Comparative analysis of some mouthrinses on the production of volatile sulfur-containing compounds

Oral malodor is mainly caused by the presence of volatile sulfur-containing compounds (VSC) produced by proteolytic periodontopathic bacteria in the oral cavity. Different solutions have been used as mouthrinses, trying to reduce malodor, and a large number is on the market. The aim of this study was to compare the effect of three commercially available mouthrinses with a simple inexpensive solution of zinc (zinc acetate 0.1%) on the production of VSC in vivo. Two of the solutions contained triclosan, one of them with fluoride and the other with sodium bicarbonate, and the third one contained herbal components. Seven healthy subjects rinsed with cysteine to induce production of VSC at baseline. After halitosis induction and VSC measurements, the subjects rinsed with the test solution, and mouth air VSC analyses were then performed by means of gas chromatography subsequent to repeated cysteine rinses after 30, 60, and 120 min. The data were calculated as percentage reduction of VSC from baseline. The percentage reduction of VSC decreased over time for all experimental groups. Zinc acetate had clearly the highest percentage reduction, starting from 95.68% at 30 min and with 69.27% after 2 h. The three other mouthrinses produced a VSC reduction of 23.92%-49.86% after 30 min, decreasing to 13.06%-37.09% after 2 h. One-way ANOVA (P = 0.05) was applied, and comparisons showed no differences between the commercially available solutions, but zinc acetate was significantly better than these. It may be concluded that some commercial mouthrinses are markedly less effective than a simple and cheap solution of zinc acetate.     

Comparative analysis of some mouthrinses on the production of volatile sulfur-containing compounds

Oral malodor is mainly caused by the presence of volatile sulfur-containing compounds (VSC) produced by proteolytic periodontopathic bacteria in the oral cavity. Different solutions have been used as mouthrinses, trying to reduce malodor, and a large number is on the market. The aim of this study was to compare the effect of three commercially available mouthrinses with a simple inexpensive solution of zinc (zinc acetate 0.1%) on the production of VSC in vivo. Two of the solutions contained triclosan, one of them with fluoride and the other with sodium bicarbonate, and the third one contained herbal components. Seven healthy subjects rinsed with cysteine to induce production of VSC at baseline. After halitosis induction and VSC measurements, the subjects rinsed with the test solution, and mouth airVSC analyses were then performed by means of gas chromatography subsequent to repeated cysteine rinses after 30, 60, and 120 min. The data were calculated as percentage reduction of VSC from baseline. The percentage reduction of VSC decreased over time for all experimental groups. Zinc acetate had clearly the highest percentage reduction, starting from 95.68% at 30 min and with 69.27% after 2 h. The three other mouthrinses produced a VSC reduction of 23.92% 49.86% after 30 min, decreasing to 13.06%-37.09% after 2 h. One-way ANOVA (P = 0.05) was applied, and comparisons showed no differences between the commercially available solutions, but zinc acetate was significantly better than these. It may be concluded that some commercial mouthrinses are markedly less effective than a simple and cheap solution of zinc acetate.     

Oral malodor reduction by a palatal mucoadhesive tablet containing herbal formulation

OBJECTIVE: The aim of the present study was to test the effect of a palatal mucoadhesive tablet containing an herbal formulation on oral malodor production and volatile sulfide compound (VSC) levels, and to evaluate its antimicrobial activity. METHODS: A total of 56 healthy young volunteers participated in experiments 1 and 2. The palatal adhesive tablets were prepared with different active ingredients (herbal formulation, zinc and chlorhexidine), or without an active ingredient as control (placebo). Measurement included odor judge scores (two judges) and VSC readings by a sulfide monitor (Halimeter). In experiment 3, the antimicrobial activity of the herbal formulation ingredients (i.e. sage, Echinacea, Lavender and Mastic gum) were tested against three oral pathogens (Streptoccocus mutans, Porphyromonas gingivalis and Candida albicans) by the agar diffusion test. RESULTS: Application of the palatal adhesive tablets containing herbal formulation resulted in a significant reduction in both oral malodor scores (p<0.001) and VSC levels (p=0.013). Herbal formulation showed higher significance in VSC reduction (p=0.001), as compared to zinc and chlorhexidine (p=0.024 and 0.032, respectively). Sage, Lavender and Mastic gum showed antimicrobial activity against all three oral pathogens. CONCLUSIONS: Results of the present study suggest that the palatal adhesive tablets containing herbal formulation may serve as an effective means of treatment for patients complaining of oral malodor.     

