Prevention of bacterial leakage through instrumented root canals by bioactive glass S53P4 and calcium hydroxide suspensions in vitro.

Objective: The capacities of bioactive glass S53P4 and calcium hydroxide suspensions to prevent microbial leakage through instrumented root canals were compared.

Study Design: Root canals of caries-free extracted human mandibular premolars were instrumented and randomly filled with calcium hydroxide or S53P4 (n = 14 each). Crowns were exposed to Enterococcus faecalis ATCC 29212 suspensions in a test setup with 2 broth chambers, and leakage was checked daily. Event times were compared using log rank test. After 50 days, teeth were fractured and inspected in a scanning electron microscope (SEM).

Results: Calcium hydroxide prevented leakage significantly better than S53P4 (P < .05). Estimated mean days to leakage were 26 for calcium hydroxide and 4 days for S53P4. The SEM observations revealed substantial calcification of the glass material in the root canal but also gaps containing clusters of coccoidal bacteria.

Conclusion: The bioactive glass material under investigation could not prevent contamination of instrumented root canals.