Aim: The Aim of this study is to evaluate the antibacterial effect of various concentrations of triple antibiotic paste against Streptococcus mutans by antimicrobial susceptibility testing.
Material and Methods: The stability and antimicrobial effect of triple antibiotic paste were tested by antibiotic susceptibility testing against Streptococcus mutans by using Agar disc diffusion method over the period of one day, 3 days and 7 days. Freshly prepared triple antibiotic past the samples were divided into three groups: Group 1, 1% TAP; Group 2, 2% TAP; Group 3, 3%; Group 4, Chlorhexidine (control). The zone of inhibition was measured after 24 hours and recorded in millimeters and the same procedure was repeated after 3 days and 7 days using triple antibiotic paste which was prepared on day one.
Result: Higher concentration of triple antibiotic paste (3%) showed superior antibacterial effect compared to 1%, 2% TAP and chlorhexidine. The antibacterial efficacy increased more rapidly after 7 days compared to 24hours and 3 days.
Conclusion: Under the limitations of this invitro study, higher concentrations of triple antibiotic paste can be used as an effective intracanal medicament.