Miconazole chewing gum for treatment of chronic oral candidosis

A chewing gum containing the antifungal drug miconazole may be convenient for topical treatment of oral candidosis. Therefore a trial was performed to examine the effect and tolerance of miconazole chewing gum in comparison with miconazole gel in the treatment of oral candidosis. The study group consisted of 32 patients with oral candidosis harboring yeasts, predominantly Candida spp. Half of the patients chewed one piece of chewing gum (dose: 3.6 mg of miconazole) four times daily; the other half dispersed a 2% gel (dose: 50 mg of miconazole) in the oral cavity four times daily. After 6 wk of treatment, there was no clinical evidence of yeast infection in either of the two groups. No significant differences between the two groups were found in clinical, mycologic, and cytologic investigations conducted after 3 and 6 wk of treatment or at the follow-up examination 4 wk after termination of the treatment. The results indicate that miconazole released from chewing gum is as effective as miconazole gel. The chewing gum reduced the dosage of miconazole for treatment of oral candidosis, and the patients approved the chewing gum as a pleasant medicament.     

Tongue brushing and mouth rinsing as basic treatment measures for halitosis

Tongue brushing and mouth rinsing are basic treatment measures for halitosis, and as such are categorised as treatment needs (TN)-1. Although TN-1 is used for treatment of physiologic halitosis treatment, pseudo-, extra oral pathologic or halitophobic patients must also be managed with TN-1 as well as other treatments. Since the origin of physiological halitosis is mainly the dorso-posterior region of the tongue, tongue cleaning is more effective than mouth rinsing. However, practitioners should always instruct their patients on how to brush their tongues to prevent harmful effects. Another approach using a chlorhexidine mouthwash is most effective in reducing oral malodour. However, chlorhexidine should not be used routinely; therefore, zinc-containing mouthwashes have been recommended for use. People can also use chewing gum to reduce oral malodour. Surprisingly, however, it has been noted that sugarless chewing gum increased methyl mercaptan, one of the principal components of oral malodour. Mint did not reduce the concentration of methyl mercaptan either, although these products are widely used for their ability to mask oral malodour. There is a need for the development of a novel food or chewing gum that could considerably reduce VSC levels in mouth air to complement TN-1.     

Effect of chewing gums containing the probiotic bacterium Lactobacillus reuteri on oral malodour

Abstract

Objective. To evaluate the effect of chewing gums containing probiotic bacteria on oral malodour. The null hypothesis was that no difference would be displayed compared with placebo gums. Materials and methods. Twenty-five healthy young adults with self-reported malodorous morning breath completed this randomized double-blind placebo-controlled cross-over trial. The design included run-in and wash-out periods interspersed by two intervention periods of 14 days each. The subjects were instructed to chew one gum in the morning and one in the evening containing either two strains of probiotic lactobacilli (L. reuteri DSM 17938 and L. reuteri ATCC PTA 5289) or placebo. The outcome measures were (i) organoleptic scores (0–5) by a certified test panel, (ii) concentration of volatile sulphur compounds (VSC) measured with a Halimeter and (iii) concentration of VSC after a cysteine rinse. Registrations were made at baseline and after each intervention period. Differences between the groups were assessed by non-parametric paired statistics and chi-square test. Results. The median organoleptic score was similar (score 2) in both groups at baseline. After 14 days of treatment, the organoleptic scores were significantly lower in the probiotic group compared with the placebo group (p < 0.05). Assessments of the VSC levels displayed no significant differences between the groups, either before or after rinsing with L-cysteine. No adverse effects were registered. Conclusion. The results demonstrated that probiotic chewing gums may have some beneficial effect on oral malodour assessed by organoleptic scores. The results indicate that the probiotic gum may affect bacteria that produce malodourous compounds other than VSCs.     

