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Objective: To investigate the effect of a novel mineral containing toothpaste in comparison to a fluoride toothpaste in children with white spot lesions., Methods: The clinical study was conducted from 2016 to 2018 at Marmara University Department of Pediatric Dentistry Clinic after approval from the ethics review committee of Yeditepe University, Istanbul, Turkey and comprised children of either gender aged 4-5 years having white spot lesions. They were randomly allocated into two groups. The FT (Fluoridated Toothpaste) group was given a 500ppm fluoridated toothpaste, while the Mineral Containing Toothpaste (MCT) group was given toothpaste containing calcium glycerophosphate, magnesium chloride, and 12% xylitol. The white spot lesions were examined using Laser Fluorescence (LF) at baseline and after a month of usage. The two readings were compared. Stimulated saliva was collected for measuring the salivary potential of hydrogen, buffering capacity, and streptococcus mutans. Data was analysed using SPSS 19., Results: Of the 26 children, 10(38%) were girls and 16(62%) were boys. The overall mean age was 4.77±0.54 years. There were 13(50%) subjects in each of the two groups. Of the 381 measurements done, 198(52%) were in the MCT group and 183(48%) in the FT group. LF scores decreased in both the groups (p=0.001). The remineralising potential was not significantly different (p=0.866), while salivary buffering capacity and potential of hydrogen increased in both the groups but the change was not significant (p>0.05). The number of children positive for streptococcus mutans decreased in both the groups (p>0.05)., Conclusions: The toothpaste containing calcium glycerophosphate, magnesium chloride and 12% xylitol had the remineralization properties needed for the prevention of gwhite spot lesions in children.

Non-cariogenic sweet substances, like sugar alcohols, are used to decrease the risk of caries by reducing the growth of dental plaque. The aim of our study was to reveal the impact of xylitol and erythritol on the growth and biofilm formation of cariogenic bacteria including as a novelty, set of clinical mutans streptococci and Scardovia wiggsiae and to assess the possible synergistic influence of these polyols. We found both xylitol and erythritol to express high growth inhibition effect on cariogenic bacteria. In synergistic effect experiments, 10% polyol combination with excess of erythritol was found to be more effective against growth of Streptococcus mutans and the combination with excess of xylitol more effective against growth of Streptococcus sobrinus and S. wiggsiae. In biofilm inhibition experiments, solutions of 10% polyols in different combinations and 15% single polyols were equally effective against mutans streptococci. At the same time, higher biofilm formation of S. wiggsiae compared to experiments without polyols was detected in different polyol concentrations for up to 34%. In conclusion, both erythritol and xylitol as well as their combinations inhibit the growth of different cariogenic bacteria. Biofilm formation of mutans streptococci is also strongly inhibited. When applying polyols in caries prophylaxis, it is relevant to consider that the profile of pathogens in a particular patient may influence the effect of polyols used.

Dental caries is a disease that results from microbiome dysbiosis with the involvement of multiple cariogenic species, including mutans streptococci (MS), lactobacilli, Scardovia wiggsiae, and several Actinomyces species that have the cariogenic traits of acid production and acid tolerance. Sugar consumption also plays an important role interacting with microbiome dysbiosis, determining the fate of caries development. In addition, the MS transmission that encompasses multiple sources can have long-term impacts on the oral microbiome and caries development in children. Intervention in MS transmission in early childhood may promote effective long-term caries prevention. Anticaries regimens aimed against the above mechanisms will be important for successful caries management. Xylitol and erythritol may serve as good components of anticaries regimens as oral microbiome modifiers, sugar substitutes, and agents to prevent MS transmission in early childhood with both oral and systemic benefits. Further studies are needed to elucidate the mechanism of the anticaries effects of xylitol and erythritol with consideration of their impacts on the microbiome and bacterial virulence, in addition to cariogenic bacteria levels as well as their benefits for overall health. On the other hand, the anticaries agent C16G2, specifically targeting Streptococcus mutans, the most common cariogenic bacterial species, has shown good safety for short-term oral topical use and promising effects in reducing S. mutans in vitro and in vivo with the promotion of oral commensal bacteria. Future study on its anticaries effect will need to include its long-term impact on the oral microbiome and effects on other important cariogenic bacteria.

