Effect of polyol gums on dental plaque in orthodontic patients

Clinical Effects of Sugar Substitutes on Cariogenic Bacteria: A Systematic Review and Meta-Analysis

BACKGROUND

The use of sugar substitutes in food products has recently increased. Limited information regarding the role of various sugar substitutes in caries prevention was found. This systematic review and meta-analysis was conducted to investigate the effects of sugar substitute consumption on reducing cariogenic bacteria in dental plaque and saliva.

METHODS

We systematically searched PubMed, EMBASE, and Web of Science (inception to July 2023) for prospective controlled trials published in English and investigated the effects of sugar substitute consumption on cariogenic bacteria in dental plaque and saliva. The primary outcome was the changes in cariogenic bacteria. Two independent reviewers screened the papers. Quality was assessed using the Cochrane risk-of-bias tools.

RESULTS

From 977 studies identified, 32 trials were included. Almost half (14/32, 44%) of the included studies had a high risk of bias. Almost all (31/32, 96.88%) were investigations of xylitol and other sugar alcohols (low-intensity sweeteners), such as sorbitol, erythritol, and maltitol. Only one trial investigated stevia, a high-intensity sweetener, whereas no studies on other high-intensity sweeteners, such as sucralose, saccharin, or aspartame, were found. Almost all studies (30/32, 93.75%) showed the consumption of low-intensity sweeteners led to a significant reduction of different types of cariogenic bacteria. The results of the meta-analysis showed that consumption of low-intensity sweeteners led to a significant reduction of cariogenic bacteria in both dental plaque and saliva compared to no treatment.

CONCLUSION

The consumption of low-intensity sweeteners helps reduce cariogenic bacteria in dental plaque and saliva. There is limited clinical evidence regarding the role of high-intensity sweeteners in reducing cariogenic bacteria.

Effect of Chewing Gum on Pain Following Orthodontic Elastomeric Separators Placement: A Randomized Controlled Trial

AIM: The aim of the study was to investigate whether chewing gum (CG) can reduce pain as compared to non-CG (NG) after orthodontic elastomeric separators placement. MATERIALS AND METHODS: Sixty patients were randomly allocated in a ratio of 1:1 to CG group (mean age = 21.82 ± 0.87 years) and NG group (mean age = 22.31 ± 1.09 years). Patients in the CG group were instructed to chew sugar-free gum for 10 min immediately after separators placement and then at 8-h intervals for 1 week, while the patients in the NG group were instructed not to chew any type of gum for the duration of the study. Patients in the two groups were asked not to use any type of analgesics. The patients were asked to register their pain level using a 10-cm horizontal line visual analog scale at 2 h, 6 h, bedtime, 24 h, and then daily for 1 week after separators placement. RESULTS: The data from 53 patients (27 in the NG group and 26 in the CG group) were analyzed. The pain scores were significantly lower in CG as compared to NG at 2 h, 6 h, bedtime, 24 h, and 2 days after separators placement. From day 3 to the end of the week duration of the study, the pain scores stayed lower in the CG group, but the difference was not statistically significant. CONCLUSION: CG significantly reduced pain resulting from orthodontic elastomeric separators placement as compared to non-CG controls.

Evaluation of the preventive effect of two concentrations of xylitol varnish versus fluoride varnish on enamel demineralization around orthodontic brackets: a randomized controlled trial

BACKGROUND

The highly prevalent white spot lesions around orthodontic brackets necessitate introducing preventive materials without relying on patient compliance.

OBJECTIVE

To evaluate the antidemineralizing effect of two concentrations of xylitol varnish.

TRIAL DESIGN

Triple-blind, four-arm, parallel-group, single-center, randomized controlled clinical trial.

