Microbiological evaluation of the efficacy of chlorhexidine in a sustained‐release device for dentine sterilization

The aim of this in‐vitro study was to evaluate the effect of chlorhexidine in solution and in a sustained‐release device as an intracanal medication. Hollow cylindrical dentine specimens prepared from bovine incisors were incubated with Streptococcus faecalis for a period of 3 weeks. The intracanal medicaments tested were 0.2% chlorhexidine gluconate solution (CM), chlorhexidine in a sustained‐release device (1.2 mg) (SRD), camphorated paramonochlorophenol (CMCP), and a control (no medication). Each medicament was introduced into the lumen of one dentine specimen and incubated for 5 min. 24 h,48 h or 7 days at 3 7°C. The bacteriological samples were taken by shaving the dentine inside the lumen with dental burs ranging in size from ISO 023–033. The dentine powder was collected in test‐tubes containing growth medium and incubated for 24 h. The optical density of the medium was recorded by means of a spec‐trophotometer at a wavelength of 540 nm. There was a statistically significant difference between the control group and all the medicaments tested.