Sugar-free chewing gum containing polyols has been demonstrated to reduce caries experience in randomised controlled clinical trials. A range of polyols (mannitol, sorbitol, xylitol and maltitol) can be found in sugar-free gums and it has been claimed that they can facilitate calcium uptake into enamel subsurface lesions promoting remineralisation., Objectives: The aim of this study was to compare the effect of polyols on remineralisation of enamel subsurface lesions in vitro by artificial saliva (AS) and by AS containing the salivary biomimetic casein phosphopeptide amorphous calcium phosphate (CPP-ACP)., Methods: The polyols (12.6% w/v) and CPP-ACP (0.376% w/v) were used at physiologically relevant concentrations approximating those released into saliva during chewing a CPP-ACP/polyol chewing gum. Enamel subsurface lesions were exposed to one of the polyols (xylitol, sorbitol, maltitol, mannitol) in AS or AS containing CPP-ACP for 7days at 37°C with a change of solution each day. Remineralisation of the enamel subsurface lesions was measured by transverse microradiography., Results: A statistical test for equivalence showed there was no difference in remineralisation between the AS solutions with or without any of the polyols. The AS+CPP-ACP solution substantially promoted remineralisation over AS alone independently of any polyol added., Conclusion: This controlled in vitro study showed that polyols at physiologically relevant concentrations did not promote remineralisation of enamel subsurface lesions by facilitating calcium uptake into the lesion., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Aim: As suppression of Streptococcus mutans in young children may prevent or delay colonisation of the oral cavity, toothbrushing with dentifrices containing anti-S. mutans activity may aid in preventing caries. The aims of this study were to compare the effects of children's dentifrices on the growth of S. mutans and non-mutans bacteria (Streptococcus sanguinis and Lactobacillus acidophilus)., Materials and Methods: The agar diffusion assay at neutral pH was used to examine the antibacterial activity of commercial dentifrices and their major constituents., Results: Dentifrices containing 1,450 ppm fluoride produced greater growth inhibition of both S. mutans and S. sanguinis than those with <500 ppm. No inhibition was seen for pure solutions of sodium fluoride or sodium monofluorophosphate at fluoride concentrations up to 100,000 ppm. Stannous fluoride exerted antibacterial effects at concentrations above 10,000 ppm. Significant growth inhibition of both S. mutans and S. sanguinis was seen with sodium lauryl sulphate at 2,500 ppm and with triclosan at 100 ppm. No inhibitory effects were seen for xylitol, sorbitol, sodium pyrophosphate or polyethylene glycol at concentrations up to 80,000 ppm., Conclusion: Sodium lauryl sulphate is the major bacterial inhibitory compound in children's dentifrices.

Background: Streptococcus mutans is one of the most common cariogenic microorganisms. Use of natural anticariogenic agents, such as Xylitol has been well-established in the literature. On the other hand, there is a scarcity of studies that have reported the antimicrobial potential of Propolis as an anticariogenic chewing agent; hence, the present study was designed., Aims: To evaluate and compare the anticariogenic action of two commercial chewing gums Propolis and Xylitol on the salivary S. mutans count in a group of children from Bengaluru city., Settings and Design: Clinical setting and experimental design., Materials and Methods: Thirty healthy children aged 8-11 years with decayed, missing, and filled teeth (dmft)/DMFT index score≥3 were included in the study. Before the test, unstimulated saliva was collected. Children divided into Group I and II were given Propolis and Xylitol chewing gums respectively; to chew for 15 min. Saliva samples were then collected at 15 min (just after spitting) and after 1 h. The amount of S. mutans in saliva was evaluated using a selective media (MSAB). In addition, compliance of the two chewing gums among the children was tested with a questionnaire., Statistical Analysis Used: Student's t-test., Results: Six samples out of 30 were excluded due to no growth. The total number of bacterial colonies was significantly reduced when compared to baseline in both the groups. Propolis gum showed statistically significant reduction in the number of colonies as compared to Xylitol. Xylitol gum was more preferred than Propolis gum by the children., Conclusions: Propolis chewing gum can be used as an anticariogenic agent in children.

Purpose: To evaluate in vitro root caries formation in human permanent teeth and to determine the effects of commercially available dentifrices containing different amounts of fluoride, while employing a well-tested artificial caries system using an acidified gel., Methods: Root surfaces from caries-free human permanent teeth (n = 10) underwent debridement and fluoride-free prophylaxis. The tooth roots were sectioned into six portions, and acid-resistant varnish was placed with two sound root surface windows exposed on each tooth portion. Each portion from a single tooth was assigned to a treatment group: (1) No treatment control; (2) Denticious 5000 dentifrice (5,000 ppm F + xylitol); (3) PreviDent 5000 (5,000 ppm F); (4) AIM dentifrice (1,500 ppm F); (5) Listerine dentifrice (1,300 ppm F); and (6) Crest Regular Paste (1,500 ppm F). Tooth portions were treated with fresh dentifrice twice daily for 180 seconds, followed by fresh synthetic saliva rinsing over a 7-day period. Controls were exposed twice daily to fresh synthetic saliva rinsing over a 7-day period. In vitro root caries were created using an acidified gel (pH 4.25, 21 days). Longitudinal sections (three sections/tooth portion, 30 sections/group; 60 lesions/group) were evaluated for mean lesion depths (water imbibition, polarized light). Statistical analyses were performed using ANOVA and Duncan's Multiple Range test., Results: Mean lesion depths were 389 +/- 43 microm for No treatment - control, 223 +/- 33 microm for Denticious 5000 dentifrice, 242 +/- 42 microm for Prevident 5000, 337 +/- 29 microm for AIM dentifrice, 297 +/- 37 microm for Listerine dentifrice, and 282 +/- 34 microm for Crest Regular Paste dentifrice. All treatment groups had mean depths significantly less than the No treatment - control group (P < 0.05). Denticious 5000 and PreviDent 5000 had significantly reduced mean depth compared with the other dentifrice treatment groups (P < 0.05).

