretical basis.Material and Methods1,collect the extacted teeth and root canal preparation34 single-canal extracted anterior teeth were cleaned the root canal and shaped using the Pro-Taper Ni-Ti rotary instruments with the Crown-Down technique.All the teeth were prepared by the same doctor. Dried preparation of root canal filling.2,Root canal fillingAll the prepared teeth were randomly divided into three groups.Group A (11 teeth) were obturated with the cold lateral condensation technique. Group B (10 teeth) were obturated with the ultrasonic lateral condensation technique. Group C (13 teeth) were obturated with the Continuous-wave Of gutta-percha vertical condensation technique. All the teeth were used the same sealer(Cortisomol) 3,temperature cycling testAfter filling all the experimental teeth, reserved the teeth in water bath at 37℃inside the place seven days after the temperature cycle test line, parameters are as follows:cold bath (5±2)℃30 seconds, warm water bath (55±2)℃30 seconds, and conversion time of 10 seconds for 500 times the temperature cycling test.4,Transparency and dyeing experimentsThe periapical 1/3 of experimental teeth immersed in 1% methylene blue dye solution for seven days, after decalcification of 5% hydrochloric acid were used 75%, 85%,95%,100%ethanol gradient dehydration of the 12 hours. Placed in a transparent solution of methyl salicylate treatment becomes a permanent transparent specimens.5,Determination of apical dye penetration distanceWith the stereo microscope (20 times) in the transparent specimens measured under apical dye penetration distance microscope with a 0.05mm gauge to measure and record nearly every specimen, the distal, buccal and lingual dye penetration depth, whichever is the maximum (accurate to 0.02mm) as the statistical data.6,Statistical analysisAll data used spssll.5 statistical package for analysis of variance, comparison between groups using LSD test. Significant level:P<0.05 significant difference from time to time, P<0.01 when the highly significant difference.Resultthe length of apical dye penetration showed significant difference(P<0.01) between Group A,B and Group A,C. There was no significant difference(P>0.05) between Group B and CConclusionsUltrasonic vertical condensation technique and the continuous-wave of gutta-percha vertical condensation root technique better than cold lateral condensation technique with gutta-percha, and the first two root canal filling techniques ability to fairly.