Combined effect of zinc ions and cationic antibacterial agents on intraoral volatile sulphur compounds (VSC)

OBJECTIVE: Volatile sulphur compounds (VSC) are major components of oral malodour. As both zinc ions and cationic antibacterial agents inhibit the formation of oral VSC, this study aimed to determine whether these agents combined have synergistic anti-VSC actions. METHODS: Baseline oral VSC measurements of mouth air from 10 volunteers following cysteine rinsing (6mM, pH 7.2) were obtained using gas chromatography (GC). Subjects rinsed for 1 min with 10ml of the test solutions, 0.3% zinc acetate (Zn), 0.025% chlorhexidine (CHX), 0.025% cetyl pyridinium (CPC), and the combinations Zn+CHX and Zn+CPC. Cysteine rinses were repeated at 1h, 2h and 3h and VSC measurements recorded. Three subjects rinsed with the Zn+CHX combination and fasted for 9h, undergoing cysteine rinses and VSC measurements at 3h intervals. 10 microl of the test solutions were also added to 1ml aliquots of human whole saliva (n=8). Following incubation at 37 degrees C for 24h VSC levels in the saliva headspace were measured by GC. Inhibition of VSC formation and the fractional inhibitory index indicating synergy were calculated. RESULTS: Zn+CHX mouthrinse had a synergistic anti-VSC effect, and was effective for at least 9h. Zn+CPC mouthrinse was less effective. Both combinations showed a synergistic inhibiting effect in-vitro. CONCLUSIONS: Synergy between Zn and the antibacterial agents confirms different mechanisms of operation.     

Fluoride and urea chewing gums in an intra-oral experimental caries model

The aim of the present investigation was to evaluate the effect of sugar-free chewing gums containing fluoride (F) and urea in an intra-oral experimental caries model. Placebo chewing gums (without any active ingredient) and no gum served as controls. Fifteen subjects participated in a cross-over, single-blind study. Demineralised enamel and dentine blocks were embedded in circular plastic discs and bonded to the buccal surfaces of the lower canines and first premolars. The discs were removed and analysed using transversal microradiography after each of the six 4-week periods during which the subjects used either test or placebo products or no product. The results revealed that frequent use of sugar-free chewing gum is sufficient to inhibit further demineralisation of previously demineralised enamel and dentine specimens in the oral cavity. Comparing F, urea and placebo gums, the data showed that there was little or no difference between the products, except for an inhibitory effect on the chewing side of the dentition after using F chewing gums.     

On the transformation of sulfur-containing amino acids and peptides to volatile sulfur compounds (VSC) in the human mouth

Halitosis is most often caused by oral conditions. Volatile sulfur compounds (VSC), constituting the major components of oral malodor, are produced by anaerobic, gram-negative bacteria retained mainly in periodontal pockets or on the tongue dorsum. Sulfur-containing amino acids serve as substrate for these bacteria. VSC have also been found to have unfavorable effect on the tissue. The aim of this study was to examine whether normal, healthy individuals with no history of halitosis were able to produce VSC from cysteine, when applied as a mouthrinse. A further aim of the study was to investigate and compare the potential of other sulfur-containing amino acids and peptides as substrates for oral VSC production and to localize the odor-production sites. A portable sulfide monitor was used for VSC registration. Results showed that all test subjects produced high oral concentrations of VSC upon rinses with cysteine, which thus seems to be a major substrate for VSC production. The other sulfur-containing substrates had much less effect. It was found that the tongue was the major site for VSC production, and that saliva per se caused low VSC production.     