Xylitol is a safe dental caries preventive when incorporated into chewing gum or confections used habitually. The goal of this paper is to identify and assess the work on xylitol and other polyols and dental caries since 2008. Xylitol is effective when used by the mother prenatally or after delivery to prevent mutans transmission and subsequent dental caries in the offspring. One new completed trial confirmed that children of mothers who used xylitol lozenges after delivery had less dental caries than a comparison group. A similar study confirmed that the use of xylitol gum by the mother either prevented or postponed MS transmission to the offspring. Xylitol use among schoolchildren delivered via a gummy bear confection reduced S. mutans levels, but a once per day use of xylitol-containing toothpaste did not. Randomized trials, with caries outcomes, assessing xylitol-containing lozenges in adults and xylitol-containing gummy bears in children will release results in the coming year. Other studies are ongoing but are not systematic and will fail to answer important questions about how xylitol, or other polyols, can address the global dental caries problem.

Streptococcus mutans metabolize carbohydrates, such as glucose and sucrose, to produce acid and enhance biofilm formation with the early colonizing bacteria to induce dental caries. Xylitol has been used as a reliable substitute for carbohydrate to inhibit the acid production of S. mutans. However, long-term xylitol consumption leads to the emergence of xylitol-resistance in S. mutans. The aim of this study was to investigate the cariogenic trait of Xylitol-resistant (X(R)) S. mutans using biofilm formation and coaggregation of xylitol-sensitive (X(S)) and X(R) S. mutans with salivary bacteria and their glucosyltransferases expression. When X(S) or X(R) S. mutans were incubated in brain heart infusion broth with bacteria from human saliva, X(R)S. mutans exhibited reduction in biofilm formation in comparison to X(S) S. mutans. The coaggregation between X(R) S. mutans and S, gordonii, S. mitis, S. oralis or S. sanguinis was less pronounced than that of X(S) S. mutans in the presence of sucrose. However, there was no difference in the coaggregation between X(R) and X(S) S. mutans in the sucrose-free condition. The level of gtfB and gtfC mRNA expression of X(R) S. mutans was lower than that of X(S) S. mutans, whilst the level of gtfD mRNA expression did not differ between the two strains. The reduction of biofilm formation in X(S) S. mutans due to decrease in glucosyltransferases expression suggests that X(R) S. mutans may be less cariogenic than X(S) S. mutans., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

To assess mutans streptococci (MS) during xylitol gum chewing (mean 3.8 g/day, 2.9 times/day) for 13 months and then for 15 months after the intervention, Japanese mothers with high salivary MS were randomized into two groups: xylitol gum (n = 56) and no gum (n = 51). The proportion of low MS levels was highest at 3 months of consumption (48.8%), but was significantly lower compared to baseline at the end of the intervention (p < 0.001). MS levels did not change during the postintervention period. The data suggest that in the xylitol group 23.3% showed persistent carryover effects by xylitol gum chewing in the postintervention period., (Copyright © 2012 S. Karger AG, Basel.)

Unlabelled: Recent researches have focused on xylitol as convenient and effective method to inhibit cariogenic bacteria. The purpose of the present study is to assess the effect of xylitol on plaque accumulation, caries activity and salivary Streptococcus Mutans in a group of Saudi mother-child pairs., Materials and Methods: The study sample included 60 mother and child pairs selected on the basis of having high salivary streptococcus mutans levels. The study sample was randomly divided into experimental group (30 pairs) and control group (30 pairs). The experimental group was given xylitol treatment and the controls received fluoride varnish. Both groups were examined to assess caries, plaque and salivary streptococcus mutans levels. Xylitol treatment in the form of chewing gum for mothers and tablets for children was consumed three times/day for three months. All subjects received oral hygiene instructions, dietary counseling and restorative treatment. The results showed that the number of mothers and children with high streptococcus levels in the experimental group decreased to a statistically significant level at the end of the three month period, similarly, the control mothers showed the same trend. A statistically significant decrease in plaque scores was evident only among the children S experimental group. The caries level of children and mothers showed no statistically significant differences between the experimental and control groups. The factors which significantly affected the streptococcus mutans count in children after three months were the child' dmft at baseline the preventive method used and the mother'salivary streptococcus mutans level.

This in vitro study aimed to analyze the effect of including xylitol into a fluoridated dentifrice to provide protection against enamel erosion with or without abrasion. Bovine enamel specimens were subjected to erosion or erosion plus abrasion (7 days) and the treatment with the following dentifrices: 10% xylitol; 10% xylitol plus 1,030 ppm F (NaF); 1,030 ppm F; and placebo. The erosive challenges were performed 4 times a day (2 min at a time). The specimens were exposed to the slurries of the dentifrices 2 times daily (15 s at a time). Half of the specimens per group were additionally abraded using an electrical toothbrush (F = 1.5 N). Between the challenges, the specimens were remineralized by artificial saliva. Enamel loss was measured profilometrically (µm). The data were statistically analyzed by two-way ANOVA and Bonferroni's post-hoc test (P < 0.05). Ten percent xylitol plus F and F dentifrices significantly reduced enamel erosion compared to placebo and xylitol dentifrices. On the other hand, all dentifrices presented a significant potential to protect against enamel erosion plus abrasion compared to placebo, with 10% xylitol plus F showing the best results. Based on this result, the inclusion of 10% xylitol increased the effect of the fluoridated dentifrice against enamel erosion plus abrasion in vitro. In situ or clinical studies are needed to confirm the data.

