Long-term effect of xylitol chewing gum on dental caries

Sugar substitutes on caries prevention in permanent teeth among children and adolescents: a systematic review and meta-analysis

OBJECTIVES

This study aimed to systematically review the effect of sugar substitute consumption on caries prevention in permanent teeth among children and adolescents.

DATA

Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) comparing the clinical effect of sugar substitutes (both high- and low-intensity sweeteners) in preventing caries in permanent teeth among children and adolescents aged 6-19 were included.

SOURCES

A systematic search was conducted in three databases (PubMed, Web of Science and Embase) without any restrictions on publication year.

STUDY SELECTION

The initial search found 1,859 items, and finally, 15 studies (11 RCTs and 4 CCTs) with a total of 6325 participants (age: 6-18 years) were included. The Cochrane risk-of-bias assessment tools were used for quality assessment. Most (80%, 12/15) were graded as having a 'moderate' or 'high' risk of bias. All trials investigated sugar alcohol, which is a low-intensity sweetener. Xylitol was the most commonly investigated (73.3%, 11/15), followed by sorbitol (46.7%, 7/15), and erythritol (13.3%, 2/15). Results of the meta-analysis showed that both xylitol (standardized mean difference [SMD]: -0.50, 95% confidence interval [CI] -0.85 to -0.16, P = 0.005) and sorbitol (SMD: -0.10, 95% CI: -0.19 to -0.01, P = 0.03) had a significant effect in preventing dental caries compared to no treatment/placebo. No clinical trials on high-intensity sweeteners such as aspartame and saccharin were found.

CONCLUSION

The consumption of xylitol or sorbitol is potentially effective in preventing caries in permanent teeth among children and adolescents. No clinical evidence is available regarding the role of high-intensity sweeteners in caries prevention.

CLINICAL SIGNIFICANCE

The use of xylitol or sorbitol as sugar substitutes has a beneficial effect in preventing dental caries among children and adolescents.

Qualitative assessment of knowledge transfer regarding preterm birth in Malawi following the implementation of targeted health messages over 3 years

Background

In 2012, we performed a needs assessment and gap analysis to qualitatively assess providers’ and patients’ knowledge and perceptions regarding preterm birth (PTB). During the study, we identified knowledge gaps surrounding methods to reduce the risk of occurrence of PTB and management options if preterm labor/birth occur. We targeted health messages toward these gaps. The objective of the present study was to assess the impact of our community health worker-based patient education program 3 years after it was implemented.

Methods

Fifteen focus groups including 70 participants were included in the study. The groups comprised either patients/patient couples or health providers. A minimum of two facilitators led each group using 22 a priori designed and standardized lead-in prompts for participants with four additional prompts for providers only. A single researcher recorded responses, and transcript notes were reviewed by the facilitators and interpreters immediately following each group discussion to ensure accuracy.

Results

The understanding of term vs preterm gestation was generally accurate. Every participant knew of women who had experienced PTB, and the general perception was that two to three women out of every ten had this experience. The majority of respondents thought that women should present to their local health clinic if they experience preterm contractions; few were aware of the use of antenatal steroids for promoting fetal lung maturity, but many acknowledged that the neonate may be able to receive life-sustaining treatment if born at a higher level of care facility. The majority of participants were aware that PTB could recur in subsequent pregnancies. All respondents were able to list ways that women could potentially reduce the risk of PTB.

Conclusion

After employing targeted health messages, the majority of participants expressed improved understanding of the definition of PTB, methods to prevent risk of PTB, and management options for preterm labor or PTB.

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.

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.

A practice-based study on the effect of a short sucrose/xylitol exposure on survival of primary teeth caries free

BACKGROUND

In a randomized double-blinded clinical trial, preschool children used sucrose or xylitol chewing gum regularly for 2 months to study the preventive effect of xylitol on acute otitis media (AOM). Salivary mutans streptococci (sm) levels of the children were measured before the exposure. Those with ≥10(5) sm CFU in 1 mL saliva were considered to have high sm levels (sm+); and those with <10(5) CFU low sm levels (sm-).

AIM

This practice-based study aims to evaluate long-term dental effects of the sucrose/xylitol exposure on primary teeth.