Plaque-growth inhibiting effect of chewing gum containing urea hydrogen peroxide

The plaque-reducing effect of a chewing gum containing hydrogen peroxide was assessed. 12 dental hygienist students participated in a double-blind 3 x randomly crossed-over study. During the 4-day test periods, from Monday to Friday, no oral hygiene measures were allowed other than chewing 2 pieces of gum for approximately 10 min 5 x daily. The 800 mg pieces of gum were V6+regular (V6+) containing 0.4 g sorbitol and 6.3 mg hydrogen peroxide, V6 placebo gum (PLAC) containing 0.45 g sorbitol and no hydrogen peroxide, and only the gum base (GB) as a negative control. The quantity of plaque was assessed using the plaque index and the visible plaque index, and by scraping "all" plaque off the teeth in half the mouth during 2.5 min for determination of plaque wet weight. With all 3 measurements, chewing of the hydrogen peroxide-releasing gum (V6+) resulted in significantly lower plaque increments, from Monday to Friday, than chewing of the gum base (P less than 0.05). Chewing of the V6 placebo gum (PLAC) resulted in plaque scores which differed from neither those recorded after use of the hydrogen peroxide releasing (V6+) nor the placebo (GB) gums. The observed plaque-growth inhibiting effect of the hydrogen peroxide-releasing chewing gum in the present study was found to be of limited clinical significance.     

Effect of sorbitol- and xylitol-containing chewing gum on salivary microflora, saliva, and oral sugar clearance

Abstract – The effect of frequent use of a sorbitol-containing nicotine chewing gum on saliva secretion rate and buffer capacity and some oral bacteria was studied in 27 patients at a smoking cessation clinic. The effect was compared with that obtained after frequent use of a chewing gum containing xylitol in a second study in 14 subjects. The results showed that sorbitol-containing nicotine chewing gum had no significant effect on salivary numbers of oral streptococci and lactobacilli during a 3-month period of active chewing five times a day. Chewing on xylitol-containing gum caused a significant decrease in salivary S. mutans after 2 months but not after 3 months. No change in secretion rate or buffer capacity was observed in the two studies. Oral sugar clearance time was reduced after 3 months with a statistically significant difference to baseline values in subjects consuming the sorbitol-containing nicotine chewing gum.     

Sugar of substitute stevioside in chewing gum: comparative double blind controllable study

In double blind controllable study on 126 volunteers - students of medical academy - influence on рН the mixed saliva of 5 kinds of chewing gums with the different contents of substitute of sugar as xylitol and sorbitol, and also the chewing sweets R.O.C.S., two kinds of chewing gums containing a basis with substitute of sugar stevioside (1.25 and 2.5%) and placebo (a basis without additives) were investigated. Products chewed within 10 minutes. In one of groups surveyed such chewing was preceded with rinsing a mouth by a test solution of saccharose. рН determined within 30 minutes. At chewing gums with substitute of sugar displacement рН the mixed saliva in the alkaline side was revealed a different degree. Thus gums with stevioside did not concede and even surpassed in this action of chewing gums with other substitutes of sugar. In comparison with placebo chewing gums and sweets restored acid-alkaline balance of oral cavities faster. Hence, use of stevioside in structure of chewing gum allows at preservation of its positive actions in oral cavity essentially to reduce concentration substitute of sugar and, hence, its collateral action by an organism.     

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.     

Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial

OBJECTIVE: A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation. METHODOLOGY: Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments. RESULTS: There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01. CONCLUSION: The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.     