This study evaluated acid production from cooked starch by Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis and Streptococcus mitis, and the effects of alpha-amylase inhibitors (maltotriitol and acarbose) and xylitol on acid production. Streptococcal cell suspensions were anaerobically incubated with various carbohydrates that included cooked potato starch in the presence or absence of alpha-amylase. Subsequently, the fall in pH and the acid production rate at pH 7.0 were measured. In addition, the effects of adding alpha-amylase inhibitors and xylitol to the reaction mixture were evaluated. In the absence of alpha-amylase, both the fall in pH and the acid production rate from cooked starch were small. On the other hand, in the presence of alpha-amylase, the pH fell to 3.9-4.4 and the acid production rate was 0.61-0.92 micromol per optical density unit per min. These values were comparable to those for maltose. When using cooked starch, the fall in pH by S. sanguinis and S. mitis was similar to that by S. mutans and S. sobrinus. For all streptococci, alpha-amylase inhibitors caused a decrease in acid production from cooked starch, although xylitol only decreased acid production by S. mutans and S. sobrinus. These results suggest that cooked starch is potentially acidogenic in the presence of alpha-amylase, which occurs in the oral cavity. In terms of the acidogenic potential of cooked starch, S. sanguinis and S. mitis were comparable to S. mutans and S. sobrinus. Alpha-amylase inhibitors and xylitol might moderate this activity., (Copyright 2009 S. Karger AG, Basel.)

Objectives: Oral bacteria implying a natural resistance may deteriorate the antibacterial efficacy of chlorhexidine on cariogenic microorganisms. Xylitol, mostly applied via chewing gum, is known to possess favorable plaque-reducing properties. The aim of this study was to investigate the effect of a xylitol rinse formulated as pure solution or combined with chlorhexidine on the viability of Streptococcus sanguis (early colonizer of human teeth) and Streptococcus mutans (the most causal strain for caries) during initial steps of biofilm formation., Method and Materials: After exposure to the test solutions, the bacteria suspended in human sterile saliva were allowed to attach to human enamel slides for 60 minutes in a preclinical flow chamber system. The bacterial vitality of suspended and attached cells was monitored using 2 fluorescent DNA stains by epifluorescence microscopy. Further parameters measured were the total bacterial cell counts on enamel slides and growth of suspended streptococci., Results: The sensitivity of S mutans to pure chlorhexidine or in combination with xylitol is contrary to the natural resistance of S sanguis to chlorhexidine. The combination of xylitol/chlorhexidine showed a statistically significant antivital effect on S sanguis cells compared to the pure agents xylitol and chlorhexidine. The bacterial cell density on enamel and bacterial reproduction on agar plates were similarly affected by the combination of xylitol/chlorhexidine or the single substances., Conclusion: The newly discovered synergistic antivital effect of xylitol combined with chlorhexidine may contribute to the favorable potential of xylitol use for the improvement of new formulations of caries-preventive mouthrinses.

Xylitol inhibits the glycolysis and growth of Streptococcus mutans, but to different degrees among strains. Thus, we studied the biochemical mechanism through which the inhibition varies, using S. mutans strains ATCC 31989, NCTN 10449, and NCIB 11723, which are highly sensitive, moderately sensitive, and resistant to xylitol, respectively, under strictly anaerobic conditions such as those found in deep layers of dental plaque. Xylitol (30 mM) decreased the rate of acid production from glucose (10 mM) in ATCC 31989, NCTC 10449, and NCIB 11723 by 86, 26, and 0%, respectively. The activities of the xylitol : phosphoenolpyruvate phosphotransferase system (PEP-PTS) relative to those of glucose : PEP-PTS were 120, 16, and 3%, respectively. In ATCC 31989 and NCTC 10449, intracellular accumulation of xylitol 5-phosphate and decreases of fructose 1,6-bisphosphate and glucose 6-phosphate were observed. Furthermore, in the presence of xylitol (30 mM), glucose : PEP-PTS activities decreased by 34, 17, and 0%, respectively. These findings indicated that the higher the xylitol : PEP-PTS activity was and the more effectively xylitol decreased glucose : PEP-PTS activity, the more sensitive the strain was to xylitol. These results suggest that the following inhibitory mechanisms are active in the xylitol-sensitive mutans streptococci: direct inhibition of glycolytic enzymes by xylitol 5-phosphate derived from xylitol : PEP-PTS and, possibly, indirect inhibition through competition for the phosphoryl donor, HPr-P, between glucose and xylitol : PEP-PTSs.

The purpose of this study was to evaluate the combined inhibitory effect of fluoride and xylitol on acid production by mutans streptococci, Streptococcus mutans NCTC10449 and Streptococcus sobrinus 6715, from glucose under strictly anaerobic conditions at fixed pH 5.5 and 7.0. The bacteria were grown in a tryptone-yeast extract broth under strictly anaerobic conditions (N2: 80%; H2: 10%; CO2: 10%). Reaction mixtures for acid production from glucose contained bacterial cells with fluoride (0-6.4 mM) and/or xylitol (60 mM). Acidic end products of glucose fermentation and intracellular glycolytic intermediates were assayed. The combination of fluoride and xylitol inhibited acid production more effectively than fluoride or xylitol alone. In the presence of fluoride and xylitol, the proportion of lactic acid in the total amount of acidic end products decreased, while the proportion of formic and acetic acids increased. Analyses of intracellular glycolytic intermediates revealed that xylitol inhibited the upper part of the glycolytic pathway, while fluoride inhibited the lower part. This study indicates that fluoride and xylitol together have synergistic inhibitory effects on the acid production of mutans streptococci and suggests that xylitol has the potential to enhance inhibitory effects of low concentrations of fluoride., (Copyright 2005 S. Karger AG, Basel.)

