Effects of menthol crystals aqueous extracts on salivary streptococci and mutans streptococci in comparison to chlorhexidine gluconate : in vivo study

Abstract EN

Background : Menthol is a chemical compound derived from mint family ; it has been applied as a medicinal remedy for many conditions for more than 3 thousand years ago, including skin infections and burns, localized pain, and in oral hygiene products and bad breath remedies like mouth wash and tooth paste.

The aim of this study was to test the effects of menthol crystals aqueous extract on the viable count of Salivary Streptococci and Mutans Streptococci and on salivary flow rate and pH in comparison to chlorhexidine gluconate 0.2 % and de-ionized water in vivo.

Materials and method : Menthol crystals aqueous extracts was prepared and estimated in mg / ml, in which 1 ml of alcohol was used to dissolve the specific amount of crystals, and then 99 ml of deionized water was added to form a solution of 100ml where as chlorhexidine gluconate used in this study as a control positive, de-ionized water was used as a control negative.

Stimulated salivary samples were collected from 15 volunteers (20-24 years) for five time intervals (before rinsing, 1 minute, 15 minutes, 30 minutes and 1 hour after rinsing), they were divided into three groups each group rinse with one of the tested agents for one minute).

Mites Salivary Agar (MSA) media was used for isolation of Streptococci and Mites Salivary Backtracking Agar (MSBA) media was used for isolation of Mutans Streptococci.

Colonies were counted using colony counter.

Salivary pH was measured using digital pH meter and volume of saliva was measured also.

Results : Counts of bacteria were recorded at different time points.

Results showed a reduction in the viability counts of Salivary Streptococci and Mutans Streptococci one minute immediately after rinsing which continue to decrease after one hour.

The reduction in the viable count of Streptococci was found to be statistically significant after 15 and 30 minutes of rinsing and highly significant after 1 hour, while for Mutans Streptococci, a significant reduction was found after 30 minutes of rinsing and highly significant after 1 hour.

Salivary flow rates and pH were measured for the three test and control groups of volunteers before and after rinsing for five time intervals.

There was an increase in the salivary flow rates and PH immediately after rinsing, and continue to increase after 30 minutes of rinsing, then decrease after 1 hour to approximate the base line.

Conclusion : Menthol proved to posses antimicrobial activities against salivary Streptococci and Mutans Streptococci, and reduces their viable counts.