Polyol chewing gums and caries rates in primary dentition: a 24-month cohort study

The effect of xylitol chewing gums and candies on caries occurrence in children: a systematic review with special reference to caries level at study baseline

PURPOSE

A systematic review of published data was carried out to assess the caries-preventive effects of xylitol chewing gums and candies in children.

METHODS

Electronic and hand searches were performed to find clinical studies on the effects of xylitol chewing gums and candies on dental caries in children (≤ 18 years). Prospective randomised or controlled clinical trials published before 2023 were included in the review.

RESULTS

The initial search identified 365 titles to be evaluated. After applying inclusion and exclusion criteria, 15 articles with either fair or low quality were reviewed. Nine articles studied chewing gums, five candies, and one both of them. In the ten evaluated xylitol chewing gum studies xylitol consumption significantly reduced caries occurrence when compared with no treatment or a placebo polyol gum. The effect was clinically significant in studies with high or moderate caries level at study baseline. The results also suggested that the caries-reducing effect of xylitol gums may differ from sorbitol/polyol gums. In five of the six heterogenous xylitol candy studies, no caries-reducing effect was found independent of caries level. In addition to caries level, also the daily xylitol dose was a confounding factor.

CONCLUSION

The present findings suggest that the caries-reducing effect of adding xylitol chewing gum to the daily diet has been well demonstrated in children and adolescents with high or moderate caries level at study baseline. Xylitol gum use could benefit subjects with active incipient caries lesions on smooth tooth surfaces.

Teeth: Small but Mighty and Mighty Important. A Comprehensive Review of Children's Dental Health for Primary Care Clinicians

Healthy teeth allow us to eat and stay well-nourished. Although primary care clinicians receive limited training about teeth, given the common nature of dental problems, it is important that they understand and recognize normal and abnormal dental conditions and can implement primary and secondary prevention of dental conditions in their practice. PubMed has been used to search the scientific literature for evidence on the following topics: normal dental development, dental abnormalities, malocclusion, teething, dental caries and related epidemiology and prevention, fluoride, dental injury and its management and prevention; and identification, prevention and treatment of gingivitis and periodontal disease. Literature review relied on randomized controlled trials, meta-analyses, systematic reviews, and Cochrane reviews when relevant and available. Other sources of evidence included cohort and case-control studies. Consensus statements and expert opinion were used when there was a paucity of high-quality research studies. The literature has been synthesized on these topics to make them relevant to pediatric primary care clinicians, and as available, the strength of evidence has been characterized when making clinical recommendations.

A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum in Dental Caries

OBJECTIVE

To determine the difference in level of dental caries in adults and children who chew sugar-free gum (SFG), compared with those who do not chew SFG or use alternatives such as lozenges, candies, rinses, tablets, and other nonchewing controls.

METHODS

Systematic review of published literature.

RESULTS

Twelve studies of interventions of SFG for dental caries outcomes were included. SFGs were found to significantly reduce caries increment, giving a preventative fraction (PF) of 28% (95% CI, 7% to 48%). Including the 8 trials that used xylitol gum only as the basis of the intervention, the PF was 33% (95% CI, 4% to 61%). No adverse effects were recorded. There was a high level of heterogeneity among the trials included.

CONCLUSION

The findings of this review provide tentative evidence that chewing SFG reduces caries increment in comparison to nonchewing controls. However, there is a considerable degree of variability in the effect and the trials included were generally of moderate quality. There is a need for future research to explore the acceptability and feasibility of the use of SFG as a public health intervention (PROSPERO 2018 CRD42018094676).

KNOWLEDGE TRANSFER STATEMENT

The results of this study can be used by clinicians when deciding how best to implement dental caries prevention regimes for their patients. With consideration of cost and patient preference, this information could help to develop national policy directives on caries prevention and dictate the direction of future clinical research.

