Dentifrices, mouthwashes, and remineralization/caries arrestment strategies

While our knowledge of the dental caries process and its prevention has greatly advanced over the past fifty years, it is fair to state that the management of this disease at the level of the individual patient remains largely empirical. Recommendations for fluoride use by patients at different levels of caries risk are mainly based on the adage that more is better. There is a general understanding that the fluoride compound, concentration, frequency of use, duration of exposure, and method of delivery can influence fluoride efficacy. Two important factors are (1) the initial interaction of relatively high concentrations of fluoride with the tooth surface and plaque during application and (2) the retention of fluoride in oral fluids after application

Effects of high-fluoride dentifrice (5,000-ppm) on caries-related plaque and salivary variables

Objectives The aim of the present study was to measure the effects of a 5,000-ppm F toothpaste on caries-related factors in dental plaque and saliva. Materials and methods A 6-week clinical trial was designed with a total of 34 participants, of which 26 completed the study. The participants were assessed on four visits, 2 weeks apart. Sampling of approximal fluid for fluoride analysis and approximal plaque for organic acid analysis was performed. Chair-side tests were performed to register the lactic acid production rate on the tongue using Clinpro™ Cario L-Pop™, approximal plaque pH using the pH "strip method" and salivary buffer capacity and counts of cariogenic microorganisms using CRT Buffer® and CRT Bacteria®. Results Six weeks’ use of 5,000-ppm fluoridated (F) toothpaste significantly increased the approximal fluid F concentration (p < 0.05). There was a significant decrease in lactic acid production rate on the tongue assessed by Clinpro™ (p < 0.05). This was accompanied by changes in interproximal plaque acidogenicity, including significant reductions in AUC5.7, AUC6.2 and maximum pH fall and an increase in minimum pH (p < 0.05). A significant increase in the salivary buffer capacity and a reduction in the salivary mutans streptococci were observed (p < 0.05). Conclusion The present study demonstrates the ability of 5,000-ppm F toothpaste to modify caries-related factors in dental plaque and saliva. Clinical relevance The 5,000-ppm F toothpaste could be regarded as a possible effective regimen against caries in the near future

Metabolic activity of Streptococcus mutans biofilms and gene expression during exposure to xylitol and sucrose

The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media: Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy (CLSM)-based analyses of the microbial vitality, respiratory activity (5-cyano-2,3-ditolyl tetrazolium chloride, CTC) and production of extracellular polysaccharides (EPS) were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters: culture growth, vitality, CTC activity and EPS production. However, xylitol exposure caused a difference in gene expression compared to the control. GtfC was upregulated only in the presence of xylitol. Under xylitol exposure, gtfB was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three. Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms