Effects Of Three Factors On Apical Microleakage After Post Canal Preparation

OBJECTIVE:This study evaluated the influence of three factors of root canal morphology,root canal obturation methods,and endodontic sealer on the apical microleakage after root canal post preparation to provide a basis for the selection of cases,treatment methods and materials in clinical diagnosis and treatment.METHODS:A total of 85 teeth were selected,all roots were grouped after taking CBCT,including 45 regular straight root canals and 40 oval root canals.The included tooth roots were divided into 9 groups and placed in 0.9% saline for use.All samples of the experimental and control groups were subjected to length measurement and root canal preparation according to the same standard.The experimental groups A were all regular straight root canals,10 samples per group,and the specific groups were as follows,A1:i Root SP+warm vertical condensation technique(WVCT),A2: i Root SP+atched-taper single cone obturation technique(SCOT),A3: Gutta Flow2+WVCT,A4:Gutta Flow2+SCOT;Experimental groups B were oval root canals,and the specific groups were as follows,B1: i Root SP+WVCT,B2: i Root SP+SCOT,B3:Gutta Flow2+WVCT,B4: Gutta Flow2+SCOT;Group C was the blank control group with a regular straight root canal and no obturation(n=5).After obturation,placed all the tooth roots in a constant temperature water bath at 37°C and 100% humidity for 7 days to dry the material,and then prepared the fiber piles.The apical microleakage was evaluated by the dye penetration method,the microscopic morphology of the interface between sealer and dentin was examed under the scanning electron microscope.The root canal obturation time and post space preparation time for each group of root canals were timed.RESULTS:Comparing the dye penetration,the results of the experimental group and the control group were as follows: A1,A2,A3,A4,B1,B2,B3,and B4 groups were(2.97 ± 0.89),(2.93 ± 1.36),(0.98 ± 0.68),(0.99 ± 0.73),(3.20 ± 1.08),(3.26 ± 1.17),(1.10 ± 0.85),(1.04 ± 0.97)mm,the total length of the infiltrating root canal in group C.Observation results of scanning electron microscopy: under the same magnification,the Gutta Flow2 sealer and the root canal wall were tightly combined.Our data were analyzed by three-factor factorial design ANOVA.The effect of root canal sealer on apical microleakage was statistically significant(P<0.05).When the root canal morphology and sealer were the same,the efficiency of SCOT was significantly higher than that of WVCT.When the root canal morphology and root canal obturation technique were the same,the post space preparation efficiency of the Gutta Flow2 sealer was significantly higher than that of i Root SP sealer.CONCLUSION:For root canals after post space preparation,the root apical microleakage was affected by root canal sealer.Gutta Flow2 was slightly better than i Root SP.There was no interaction between root canal morphology,root canal obturation and root canal sealer.The operation time of SCOT was short.Gutta Flow2 root canal sealer has high removal efficiency during post space preparation.