RESUMO
AIMS: The present study aims at recording the antibacterial efficacy of various disinfectants used at different time periods against Staphylococcus aureus and viridans streptococcal species of bacteria isolated from complete dentures. MATERIALS AND METHODS: Fifty complete denture patients were selected for the study and swabs were collected from their complete denture surfaces. The isolated bacteria were subjected to six experimental groups which includes four groups of chemical denture disinfectants and two tree extracts groups. Isolation of the bacteria S. aureus and viridians streptococcal species was done by means of selective media and confirmed by means of biochemical tests. The bacteria were subjected to biofilm assays. The biofilm-forming bacteria with optical density (O.D.) values of more than 1.5 were selected for the study. About 150 acrylic specimens were fabricated and were contaminated by the 2 isolated bacteria mentioned above. The contaminated samples were disinfected by immersion for 10, 20, and 30 minutes in six disinfectants, namely: (1) 1% sodium hypochlorite, (2) 2% chlorhexidine, (3) 2% glutaraldehyde, (4) 3.8% sodium perborate, (5) 2% aalam extract, and (6) 2% neem extract. RESULTS: ANOVA test was performed for both S. aureus and viridans streptococcal species with regard to various synthetic and tree extracts as well as time duration of disinfection. F values for disinfection vs S. aureus is 205.4 (p < 0.001) and the relevant Scheffe post hoc test values is in the following order: 3 < 1, 4 < 6, 2 < 5. F values for disinfection vs viridans streptococcal species is 364.7 (p < 0.001) and the relevant Scheffe post hoc test values is in the following order: 3 < 4 < 1, 6, 2 < 5. CONCLUSION: For biofilm-forming S. aureus, 2% glutaraldehyde showed best antibacterial efficacy which was followed by 1% sodium hypochlorite and 3.8% sodium perborate. When it comes to biofilm-forming viridans streptococcal species, 2% glutaraldehyde showed best antibacterial efficacy. Next to 2% glutaraldehyde, 3.8% sodium perborate exhibited good disinfection potential. CLINICAL SIGNIFICANCE: Complete denture patients have a plethora of microorganisms habitating their complete dentures. Some bacteria are capable of causing systemic illness such as aspiration pneumonia and endocarditis. Hence, constant removal and disinfection of biofilms from the denture surface is vital to the local and systemic wellness of the patient. The most common bacteria capable of causing pneumonia and endocarditis that are isolated from complete dentures include S. aureus and viridans streptococcal species. The present study evaluates antibacterial efficacy of different disinfection agents especially against these biofilm-forming bacteria for different time periods. How to cite this article: Andonissamy L, Karthigeyan S, Ali SA, et al. Effect of Chemical Denture Disinfectants and Tree Extracts on Biofilm-forming Staphylococcus aureus and Viridans Streptococcus Species Isolated from Complete Denture. J Contemp Dent Pract 2019;20(11):1307-1314.