Oral and Systemic Effects of Xylitol Consumption

Recent results of randomized trials testing the efficacy of xylitol in caries prevention have been conflicting. This narrative review reveals the sources of discrepancy. The following databases were searched for the terms "xylitol" or "artificial sweeteners" restricted to the English language: PubMed, Web of Science, Evidenced-Based Medicine, Scopus, and the Cochrane database. In a separate search, the terms "dental caries" or "cariogenicity" or "glucosyltransferase" or "low glycemic" or "low insulinemic" or "dysbiosis" or "gut microbiome" were used and then combined. In section I, findings regarding the role of xylitol in dental caries prevention, the appropriateness of research methods, and the causes for potential biases are summarized. In section II, the systemic effects of xylitol on gut microbiota as well as low-glycemic/insulinogenic systemic effects are evaluated and summarized. The substitution of a carbonyl group with an alcohol radical in xylitol hinders its absorption and slowly releases sugar into the bloodstream. This quality of xylitol is beneficial for diabetic patients to maintain a constant glucose level. Although this quality of xylitol has been proven in in vitro and animal studies, it has yet to be proven in humans. Paradoxically, recent animal studies reported hyperglycemia and intestinal dysbiosis with artificial sweetener consumption. Upon careful inspection of evidence, it was revealed that these reports may be due to misinterpretation of original references or flaws in study methodology. Any systemic benefits of xylitol intake must be weighed in consideration with the well-established adverse gastrointestinal consequences. The contribution of xylitol to gut dysbiosis that may affect systemic immunity warrants further research.

Streptococcus mutans forms xylitol-resistant biofilm on excess adhesive flash in novel ex-vivo orthodontic bracket model

INTRODUCTION

During orthodontic bonding procedures, excess adhesive is invariably left on the tooth surface at the interface between the bracket and the enamel junction; it is called excess adhesive flash (EAF). We comparatively evaluated the biofilm formation of Streptococcus mutans on EAF produced by 2 adhesives and examined the therapeutic efficacy of xylitol on S mutans formed on EAF.

METHODS

First, we investigated the biofilm formation of S mutans on 3 orthodontic bracket types: stainless steel preadjusted edgewise, ceramic preadjusted edgewise, and stainless steel self-ligating. Subsequently, tooth-colored Transbond XT (3M Unitek, Monrovia, Calif) and green Grengloo (Ormco, Glendora, Calif) adhesives were used for bonding ceramic brackets to extracted teeth. S mutans biofilms on EAF produced by the adhesives were studied using the crystal violet assay and scanning electron microscopy. Surface roughness and surface energy of the EAF were examined. The therapeutic efficacies of different concentrations of xylitol were tested on S mutans biofilms.

RESULTS

Significantly higher biofilms were formed on the ceramic preadjusted edgewise brackets (P = 0.003). Transbond XT had significantly higher S mutans biofilms compared with Grengloo surfaces (P = 0.007). There was no significant difference in surface roughness between Transbond XT and Grengloo surfaces (P >0.05). Surface energy of Transbond XT had a considerably smaller contact angle than did Grengloo, suggesting that Transbond XT is a more hydrophilic material. Xylitol at low concentrations had no significant effect on the reduction of S mutans biofilms on orthodontic adhesives (P = 0.016).

CONCLUSIONS

Transbond XT orthodontic adhesive resulted in more S mutans biofilm compared with Grengloo adhesive on ceramic brackets. Surface energy seemed to play a more important role than surface roughness for the formation of S mutans biofilm on EAF. Xylitol does not appear to have a therapeutic effect on mature S mutans biofilm.

Dental Flossing and Interproximal Caries: a Systematic Review

Our aim was to assess, systematically, the effect of flossing on interproximal caries risk. Six trials involving 808 subjects, ages 4 to 13 years, were identified. There were significant study-to-study differences and a moderate to large potential for bias. Professional flossing performed on school days for 1.7 years on predominantly primary teeth in children was associated with a 40% caries risk reduction (relative risk, 0.60; 95% confidence interval, 0.48–0.76; p-value, < 0.001). Both three-monthly professional flossing for 3 years (relative risk, 0.93; 95% confidence interval, 0.73–1.19; p-value, 0.32) and self-performed flossing in young adolescents for 2 years (relative risk, 1.01; 95% confidence interval, 0.85–1.20; p-value, 0.93) did not reduce caries risk. No flossing trials in adults or under unsupervised conditions could be identified. Professional flossing in children with low fluoride exposures is highly effective in reducing interproximal caries risk. These findings should be extrapolated to more typical floss-users with care, since self-flossing has failed to show an effect.