METHODS

A total of 120 orthodontic patients were randomly assigned to four groups (n = 30), using a computer-generated randomized block list. The treatment groups were: 10% xylitol, 20% xylitol, 5% fluoride, and placebo. Tooth demineralization was measured with DIAGNOdent at T1 (before treatment), followed by varnish application. At T2 (third month), the varnish was re-applied, and at the third (T2) and sixth (T3) months, and after treatment (T4), the demineralization was measured. The white spot lesion frequency was assessed visually after treatment. The participants, the clinician, and data assessors were all blinded to group assignments.

RESULTS

A total of 115 patients underwent per-protocol analyses. At T2, the mean DIAGNOdent numbers in the fluoride and 10% xylitol groups were significantly lower than the placebo group (P = 0.00), with a mean difference of 0.63 (95% CI, 0.15-1.10) and 0.5 (95% CI, 0.04-0.95), respectively. At T3, the fluoride and 10% xylitol groups had significantly lower mineral loss than the placebo group (P=0.046) with a mean difference of 0.52 (95% CI, 0.14-0.89) in the fluoride and 0.45 (95% CI, 0.03-0.86) in the 10% xylitol groups, respectively. However, at T4, only the mean for the 10% xylitol group was significantly different (P=0.049) from the placebo group, with a mean difference of 1.18 (95% CI, 0.42-1.93). Visual assessment showed that after treatment, the prevalence of white spot lesions in the fluoride (P=0.03) and 10% xylitol (P=0.00) groups was less than the placebo group with the odds ratio of 0.67 (95% CI, 0.46-0.96) and 0.43 (95% CI, 0.28-0.64), respectively.

CONCLUSION

The 10% xylitol varnish short-term effects on caries control were significantly greater than 20% xylitol varnish and placebo but similar to fluoride varnish. However, the 10% xylitol long-term effect was almost better than fluoride varnish.

TRIAL REGISTRATION

The protocol was registered at IRCT.ir under the code IRCT20180913041032N1.

Effects of xylitol impregnated toothbrushes on periodontal status and microbial flora in orthodontic patients

OBJECTIVES

To investigate whether the use of xylitol-impregnated toothbrushes affects periodontal condition and microbial flora in orthodontic patients with poor oral hygiene.

MATERIALS AND METHODS

Forty-four patients with baseline mean Turesky plaque index scores ≥1.5 were randomly divided into two groups. Half received xylitol-containing toothbrushes and the other half, xylitol-free toothbrushes. The periodontal measurements and saliva samples were taken at baseline (T0), 1 month later (T1), and 3 months after brushing (T2) to evaluate periodontal health and microflora changes. Periodontal status was assessed with plaque index (PI), gingival index (GI), and bleeding on probing (BOP) scores. Data were statistically analyzed with Mann-Whitney U and Friedman tests.

RESULTS

All periodontal parameters significantly decreased from T0 to T1 and from T0 to T2 in both groups. The PI and GI scores reduced significantly in the control group, while BOP scores reduced in both groups between T1 and T2. Intergroup comparisons showed significant differences for BOP, PI, and GI at T0, T1, and T2 times, respectively. For microbial parameters, there were no statistically significant differences within groups from T0 to T1. Total bacterial counts significantly decreased in the xylitol group between T1 and T2. Decreases in Streptococcus mutans and total bacteria were significant in both groups from T0 to T2. No significant differences were found between the groups in microbial flora at any time.

CONCLUSIONS

A 3-month use of xylitol-containing toothbrushes showed almost the same changes and provided no positive effects on periodontal and microbial parameters compared to the control group.

[Preventive and therapeutic advantages of sugar-free chewing gums in orthodontics. A study conducted on practitioners and patients]

OBJECTIVE

The objective of this study is to assess the level of knowledge in a cohort of oral health professionals and patients about preventive and therapeutic actions of sugar-free chewing gums.

