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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. [ABSTRACT FROM AUTHOR]

A novel vanadate- and molybdate-sensitive human skin epidermal acid phosphatase was purified and characterized. The enzyme was extracted from epidermal sheets with a 0.1% Triton X-100 solution buffered at pH 7.0. The purification procedure consisted of molecular permeation chromatography on Sephadex G-200 followed by chromatography on hydroxylapatite using an ammonium sulfate gradient. The molecular weight of the enzyme was 82,000 and the isoelectric point was at pH 5.6. At the optimum pH (5.1) the enzyme hydrolyzed most rapidly l-naphthyl phosphate (Km = 0.28 mM) and 4-nitrophenyl phosphate (Kin = 0.28 mM). In general, the best substrates had an aromatic leaving group. Fluoride (Ki = 39 μM; noncompetitive) and phosphate (competitive) inhibited by binding to different binding sites of the enzyme. The most potent inhibitors were vanadate (Ki = 1.9 × 10-6 M), tungstate (Ki = 1.4 × 10-7 M), and molybdate (Ki = 2.0 × 10-9 M). Chemical modification and kinetic experiments suggested that the activity of the enzyme is based on imidazole, tyrosyl, and carboxyl groups. Benzoyl peroxide was a relatively potent inhibitor (Ki = 5.0 × 10-5 M; noncompetitive). This enzyme resembled the prostatic acid phosphatase with regard to substrate specificity, inhibition characteristics, and functional groups. [ABSTRACT FROM AUTHOR]

The proteolytic profile of Treponema vincentii ATCC 35580 was studied using PZ- PLGPA (phenylazobenzyloxycarbonyl-L-prolyl-L-leucylglycyl-L-prolyl-D-arginine; a substrate of bacterial collagenases) and amino acid 2-naphthylamides (2NA) as substrates. The cell extracts showed high activity toward PZ-PLGPA, Nα-L-arginyl-2NA and Nγ-L-glutamyl-2NA. Gel permeation chromatography revealed 2 major endopeptidases (I and II) hydrolyzing PZ-PLGPA, the molecular weights of which were 75,000 and 23,000, respectively. Enzyme I was stable enough for subsequent fast protein liquid chromatography on an anion exchange column. The enzyme had a broad pH optimum of 6.5 to 7.5 with PZ-PLGPA as substrate, hydrolyzed gelatin and was moderately inhibited by metal chelators, but was very sensitive to p-chloromercuribenzoic acid (PCMB). Enzyme II with a pH optimum of 7 to 8 was more labile, quite sensitive to PCMB and moderately inhibited by chelators. A high-molecular weight arginine aminopeptidase (mol wt. > 200,000) was sensitive to PCMB and showed a value of 0.55 mM for Km in the hydrolysis of Nα-L-arginyl-2NA. The hydrolysis of PZ-PLGPA and gelatin suggests that this organism may contain collagenolytic proteinases. Because the insoluble proteinase substrate Azocoll was not hydro1yzed, these enzymes may be active on soluble collagenous substances only. T. vincentii ATCC 35580 typifies an organism rich in PZ-PLGPA-endopeptidase, argimne aimnopeptidase and γ-glutamylpeptidase activity. [ABSTRACT FROM AUTHOR]

A previous clinical trial showed that long-term use of saliva-stimulating polyol (xylitol and sorbitol) chewing gums was associated with arrest of dental caries in young subjects. After a 20-22-month intervention (when the subjects were 8 years old), a total of 23 primary teeth with extensive dentin caries lesions whose surface in clinical examination was found to be totally rehardened (remineralized) could be removed because the teeth were near their physiologic exfoliation time. These teeth were subjected to histologic, microhardness, and electron microscopic tests. The majority of the specimens had been remineralized from the surface by a non-cellular-mediated process within the remaining collapsed, organic extracellular matrix associated with the remaining dentinal surface. Many of the underlying dentinal tubules were filled with a matrix that had been subsequently mineralized. Dental microanalyses showed that the topmost (outer) 20-μm-thick rehardened layer of the lesions exhibited the highest Ca:P ratio, which leveled off at a depth of approximately 150 μm. The rehardened surface layer (normally <0.1 mm in thickness) was significantly (P < 0.001) harder than sound dentin and nearly as hard as sound enamel. Although the main source of the mineral present in the rehardened layer was most likely of salivary origin, some extracellular remineralization was probably mediated by odontoblasts. The results complete the clinical diagnoses of the original trial and suggest that regular use of polyol chewing gums may induce changes in dentin caries lesions, which in histologic and physiochemical studies show typical characteristics of rehardening and mineralization. [ABSTRACT FROM AUTHOR]

