Thesis (M.Sc.)--Chulalongkorn University, 2009

The purpose of this study is to compare the dye leakage of root-end preparation technique using MTA and root-end preparation technique using flowable resin composite with and without human blood contamination. Sixty-eight human upper anteriors were collected and randomly divided into four experimental (n=15) and two control groups (n=4). Two experimental groups of class I root-end preparation were retroprepared with an ultrasonic tip (KiS-1D) to the depth of 3 mm and filled with MTA with and without blood contamination. Another two groups of concave cavity root-end preparation were filled with flowable resin composite with and without blood contamination. The leakage of dye was evaluated by dye vacuum penetrating test and dye extraction method. Two-way ANOVA was used to test for significant differences of the leakage among the groups of specimens at the significant level of 0.05. The concave cavity root-end preparation filled with flowable resin composite without blood contamination displayed significantly less leakage (p<0.05) than all other groups. Leakage of retrofillings using MTA and flowable resin composite was affected by both the root-end preparation techniques and the blood contamination. The concave cavity root-end preparation filled with flowable resin composite without blood contamination displayed the least leakage.