MATERIALS AND METHODS

A forward-looking monocentric study of perception regarding the level of information about the effects of sugar-free chewing gums consumption was conducted on 135 young patients, from 11 to 17 years old, carriers of fixed orthodontic appliances and treated in the Department of Orthodontics in the Oral Medicine and Surgery Center of the University Hospitals of Strasbourg. Besides, 34 practitioners in the Department of Orthodontics and Pediatric Dentistry were also included. Data were collected between May 2016 and July 2016. A specific questionnaire, using the adapted terminology and dealing with the same items was developed for each studied population.

RESULTS

The majority of the individuals of both studied populations believe that the consumption of sugar-free chewing gum leads to a greater risk of orthodontic device unsticking or fracture and that it is not associated to a decrease of the orthodontic pain.

DISCUSSION

Our results confirm the fact that the knowledge, mainly acquired in an empirical way, is against the data of the current literature. The evaluation of the level of knowledge demonstrated that there is a real lack of information about the preventive interests of the consumption of sugar-free chewing gums during orthodontic treatment.

CONCLUSIONS

This study highlights the need for information campaigns and oral prevention in general population, as well as in healthcare professionals, concerning the preventive and analgesic interests of sugar-free chewing gums during orthodontic treatments.

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.

Xylitol in preventing dental caries: A systematic review and meta-analyses

Xylitol is a sugar alcohol having the properties that reduce levels of mutans streptococci (MS) in the plaque and saliva. To assess the role of xylitol in preventing dental caries. Systematic review and meta-analysis developed by Cochrane cooperation were adapted. Electronic search was carried out in PubMed through the period up to 2014. Included clinical studies were done on (1) humans (2) participants include both individuals and as pairs (mother-child) (3) participants using orthodontic appliances (4) xylitol dispensed in any form (5) compare the effect of xylitol on dental caries and on other phenotype that determines the preventive effect on dental caries, such as decayed, missing, and filled (DMF/dmf) and salivary or plaque MS level. Twenty articles of the 477 articles initially identified. Among 20 studies indexed, 16 articles were accessed, systematically reviewed, and the meta-analysis was carried out. The evaluation of quality of the studies was done using risk of bias assessment tool. The quality of the studies was high risk and unclear risk for six and five trials. The meta-analysis shows a reduction in DMF/dmf with the standard mean (SM) of -1.09 (95% confidence interval [95% CI], -1.34, -0.83) comparing xylitol to all controls. The effect of DMF/dmf reduction by xylitol to fluoride varnish was with the SM of -1.87 (95% CI, -2.89, -0.84). The subgroup analysis, there was a reduction in MS count with SM of 0.30 (95% CI, 0.05, 0.56) when compared with all other caries preventive strategies; however, it was insignificant. Xylitol was found to be an effective strategy as self-applied caries preventive agent.

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.

Long-term clinical and bacterial effects of xylitol on patients with fixed orthodontic appliances

Background

The objective of this study was to evaluate long-term clinical and bacterial effects of using 6 g of xylitol per day for 3 months on patients with full fixed orthodontic appliances.

Methods

The study was a pilot clinical trial that included 41 subjects who were undergoing orthodontic treatment. The subjects were randomly divided into three groups. Group A received xylitol chewing gum, group B received xylitol dissolvable chewable tablets, and Group C served as the control group and did not receive xylitol gums or tablets. Clinical examination and the collection of plaque and saliva samples were carried out at baseline and 3, 6, and 12 months. All three groups were given oral hygiene instruction and were put on a 6-month cleaning and topical fluoride schedule. Plaque scores and bacterial counts were used to evaluate the effectiveness of the different approaches at reducing the caries risk.

Results

Xylitol groups did not experience any more reduction in plaque score, plaque MS counts, or salivary MS counts than the control group nor did they have lower values at any of the time points. Chewing gum did not significantly increase the incidence of debonded brackets over the other groups.

Conclusions

Xylitol does not have a clinical or bacterial benefit in patients with fixed orthodontic appliances. Oral hygiene instructions and 6-month topical fluoride application were effective at reducing plaque scores and bacterial counts in patients with full fixed appliances regardless of whether or not xylitol was used.