Effect of eucalyptus extract chewing gum on periodontal health: a double-masked, randomized trial

BACKGROUND: Studies in vitro showed that eucalyptus extracts possess antibacterial activity against cariogenic and periodontopathic bacteria; however, the clinical effects with respect to periodontal health in humans remain unproven. The objective of this study was to evaluate the effect of chewing gum containing eucalyptus extract on periodontal health in a double-masked, randomized, controlled trial. METHODS: Healthy humans with gingivitis but not deep periodontal pockets were randomly assigned to the following groups: high-concentration group (n=32): use of 0.6% eucalyptus extract chewing gum for 12 weeks (90 mg/day); low-concentration group (n=32): use of 0.4% eucalyptus extract chewing gum for 12 weeks (60 mg/day); and placebo group (n=33): use of chewing gum without eucalyptus extract for 12 weeks. Plaque accumulation (PLA), gingival index (GI), bleeding on probing (BOP), periodontal probing depth (PD), and clinical attachment level (CAL) were measured at weeks 0, 4, 8, 12, and 14. Significance was analyzed with repeated-measures two-way analysis of variance followed by the Games-Howell pairwise comparison test. RESULTS: The interaction between the effects of eucalyptus extract chewing gum and the intake period was statistically significant for PLA, GI, BOP, and PD but not for CAL. The low- and high-concentration groups exhibited statistically significant (P <0.05) improvements compared to the placebo group for PLA, GI, BOP, and PD. CONCLUSIONS: Eucalyptus extract chewing gum had a significant effect on PLA, GI, BOP, and PD. The use of eucalyptus extract chewing gum may promote periodontal health.     

Use of a novel group of oral malodor measurements to evaluate an anti-oral malodor mouthrinse (TriOralTM) in humans

OBJECTIVE: This study compared the ability of a test mouthwash containing zinc chloride and sodium chlorite (TriOral) to reduce intrinsic oral malodor, to that of two other mouthrinses, one with zinc chloride only and the other with no zinc chloride/no sodium chlorite, using a novel group of oral malodor parameter measurements. METHODOLOGY: Forty-eight subjects completed the study; 16 in the test group, 17 in the zinc only group, and 15 in the no zinc chloride/ no sodium chlorite group. At baseline and after two and four weeks, parameters assessed were 1) malodorants in the headspace of and in solution in resting whole saliva determined organoleptically, 2) breath volatile sulfur compounds (VSC) measured with a sulfide monitor (Halimeter), 3) fresh and incubated saliva oxidation-reduction potential (E(h)) measured with a platinum electrode, and 4) level of saliva indolic compounds (IC), indole and skatole, determined colorimetrically with Kovac's reagent. The VSC, E(h), and IC data for the three mouthrinses were analyzed statistically by repeated measures ANOVA between groups, and by 2-way ANOVA within groups. Corresponding organoleptic data were analyzed by Kruskal-Wallis and Friedman non-parametric tests. RESULTS: Organoleptic, VSC, and E(h) evaluations clearly showed the zinc chloride/sodium chlorite test mouthrinse to be more effective than the other two rinses. In all cases, the level of significance was p < 0.001 between the test mouthrinse and its no zinc chloride/no sodium chlorite control; between test mouthrinse and the zinc chloride only product, significance was p < 0.05, < 0.001 and < 0.01 for the organoleptic, VSC, and E(h) tests, respectively. Noteworthy was the observation that the mean organoleptic saliva headspace score with the test mouthrinse was reduced to zero, and VSC levels fell below 50 ppb S by the end of the study, a level where the breath is usually non-odorous. The test mouthwash also appeared more effective in reducing the salivary IC levels, but the results did not reach significance at p < 0.05 unless IC levels were amplified in the saliva by incubation overnight at 37 degrees C. Correlations between the various procedures were highly significant, achieving in almost all cases a probability level of p < 0.001. CONCLUSION: The results supported the conclusion that the zinc chloride plus sodium chlorite mouthrinse (TriOral) is more effective in reducing oral malodor than a zinc chloride alone mouthrinse, and even more effective than its no zinc chloride/no sodium chlorite mouthrinse control. The methods used in this study were consistent with one another, and highly effective in measuring various parameters that characterize oral malodor.     

