Plant Extracts of Psidium guajava, Mangifera and Mentha sp. inhibit the Growth of the Population of Single-species Oral Biofilm

Abstract

The use of oral gargle has gained popularity recently. Despite being either alcohol-based or plant-based, the main purpose for the usage of oral gargle is to prevent the accumulation of heavy plaque or oral malodour, that usually caused by the growth of oral biofilm. In this study, the antimicrobial effect of Psidium guajava, Mangifera sp. and Mentha sp. was tested against the single-species biofilm consisting of Streptococcus sanguinis and Streptococcus mitis. The biofilms were allowed to grow on the saliva-coated glass beads in Nordini’s Artificial Mouth (NAM) model to represent the oral cavity for 24 hours. The saliva would form the experimental pellicle on the glass beads. The results obtained showed that biofilm of Streptococcus mitis displayed a maximum adherence (11.53%) compared to Streptococcus sanguinis (1.83%) on the untreated experimental pellicle. When the aqueous extraction of plant extract was applied on the experimental pellicle, the bacterial adherence was significantly reduced to 1.54% (Streptococcus mitis) and 0.21% (Streptococcus sanguinis). This result indicates that the selected plant extracts can be used to inhibit the heavy growth of oral biofilm.