Long-Term Effect of Erythritol on Dental Caries Development during Childhood: A Posttreatment Survival Analysis

Objective: To assess the effect of daily consumption of erythritol, xylitol, and sorbitol candies on caries development in mixed dentition during a 3-year intervention and 3 years after the intervention. Methods: 485 Estonian first- and second-grade primary school children participated. Children were randomly allocated to an erythritol, xylitol, or sorbitol (control) group. Polyol-containing candies were administered on school days with a daily polyol consumption of 3 × 2.5 g. Yearly, caries development was assessed by calibrated dentists using the ICDAS criteria. Six years after initiation of the study and 3 years after cessation of daily polyol consumption, 420 participants were re-examined to identify potential long-term effects of polyol consumption. Survival curves were generated at the end of the intervention period and 3 years after intervention. The model included age of the subjects, schools, tooth surface ages and years of surface exposure to intervention. ICDAS scoring system-based events included enamel/dentin caries development, dentin caries development, increase in caries score, and dentist intervention. Results: At the end of the intervention, time to enamel/dentin caries development, dentin caries development, increase in caries score, and dentist intervention were significantly longer in the erythritol group as compared to the sorbitol group. Except for increase in caries score, all effects persisted 3 years after cessation of daily polyol consumption. Conclusions: A caries-preventive effect of 3-year erythritol consumption as compared to sorbitol was established in children with mixed dentition. The effect persisted up to 3 years after the end of the intervention.

Erythritol Is More Effective Than Xylitol and Sorbitol in Managing Oral Health Endpoints

Objective. To provide a comprehensive overview of published evidence on the impact of erythritol, a noncaloric polyol bulk sweetener, on oral health. Methods. A literature review was conducted regarding the potential effects of erythritol on dental plaque (biofilm), dental caries, and periodontal therapy. The efficacy of erythritol on oral health was compared with xylitol and sorbitol. Results. Erythritol effectively decreased weight of dental plaque and adherence of common streptococcal oral bacteria to tooth surfaces, inhibited growth and activity of associated bacteria like S. mutans, decreased expression of bacterial genes involved in sucrose metabolism, reduced the overall number of dental caries, and served as a suitable matrix for subgingival air-polishing to replace traditional root scaling. Conclusions. Important differences were reported in the effect of individual polyols on oral health. The current review provides evidence demonstrating better efficacy of erythritol compared to sorbitol and xylitol to maintain and improve oral health.

Comparing the efficacy of xylitol-containing and conventional chewing gums in reducing salivary counts of Streptococcus mutans: An in vivo study

Objective:

Dental caries is among the most common chronic diseases in humans. Streptococcus mutans is generally responsible for most cases of dental caries. The present study sought to compare the effects of xylitol-containing and conventional chewing gums on salivary levels of S. mutans.

Materials and Methods:

This study adopted a crossover design. Two type of chewing gums (one containing 70% xylitol and approved by the Iranian Dental Association, and another containing sucrose) were purchased. The participants were 32 individuals aged 18–35 years whose oral hygiene was categorized as moderate or poor based on a caries risk assessment table. Salivary levels of S. mutans were measured at baseline, after the first and second phases of chewing gums, and after the washout period. The measurements were performed on blood agar and mitis salivarius-bacitracin agar (MSBA). Pairwise comparisons were then used to analyze the collected data.

Results:

Salivary levels of S. mutans in both groups were significantly higher during the two stages of chewing gum than in the washout period or baseline. Moreover, comparisons between the two types of gums suggested that chewing xylitol-containing gums led to greater reductions in S. mutans counts. This effect was more apparent in subjects with poor oral hygiene than in those with moderate oral hygiene.

Conclusions:

Xylitol-containing chewing gums are more effective than conventional gums in reducing salivary levels of S. mutans in individuals with poor–moderate oral hygiene.

Oral health promotion: the economic benefits to the NHS of increased use of sugarfree gum in the UK

INTRODUCTION

The effect of sugarfree gum (SFG) on the prevention of dental caries has been established for some time. With increased constraints placed on healthcare budgets, the importance of economic considerations in decision-making about oral health interventions has increased. The aim of this study was to demonstrate the potential cost savings in dental care associated with increased levels of SFG usage.

METHODS

The analysis examined the amount of money which would hypothetically be saved if the UK 12-year-old population chewed more SFG. The number of sticks chewed per year and the caries risk reduction were modelled to create a dose response curve. The costs of tooth restoration, tooth extraction in primary care settings and under general anaesthetic were considered, and the effects of caries reduction on these costs calculated.

RESULTS

If all members of the UK 12-year-old population chewed SFG frequently (twice a day), the potential cost savings for the cohort over the course of one year were estimated to range from £1.2 to £3.3 million and if they chewed three times a day, £8.2 million could be saved each year. Sensitivity analyses of the key parameters demonstrated that cost savings would still be likely to be observed even in scenarios with less significant increases in SFG use.

