A Preliminary Study Of The Root Canal Sealing Ability Of Resin Material-ParaCore

ObjectiveThe study aimed to comparatively evaluate the root canal sealing ability of the resin bond material-ParaCore /dental adhesive and gutta-percha/AH plus which were used as root canal filling materials by establishing a glucose leakage model. The examination of the interfaces of the two filling materials-dentine by Scanning electron microscopic was also performed. So as to provide some basis to the selection of materials required in the clinical treatment. Methods37 extracted human single-canal straight anterior and Mandibular first premolar teeth were root-prepared after their crowns were decoronated at the cementum-enamel junction(CEJ), 35 of which were randomly divided into 3 groups; 15 teeth for experimental group and each 10 for positive control group and negative control group. After conducting root canal preparation by crown-down technique with Protaper. Then the experimental group was filled with ParaCore/ dental adhesive; the rest groups were filled with Gutta-Percha/ AH plus. Root surfaces of the experimental group and the positive control group were coated with two layers of nail polish except for the apical 2 ㎜ and the whole root surfaces of the negative control were coated with nail polish. The coronal part of each root was immersed in 1mol/L glucose solution and the apical part was immersed in 1ml distilled water. Then measured the concentration of glucose that leakage along the filling canal by GOD method once a week in 6 weeks. The remaining 2 teeth which were already decoronated and completed root-prepared were respectively filled with ParaCore and gutta-percha, both of which were cut longitudinally along the root center. Then the samples were used for examining the filling materials-dentine interface by scanning electron microscopic. Results1.The negative control group was not detected out glucose. The experimental group was a little, while all of the positive control group were detected out glucose in the first week. W normality test result of the experimental group and the positive control group in each week: P﹤0.05, so data did not obey normal distribution. And use statistical nonparametric test(Mann-Whitney U), the first week: P=0.031﹤0.05,in the other 5 weeks: P﹤0.001, and there was significantly difference between experimental group and positive control group.2.While in 6 weeks, the concentration of the positive control group and the experimental group increased over time. And the growth rate in positive control was higher than that experimental group.3.SEM revealed a totally tight bonding between resin and dentin wall by mixing layer, but still the gaps existed in a few area; There was no bonding between gutta-percha and dentin wall and the gaps was evident at a low magnification. ConclusionThe results showed that resin bond material-ParaCore possesses a better root canal sealing ability than gutta-percha when used in root-filing.