Stability of Doxycycline Absorbed on Root Canal Dentin After Obturation With Gutta-Percha/Ah26 and Resilon/Realseal At Different Time Intervals

Objective: eradication of microorganisms present in the root canal system is paramount for the successful outcome of root canal therapy. the purpose of this study was to com-pare the of doxycycline absorbed from mtad into root canal dentin after obturation with gutta-percha/ah26 and resilon/realseal at different time intervals.materials and methods: fifty-one extracted human teeth were instrumented. thirty sam-ples were obturated with either gutta-percha/ah26 or resilon/self-etch realseal after fi-nal irrigation with mtad. fifteen samples were kept unobturated (positive control); six samples were obturated with either gutta-percha/ah26 or resilon/self-etch realseal without mtad irrigation (negative control).after aging for 1, 3 or 6 weeks, dentin debri were collected, the doxycycline compound was extracted and its amount was quantified using high performance liquid chromatogra-phy. the statistical significance of the change in doxycycline concentrations was tested with two-way anova.results: the mean concentration of doxycycline in dentin for one, three and six-week guttapercha/ah26 samples was 1.8±0.36, 1.22±0.22 and 0.67±0.11 respectively, whereas these concentrations in resilon/realseal samples were 1.60±0.26, 0.80±0.14 and 0.59±0.01 respectively. regarding the positive control group, these concentrations were 2.09±0.11, 1.54±0.12 and 0.72±0.07 respectively for 1, 3 and 6-week intervals. no dox-ycycline was detected in negative control groups. the doxycycline concentrations showed a significant difference forobturating materials (p=0.008). these concentrations were higher in the gutta-percha/ah26 samples than resilon/realseal samples in each time in-terval.conclusion: the remaining amount of doxycycline bonded to dentin was higher when root canals were obturated with gutta-percha/ah26 compared to resilon/realseal. the stability of doxycycline showed a time dependent decrease.