Longitudinal study on microleakage of three root-end filling materials by the fluid transport method and by capillary flow porometry

Aim (i) To compare the root-end sealing ability of IRM Caps (IRM), Fuji IX Capsules (Fuji IX) and Pro Root MTA Tooth-Coloured Formula (MTA) in teeth obtained from cadavers. (ii) Further research on leakage study methodology by means of comparison of the fluid transport method (FTM) and capillary flow porometry (CFP). Methodology Root canal treatment was performed on 33 cadaver teeth in situ 2 weeks prior to root resection and ultrasonic retropreparation (S12/90degreesD-tip on Suni-Max), after which the teeth were retrieved from the cadavers. Two teeth were kept as positive and negative controls. The other teeth were divided in three different groups at random, with each group receiving one of the retrofill materials. Retrofills were exposed to water 5 min after placement. The teeth were stored at 37 degreesC for 12 h after which the root filling was removed. Microleakage (L in muL day(-1)) was measured for 24 h under a pressure of 1.2 atm using FTM and recorded as L = 0, 0 < L less than or equal to 10, L > 10. The measurements were repeated after 1 and 6 months. After 6 months, leakage was also assessed by CFP in order to measure through pores and their diameters. Results were analysed statistically using nonparametric Kruskal-Wallis and Mann-Whitney U-tests, and Spearman correlation coefficients between the results of both methods were calculated. The level of significance was set at 0.05. Results (i) A statistically significant difference could be demonstrated between Fuji IX and IRM at 1 month with FTM. FTM revealed a significant difference between Fuji IX and the other materials at 6 months, whereas CFP did not. However, using both methods, Fuji IX showed the best result. (ii) When comparing both techniques, CFP demonstrated through pores in all teeth, whereas with FTM in only 14 of the 31 teeth could through pores be demonstrated. A positive correlation between both methods was demonstrated. Conclusions Under the conditions of this study (i) the conventionally setting glass-ionomer cement Fuji IX showed the best results when used as a root-end material and (ii) CFP appeared to be a useful method for leakage evaluation of through pores in endodontics.