CONCLUSION

This study shows that if levels of SFG usage in the teenage population in the UK could be increased, substantial cost savings might be achieved.

Non-surgical treatment of dentin caries in preschool children--systematic review

Background

Untreated dentin caries in primary teeth is commonly found in preschool children worldwide. Recently, the use of simple non-surgical approaches to manage the situation has been advocated.

The aim of the study was to systematically review and evaluate the literature on effectiveness of non-surgical methods in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children.

Methods

A systematic search of the main electronic databases (Pubmed, Cochrane Collaboration, EMBASE) was conducted to identify peer reviewed papers published in English in the years 1947–2014. Keywords and MeSH terms used in the search were “dental caries”, “primary dentition” and various non-surgical treatments (fluoride, sealant, resin infiltration, xylitol, chlorhexidine, CPP-ACP, ozone, etc.). The inclusion criteria were clinical studies conducted in children under 6 years old, and reported findings on caries arrest or caries progression in primary teeth. Retrieved papers were read by two reviewers independently to assess suitability for inclusion, and the final decision was made by consensus. Quality of the included studies was assessed and data were extracted for analysis.

Results

The search identified 323 papers for screening. Among these, 290 papers did not satisfy the study inclusion criteria. Consequently, 33 full papers were retrieved and reviewed. Finally, 4 studies were included. Three studies reported that topical applications of silver diammine fluoride (SDF) solution could arrest dentin caries in preschool children. One study supported that having a daily toothbrushing exercise in kindergarten using toothpaste with 1000 ppm fluoride could stabilize the caries situation in young children.

Conclusions

There is limited evidence to support the effectiveness of SDF applications or daily toothbrushing with fluoride toothpaste in arresting or slowing down the progression of active dentin caries in primary teeth in preschool children. More well-designed randomized controlled trials are required to confirm these findings.

Delivery of Active Agents from Chewing Gum for Improved Remineralization

Most surrogate measures of caries were developed to test products containing fluoride, typically at relatively high and closely controlled oral concentrations. However, since the primary mechanism for the remineralization of early enamel caries lesions by chewing gum is through stimulation of saliva, delivering Ca and Pi to the demineralized enamel lesion, established methods may lack the sensitivity to detect the additional benefit of an active agent without the strong remineralizing potential of fluoride. Issues related to the release of active agents from the gum matrix, dilution in the saliva, and limited oral retention time, along with taste, safety, regulatory, and cost concerns, impose further limitations. This paper reviews the efficacy of some active agents used in chewing gum for improved remineralization and includes results from in situ testing of calcium-containing gums, including calcium lactate, tetracalcium phosphate/dicalcium phosphate anhydrous, calcium citrate/encapsulated phosphate, and a calcium lactate/sodium phosphate blend. Despite promising in vitro data from these agents, they did not provide consistently superior results from in situ testing. There is a need to develop better predictive in vitro models for chewing gum, as well as improved sensitivity of in situ models to discriminate relatively small amounts of remineralization against a background of high biological variability.

Effect of xylitol versus sorbitol: a quantitative systematic review of clinical trials

OBJECTIVES

This study aimed to appraise, within the context of tooth caries, the current clinical evidence and its risk for bias regarding the effects of xylitol in comparison with sorbitol.

METHODS

Databases were searched for clinical trials to 19 March 2011. Inclusion criteria required studies to: test a caries-related primary outcome; compare the effects of xylitol with those of sorbitol; describe a clinical trial with two or more arms, and utilise a prospective study design. Articles were excluded if they did not report computable data or did not follow up test and control groups in the same way. Individual dichotomous and continuous datasets were extracted from accepted articles. Selection and performance/detection bias were assessed. Sensitivity analysis was used to investigate attrition bias. Egger's regression and funnel plotting were used to investigate risk for publication bias.

RESULTS

Nine articles were identified. Of these, eight were accepted and one was excluded. Ten continuous and eight dichotomous datasets were extracted. Because of high clinical heterogeneity, no meta-analysis was performed. Most of the datasets favoured xylitol, but this was not consistent. The accepted trials may be limited by selection bias. Results of the sensitivity analysis indicate a high risk for attrition bias. The funnel plot and Egger's regression results suggest a low publication bias risk. External fluoride exposure and stimulated saliva flow may have confounded the measured anticariogenic effect of xylitol.

CONCLUSIONS

The evidence identified in support of xylitol over sorbitol is contradictory, is at high risk for selection and attrition bias and may be limited by confounder effects. Future high-quality randomised controlled trials are needed to show whether xylitol has a greater anticariogenic effect than sorbitol.