Purpose: The aim of this study was to evaluate the lactic acid concentration in supragingival plaque from caries-active pre-school children after a short-term use of either xylitol- or sorbitol-containing chewing gums., Material and Methods: The investigation consisted of a prospective crossover design with 10 healthy children aged 2-4 years each with at least two caries lesions within the dentine (ds > or = 2). The children were instructed to chew 6 pieces of a test or a control gum every day for a 14-day period. The test gum contained 65% xylitol and the control gum was sweetened with sorbitol. At baseline and after 14 days, salivary mutans streptococci were enumerated with a chair-side test (Strip mutans) and dental plaque was collected from the upper maxillary incisors. After a washout period of 6 weeks, the same procedure was repeated with the corresponding test or control gum. Lactic acid was determined enzymatically in glucose-challenged plaque suspensions., Results: The lactic acid concentration was significantly reduced (p<0.05) by 22% compared with baseline following the xylitol gum regimen but was unaltered after the control gum. The levels of salivary mutans streptococci were mainly unaffected by both chewing gums., Conclusion: A 14-day use of xylitol-containing chewing gums, corresponding to a daily amount of 5 grams of xylitol, could diminish glucose-initiated lactic acid formation in supragingival plaque in caries-active pre-school children.

A number of studies involving xylitol chewing gum have demonstrated that xylitol is both noncariogenic and anticariogenic. The ability of xylitol to act as an anticariogenic agent most likely is due to its ability to be transported into caries-causing oral bacteria and inhibiting fermentation either by depleting the cell of high-energy phosphate or by poisoning the glycolytic system. In vitro tests were conducted to determine the concentration of xylitol required to inhibit the growth of three strains of oral streptococcus (S. mutans, S. salivarius, and S. sanguis). All three strains were inhibited significantly at xylitol concentrations of 12.5% and higher; however, only S. mutans was inhibited significantly at a xylitol concentration of 1.56%.

Long-term xylitol consumption leads to the emergence of xylitol-resistant (X-R) mutans streptococci. The aim of the present study was to compare cariogenic traits in X-R and xylitol-sensitive (X-S) strains. Six strains of mutans streptococci, three X-R and three X-S strains, were studied. Xylitol resistance and sensitivity were confirmed by growth in xylitol-supplemented media. Acid production from glucose or fructose or uptake of xylitol was initiated by adding (14)C-labelled glucose, fructose or xylitol to bacterial suspensions. The resultant metabolites were identified by HPLC. Lactate was the major metabolite from glucose, whether the bacteria were grown in the presence or the absence of xylitol. Lactate production per colony-forming unit was lower in X-S cells than in X-R cells. Fructose was metabolized by both X-R and X-S cells. Both X-R and X-S cells took up xylitol, but xylitol-5-P was detected in X-S cells only. Total polysaccharides were measured through production of C(14)-labelled ethanol-insoluble polymers from [U(14)-C]-sucrose. No difference in polysaccharide production was found between X-R and X-S cells. The present study thus does not support the contention that X-R are less cariogenic than X-S mutans streptococci.

Background: The authors examined the effect of xylitol, a naturally occurring sweetener, on levels of Streptococcus mutans and S. sobrinus. They also investigated xylitol's mechanism of action., Methods: The authors compared cariogenic bacteria levels before and after exposure to xylitol products in children and adults. In the first study, 187 children received xylitol-containing snacks in school for four weeks. In the second study, two adults received xylitol candy for four weeks. Unstimulated saliva samples were taken from all subjects. Gingival samples also were taken from the adults. The authors plated the samples on selective microbiological media. Individual isolates were plated on media with varying concentrations of xylitol, and were identified using specific DNA probes. Genetic relatedness was determined via pulse-field gel electrophoresis., Results: The children's salivary S. mutans levels remained stable before and after xylitol exposure. Further analysis of the S. mutans isolates was conducted for seven children. Bacteria from five of these children grew with 10 percent or less xylitol at baseline, while the bacteria from all seven children grew with 15 percent xylitol after exposure to the xylitol-containing snacks, suggesting that the S. mutans increased in tolerance to xylitol during exposure. Six children had isolates with the same genotype at both time points. S. mutans and S. sobrinus levels were reduced in one of the adults as a result of xylitol exposure, and the bacterial isolates became more xylitol tolerant. In the second adult, S. mutans and S. sobrinus levels increased, while the subject maintained the same proportion of susceptible and tolerant strains as that at baseline., Conclusions: Overall, consumption of xylitol-containing snacks and candy did not reduce S. mutans levels. However, bacteria from five children and one adult became more xylitol tolerant., Clinical Implications: These results provide a basis on which xylitol-containing products can be recommended and xylitol's mechanism of action can be explained to patients.

