Experimental And Clinical Study Of Anticaious Activity Of Propolis Toothpaste

Background & Object:Dental caries is one of the common diseases caused by multiple factors and results in dental hard tissue destruction chronically. It is one of the most common oral diseases in human beings. WHO has already taken it, together with cancer and cardiovascular diseases, as the major diseases that should be paid more attention to prevent and treat.Dental plaque is suggested as the indispensable microenvironment of caries. At present, people think that acidic fermentation products produced by the microorganisms in dental plaque in the presence of carbohydrate can dissolve the tooth hard tissue and form dental caries. So the dental plaque control can prevent dental caries effectively. Propolis, a natural non-toxic beehive product, has been shown its antimicrobial activity against a wide range of pathogenic microorganisms. Recent studies have proven propolis could inhibit the growth and adhesion of cariogenic bacteria, reduce the accumulation of supragingival plaque and the incidence of dental caries. It is an effectively way to prevent caries to add propolis into toothpaste, as brushing teeth with toothpastes is a usual way for oral hygiene.In the present study, the effect of ethanolic extracts of propolis (EEP) on bacteria was firstly studied. Then an anticaries toothpaste containing propolis based on the antibacteria activity of propolis was made. The propolis toothpaste's effect on the accumulation of supragingival plaque and the plaque pH were studied.Methods1. To study the inhibitory effect of propolis on the growth of Streptococcus mutans(SM) and Streptococcus sobrinus (SS), paper disks agar diffusion method was used by serially diluting the EEP. The minimum inhibitory concentrations (MICs) were found as a reference for later study on toothpaste.2. Paper disks agar diffusion method was used to study the inhibitory effect of propolis toothpaste on growth of SM and SS. The test groups were containing 50mg/ml, 25mg/ml, 10mg/ml and 5mg/ml propolis respectively, while non-propolis toothpaste and 20mg/ml chlorhexidine (CHD) as respectively the negative control and the positive one.3. A double-blind parallel, controlled clinical trail was designed to investigate the effectiveness of the toothpaste containing 10mg/ml propolis in controlling supragingival plaque. Forty healthy volunteers brushed with the propolis or non-propolis toothpaste twice a day for at least 2 minutes over a period of 4 weeks, were selected into the clinical trial. At the beginning of the trial, each volunteer was scored for plaque and constituent ratio of plaque was also examined. Each volunteer was allocated a toothpaste according to a predetermined randomization scheme. The volunteers were re-examined at the end of one week and 4 weeks. The volunteers refrained from using any other oral hygiene products during the period of the trial.4. This study was a before-after study and 10 healthy young volunteers were involved. Plaque pH change was measured by inserting a pH microelectrode into the interproximal space between the first and second premolar in the two right quadrants within 60 minutes (on ten points: 0, 2nd , 5th , 10th , 15th , 20th , 30th , 40th , 50th and 60th min) after 100mg/ml sucrose rinsing followed by having using propolis-free and propolis-containing toothpaste for four weeks. This experiment was performed to evaluate the superiority of using propolis-containing toothpaste after sucrose challenge on the recovery of dental plaque pH in situ.Results1. The results showed the MIC of EEP for SM was 0.3125% (3.125mg/ml), for SS was 0.625% (6.25mg/ml), showing a well concentration-dependent activity.2. Excepting the 5mg/ml propolis toothpaste, the other test groups were significantly better than the negative control, and the effects were suggested a well concentration-dependent activity. The 50 mg/ml propolis toothpaste has the same inhibiting effect for SM as CHD(P>0.05), as well close to CHD for SS.3. Results of PI scores were significantly difference between the propolis toothpaste group and the negative control group after 4 weeks(P<0.05). PI scores of propolis toothpaste group were significantly difference between the first and the fourth week(P<0.05).4. The plaque pH decreased and then rose slowly after sucrose challenge following 4 weeks use both of toothpaste respectively. But the pH decreased less in the propolis-containing group, which was never below the critical pH 5.5 and significantly higher than the baseline Stephan curve at 5th min and 10th min after sucrose challenge (P<0.05). While there was no difference between the propolis-free group and the baseline Stephan curve in each time point (P>0.05).Conclusions1. EEP can inhibit the growth of SM and SS, which displays the quality of propolis for preventing caries risk.2. The propolis toothpaste can inhibit the growth of SM and SS, and the propolis toothpaste has antibacterial activity.3. The propolis toothpaste can reduce the accumulation of supragingival plaque and decrease the coccus ratio in plaque, thus attain to prevent dental caries.4. Propolis-containing toothpaste can affect acid production produced by bacteria in dental plaque and reduce the range of plaque pH decreasing, so propolis toothpaste has anticarious activity.