Effects Of Phenoaldehyde Resin Sealing Root Canal Wall On Apical Microleakage Of Continuous-wave Condensation Method

Objective: Using dye penetration and tooth clearing technique,to evaluate the effects of phenoaldehyde resin sealing root canal wall on the apical microleakage of continuous-wave condensation method.Methods:64 human permanent teeth with a single root canal were collected in this study.60 of all the teeth were randomly divided into 4 experimental groups(A、B、C、D,n=15).The samples remained were assigned to two groups(n=2),positive control group E and negative control group F.All the crowns of the teeth were removed at cement-enamel junction.The canals were cleaned and shaped with K files using technique followed by using Gates-Glidden drills.The detailed treatment of root canal in each group was shown in table one.All the prepared canals were obturated with continuous-wave condensation method to 2mm below root orifice.Glass ionomer cement was used to seal the access cavities.The teeth in experimental groups were coated with two layers of nail varnish except for the apical 2mm,teeth in the positive control group C were not coated with nail varnish,and in the negative control group D had the entire root surface coated with nail varnish.After the nail varnish solidified,all the samples were put into the Indian ink.After 7days,nail varnish were removed from the samples.Firstly,the samples were decalcified in 5%hydrochloric acid.Secondly,they were dehydrated in 75%,85%,95%,100%alcohol.Finally,they were clear in the methyl salicylate.The samples were studied under a stereomicroscope(×10),calculated the longest distance from apex to the coronal end point of dye penetration using the vernier caliper.The measurement was accurated to 0.01 mm.For the analysis of data Statistical Package for Social Science(SPSS)version 21.0 was used.The values ofapical microleakage were expressed as.Data were analyzed with t-test.Statistical significance was set at P<0.05.Results:The results of samples obturated by zoe indicated that the values of apical microleakage of group A and C were respectively 4.3227 ±0.94279 mm,3.8867 ± 1.07109 mm.T-test of Group A and C indicated that there was no significant difference between them(P > 0.05).The results of samples obturated by AH-plus indicated that the values of apical microleakage of Group B and D were respectively 1.9173 ±0.43967 mm,2.0747 ± 0.75625 mm.T-test of Group B and D indicated that there was no significant difference between them(P>0.05).The dye penetration results of apical microleakage of the two root canal sealers showed that the apical microleakage of ZOE and AH-plus were respectively 4.1047 ± 1.01592 mm,1.9960 ± 0.61304 mm.T-test of the two samples indicated that there was significant difference between them(P <0.05).The apical microleakage of AH-plus was less than that of ZOE.Conclusion:Phenoaldehyde resin sealing root canal wall had no effect on apical microleakage of continuous-wave condensation method.