Xylitol possesses a unique property distinct from the other caries-preventive sweeteners. This sugar alcohol cannot be metabolized to acids but is taken up by Streptococcus mutans and accumulated as a toxic sugar-phosphate in the cells, resulting in growth inhibition. Due to the accumulation, xylitol induces biological responses including the emergence of xylitol-insensitive populations. Therefore, we expected another response induced by xylitol and found a new phenomenon, that cells repeatedly cultured in the presence of xylitol evolved into those exhibiting an elevated dextran-dependent aggregation phenotype. This phenotype was found to result from expression of the gbpC gene, which was previously reported to be expressed only under certain stress conditions. Construction of a Strep. mutans isogenic mutant carrying the gbpC::lacZ fusion gene indicated that gbpC expression of cells repeatedly cultured in the presence of xylitol was elevated 20-fold. DNA transfer experiments indicated that this phenotypic change did not appear to be due to a mutation. These cells also exhibited decreased adhesion to glass surfaces when grown in the presence of sucrose. This may be one of the ways by which some populations of Strep. mutans are removed from dental plaques.

This study aimed to determine the effect of xylitol on the development and remineralization of caries in vitro, and to compare this effect with that of fluoride alone and in combination. Two experiments were devised. In experiment 1, bovine incisors were each sectioned into 4 portions which were randomly assigned to 4 demineralizing agents: A) acidic buffer (x), B) x + 0.5 ppm fluoride, C) x + 20% xylitol, and D) x + 20% xylitol + 0.5 ppm fluoride. Caries-like lesions were produced in specimens. In experiment 2, carious lesions were produced in teeth. Five lesion-bearing slabs were cut from each tooth. While one was reserved as control (UN), others were randomly assigned to 4 remineralizing agents: 1) artificial saliva (y), 2) y + 0.05 ppm fluoride, (3) y + 20% xylitol, and 4) y + 20% xylitol + 0.05 ppm fluoride. Mineral loss (delta Z) and lesion depth (ld) were quantified after 4-week remineralization. In experiment 1, numerical values of delta Z and ld observed can be ranked as A > C > B > D. These differences were significant only in B and D when compared with A for delta Z, but not between any group for ld. In experiment 2, the numerical values of delta Z and ld for control UN (unremineralized) and remineralized groups (1-4) ranked as UN > 3 > 4 > 1 > 2. Compared with UN, this difference was significant in all groups with ld, but not in any group with delta Z. We concluded that tolerable levels of xylitol alone may not show a significant caries inhibiting and remineralizing effect, but may act as a caries inhibitor additively with fluoride.

Xylitol has attracted much attention as an alternative sweetener. Essentially all clinical studies concerning the effect of xylitol on caries development consent to its non-cariogenicity and to the beneficial effect of substituting sucrose with xylitol in chewing gums and sweets. However, claims of anti-caries or therapeutic effects, and superiority of xylitol over other polyols are still to be confirmed by well designed and conducted studies from independent research groups.

Xylitol is a naturally occurring sweetener. Beyond being non-cariogenic, it exhibits both passive and active anti-caries properties and is used in confectionery and oral care products.

The aim was to determine the effect of xylitol, fluoride and xylitol/fluoride combined on the erosion of dental enamel by pure orange juice in vitro. Freshly extracted bovine incisors were sectioned vertically into four equal portions. Each portion was then coated with an acid-resistant nail varnish except for an enamel window on the labial surface of the tooth. These were then divided into four groups with each group containing one portion of each tooth selected randomly. Four erosive agents were prepared as follows: (A) pure orange juice only; pure orange juice plus either (B) xylitol (25% w/v) or (C) fluoride (0.5 parts/10(6)) or D) xylitol/fluoride (25% and 0.5 parts/10(6) respectively). Each group was assigned to one of the erosive agents and immersed six times daily for a period of 5 min on each occasion and stored in artificial saliva between exposures and for 12 hr overnight, for 24 days making a total of 12 hr of exposure to the assigned erosive agent. Sections were cut from each enamel specimen ground to a thickness of 80 microns and microradiographed. Mineral loss was quantified by a two-step image analysis. Mineral loss was significantly lower (p < 0.05) in group D (xylitol/fluoride) only when compared with group A (pure orange juice only). The numerical values of mineral loss could be ranked as follows: group D < group C < group B < group A. It was concluded that xylitol and fluoride have an additive effect in the reduction of dental erosion by pure orange juice in vitro.

The hypothesis to be tested in this study was that toothpastes containing sodium lauryl sulfate (SLS) is unsuitable vehicles for xylitol. The bacteriostatic (and cariostatic) effect of xylitol is assumed to be caused by intracellular accumulation of xylitol-5-P in plaque bacteria. Experiments were designed to investigate whether presence of SLS would affect the uptake of xylitol by interacting with the bacterial membranes and thus inhibit xylitol-5-P formation. It was shown in an in vitro study that even very low concentrations of the strong anionic detergent SLS inhibited uptake of xylitol and xylitol-5-phosphate formation by dental plaque totally. The mild nonionic detergent ethoxylated stearyl alcohol (30x EO) had no such effect. In vivo experiments with toothpastes containing xylitol and either the strong or the mild detergent, showed that xylitol in toothpaste with SLS was not available for the plaque bacteria and gave no adaptation to xylitol, whereas in the presence of 30x EO it was available, and a xylitol adaptation was observed. Glucose metabolism, which was also studied for the plaque samples, was not significantly affected by presence of any of the 2 detergents, indicating that the amounts of xylitol in toothpastes were presumably too low to give clinical significant effects, even when mild detergents are used.