DESIGN

For analyses, individuals were divided into sub groups according to their study group in the original AOM trial and baseline sm levels. Outcome events owing to dental caries of their all primary teeth were followed from dental records up to 12 years. Survival of teeth caries free was determined by Kaplan-Meier method and analysed statistically by Wilcoxon testing.

RESULTS

Survival of primary teeth caries free of children with high sm levels in the sucrose group was significantly shorter compared with all other groups when followed until shedding.

CONCLUSIONS

Two months' regular exposure to sucrose was sufficient to induce dental caries in primary teeth of children with elevated sm levels at baseline.

Six months of high-dose xylitol in high-risk caries subjects--a 2-year randomised, clinical trial

Objectives

The hypothesis was that the daily use of a high dose of a xylitol chewing gum for 6 months would reduce the increment of decayed permanent first molar surfaces (ΔD₆S) in high-risk schoolchildren after 2 years.

Methods

In this randomised, clinical trial, 204 schoolchildren with a high caries risk were assigned to two experimental groups, xylitol and non-xylitol. Caries status, salivary mutans streptococci, and lactobacilli were re-evaluated 2 years later in 74 xylitol-treated and 83 non-xylitol-treated schoolchildren. Differences in mean ∆D₆S between groups registered at baseline and at follow-up were evaluated using the nonparametric Mann–Whitney U test.

Results

Outcome was the development of detectable carious lesions initial (D₁–D₂) and manifest (D₃) in the permanent first molars. In the xylitol group, the difference in proportion of children with decayed first permanent molars at baseline and follow-up was 1.43 % for manifest lesion and 2.86 % for initial lesions; while in the non-xylitol group was 10.26 % (p < 0.01) and 16.66 % (p < 0.01), respectively. A statistically significant difference regarding means was also observed in the non-xylitol group: the ∆D₆S for manifest lesion was 0.18 (p = 0.03) and 0.67 (p = 0.02) for initial lesion.

Conclusion

The use of a chewing gum containing a high dose of xylitol for a period of 6 months has been shown to produce a long-term effect on caries development in high caries-risk children.

Clinical relevance

A school-based preventive programme based on 6 months’ administration of a high dose of xylitol via chewing gum proved to be efficacious in controlling caries increment in high-risk children.

The caries-preventive effect of xylitol/maltitol and erythritol/maltitol lozenges: results of a double-blinded, cluster-randomized clinical trial in an area of natural fluoridation

OBJECTIVE

Xylitol studies suggest caries reductions in the order of 50%. Based on animal/microbial studies, erythritol potentially has caries-preventive properties. However, clinical studies are required to confirm this. The aim of the study was to investigate the additional caries-preventive effect of xylitol/maltitol and erythritol/maltitol lozenges delivered at school, relative to controls receiving comprehensive prevention, in a low-caries prevalence population.

METHODS

A 4-year, cluster-randomized, double-blinded clinical trial. Five hundred and seventy-nine 10-year-old consenting subjects from 21 schools were randomly assigned to one of five groups. Four groups used the lozenges on school days, in three teacher-supervised sessions daily, over 1 or 2 years. The daily amount was 4.7 g/4.6 g for xylitol/maltitol and 4.5 g/4.2 g for erythritol/maltitol. The groups received free examinations and care in the public health centre. Four hundred and ninety-six children were analysed. The main outcome measure was dentin caries increment based on a clinical examination at 4 years since the start. The groups were compared in relation to the increment using hierarchical logistic regression to adjust for potential clustering.

RESULTS

Use of xylitol/maltitol or erythritol/maltitol lozenges did not result in caries reduction. A strong relationship between baseline caries prevalence and the 4-year increment was observed (OR = 7.38; 95% CI: 3.78-14.41).

CONCLUSIONS

The results suggest that in relatively low-caries conditions the school-based use of xylitol/maltitol or erythritol/maltitol lozenges would not have additional caries-preventive effect when compared with comprehensive prevention.