Sugar alcohol sweeteners as alternatives to sugar with special consideration of xylitol

INTRODUCTION

Dental caries is a diet-associated disease which continues to be a serious health problem in most industrialized and developing countries. Strategies to maximize caries prevention should automatically consider the use of sugar substitutes. It is important that public health authorities are made cognizant of the availability of new polyol-type sugar substitutes.

REVIEW SUMMARY

Clinical studies have shown that xylitol, a natural, physiologic sugar alcohol of the pentitol type, can be used as a safe and effective caries-limiting sweetener. Habitual use of xylitol-containing food and oral hygiene adjuvants has been shown to reduce the growth of dental plaque, to interfere with the growth of caries-associated bacteria, to decrease the incidence of dental caries, and to be associated with remineralization of caries lesions. Numerous public regulatory bodies have endorsed the use of xylitol as a caries-limiting agent. Other sugar alcohols that have been successfully used as sugar substitutes include D-glucitol (sorbitol), which, however, owing to its hexitol nature, normally has no strong effect on the mass and adhesiveness of bacterial plaque and on the growth of mutans streptococci. A tetritol-type alditol, erythritol, has shown potential as a non-cariogenic sugar substitute. Combinations of xylitol and erythritol may reduce the incidence of caries more effectively than either alditol alone.

CONCLUSIONS

Partial sugar substitution with polyols is an important dietary tool in the prevention of dental caries that should be used to enhance existing fluoride-based caries prevention programmes. The most effective method of conveying this information to the public is through a proper health claim for these alditols in food labelling. The present review summarizes clinical and biochemical aspects of the above three dietary polyols and emphasizes the role of sugar substitution as a potential health-promoting strategy.

Sugar-free chewing gum and dental caries: a systematic review

Objective:

To appraise existing evidence for a therapeutic / anti-cariogenic effect of sugar-free chewing gum for patients.

Method:

9 English and 2 Portuguese databases were searched using English and Portuguese keywords. Relevant articles in English, German, Portuguese and Spanish were included for review. Trials were excluded on lack of randomisation, control group, blinding and baseline data, drop out rate >33%, no statistical adjustment of baseline differences and no assessment of clinically important outcomes. Reviews were excluded on lack of information, article selection criteria, search strategy followed, search keywords, searched databases or lack of study-by-study critique tables. In cases of multiple reports from the same study, the report covering the longest period was included. Two reviewers independently reviewed and assessed the quality of accepted articles.

Results:

Thirty-nine articles were included for review. Thirty were excluded and 9 accepted. Of the 9 accepted, 2 trials of reasonable and good evidence value did not demonstrate any anti-cariogenic effect of sugar-free chewing gum. However, 7 articles, with 1 of strong, and 6 of good evidence value, demonstrated anti-cariogenic effects of chewing Sorbitol, Xylitol or Sorbitol/Xylitol gum. This effect can be ascribed to saliva stimulation through the chewing process, particularly when gum is used immediately after meals; the lack of sucrose and the inability of bacteria to metabolize polyols into acids.

Conclusion:

The evidence suggests that sugar-free chewing gum has a caries-reducing effect. Further well-designed randomised trials are needed to confirm these findings.

Sugar alcohols, caries incidence, and remineralization of caries lesions: a literature review

Remineralization of minor enamel defects is a normal physiological process that is well known to clinicians and researchers in dentistry and oral biology. This process can be facilitated by various dietary and oral hygiene procedures and may also concern dentin caries lesions. Dental caries is reversible if detected and treated sufficiently early. Habitual use of xylitol, a sugar alcohol of the pentitol type, can be associated with significant reduction in caries incidence and with tooth remineralization. Other dietary polyols that can remarkably lower the incidence of caries include erythritol which is a tetritol-type alditol. Based on known molecular parameters of simple dietary alditols, it is conceivable to predict that their efficacy in caries prevention will follow the homologous series, that is, that the number of OH-groups present in the alditol molecule will determine the efficacy as follows: erythritol >/= xylitol > sorbitol. The possible difference between erythritol and xylitol must be confirmed in future clinical trials.

The impact of polyol-containing chewing gums on dental caries: a systematic review of original randomized controlled trials and observational studies

BACKGROUND

The authors conducted a systematic review of original studies that was designed to assess the impact of polyol-containing chewing gum on dental caries compared with the effect with no chewing gum.