Prevention of plaque growth with chewing gum containing chlorhexidine acetate

The purpose of the study was to assess the anti-plaque effect of chlorhexidine (CHX) in chewing gum. The 0.80 g pieces of test gum contained 5 mg chlorhexidine acetate with or without a hydrogen peroxide releasing agent. The gum base with flavouring agents but containing neither CHX nor H2O2 was used as a control. 12 dental hygiene students volunteered to participate in the 3 x crossed-over double blind clinical trial. During the 4-day test periods, no other oral hygiene measures were allowed than chewing 2 pieces of gum at the time for approximately 10 min, 5 times daily. Between test periods, meticulous mechanical oral hygiene measures were practised for 3 days. At the beginning and at the end of each test period, the quantity of plaque was assessed using the plaque index, plaque wet weight, and the area of plaque on the tooth surface as criteria. The results indicated that both CHX gums completely inhibited the increase in plaque index and plaque weight. With regard to area of plaque, the difference between the 2 test gums and the control gum was less marked but still present. The test persons subjectively assessed the gum base to have a poor cleansing effect but also the least unpleasant taste. It was concluded that use of both the chlorhexidine gum and the gum-containing chlorhexidine in addition to the hydrogen peroxide releasing agent had an excellent plaque growth inhibiting effect during the 4-day test periods.     

Effect of sorbitol- and xylitol-containing chewing gum on salivary microflora, saliva, and oral sugar clearance

The effect of frequent use of a sorbitol-containing nicotine chewing gum on saliva secretion rate and buffer capacity and some oral bacteria was studied in 27 patients at a smoking cessation clinic. The effect was compared with that obtained after frequent use of a chewing gum containing xylitol in a second study in 14 subjects. The results showed that sorbitol-containing nicotine chewing gum had no significant effect on salivary numbers of oral streptococci and lactobacilli during a 3-month period of active chewing five times a day. Chewing on xylitol-containing gum caused a significant decrease in salivary S. mutans after 2 months but not after 3 months. No change in secretion rate or buffer capacity was observed in the two studies. Oral sugar clearance time was reduced after 3 months with a statistically significant difference to baseline values in subjects consuming the sorbitol-containing nicotine chewing gum.     

A chewing gum with mineral additives]

Finely dispersed hen egg shell was added to a new chewing gum as a mineral component. The studies carried out in 28 schoolchildren have shown that 15 min chewing of this gum results in a marked elevation of salivary Ca levels and in improvement of the hygienic status of the oral cavity. This fact recommends this chewing gum as an additional means for care of the oral cavity for both hygienic purposes and for improving the mineralizing potential of the saliva.     

The effect of adding calcium lactate to xylitol chewing gum on remineralization of enamel lesions

The purpose of the study was to determine whether adding calcium lactate to chewing gum containing xylitol enhances remineralization of enamel surfaces using an early caries lesion model. Enamel slabs were cut from human extracted sound teeth and artificial subsurface lesions created within each. Half the enamel slabs were used as controls and stored in a humidifier while half were mounted into oral appliances worn by 10 volunteers (22-27 years old, 2 males and 8 females) in a three-leg trial, during which they wore the appliance without chewing gum, chewed gum containing xylitol + calcium lactate or chewed gum containing only xylitol 4 times a day for 2 weeks. Calcium concentrations in the enamel surfaces of control and test slabs were measured by X-ray spectrometry and degrees of remineralization were calculated. The mean degree of remineralization was greater after chewing xylitol-Ca gum (0.46 +/- 0.10) than after no gum (0.16 +/- 0.14) or after chewing xylitol gum (0.33 +/- 0.10) (p < 0.01). In conclusion, chewing gum containing xylitol + calcium lactate could enhance remineralization of enamel surface compared to chewing gum containing only xylitol or no gum chewing.