Effects of xylitol as a sugar substitute on diabetes-related parameters in nondiabetic rats

Abstract The present study was examined the effects of xylitol feeding on diabetes-associated parameters in nondiabetic rats. Seven-week-old male Sprague-Dawley rats were randomly divided into three groups: control (five rats), sucrose (six rats), and xylitol (six rats). Animal had free access to a commercial rat pellet diet, and ad libitum water, 10% sucrose solution, and 10% xylitol solution were supplied to the control, sucrose, and xylitol groups, respectively. After 3 weeks of feeding of experimental diets, food intakes were significantly (P<.05) lower in the sucrose and xylitol groups compared with the control group. Drink intake was significantly higher in the sucrose group but significantly lower in the xylitol group compared with the control group. Body weight gain was significantly lower in the xylitol group compared with the sucrose group. Weekly nonfasting blood glucose was significantly increased, but fasting blood glucose was significantly decreased, in the sucrose group compared with the control and xylitol groups. Significantly better glucose tolerance was observed in the xylitol group compared with the control and sucrose groups. Serum insulin and fructosamine concentrations were not significantly influenced by the feeding of xylitol or sucrose. Relative liver weight and liver glycogen were significantly increased in the xylitol group compared with the sucrose group, whereas no difference was observed between the xylitol and control groups. Serum total cholesterol and low-density lipoprotein-cholesterol were significantly decreased in the sucrose and xylitol groups, and serum triglyceride of the xylitol group, but not the sucrose group, was significantly increased compared with the control group. Data of this study suggest that xylitol can be a better sweetener than sucrose to maintain diabetes-related parameters at a physiologically safer and stable condition.

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 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.

Field Trial on Caries Prevention with Xylitol Candies among Disabled School Students

BACKGROUND

In a 1999 survey high caries levels were found among physically disabled school students in Kuwait.

OBJECTIVES

A field study was planned to test the efficacy of xylitol candies in preventing caries among individuals in two special schools in Kuwait.

METHODS

Altogether 176 students were examined in 2002 and 145 (105 in xylitol group and 40 in the control group) after 18 months' intervention. The WHO criteria were used in recording caries according to surfaces (third molars were excluded) by 2 calibrated examiners (E.H., M.S.). The students were allocated to the xylitol group only if the parent/caregiver returned the informed consent form. School health nurses distributed xylitol candies to the students 3 times during the school day (after breakfast and lunch, and before leaving the school).

RESULTS

In the xylitol group, the baseline DS and DMFS scores were 3.4 and 8.2 and in the follow-up 1.9 and 7.1, respectively. In the control group, the baseline scores were DS 3.9 and DMFS 9.8, and the follow-up scores DS 3.9 and DMFS 13.2.

CONCLUSION

Xylitol seemed to have a strong preventive and a clear remineralizing effect on caries.

Children's acceptance of milk with xylitol or sorbitol for dental caries prevention

Background

Xylitol, a polyol sugar, has been shown to reduce dental caries when mixed with food or chewing gum. This study examines the taste acceptability of xylitol in milk as a first step toward measuring the effectiveness of xylitol in milk for the reduction of dental caries in a public health program.

Methods

Three different types of milk (Ultra High Temperature (UHT), powder and evaporated) were tested for acceptability by 75 Peruvian children (25 per milk group, ages 4 to 7 years). Each group evaluated xylitol and sorbitol in one type of milk. In the first phase, each child was presented with a tray of four plastic cups containing 50 ml of milk with 0.021 g/ml xylitol, 0.042 g/ml xylitol, 0.042 g/ml sorbitol or no sugar. Each child was asked to taste the samples in a self-selected order. After tasting each sample, the child placed the milk cup in front of one of three cartoon faces (smile, frown or neutral) representing the child's response to the taste of each sample. In the second phase, the child was asked to rank order the milk samples within each category (smile, frown or neutral). Ranks within categories were then combined to obtain a rank ordering for all the test samples.

Results

The ranking from best to worst for the samples across categories (UHT, powder, evaporated) was xylitol (0.0.042 g/ml), sorbitol (0.042 g/ml), xylitol (0.021 g/ml) and milk alone (Friedman's ANOVA). Xylitol and sorbitol were preferred over milk alone, and xylitol (0.042 g/ml) was preferred to sorbitol (0.042 g/ml)(p < .05 sign test).