REVIEW METHODS

The authors searched MEDLINE, The Cochrane Library and Google Scholar up to May 2008 to identify peer-reviewed articles that compared polyol-containing chewing gum with no chewing gum. The authors extracted study characteristics, data on incremental dental caries and quality by consensus. Data on prevented fraction (PF) were pooled across studies.

RESULTS

The results of 19 articles with data from 14 study populations showed that the use of xylitol, xylitol-sorbitol blend and sorbitol were associated with mean PF (95 percent confidence interval) of 58.66 percent (35.42-81.90), 52.82 percent (39.64-66.00) and 20.01 percent (12.74-27.27), respectively. For the sorbitol-mannitol blend, it was 10.71 percent (-20.50-41.93), which was not statistically significant. Sensitivity analyses confirmed the robustness of the findings.

CLINICAL IMPLICATIONS

Although research gaps exist, particularly on optimal dosing and relative polyol efficacy, research evidence supports using polyol-containing chewing gum as part of normal oral hygiene to prevent dental caries.

The potential of dental-protective chewing gum in oral health interventions

BACKGROUND

The authors provide an overview of chewing gum as a delivery vehicle for dental-protective agents, highlighting xylitol and its potential application in caries-prevention programs for children.

TYPES OF STUDIES REVIEWED

The authors reviewed selected clinical investigations and previous reviews associated with chewing gum containing substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol and their effects on reducing caries. They searched the MEDLINE database by using the key words "dental caries," "oral health," "calcium," "bicarbonate," "carbamide," "chlorhexidine," "fluoride" and "xylitol."

RESULTS

Chewing gum is being used as a delivery vehicle for substances such as calcium, bicarbonate, carbamide, chlorhexidine, fluoride and xylitol to improve oral health and reduce caries. These substances exhibit properties that are protective of the oral environment and mediate common oral diseases. The debate for advocating xylitol use in caries prevention is advancing; however, chewing gum use by young schoolchildren in the United States is hindered by choking hazard concerns and lack of specific xylitol dosing recommendations.

CLINICAL IMPLICATIONS

The use of chewing gum containing dental-protective substances, particularly xylitol, in caries-prevention programs can reduce the tooth decay epidemic. Chewing gum use by children in the school setting should be reconsidered.

Xylitol-supplemented nutrition enhances bacterial killing and prolongs survival of rats in experimental pneumococcal sepsis

BACKGROUND

Xylitol has antiadhesive effects on Streptococcus pneumoniae and inhibits its growth, and has also been found to be effective in preventing acute otitis media and has been used in intensive care as a valuable source of energy.

RESULTS

We evaluated the oxidative burst of neutrophils in rats fed with and without xylitol. The mean increase in the percentage of activated neutrophils from the baseline was higher in the xylitol-exposed group than in the control group (58.1% vs 51.4%, P = 0.03 for the difference) and the mean induced increase in the median strength of the burst per neutrophil was similarly higher in the xylitol group (159.6 vs 140.3, P = 0.04). In two pneumococcal sepsis experiments rats were fed either a basal powder diet (control group) or the same diet supplemented with 10% or 20% xylitol and infected with an intraperitoneal inoculation of S. pneumoniae after two weeks. The mean survival time was 48 hours in the xylitol groups and 34 hours in the control groups (P < 0.001 in log rank test).

CONCLUSION

Xylitol has beneficial effects on both the oxidative killing of bacteria in neutrophilic leucocytes and on the survival of rats with experimental pneumococcal sepsis.

Linear response of mutans streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial [ISRCTN43479664]

Background

Xylitol is a naturally occurring sugar substitute that has been shown to reduce the level of mutans streptococci in plaque and saliva and to reduce tooth decay. It has been suggested that the degree of reduction is dependent on both the amount and the frequency of xylitol consumption. For xylitol to be successfully and cost-effectively used in public health prevention strategies dosing and frequency guidelines should be established. This study determined the reduction in mutans streptococci levels in plaque and unstimulated saliva to increasing frequency of xylitol gum use at a fixed total daily dose of 10.32 g over five weeks.

Methods

Participants (n = 132) were randomized to either active groups (10.32 g xylitol/day) or a placebo control (9.828 g sorbitol and 0.7 g maltitol/day). All groups chewed 12 pieces of gum per day. The control group chewed 4 times/day and active groups chewed xylitol gum at a frequency of 2 times/day, 3 times/day, or 4 times/day. The 12 gum pieces were evenly divided into the frequency assigned to each group. Plaque and unstimulated saliva samples were taken at baseline and five-weeks and were cultured on modified Mitis Salivarius agar for mutans streptococci enumeration.

