[The preparation and in vitro release test of sustained release delivery gutta-percha point containing metronidazole].

Purpose: To develop sustained release delivery gutta-percha point containing metronidazole (SRDGM) for root canal disinfection, and determine the drug concentration in vitro and the time that the device maintains the effective drug concentration.

Methods: The gutta-percha was selected as the carrier and adsorbed metronidazole etc. The point was coated with mixation of ployethylene glycol and acetate fibre to prepare the groups of SRDGM.The group that released the longest period of the effective drug was selected for the following study. Eight teeth were selected, the SRDGM was used to disinfect the root canal. The adsorption was measured for 24 hours and 10 days.

Results: The SRDGM contained metronidazole 2013 microg, it could release 68.24% of the total drug in 24 hours in vitro. The effective metronidazole concentration released lasted more than 10 days. On the 10th day, there was also 33.13 microg/ml metronidazole released which was more than minitory inhibitory concentration of metronidazole.

Conclusions: SRDGM could carry the metronidazole and control the release rate. It could maintain the effective drug concentration for a long time (>10 days) in root canal.