Conclusion

Milk sweetened with xylitol is well accepted by Peruvian children ages 4–7 years.

Xylitol in the prevention of oral diseases

Special needs populations such as the mentally disabled or developmentally disabled present a unique challenge for the dental professionals providing dental treatment. Among those challenges is oral health promotion through primary prevention of dental caries and periodontal disease. There are many barriers to adequate oral care for these special needs patients that include cost, physical limitations, low levels of perceived need and lack of dental knowledge by residents and staff, if the person resides in an institution. Primary prevention to maintain oral comfort and function for these patients is a priority to support their quality of life. Typical oral health problems of these patients include hyposalivation, root-surface caries, poor oral hygiene, a high prevalence of periodontal disease and dental caries. The purpose of this paper is to review information for the inclusion of xylitol in primary preventive regimens as an adjunct for the prevention of oral diseases for special needs patients.

Risk-based early prevention in comparison with routine prevention of dental caries: a 7-year follow-up of a controlled clinical trial; clinical and economic aspects

Background

The results in an earlier study with 2–5-year-old children indicated that, in comparison with conventional prevention, a risk-based prevention programme was effective in reducing dental caries in a low-caries community. The aim of the present study was to examine the clinical and economic findings seven years after the cessation of the targeted programme, from the perspective of public health care.

Methods

The present material was collected from the dental records of the public health care centres, and included all dental visits after the 5-year examination until the 12-year examination. The groups were compared in relation to clinically detected caries at the age of 12 years, the number of dental visits needed from 5 to 12 years of age, and the estimation of running costs during these years. Statistical analyses included univariate analysis of variance, and calculation of absolute risk reduction and number needed to treat (NNT) values.

Results

At the age of 12 years, DMF was significantly related to the risk category determined ten years earlier, in both study groups. In the risk-based group, the absolute risk reduction for caries in permanent dentition was 0.13 (95% confidence interval 0.06 – 0.21), and the associated NNT value was 8 (95% confidence interval 5 – 17). The total number of preventive, as well as restorative visits was lower in the risk-based than in the routine prevention group. The findings indicate that early risk-based prevention can be correctly targeted, clinically effective, and economically profitable also from the long-term point of view.

Conclusion

Early prevention of dental caries also has long-term benefits in a 7-year follow-up perspective. This seems to hold true as regards targeting, as well as clinical and economic effectiveness. Success in risk-based prevention enables successful work division, and consequently, economic effectiveness.

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.

A review of saliva: normal composition, flow, and function

An adequate supply of saliva is critical to the preservation and maintenance of oral tissue. Clinicians often do not value the many benefits of saliva until quantities are decreased. Much is written on the subject of salivary hypofunction, but little attention is paid to normal salivary flow and function. This article is a brief, up-to-date overview of the literature on the basics of normal salivary composition, flow, and function. A review of the literature was conducted using MEDLINE and Healthstar (1944 through 1999); articles were selected for inclusion on the basis of relevance and significance to the clinician.

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.

The effects of xylitol-containing chewing gums on dental plaque and acidogenic potential

The aim of this study was to test the hypothesis that the chewing of xylitol- or xylitol/sorbitol-containing chewing gum reduces plaque formation and the acidogenic potential of dental plaque. Thirty healthy volunteers aged from 19 to 28 yrs were randomly allocated to one of three test groups, chewing either xylitol-, xylitol/sorbitol-, or sucrose-sweetened gums. A three-day plaque accumulation period of no oral hygiene was instituted prior to and at the termination of the chewing gum program, which lasted 33 days. Plaque quantity was assessed on the basis of protein content of individual plaque samples collected by a standardized technique. Acidogenic potential of individual baseline and test plaque samples was assessed by the quantity of various organic acids formed from D-(U-14C)glucose. Identification of extracellular and intracellular metabolites was performed by HPLC. Statistical evaluation of data was performed according to paired comparisons of individual baseline and post-chewing data. Plaque formation, acidogenic potential, and glycolytic profiles were similar at baseline and after the gum-chewing periods. Also, there was no intracellular accumulation of glycolytic metabolites within the plaque bacteria to indicate the inhibition of glycolysis. The study thus leads to the conclusion that, in young adults with low caries experience, exposure of the oral cavity to acceptable doses of xylitol or xylitol and sorbitol has no effect on the microbial deposits on the teeth.