Results

There were no significant differences in mutans streptococci level among the groups at baseline. At five-weeks, mutans streptococci levels in plaque and unstimulated saliva showed a linear reduction with increasing frequency of xylitol chewing gum use at the constant daily dose. Although the difference observed for the group that chewed xylitol 2 times/day was consistent with the linear model, the difference was not significant.

Conclusion

There was a linear reduction in mutans streptococci levels in plaque and saliva with increasing frequency of xylitol gum use at a constant daily dose. Reduction at a consumption frequency of 2 times per day was small and consistent with the linear-response line but was not statistically significant.

The use of sorbitol- and xylitol-sweetened chewing gum in caries control

BACKGROUND

The author compared the caries-inhibitory action of sorbitol- and xylitol-sweetened chewing gum and assessed the role of these products in caries prevention.

TYPES OF STUDIES REVIEWED

The author reviewed studies including randomized field trials with substantial numbers of participants and observational studies. He did not review case studies. He found studies through a MEDLINE search and by hand searching.

RESULTS

When compared with sugar-sweetened gum, sorbitol-sweetened gum had low cariogenicity [corrected] when it was chewed no more than three times per day. Xylitol-sweetened gum was noncariogenic in all of the protocols tested. Some studies claimed that xylitol-sweetened gum had an anticariogenic effect, though these claims need further study. There also is good evidence that when mothers of infants and young children chew xylitol-sweetened gum, it will block transmission of mutans streptococci from mother to child.

CLINICAL IMPLICATIONS

The evidence is strong enough to support the regular use of xylitol-sweetened gum as a way to prevent caries, and it can be promoted as a public-health preventive measure. Chewing xylitol-sweetened gum, especially for patients who like chewing gum, can be fitted readily into a regimen that includes frequent fluoride exposure, good oral hygiene and regular dental appointments.

Chlorhexidine and xylitol gum in caries prevention

This paper presents the current best evidence on the respective and comparative outcomes of chlorhexidine and xylitol and extrapolates these data to individuals with special needs. It analyzes the probable mechanisms of action for both chlorhexidine and xylitol then reviews individual products and discusses the anticipated effectiveness of these products in individuals with special needs.

The next step in infectious disease: taming bacteria

Except for immunization programs our warfare with bacteria has always been a frontal assault with antibiotics. In this warfare we win battles, but with every new battle the enemy gets stronger. We need other options. Recent experience suggests two alternatives. First, public health measures designed to control the spread of infectious disease are associated with the selection of less virulent strains of microorganisms. Second, the same selection pressures obtained by public health measures outside the body are brought into play when we inhibit the adherence of bacteria within the body. Two recent studies using food sugars known to inhibit bacterial adherence show long-term benefits best explained by the previously observed decreases in bacterial virulence, following chronic exposure to the respective substances. Cranberry juice selects for less uropathogenic strains of Escherichia coli and xylitol for less caries producing Streptococcus mutans. The ability of these substances to reduce bacterial adherence in the human host has been known for some time, but poorly utilized. Their in vitro ability to decrease virulence has been reported but not clinically studied.

Saliva in health and disease: an appraisal and update

Saliva plays an important role in oral health monitoring, regulating and maintaining the integrity of the oral hard tissues and some soft tissues. This paper reviews the role of saliva, the prevalence of oral dryness and the consequent importance of salivary flow as well as the relationship between xerostomia and salivary gland hypofunction amongst the causes of oral dryness. Other aspects of oral conditions associated with saliva are also reviewed including Sjögren's Syndrome and oesophageal function. Finally, knowledge, and the current use of salivary tests and the utilisation of saliva as a diagnostic fluid are surveyed.

Can the pentitol-hexitol theory explain the clinical observations made with xylitol?