While fluoride is an effective anti-caries agent, the search for more effective alternative therapies continues. A wide range of non-fluoride anti-caries agents has been postulated, and this paper reviews some of the pre-clinical models that have been utilized in their evaluation and some of the pitfalls that must be avoided. Using data on the potential anti-caries efficacy of phosphopeptides obtained from casein, the caution that must be applied in extrapolating laboratory data to predict clinical performance is discussed. Evaluation strategies that focus on only one potential mode of action (e.g., inhibition of demineralization) may overestimate the true clinical efficacy which may arise from a combination of two or more effects (e.g., inhibition of demineralization and stimulation of remineralization). Although laboratory and in situ data predict anti-caries efficacy for sodium trimetaphosphate in combination with fluoride, this was not found in three-year clinical trials. A possible reason for this, the lack of suitable calibration methods, is discussed. Finally, some comments on the appropriateness of laboratory evaluation strategies are made.

Many mechanisms have been proposed to explain the caries preventive effect of xylitol as a total or partial dietary sugar substitute. This article reviews the current knowledge of the effect of xylitol on the microbial population of dental plaque, particularly on mutans streptococci, in the light of an ecological concept of the oral environment and of the potential clinical significance. A noncariogenic commensal plaque flora constitutes the biotic component of a balanced ecosystem compatible with dental health. Dietary sugars, particularly sucrose, and sugar substitutes are abiotic environmental factors that can shift the delicate balance of the ecosystem towards a more or less cariogenic microbiota. Most dietary sugars are fermented by plaque microorganisms, favour the establishment of a cariogenic microflora and contribute to bacterial virulence. The vast majority of plaque bacteria, however, are incapable of fermenting xylitol into cariogenic acid end-products. There is no evidence that the plaque microbiota can adapt to metabolise xylitol or can be enriched with xylitol-metabolising cells even after long exposure to xylitol. Accumulated intracellularly as a non-metabolisable metabolite by mutans streptococci, xylitol inhibits its growth in vitro and reduces the amount of plaque and the number of mutans streptococci in both the plaque and saliva of xylitol consumers. When present in the oral environment xylitol not only prevents a shift of the bacterial community towards a more cariogenic microflora but also selects for a mutants population that was shown to have weakened virulence factors in preliminary in vitro experiments and in rats. Further research is needed to fully understand the clinical importance in the prevention of caries of this xylitol-selected population.

There is an extensive peer-reviewed literature on xylitol chewing gum as it pertains to effects on tooth decay in human subjects, on human dental plaque reduction, on inhibition of dental plaque acid production, on inhibition of the growth and metabolism of the mutans group of streptococci which are the prime causative agents of tooth decay, on reduction of tooth decay in experimental animals, and on xylitol's reported contribution to the remineralisation of teeth. The literature not only supports the conclusion that xylitol is non-cariogenic but it is now strongly suggestive that xylitol is caries inhibitory, that is, anti-cariogenic in human subjects, and it supplies reasonable mechanistic explanation(s).

Several studies indicate that xylitol is not metabolized to acids either in pure cultures of oral microorganisms in vitro or in dental plaque in vivo. Chronic consumption of xylitol-sweetened chewing gum resulted in reduction of dental plaque, suppression of mutans streptococci, and reduced adhesiveness of plaque. So far, four field studies with regimens including chewing gum and other xylitol-containing products and four clinical trials have been carried out. All of the latter studies showed that a daily intake of two to three pieces of xylitol gum resulted in a defined reduction of caries. There are indications that regular and prolonged use of xylitol chewing gum may have a caries-preventive effect.

Ten adults participated in the study which consisted of four experimental periods each lasting 2 weeks, during each of which subjects were assigned to one of four gum-chewing regimens: no gum, sucrose gum, sorbitol gum and xylitol gum. At the start and end of each test period unstimulated and stimulated salivary flow rates were determined. At the end of each test period the acidogenic potential of 48-hour dental plaque was measured using a Beetrode pH microelectrode. No statistically significant (p < 0.05) effect on salivary flow rate was observed. The xylitol chewing gum regimen resulted in significantly higher plaque pH than no gum, sucrose gum and sorbitol gum at 2, 10, 20, 30 and 60 min following a 10% sucrose rinse. In addition, xylitol gum regimen exhibited a significantly higher minimum pH and smaller area of the curve below pH 6. The results suggest that the regular use of xylitol-sweetened gum may serve to reduce the acidogenic potential of dental plaque.

The levels of salivary lactobacilli and yeasts were determined annually in half of the subjects of the xylitol (X) and fluoride (F) groups of a 3-year caries study. These measurements were carried out with Dentocult (DC) and Oricult (OC) dip-slide methods. A high level of lactobacilli prevailed throughout the study in these subjects. Significant changes were registered in some subgroups--that is, improvement in one of the X institutions and worsening in one of the F and one of the X institutions. At base line the counts of OC were worse in the X than in the F group. In the total material some improvement occurred during the course of the study, mainly in the X group. The changes associated with the preventive program should also be considered as related to the improvement in oral hygiene, restorative treatment, and the mere study effect.