Effect of Chewing Xylitol Containing and Herbal Chewing Gums on Salivary Mutans Streptococcus Count among School Children

Background:

The present study aims to assess and compare the reduction in salivary Mutans Streptococci counts after chewing Xylitol, herbal and placebo gums among high school children.

Methods:

The study was conducted among 72 school children (12–15 years) from 3 randomly selected schools (blocks). Xylitol, herbal and placebo gums were randomly allocated to 3 blocks. Subjects were instructed to chew one pellet four times a day for 21 days. The mean reduction in salivary Streptococcus mutans count was assessed.

Results:

The 100% Xylitol sweetened chewing gum “Xylitol”has shown statistically significant reduction in salivary Mutans Streptococci colony forming units at the end of 21 days (P < 0.01). The reduction was not statistically significant in herbal and placebo chewing gum.

Conclusions:

Hundred percentage Xylitol sweetened chewing gum was found to be more effective in reducing salivary Mutans Streptococci count when compared to herbal and placebo chewing gums.

Comparison of the effect of two sugar-substituted chewing gums on different caries- and gingivitis-related variables: a double-blind, randomized, controlled clinical trial

OBJECTIVE

The aim of this study was to compare the effect of two sugar-substituted chewing gums besides toothbrushing on different clinical, microbiological, and biochemical caries- and gingivitis-related variables.

MATERIALS AND METHODS

The study was designed as a double-blind, randomized, controlled trial with three parallel arms. A total of 130 dental students, who volunteered after signing an informed consent, were randomly allocated to receive one of the following interventions: hexitol-sweetened gum containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), pentitol-sweetened gum containing no CPP-ACP, and control group with no gum. Subjects within the experimental groups chewed two gum pellets for 20 min three times a day after meals. The daily consumption level of both polyols was 6.0 g. Clinical examinations and salivary samplings were conducted at baseline and after 30 days of gum use. Pre- and post-intervention stimulated whole saliva samples were quantified for calcium/phosphate ionic concentration, total facultative bacterial load, Streptococcus mutans/Lactobacillus spp. counts, and Gram-negative percentage.

RESULTS

A statistically significant reduction in visible plaque score was displayed in the hexitol/CPP-ACP gum group after the intervention when compared with baseline, but the order of the effect was in the same order as the differences between the groups at baseline. A similar tendency was seen in both the pentitol/non-CPP-ACP gum and control groups regarding total salivary facultative bacterial load and S. mutans count, but median values of these parameters were more significantly reduced in the pentitol/non-CPP-ACP gum group in comparison with those of the control group. Alterations of salivary Lactobacillus spp. were demonstrated only in the pentitol/non-CPP-ACP gum group.

CONCLUSION

Although these findings might indicate that a 30-day protocol of daily chewing of pentitol-sweetened gum containing no CPP-ACP might have some a reducing effect on the salivary levels of facultative bacteria, S. mutans and Lactobacillus spp., there was only a marginal, if any, benefit from the chewing gums under study on some microbiological caries- and gingivitis-related variables.

CLINICAL RELEVANCE

Taking into account that for transferring results into clinically relevant conclusions the findings need to be strong and consistent, adhering to single significant differences appears not appropriate. Hence, the clinical significance of chewing gums as an adjunctive tool for daily oral care remained questionable.

Xylitol concentrations in artificial saliva after application of different xylitol dental varnishes

Objective

The present study analyzed xylitol concentrations in artificial saliva over time after application of varnishes containing 10% and 20% xylitol.

Material and Methods

Fifteen bovine enamel specimens (8x4 mm) were randomly allocated to 3 groups (n=5/group), according to the type of varnish used: 10% xylitol, 20% xylitol and no xylitol (control). After varnish application (4 mg), specimens were immersed in vials containing 500 µL of artificial saliva. Saliva samples were collected in different times (1, 8, 12, 16, 24, 48 and 72 h) and xylitol concentrations were analyzed. Data were assessed by two-way repeated-measures ANOVA (p<0.05).

