Several sugar alcohols (polyols) have been promoted as potential sugar substitutes in caries limitation. However, differences in the effects of simple alditol-type sugar alcohol homologues on dental plaque have not been compared in clinical tests. The effects of 6-month use of erythritol (a sugar alcohol of the tetritol type), xylitol (a pentitol) and D-glucitol (sorbitol, a hexitol) were investigated in a cohort of 136 teenage subjects assigned to the respective polyol groups or to an untreated control group (n = 30–36 per group). The daily use of the polyols was 7.0 g in the form of chewable tablets, supplemented by twice-a-day use of a dentifrice containing those polyols. The use of erythritol and xylitol was associated with a statistically significant reduction (p < 0.001 in most cases) in the plaque and saliva levels of mutans streptococci. The amount of dental plaque was also significantly reduced in subjects receiving erythritol and xylitol. Such effects were not observed in other experimental groups. Chemical analyses showed D-glucitol to be a normal finding in dental plaque while xylitol was less consistently detected. Erythritol was detected in measurable amounts only in the plaque of subjects receiving this polyol. Erythritol and xylitol may exert similar effects on some risk factors of dental caries, although the biochemical mechanism of the effects may differ. These in vivo studies were supported by cultivation experiments in which xylitol, and especially erythritol, inhibited the growth of several strains of mutans streptococci.

Objective: The aim of this study was to test the efficacy of long-term, daily intake of erythritol and xylitol candy, compared with sorbitol candy, on the development of enamel and dentin caries lesions. Methods: The study was a double-blind randomized controlled prospective clinical trial. Altogether 485 primary school children, first- and second-graders at baseline, from southeastern Estonia participated in this 3-year intervention. Each child consumed four erythritol, xylitol or sorbitol (control) candies three times per school day. The daily intake of polyol was about 7.5 g. The International Caries Detection and Assessment System (ICDAS) was used in the clinical examinations by four calibrated examiners at baseline and at 12, 24 and 36 months. Results: The annual examination analyses and the follow-up analyses confirmed that the number of dentin caries teeth and surfaces at 24 months follow-up and surfaces at 36 months follow-up was significantly lower in the mixed dentition in the erythritol group than in the xylitol or control group. Time of enamel/dentin caries lesions to develop and of dentin caries lesions to progress was significantly longer in the erythritol group compared to the sorbitol and xylitol groups. Also the increase in caries score was lower in the erythritol group than in the other groups. Conclusions: In the follow-up examinations, a lower number of dentin caries teeth and surfaces was found in the erythritol group than in the xylitol or control groups. Time to the development of caries lesions was longest in the erythritol group. Trial registration: ClinicalTrials.gov Identifier NCT01062633.

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.

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The gene coding for gelatinase (also called metalloendopeptidase II; microbial proteinase, EC 3.4.24.4) of Enterococcusfaecalis subsp. liquefaciens strain OG1-10 was cloned in an Escherichia coli-Enterococcus shuttle vector, and its nucleotide sequence was determined. The DNA sequence encodes one large open reading frame (ORF) with 509 amino acid residues. The ORF contains a signal sequence in its N-terminal region, whereas the N-terminal amino acid sequence determined from the purified extracellular proteinase starts at residue 192 deduced from the ORF. This implies that the gelatinase is synthesized as a prepropolypeptide or prezymogen. The mature gelatinase contains 318 amino acid residues (molecular weight, 34,582) and has significant homology with neutral proteinases from BaciUus species and elastase from Pseudomonas aeruginosa.