Tooth and tooth surface survival rates in birth cohorts from 1965, 1970, 1975, and 1980 in Lahti, Finland

Differences in the tooth and tooth surface survival rates between four cohorts born in 1965, 1970, 1975, and 1980 were analysed in a historical cohort study including data on the permanent teeth of children aged 5-7 years at baseline and 19 years at the end of the study. A statistically significant reduction in caries occurrence in fissured surfaces in the three oldest cohorts was seen during the 3 years after the eruption of the teeth. Caries occurrence in the cohorts born in 1975 and 1980 did not differ from each other. The occurrence of caries in smooth surfaces was low in all age cohorts. Therefore, despite a systematic decrease in caries occurrence towards the younger cohorts, no significant differences were found between the cohorts in smooth surface decay. After the 3 first posteruptive years, practically no differences in survival rates between the cohorts were observed. In the two youngest cohorts, the figures during the 3 first years after eruption did not differ from the figures for the later years. Throughout the study, caries occurrence was symmetric and no gender differences were observed. No postponement of decay was found by the end of the follow-up time.

Timing of first restorations before, during, and after a preventive xylitol trial

An independent longitudinal retrospective analysis of the timing, number, and cost of tooth restorations was conducted for all subjects (n = 313) in the age cohort of a municipal health center, in which two consecutive field trials of up to 3 years on the caries-preventive effect of the use of xylitol chewing gum were conducted (Ylivieska study, 1982-85). A computer program calculated the post-eruptive timing of the first restorations on each permanent tooth surface, and survival analysis methods were applied before, during, and after the trials. The cost of restorations was then calculated. The total number of new restored surfaces was 4.0 per child in the xylitol group and 9.3 in the controls during the decade after onset of the trial. The number of restorations on the occlusal surfaces of the first molars leveled off at 40-50% in the xylitol group and at about 60-70% in the control group. Plateaus for the second molars were at 30-40% and 60-70%, respectively. The time lag for the first restorations was longer in the xylitol group for the proximal and other smooth surfaces. A marked difference in favor of the xylitol group was observed in the proximal surfaces of the upper incisors (for example, the mesial surface of the upper mesial incisor for girls: log-rank chi-square = 11.1, p < 0.001). The preventive effect was most pronounced in teeth that had erupted during the trial. This analysis indicated that participation of subjects in the xylitol chewing gum trials resulted in a significant reduction in the number of first restorations and hence in costs during the decade after the onset of gum use.

Effect of xylitol on growth of nasopharyngeal bacteria in vitro

Xylitol is known to reduce caries by inhibiting the growth of Streptococcus mutans. We hypothesized that xylitol could also affect the growth of other nasopharyngeal bacterial flora, which could be important when considering respiratory infections caused by these bacteria. We studied this in vitro by adding xylitol to the medium and observed that 1 and 5% xylitol reduced markedly the growth of alpha-hemolytic streptococci, including S. pneumoniae. It reduced slightly the growth of beta-hemolytic streptococci but not that of Haemophilus influenzae or Moraxella catarrhalis. The inhibitory growth pattern was similar to that previously seen with S. mutans, which may indicate a similarity in the enzymatic processing of five-carbon sugars such as xylitol. This sugar alcohol is a widely used sweetener, and the concentrations used in our experiments are easily achieved in the oral cavity. If xylitol reduces the growth of S. pneumoniae in the nasopharynx, it could also reduce the carriage of this pathogen and thus have clinical significance in the prevention of pneumococcal diseases.