Results

Colorimetric analysis was not able to detect xylitol in saliva samples of the control group. Salivary xylitol concentrations were significantly higher up to 8 h after application of the 20% xylitol varnish. Thereafter, the 10% xylitol varnish released larger amounts of that polyol in artificial saliva.

Conclusions

Despite the results in short-term, sustained xylitol releases could be obtained when the 10% xylitol varnish was used. These varnishes seem to be viable alternatives to increase salivary xylitol levels, and therefore, should be clinically tested to confirm their effectiveness.

Dissolution-guided wetting for microarray and microfluidic devices

The trapping of air bubbles presents a substantial impediment for the user in the increasingly widespread use of lab-on-a-chip products having microcavities in the forms of microwells, traps, dead ends and corners. Here we demonstrate a simple, effective, and passive method to eliminate air bubbles by coating hydrophilized microarray and microfluidic devices with a monosaccharide such as D-glucose or D-sorbitol, where the microcavities are filled with a conformal, elliptical, cone-shaped monosaccharide solid. These devices were stored in air for up to 6 months with a complete rewetting of the microcavities by dissolution of the monosaccharide with an aqueous solution.

Effect of xylitol gum on the level of oral mutans streptococci of preschoolers: block-randomised trial

OBJECTIVES

To assess the influence of xylitol chewing gum consumption on mutans streptococci level of 3-4 years old Japanese preschoolers.

METHODS

248 participants were examined regarding caries-related factors at baseline and were followed up at 6, 9, and 12 months after the baseline: assessors were blinded, subjects were open labelled and blocked parallel randomised; 142 were selected to use xylitol gum for 3 months (from months 6 to 9) and 106 were controls.

RESULTS

161 participants were analysed (xylitol n = 76, control n = 85). Nineteen caries-related variables, including xylitol gum consumption, were analysed for any association with the main outcome, plaque mutans streptococci scores development within the intervention period, by logistic regression. Six showed statistically significant associations by univariate analysis (P < 0.05). However, only xylitol gum consumption remained a significant negative association (P < 0.05) by multiple analyses. Interestingly, over 10% xylitol group children experienced diarrhoea, which was larger than previous investigations.

CONCLUSION

  Xylitol gum is effective in avoiding increased plaque mutans streptococci in young children.

Microbial and bioconversion production of D-xylitol and its detection and application

D-Xylitol is found in low content as a natural constituent of many fruits and vegetables. It is a five-carbon sugar polyol and has been used as a food additive and sweetening agent to replace sucrose, especially for non-insulin dependent diabetics. It has multiple beneficial health effects, such as the prevention of dental caries, and acute otitis media. In industry, it has been produced by chemical reduction of D-xylose mainly from photosynthetic biomass hydrolysates. As an alternative method of chemical reduction, biosynthesis of D-xylitol has been focused on the metabolically engineered Saccharomyces cerevisiae and Candida strains. In order to detect D-xylitol in the production processes, several detection methods have been established, such as gas chromatography (GC)-based methods, high performance liquid chromatography (HPLC)-based methods, LC-MS methods, and capillary electrophoresis methods (CE). The advantages and disadvantages of these methods are compared in this review.

Microbiological Evaluation of Octenidine Dihydrochloride Mouth Rinse after 5 Days' Use in Orthodontic Patients

Objective: To determine the absolute and relative antibacterial activity of octenidine dihydrochloride (OCT) against total and cariogenic bacteria in saliva samples of patients with fixed orthodontic appliances during 5 days of usage.

