Influence of different conditions on the bonding effect between root canal wall and resin sealer

LU Jing; FANG Chang-yun

doi:10.3969/j.issn.1005-2593.2014.08.006

Abstract：AIM:To study the bonding effect between resin sealer and root canal walls conditioned with dif-ferent treatments.METHODS:Canals of 64 single-rooted premolars were routinely prepared and then randomly divid-ed into 6 test groups(n=10)and 1 control group(n=4).The canals in group P1,P2,P3 were treated with 350 g/L phosphoric acid for 5,10 and 15 seconds respectively;those in group E1,E2 and E3 were treated with 170 g/L EDTA for 30 ,60 and 90 seconds respectively.Canals in group C were treated with distilled water for 90 seconds.8 speci-mens of each test group and 2 of control group were longitudinally sectioned in labio-lingual direction,then examined under SEM for the evaluation of smear layer removal.14 remaining specimens were obturated by a combination of Lux-aCore-Dual and gutta percha using a single cone technique.The roots were cross-sectioned into 3 parts (uper,middle and apex)and the bonding surface was examined under SEM.RESULTS:The value of smear layer in group P3 was lower than that in groups P1 and P2(P<0.05),in Groups E2 and E3 was lower than that in Group E1(P<0.05), and in all of test groups was lower than in control group(P<0.05).Group P3,E2 and E3 showed no statistical differ-ence(P>0.05).The apical portion showed higher value than cervical and middle portions(P<0.05),yet there was no statistical difference between the latter two(P>0.05 ).After obturation,many long resin tags and uniform hybrid layer were observed in group P3,E2 and E3,especially in the cervical part.However the bonding effect of EDTA groups was a little better than phosphoric acid groups.In other groups,fewer and short resin tags were found,with no hybrid layer formed.CONCLUSION:Conditioning of root canal with 170 g/L EDTA solution for 60s may produce most benefitial effects,but in the the apical portion the effect is less benefitial.