Effect of sucrose and xylitol diets on dentin formation and caries in rat molars

To investigate the effects of a high sucrose diet and xylitol on secondary dentinogenesis and dentinal caries, a part of the sucrose in a high-cariogenic diet was replaced by xylitol. Fifty-four 3-wk-old Wistar rats were labeled with tetracycline and divided into groups. One group received a high sucrose diet (43% sucrose). In two other groups 5% and 20% of the sucrose was replaced by xylitol. A control group received non-cariogenic food. Six weeks later the mandibles were sectioned sagittally. Schiff staining was used to classify the caries, and the areas of dentin formed during the experiment and dentinal caries in first and second molars were measured planimetrically. The high sucrose diet reduced dentin formation of the molars, and this reduction was further increased by xylitol. Caries initiation and dentinal caries progression were significantly reduced by 20% xylitol, whereas only a slight reduction in caries progression was observed with 5% xylitol. Also, a negative correlation between the dentin formation and dentinal caries progression was observed in the high sucrose and 5% xylitol groups. In conclusion, xylitol together with high sucrose reduced dentin formation and dentinal caries progression, and the effect was dose-dependent.

Effect of polyol gums on dental plaque in orthodontic patients

Sixty 11- to 15-year-old children wearing fixed orthodontic appliances were given chewing gums containing polyol for daily use after meals and snacks, to study whether the chewing of gums that contained slowly fermentable polyols (xylitol and sorbitol) affects the amount of dental plaque and the number of mutans streptococci present in plaque and saliva. The 60 subjects were randomly divided into four groups, each of which was provided with a supply of 1.35 gm pellet-shaped gums for a period of 1 month, as follows: (1) xylitol; (2) sorbitol; (3) xylitol-sorbitol mixture I (3:2); and (4) xylitol-sorbitol mixture II (4:1). In each group, two pellets with a total initial gum mass of 2.7 gm (maximum polyol dose per day: 10.5 gm), were used six times a day. The fresh and dry weight of dental plaque, collected at baseline and 28 days later from incisors, canines, and premolars from the area between gingival margin and the bracket, reduced in all groups, but most significantly (by 43% to 47%) in children receiving xylitol gum. The plaque and saliva levels of mutans streptococci did not change in the sorbitol group, but was significantly (in most cases) reduced by 13% to 33% in groups that received gum containing xylitol. Provided that the quantity of dental plaque and the plaque and salivary levels of mutans streptococci can be regarded as risk factors in dental caries, these results suggest that regular use of polyol gum--and especially gum that contains xylitol as the predominant sweetener--can reduce the caries risk in young patients wearing fixed orthodontic appliances.

Saliva stimulation and caries prevention

The protective role of saliva is demonstrated by the rampant caries seen in human subjects with marked salivary hypofunction, and in desalivated animals. In normal cases, however, the relationship between saliva flow and coronal or root caries experience is doubtful, and to examine the concept that stimulation of saliva might have protective effects against caries, one must look beyond a simple correlation between caries and flow rate. Protective properties of saliva which increase on stimulation include salivary clearance, buffering power, and degree of saturation with respect to tooth mineral. These benefits are maximized when saliva is stimulated after the consumption of fermentable carbohydrates, by reducing the fall in plaque pH leading to demineralization and by increasing the potential for remineralization. Plaque acid production is neutralized, and experimental lesions in enamel are remineralized, when gum is chewed to stimulate saliva after a carbohydrate intake. The pH-raising effects are more easily explained by the buffering action of the stimulated saliva than by clearance of carbohydrates. The remineralization action depends upon the presence of fluoride. These findings suggest that the protective actions of saliva can be mobilized by appropriate salivary stimulation, and that in addition to established procedures such as tooth cleaning and fluoride regimens, eating patterns which lead to saliva stimulation to increase the potential for saliva protection might be included in recommendations for caries prevention. Confirmation of this concept in clinical tests is required.

Cariologic aspects of xylitol and its use in chewing gum: a review

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.

