Effect of essential oils containing and alcohol-free chlorhexidine mouthrinses on cariogenic micro-organisms in human saliva.

OBJECTIVE: The aim of this study was to evaluate the effect on mutans streptococci and lactobacilli in saliva of mouthrinsing with essential oils and an alcohol-free chlorhexidine. MATERIALS AND METHOD: Twenty healthy volunteers (mean age 59 years) participated in the double-blind randomized cross-over study. Three mouthrinses were used in 16 days rinsing periods in addition to their regular mechanical oral hygiene: a solution with essential oils (EO; Listerine), a solution with alcohol-free chlorhexidine (CHX; Paroex) and water (negative control). The mouthrinse periods were separated by 3-month washout periods. At days 0 (baseline) and 17 (end) of each mouthrinse period, paraffin stimulated whole saliva was collected in order to analyse CFU/ml saliva of mutans streptococci and lactobacilli. RESULTS: Only the CHX rinse showed a significant difference for CFU mutans streptococci between baseline and end (p = 0.004). The CFU mutans streptococci at the end of the rinse periods showed statistically significant differences between CHX vs EO (p = 0.039) and CHX vs water (p = 0.022). The difference in CFU lactobacilli between baseline and end was significant for CHX (p = 0.031), but not for the other rinses. No statistically significant differences for lactobacilli were found at the end of the rinse periods between the mouthrinses. CONCLUSION: A significant reduction in amount of cariogenic bacteria in saliva was observed after 16 days of alcohol-free chlorhexidine mouthrinse but not after the essential oils rinse. The high number of participant's not changing to a bacterial class with a reduced number of micro-organisms showed that both rinses had little clinical significance as a caries preventing treatment method, which can decrease the number of CFU cariogenic micro-organisms.

Effects of mouthrinses containing essential oils and alcohol-free chlorhexidine on human plaque acidogenicity.

The aim of this in vivo study was to evaluate the effect of two antimicrobial mouthrinses on dental plaque acidogenicity after a sucrose challenge. Twenty subjects, with a mean age of 59 years, participated in a double-blind intraindividual randomized study. Three mouthrinses were used in 16-day rinsing periods in addition to their regular mechanical oral hygiene: a solution with essential oils (EO), solution with alcohol-free chlorhexidine (CHX) and water (negative control). The three test periods were separated by 3-month washout periods. Changes in plaque acidogenicity were evaluated after a sucrose challenge at day 0 (baseline) and at day 17 of each mouthrinse period using the microtouch method. Both CHX and EO resulted at day 17 in statistically significant less attenuated pH falls compared to the water rinse. The CHX mouthrinse resulted in the least pronounced pH values compared with EO (ns) during the whole 30-min period. When calculated as area under the curve (AUC), significantly lower values (AUC(6.2) ) were found for CHX and EO at day 17 compared to day 0. A significant difference for AUC(6.2) between CHX and water was found at day 17. No statistically significant differences were found for any of the comparisons with AUC(5.7). The results from this study indicate that both the essential oils and the alcohol-free chlorhexidine reduced plaque acidogenicity after a sucrose challenge. Large interindividual variations were observed.