Materials and Methods: The study group consisted of 5 male and 13 female subjects who were selected from patients in the Clinic of Orthodontics. Each patient was given physiologic saline (PS), chlorhexidine gluconate (CHX), polyvinylpyrrolidone-iodine complex (PVP-I), and OCT every morning for 5 days, each separated by a 2-week interval. Total and cariogenic bacteria in saliva samples of orthodontically treated patients with fixed appliances were collected during 5 days of usage. Unstimulated saliva was collected as a baseline sample. Saliva samples were collected at 15 minutes, and on the second, third, and fifth day after rinsing the mouth with any of the solutions for 30 seconds, and bacterial counts were detected.

Results: OCT showed an ultimate reduction of total viable oral bacteria, Lactobacillus species, and Streptococcus mutans in vivo. OCT also had a significantly greater inhibitory effect than 0.2% CHX and 7.5% PVP-I, from the beginning of the study until the fifth day after the orthodontic appliances were bonded (P &lt; .1).

Conclusions: OCT compared favorably with respect to CHX and PVP-I complex in orthodontically treated patients with fixed appliances (P ≤ .1).

Xylitol concentration in saliva and dental plaque after use of various xylitol-containing products

The study consisted of two sets of experiments, one in saliva and one in dental plaque. The xylitol concentration in saliva was determined enzymatically in 12 children (mean age 11.5 years) after a standardised use of various xylitol products: (A) chewing gums (1.3 g xylitol), (B) sucking tablets (0.8 g xylitol), (C) candy tablets (1.1 g xylitol), (D) toothpaste (0.1 g xylitol), (E) rinse (1.0 g xylitol), and (F) a non-xylitol paraffin. Unstimulated saliva was sampled 1, 3, 8, 16 and 30 min after use. The concentration in dental plaque was determined after mouthrinses with contrasting amounts of xylitol (LX = 2.0 g, HX = 6.0 g, and control) and supragingival plaque was collected and pooled after 5, 15 and 30 min. The mean xylitol concentration in saliva at baseline was approximately 0.1 mg/ml. All xylitol-containing products resulted in significantly increased levels (p < 0.05) immediately after intake and remained elevated for 8-16 min in the different groups. The highest mean value in saliva was obtained immediately after use of chewing gums (33.7 +/- 16.4 mg/ml) and the lowest was demonstrated after using toothpaste (8.2 +/- 4.9 mg/ml). No significant differences were demonstrated between chewing gums (A), sucking tablets (B), candy (C) and rinses (E). In dental plaque, the mean values were 8.6 +/- 5.4 and 5.1 +/- 4.0 mg/ml 5 min after HX and LX rinses. Concerning the higher concentration, the values remained significantly elevated (p < 0.05) during the entire 30-min follow-up. In conclusion, commonly advocated xylitol-containing products gave elevated concentrations of xylitol in unstimulated whole saliva and dental plaque for at least 8 min after intake.

An efficacy and safety analysis of a chlorhexidine chewing gum in young orthodontic patients

AIM

The objective of the present study was to investigate the impact of a chlorhexidine (CHX) chewing gum in teenage orthodontic patients on plaque levels, gingival bleeding tendency and tooth staining.

MATERIALS AND METHODS

A randomized-controlled, double-blind, parallel study was conducted on 31 teenagers in fixed orthodontic therapy. Subjects of the CHX gum group were asked to continue their oral hygiene procedures in conjunction with chewing two pieces of a 5 mg CHX-containing chewing gum for 10 min. twice a day for 3 months. Subjects of the placebo gum group received the same instructions; however, using a CHX-free chewing gum. Plaque levels, gingival bleeding on probing and tooth staining were monitored at baseline and subsequently after 1-3 months.

RESULTS

Plaque levels significantly decreased from baseline at lingual/palatal sites in the placebo gum group. In the CHX gum group, a similar, yet non-significant trend was observed. At buccal sites, plaque levels remained unaffected in both groups. Gingival bleeding tendency significantly decreased in both groups, predominantly at lingual/palatal sites. There were no significant between-group differences in any of the efficacy parameters at any time point. However, the increase in staining was nearly five times higher in the CHX gum group.

