The aim of the study was to evaluate the antibacterial effect of slow release devices (SRD) medicaments containing chlorhexidine (CHX) or calcium hydroxide (CH) in gutta percha points. Eight anaerobic, 2 anaerobic facultative strains, and 2 cultures of bacteria samples randomly taken from necrotic root canals, incubated in anaerobic and aerobic broth for 48 hours. Every bacterial group was spread on 3 BHI agar plates and the SRD medicaments with plain gutta percha points as a control were placed in every plate. After incubation at 37°C for 48 h in a humid atmosphere, the BHI agar plates were examined for a bacterial inhibition zone. The diameter of the halo formed in the bacterial lawn was measured in mm in two perpendicular locations for each sample. The SRD containing CHX showed significantly (P<0.001) larger inhibition zones than the other groups. The inhibition zones of the CHX samples were between 5.7 ±1.3mm (E. facilaelis) to maximum of 20.2±1.4 mm (rothra dentocarlosa). The SRD containing CH showed maximal inhibition zone of 0.33±0.5 mm with S sanguis and no inhibition zones in 5 groups. The control group showed no inhibition zones in any bacterial group.
Conclusions: The SRD with CHX posses an effective antibacterial activity and should be considered for use as an intracanal medicament.