A re-analysis of caries rates in a preventive trial using Poisson regression models

The analysis of caries incidence in clinical trials has several challenging features: (1) The distribution of the number of caries onsets per patient is skewed, with the majority of patients having few or no cavities; (2) the number of surfaces at risk varies (i) over time and (ii) between patients, due to eruption and exfoliation patterns, dental diseases, and treatments; (3) surfaces within a patient differ in their caries susceptibility, and (4) caries onsets within a patient are correlated due to shared host factors. Recent statistical developments in the area of correlated data analyses permit incorporation of some of these characteristics into the analyses. With Poisson regression models, the expected number of caries onsets can be related to the number of surfaces at risk, the time they have been at risk, and surface- and subject-specific explanatory variables. The parameter estimated in these models is an epidemiological measure of disease occurrence: the disease incidence rate (caries rate) or the rate of change from healthy (sound) to diseased (carious). Differences and ratios of these rates provide standard epidemiological measures of excess risk. To illustrate, Poisson regression models were used for exploratory analyses of the Ylivieska xylitol study.

A dietary procedure for preventing dental caries in young adults

Significant improvement in the dental caries status of children in the United States has been seen in recent decades. The percentage of children who are free from dental caries, however, rapidly decreases with age. By the time young people enter colleges or universities, only a few are caries free. Colleges and universities are places where the young are simultaneously, and perhaps for the last time, reachable as large cohorts before their lives undergo further "individualization." This makes college age a time that is crucial for channeling information about proper oral health practices by organizing mass-directed strategies for prevention of dental caries. It is now clear that dental caries can effectively be prevented. This calls for placing strong emphasis on dietary behavior and on the use of sugar substitutes as part of the strategy. Scientific evidence also suggests that the addition of small daily quantities of xylitol, a natural carbohydrate sweetener, to the diet of children and young adults causes significant reduction in the incidence of dental caries. On the basis of detailed long-term clinical trials carried out during the past 20 years, it appears that a reduction ranging from 30% to more than 85% in dental caries can be achieved simply by using a few xylitol chewing gums daily over a period of 1 to 3 years. In individual cases, virtually total, long-term protection against caries has been observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of xylitol consumption on the plaque-saliva distribution of mutans streptococci and the occurrence and long-term survival of xylitol-resistant strains

Since the exposure of mutans streptococci to xylitol is known to select for xylitol-resistant (XR) natural mutants, the occurrence and long-term survival of such xylitol-resistant strains was evaluated in a cross-sectional sampling of participants of the Ylivieska xylitol study four years after the original two-year experimental period. Paraffin-stimulated whole saliva was first collected, and then plaque was collected and pooled. The salivary and dental plaque mutans streptococci were enumerated after growth on TSY20B agar. The proportion of XR strains was determined by autoradiography with 14C-xylitol. A strong and significant correlation (r = 0.645 and p = 0.005) between the number of mutans streptococci in saliva and in dental plaque was observed in non-consumers of xylitol. Such a correlation totally disappeared (r = 0.098 and p = 0.612) in xylitol-exposed consumers (habitual and former xylitol-consumers). The proportion of the salivary XR mutants (35%) in non-consumers (n = 16) was significantly lower than in the xylitol-exposed consumers (79%) (n = 27), (p = 0.0001) or in former consumers (75%) (n = 13), (p = 0.0008) or in the habitual consumers (83%) (n = 14), (p = 0.004). The proportion of XR mutants in dental plaque was, on the average, much lower than in the corresponding saliva. The proportion of XR in the plaque of xylitol non-consumers was half of that of the xylitol-exposed group, but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Is there a long-term caries-preventive effect of sugar restrictions during World War II?

Wartime decrease in caries prevalence among children explained by restrictions in sugar availability and consumption is widely documented. The aim of the present investigation was to study possible long-term effects of this regimen on dental caries. Norwegian age cohorts who were 7 years old during World War II were reexamined in 1983. On the basis of DMF recordings of their first permanent molars, a long-lasting beneficial effect of the wartime caries decrease could not be demonstrated.

Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The growth in the dental literature continues to escalate, as evidenced by the publication of at least 326 new books in 1988 and 1989 and more than 20 new journals in 1989. There still appears to be undue emphasis on quantity instead of quality of research. This proliferation in the literature poses ever increasing difficulties to this Committee in filtering out the articles that are of particular interest to the members of the Academy and identifying those that are most likely to have a major impact on dental practice and service. The subjects covered include periodontics, caries and preventive dentistry, craniomandibular disorders, occlusion, pulp biology, ceramics, and restorative dental materials.