Biological Assessment of Three Experimental Toothpaste Additives

Abstract

This study was conducted to determine in vitro, the inhibitory effect of the Probiotic strain, Propolis extract and Miswak extract in experimental toothpaste against Streptococcus mutans (S. mutans) growth as well as different mixtures from the previous compounds. While in vivo study, was evaluated the effect of one of the mixture in experimental toothpaste that was proved its best efficacy in vitro study on the salivary S. mutans counts in high caries risk paticipants in a three months period. A total of 120 samples of experimentally prepared toothpastes were divided into four main groups, thirty each, according to the type of additives incorporated in the experimental toothpaste base (the first group was the experimental toothpaste base as control, second group samples was Propolis extract in experimental toothpaste base, third group was Miswak extract in experimental toothpaste base and the fourth group was Probiotic strain in experimental toothpaste base). Each group was subdivided into three subgroups, ten each, according to the concentration of the incorporated additive in the experimental toothpaste (20%, 10%, 5%, each for Propolis, Miswak and Probiotic strain). The minimum inhibitory concentration (MIC) of each additive incorporating into the experimental toothpaste was evaluated. In addition, a total of 120 samples of experimental toothpastes were divided into four main groups, thirty each, according to the mixture of the MIC of each of Propolis extract, Miswak extract and probiotic strain was incorporated into the experimental toothpaste base (the first group (M1) was the mixture between Propolis and Probiotic strain, second group (M2) was the mixture between the Miswak and Probiotic strain, third group (M3) was between the Propolis and Miswak, fourth group (M4) was the mixture between propolis, Miswak and Probiotic strain, and commercially herbal toothpaste served as positive control). Each of the previously mentioned four main groups was divided into three subgroups, ten each, according to the storage time of each sample before testing (24 hours, 15 days, 30 days). Moreover in vivo study, the best mixture in experimental toothpaste that was found to be effective in vitro study and safe, was used to evaluate its effect on salivary streptococcus mutans counts in a single group of seven subjects with high caries risk at three intervals; before the study, after one month and after three months. The results showed that the minimum inhibitory concentration of each additive in experimental toothpaste was 5% for Propolis content in experimental toothpaste as well as for Miswak content, while 20% for Probiotic pellet in experimental toothpaste. Also, it was found that the most effective mixture After 30 days of experimental toothpastes storage was the mixture between propolis, Miswak and Probiotic strain which was showed the statistically significantly highest mean inhibition zone diameter. While there was no statistically significant difference between the mixture between the Propolis and Probiotic strain and the mixture between the Propolis and Miswak; both showed statistically significantly lower mean inhibition zone diameters. However, the mixture between the Miswak and Probiotic strain showed the statistically significantly lowest mean inhibition zone diameter. As regards the in vivo study results showed an obvious decrease in mean Log10 CFU/ml of salivary S. mutans counts in a group of high caries risk using the experimental toothpaste (M4) throughout the three months period of treatment.