Abstract:

Objective　To prepare the controlled-release delivery gutta-percha points containing metronidazole compound (CDGMC) and to determine its release ratein vitro.Methods　The drug points were made by using compound drugs and gutta- percha as a carrier, and CDGMCwere prepared followed by enveloping a release membrane outward. The best formulawas select- ed according to the release parameters of the drugs extracted in the release experimentsin vitro. The CDGMCwere placed into the extracted teeth after root canals were routinely prepared. The non-drug CDGMC was used as the control. The absorbency of the drugs in normal saline (37℃,pH7.4) was determined timely. The percentage of release and cumulated release of the drugswere calculated according to the concentrations of drugs in medium.Results　Thein vitroexperiments showed that this system con- tained 1 880μg ofmetronidazole and 267μg of ciprofloxacin. The experiments in healthy single root canal showed thatthe drug re- lease amounts around the perioapical areawere metronidazole 88·54μg/ml and ciprofloxacin 9·05μg/ml in 10 days.Conclusion　 CDGMC can continuously release effective drug concentrations more than 10 days and could be considered as an ideal method for clinical application.

Key words: metronidazole, ciprofloxacin, controlled-release delivery system