The natural dietary carbohydrate xylitol has been used as a source of energy in infusion therapy and found to act curatively in certain clinical situations. Xylitol has also been used as a sweetener in the diabetic diet and as a non- or anticariogenic agent. Xylitol is a sugar alcohol (polyhydric alcohol) of the pentitol type. The various advantageous clinical effects associated with enteral and parenteral administration of xylitol can be considered to result from the five-carbon (pentitol) nature of the molecule and from the molecule's special configuration even when compared with other pentitols. Such effects may be regarded as simple consequences of evolutionary expediency in a situation where human nutrition and man's significant energy-yielding metabolic pathways are associated with the six-carbon nature of D-glucose and the close derivatives and polymers of D-glucose and related sugars, and the physiologic involvement of the five-carbon xylitol in several ancillary pathways. Consequently, most clinical effects occasioned by xylitol cannot be expected to be caused by six-carbon hexitols such as D-mannitol and D-glucitol. A simple pentitol-hexitol theory seems to explain most of the clinical effects associated with the administration of xylitol. This theory is in congruence with the general evolutionary development in which the metabolism of C(6)-based carbohydrates is often inhibited by C(5)-based ones (as manifested in certain bacterial infections in man), or where the presence of the C(5)-based xylitol forwards therapeutically significant metabolic pathways (as observed in parenteral nutrition and treatment of certain enzyme deficiencies). The validity of the theory can be verified in controlled clinical trials.

Sorbitol compared with xylitol in prevention of dental caries

OBJECTIVE

To summarize published data on the comparative efficacy of sorbitol and xylitol for prevention of dental caries.

DATA SOURCES

Published double-blind comparative trials, using sorbitol and xylitol products, identified by MEDLINE (January 1966-December 1998) and International Pharmaceutical Abstracts (January 1970-December 1998) searches.

DATA SYNTHESIS

Clinical trials generally used sorbitol and xylitol gums, which patients chewed three to five times daily for 20-40 months. Xylitol was superior to sorbitol in two longer, secondary dentition trials (30-63% reductions), but not in two primary dentition trials.

CONCLUSIONS

The data suggest that xylitol-containing gums may provide superior efficacy in reducing caries rates in high-risk populations.

The optimum time to initiate habitual xylitol gum-chewing for obtaining long-term caries prevention

Habitual xylitol gum-chewing may have a long-term preventive effect by reducing the caries risk for several years after the habitual chewing has ended. The goal of this report was (1) to determine if sorbitol and sorbitol/xylitol mixtures provide a long-term benefit, and (2) to determine which teeth benefit most from two-year habitual gum-chewing - those erupting before, during, or after habitual gum-chewing. Children, on average 6 years old, chewed gums sweetened with xylitol, sorbitol, or xylitol/sorbitol mixtures. There was a "no-gum" control group. Five years after the two-year program of habitual gum-chewing ended, 288 children were re-examined. Compared with the no-gum group, sorbitol gums had no significant long-term effect (relative risk [RR], 0.65; 95% confidence interval [c.i.], 0.39 to 1.07; p < 0.18). Xylitol gum and, to a lesser extent, xylitol/sorbitol gum had a long-term preventive effect. During the 5 years after habitual gum-chewing ended, xylitol gums reduced the caries risk 59% (RR, 0.41; 95% c.i., 0.23 to 0.75; p < 0.0034). Xylitol-sorbitol gums reduced the caries risk 44% (RR, 0.56; 95% c.i., 0.36 to 0.89; p < 0.02). The long-term caries risk reduction associated with xylitol strongly depended on when teeth erupted (p < 0.02). Teeth that erupted after 1 year of gum-chewing or after the two-year habitual gum use ended had long-term caries risk reductions of 93% (p < 0.0054) and 88% (p < 0.0004), respectively. Teeth that erupted before the gum-chewing started had no significant long-term prevention (p < 0.30). We concluded that for long-term caries-preventive effects to be maximized, habitual xylitol gum-chewing should be started at least one year before permanent teeth erupt.

Xylitol in caries prevention: what is the evidence for clinical efficacy?

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.

Prevention of early childhood caries

This paper reviews the methods used for the prevention of early childhood caries (ECC). The education of mothers or caregivers to promote healthy dietary habits in infants has been the main strategy used for the prevention of ECC. This review found that education has a modest impact on the development of ECC. While education should be promoted especially in high risk communities and population groups (low-income families and native populations), it should not be the only preventive strategy of ECC. Early screening for signs of caries development, starting from the first year of life, could identify infants and toddlers who are at risk of developing ECC and assist in providing information to parents about how to promote oral health and prevent the development of tooth decay. High risk children include those with early signs of ECC, poor oral hygiene, limited exposure to fluorides, and frequent exposure to sugary snacks and drinks. These children should be targeted with a professional preventive program that includes fluoride varnish application, fluoridated dentifrices, fluoride supplements, sealants, diet counseling, and chlorhexidine. Prevention of ECC also requires addressing the social and economic factors that face many families where ECC is endemic.