CONCLUSIONS

There seems to be no indication for a CHX chewing gum in teenage orthodontic patients when used as an adjunct to normal oral hygiene practices.

Mutans streptococci dose response to xylitol chewing gum

Xylitol is promoted in caries-preventive strategies, yet its effective dose range is unclear. This study determined the dose-response of mutans streptococci in plaque and unstimulated saliva to xylitol gum. Participants (n = 132) were randomized: controls (G1) (sorbitol/maltitol), or combinations giving xylitol 3.44 g/day (G2), 6.88 g/day (G3), or 10.32 g/day (G4). Groups chewed 3 pellets/4 times/d. Samples were taken at baseline, 5 wks, and 6 mos, and were cultured on modified Mitis Salivarius agar for mutans streptococci and on blood agar for total culturable flora. At 5 wks, mutans streptococci levels in plaque were 10x lower than baseline in G3 and G4 (P = 0.007/0.003). There were no differences in saliva. At 6 mos, mutans streptococci in plaque for G3 and G4 remained 10x lower than baseline (P = 0.007/0.04). Saliva for G3 and G4 was lower than baseline by 8 to 9x (P = 0.011/0.038). Xylitol at 6.44 g/day and 10.32 g/day reduces mutans streptococci in plaque at 5 wks, and in plaque and unstimulated saliva at 6 mos. A plateau effect is suggested between 6.44 g and 10.32 g xylitol/day.

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.

Effect of xylitol on mutans streptococci and lactic acid formation in saliva and plaque from adolescents and young adults with fixed orthodontic appliances

This study aimed to investigate two dose regimens of xylitol-containing tablets on the ecology of dental plaque and saliva during treatment with fixed orthodontic appliances. The study group comprised 56 healthy patients (mean age 15.8 yr) randomly assigned into the following groups: A, (n = 23) two xylitol tablets two times a day (1.7 g xylitol d(-1)) for 18 wk; B, (n = 23) two tablets four times per day (3.4 g xylitol d(-1)) for 18 wk; and C, (n = 10) no tablets. The levels of mutans streptococci (ms) were enumerated in plaque and saliva and the proportion of xylitol-sensitive (X(S)) strains in saliva was determined by autoradiography with [(14)C]-xylitol at baseline and at 6, 12, and 18 wk. The lactic acid formation rate was assessed enzymatically in sucrose-challenged plaque suspensions. A drop in salivary ms levels was found in Group A after 6 wk but not after 12 or 18 wk. The proportion of X(S) ms was decreased after 6 wk in groups A and B and remained so during the experimental period. The lactic acid formation rates decreased slightly ( approximately 10%) in the two xylitol groups compared with baseline. In conclusion, our results showed that although an alteration of ms strains was demonstrated following a regular daily low-dose intake of xylitol, the long-term total ms counts in plaque and saliva as well as plaque acidogenicity remained unchanged.

Xylitol inhibition of anaerobic acid production by Streptococcus mutans at various pH levels

Xylitol inhibits the glycolysis and growth of Streptococcus mutans. We studied the inhibitory effect of xylitol on the acid production of S. mutans at several pH levels under the strictly anaerobic conditions found in the deep layer of dental plaque. Xylitol inhibited the rate of acid production from glucose and changed the profile of acidic end products to formate-acetate dominance, with a decrease in the intracellular level of fructose 1,6-bisphosphate and an intracellular accumulation of xylitol 5-phosphate (X5P). These results were notable at pH 5.5-7.0, but were not evident at pH 5.0. Since the activity of phosphoenolpyruvate phosphotransferase for xylitol was greater at higher pH, it is suggested that xylitol could be incorporated more efficiently at higher pH and that the resultant accumulation of X5P could inhibit the glycolysis of S. mutans more effectively.