| Aim:To compare the coronal leakage of three root canal filling materials and provide the theory basis for how to select the ideal material for root canal obturation.Methods:The root canals of 146 isolated rooted human anterior teeth or bicuspid teeth were prepared by step-down technique,and randomly divided into two experimental groups of CLC and Obtura-Ⅱ.The group of CLC:73 isolated teeth were randomly divided into three experimental groups(C1,C2,C3) of 21 teeth each and two control groups(C4,C5)of 5 teeth each.Group C1,C2 were filled respectively with gutta-percha using Cortisomol and AH-plus as sealer. Group C3 was filled with Resilon using Epiphany as sealer.Group C4 was the positive control and Group C5 was the negative control.The control groups were only obturated by gutta-percha point with no paste.Choose 15 teeth from each three experimental groups(C1,C2,C3)and put them in 2%methylene blue for five days.The control groups were also suspended in 2%methylene blue for five days. After that,teeth were cleared and split longitudinally.Linear dye penetration was measured with vernier caliper under root canal microscope.The Group of Obtura-Ⅱ:73 isolated teeth were divided randomly into three experimental groups (O1,O2,O3)of 21 teeth each and two control groups(O4,O5)of 5 teeth each. Group O1,O2 were obturated by Obtura-Ⅱinjection technique using Cortisomol and AH-plus as sealer.Group O3 was obturated by Obtura-Ⅱinjection technique condensed Resilon using Epiphany as sealer.Group O4 was the positive control. Group O5 was the negative control.The control groups were only obturated in Obtura-Ⅱinjection technique with no paste.Choose 15 teeth from each three experimental groups(O1,O2,O3)and put them in 2%methylene blue for five days. The control groups were also suspended in 2%methylene blue for five days.After that,teeth were cleared and split longitudinally.Linear dye penetration was measured with vernier caliper under root canal microscope.Ultrastructural evaluation between filling materials and dentin wall of remaing 6 teeth each in six experimental groups(C1,C2,C3,O1,O2,O3)was observed under scanning electron microscope.Results:The dye penetration of group C1,C2,C3 were(2.35±0.58) mm,(1.88±0.24)mm,(1.57±0.24)mm.Positive control group demonstrated coronal and apical dye penetration.Negative control group showed no dye penetration. The analysis of variance showed a statistically significant difference between the group C1 and C2,C3(P＜0.01).There is also a statistically significant difference between the group C2 and C3(P＜0.05).The dye penetration of group O1,O2,O3 were(2.60±0.44)mm,(2.19±0.41)mm,(1.82±0.30)mm.Positive control group demonstrated coronal and apical dye penetration.Negative control group showed no dye penetration.The analysis of variance showed a statistically significant difference between the group O1 and O2,O3(P＜0.01).There is also a statistically significant difference between the group O2 and O3(P＜0.05).SEM revealed a totally tight bonding between Resilon—Epiphany and dentin wall,but still the gaps existed in a few area by both CLC and Obtura-Ⅱ.Under high power lens, resin filling material tightly integrated with the dentin wall in gap-free regions,in the gap-containing regions resin tags were sparse;the gaps is evident between the filling material and dentin wall in the group of gutta-percha/AH-plus,resin tags were sparse,even completely absent under the high power lens;There is no bonding between Cortisomol and dentin wall in group of gutta-percha/Cortisomol. Conclusion:Resilon-Epiphany used as endodontic filling material could effectively reduce coronal leakage,and has a better sealing ability than gutta-percha/AH-plus and gutta-percha/Cortisomol. |
