Antimicrobial activity of chitosan in combination with silver diamine fluoride against Streptococcus mutans - An in-vitro study

Abstract

Silver diamine fluoride (SDF) is a recently introduced caries arresting agent. Some of its side effects include staining of teeth and cytotoxicity. Chitosan has an anti-cariogenic and plaque-reducing effect. Thus, considering the side-effects of SDF and the antibacterial efficacy of chitosan, the present study was done to evaluate the antibacterial effectiveness of SDF and chitosan in combination against Streptococcus mutans. 60 sterile Petri dishes were sub-divided into five groups of 12 Petri dishes each: Group 1: 38% SDF, Group 2: 2% chitosan, Group 3: 3% chitosan, Group 4: 38% SDF + 2% chitosan, Group 5: 38% SDF + 3% chitosan. Three different volumes: 30 µl,60 µl,90 µl were used. The agar well diffusion method was used to evaluate the antibacterial activity. The highest zone of inhibition was found in Group 1: 38% SDF at 90 µl and the lowest was found in group 3: Chitosan 3% at 30 µl. Group 1- 38% SDF showed higher antibacterial activity amongst all the other four groups under study. And a comparable antibacterial effect between group 1: 38% SDF at 30 µl and Group 5: 3% chitosan and 38% SDF at 30 µl. SDF at 38% showed higher antibacterial activity against S. mutans and a comparable antibacterial effect between group 1: 38% SDF at 30 µl and Group 5: 3% chitosan and 38% SDF at 30 µl. Thus, considering the side effects of SDF, further studies are required in this aspect to test the cytotoxicity of SDF and chitosan in combination.