The carbohydrate to protein ratio of dental plaque was analyzed in a field study assessing the effect of partial substitution of dietary sucrose by xylitol (X group) in comparison with systemic fluoride (F group) and restorative treatment solely (C group). The biochemical analysis was supplemented by quantitative assessment of plaque through the visible plaque index (VPI). The present substudy was carried out cross-sectionally and longitudinally (n = 83) in initially 6- to 11-year-old children. Missing base-line values for the carbohydrate to protein ratio were partly compensated for through reexamination of the carbohydrate to protein ratio 15 months after termination of the trial. The latter series served as reference to indicate the base-line situation. A lower carbohydrate to protein ratio was measured in the X and F groups than in the C group. Improvement of the VPI values was obtained only in the X group. Our results suggest the potential value of parallel quantitative and qualitative assessment of plaque.

Previous rat caries experiments in our laboratory demonstrated an anti-cariogenic and most probably a remineralizing effect of xylitol. The purpose of the present study was to compare the caries-inhibiting property of xylitol and fluoride in drinking water. The study consisted of two experiments with Osborne-Mendel rats, superinfected with S. mutans. In the first experiment, the rats were fed ad libitum a cariogenic diet containing 20% sucrose and 5% glucose (diet SSP 20/5) and tap water containing 0%, 2%, or 4% xylitol. An additional control group was fed diet SSP 20/5 supplemented with 5% xylitol. In the second experiment, the rats were also fed diet SSP 20/5, but received tap water, demineralized water (both containing less than 0.1 ppm F-), or tap water containing 10 and 40 ppm fluoride. Some animals in the 4% xylitol drinking water group showed a mild osmotic diarrhea for the first four days and a retarded increase in body weight of limited duration. S. mutans colonized to a similar level in all groups of both experiments. Fluoride as well as xylitol in the drinking water reduced the fissure caries scores significantly. However, 10 and 40 ppm fluoride had a more pronounced inhibiting effect on the caries experience than did 4% xylitol in the drinking water or 5% xylitol in the diet.

The aim was to assess caries increment as influenced by partial substitution of sucrose by xylitol (X group) over a 2-year period in comparison with systemic fluoride (F group) and restorative treatment only (C group). The study differed from the 3-year field study of the same series primarily in that existing base-line differences were eliminated because the protocol required that all the new subjects entering the institutions in the 1st year were to be included for a 2-year trial. During this period the number of dropouts was 243 (19.9% of all subjects), the final material consisting of 976 children (6-12 years old). The 2-year DMFS increment was 3.8 in the X group, 4.8 in the F group, and 6.0 in the C group. The corresponding ratio (RS) between caries incidence and the tooth surface population at risk was RSX, 4.5; RSF, 5.5; and RSC, 7.5. The xylitol regimen resulted in a lower increment of caries than measured in the F and C groups (p less than 0.001; convariance analysis, with base-line prevalence, number of permanent teeth, and visible plaque index as covariants.

The consumption of sucrose and xylitol and the exposure to fluoride (F) were analyzed in a field study aimed at assessing the value of peroral xylitol as a caries-preventive measure. The coverage of the general background referred to the conditions of 689 institutionalized children observed for a 3-year-period. The material in the dietary substudy consisted of 286 subjects aged 8-13 years. The intake and excretion of F was monitored at all institutions in a total of 380 children. The frequency of the consumption of sucrose was high, its intake increasing over the weekend in comparison with weekdays. The consumption of the xylitol-containing products did not reduce the frequency of sucrose intake. Varying and fluctuating levels of exposure to systemic F was registered, as also reflected in the urinary F/creatinine quotient.

Salivary Streptococcus mutans was quantified to detect possible age-, sex-, and group-dependent differences at the end of a 3-year field study assessing the value of partial substitution of sucrose with xylitol (X group) in comparison with systemic administration of fluoride (F group) and restorative treatment solely (C group). The material of this substudy consisted of 390 institutionalized children aged 9-14 years. S. mutans was determined through the spatula technique and grouped into categories 0, less than 10(5), 10(5)-10(6), and and greater than 10(6) CFU/ml saliva. Zero to less than 10(5) values included more than 80% of the subjects of the X group. The cross-sectional comparison between groups showed lower S. mutans values in the X group than in the F and C groups. These differences between groups were highly significant. S. mutans was not dependent on age or sex.

The oral hygiene conditions were evaluated within a 3-year field study aimed at assessing the cariostatic value of partial substitution of sucrose by xylitol (X group) in comparison with systemic fluoride (F group) and restorative treatment only (C group). Parallel to caries and further associated studies the visible plaque index, based on the total number of permanent and deciduous teeth, was determined longitudinally at annual examinations in 688 institutionalized children, initially 6 to 11 years old. The observations were analyzed with regard to sex, age, experimental grouping, and total development. The oral hygiene conditions were generally poor. At the base-line examination only 26% of the children had acceptable oral hygiene; at the end this level was reached by 42%. A definite improvement was measured only in the X group, in which the final values differed significantly (p less than 0.001) from the base-line values and also from the end situation in the F and C groups. It is concluded that the development was influenced by several factors, such as different snacking habits and access to sweets, the study per se, and xylitol-induced effects.