Background: Dental caries remains one of the most common multifactorial infectious diseases of mankind. Prior studies have shown that the bark and leaf extracts of guava have some pharmacological activities like anti – inflammatory, anti oxidant properties, etc. Conversely, not many studies have shown the efficacy of guava leaf extract as an anti cariogenic activity. The purpose of the study was to find out whether there is an inhibitory effect of guava crude extract on microbial flora of dental caries and to compare its efficacy with kanamycin antibiotic discs.
Method: Caries samples were placed in brain heart infusion (BHI) broth and incubated for 24 hours at 37ºc. After incubation the samples were inoculated on suitable solid media and various concentrations of crude extract 8, 16 and 32 fold of the minimal inhibitory concentration (MIC) were placed and incubated for 24hours.
Results: The antibacterial activity of the guava leaf extract against the microbial flora was tested by agar diffusion method, the largest clear zone of 13.42857 mm was obtained in 32 × MIC chewable tablets, whereas the positive control kanamycin produced a clear zone of 13 mm. The crude extract at the concentration of 32× MIC provided the highest inhibitory activity against the microorganisms followed by 16× MIC and 8× MIC concentrations.
Conclusion: Though guava leaf extract appears to be efficient against dental caries, further in vivo studies need to be performed with larger sample size taking the safety dosage into consideration.