Several studies indicate that xylitol (X) consumption is associated with certain biochemical changes in dental plaque and whole saliva. In making X-containing saliva stimulants more cost-effective and palatable, manufacturers may use maltitol syrup (MS, which normally contains some sorbitol and higher polyols) or polydextrose (PD, a polysaccharide molecule with a mass >22 kDa) as bulking agents. Combinations of X with MS and PD have not been tested regarding their salivary effects. One hundred and eighty-eight young subjects (mean age, 22 years) of both sexes were divided into three groups of equal size for a 4-month study. The subjects in one group used X-MS dragées (in 7 daily episodes; 8 g X per day), while the subjects in another group used X-PD dragées in as many daily episodes (8 g X per day). Subjects in the third (comparison) group did not receive saliva stimulants. Paraffin-stimulated whole saliva samples were collected at baseline, after 2 months, and at endpoint. The usage of X-MS was associated with a significant (P < 0.05) reduction in the salivary sucrase activity. After 4 months, the activity of enzymes hydrolyzing Nα-benzoyl-DL-arginyl-p- nitroaniline was significantly reduced in all groups, while the levels of free sialic acid were reduced in group X-PD only (P < 0.05). These salivary changes most likely reflected microbial shifts in the oral cavity and suggest that information from saliva studies may be of avail when deciding which bulking agents should be used in xylitol-based saliva stimulants. [ABSTRACT FROM AUTHOR]

The cell extracts of two human oral strains (FN2 and FN3) of Fusobacterium nucleatum displayed exceptionally high γ-glutamylpeptidase activity as determined with N-γ- l-glutamyl-2-naphthylamine as substrate. This activity was so dominant that the hydrolysis of other N-aminoacyl-2-naphthylamines progressed at a rate <10% of the former. Two major enzymes (I and II) were partially purified from FN2. I had a molecular weight of 115,000 and did not hydrolyze γ-glutamylcysteinylglycine (glutathione). II had a molecular weight of 70,000 and rapidly liberated only glutamic acid from glutathione. Strain FN3 contained several enzymes hydrolyzing γ-glu-2NA. Direct anion exchange chromatography of FN3 cell extracts separated one enzyme that liberated both glutamic acid and glycine from glutathione, one that was inactive against glutathione (but hydrolyzed γ-glu-2NA), and one that liberated only glutamic acid. Although γ-glu-2NA was a good synthetic substrate, glutathione was hydrolyzed at least 500 times faster by an enzyme present in both strains. These results indicate that the presence of γ-glutamylpeptidase activity is very characteristic of these F. nucleatum strains. [ABSTRACT FROM AUTHOR]

Treponema denticola ATCC 35405, a human oral spirochete associated with periodontal disease, was shown to contain three enzymes (I, II, and III) with proline iminopeptidase activity. II and III were considered to be true iminopeptidases, whereas enzyme I was found to be a benzoylarginine peptidase with iminopeptidase activity. Enzyme III, the dominant proline iminopeptidase of T. denticola in terms of its activity toward N- l-prolyl-2-naphthylamine, was considered to be a sulfhydryl peptidase: 0.167 μ M p-chloromercuribenzoic acid totally inactivated the enzyme, and 1.0 m M dithiothreitol restored 92% of activity. The activity of this enzyme was not affected by metal chelators. Chemical modification of enzyme III suggests that tyrosyl (or histidyl) and carboxyl groups may be necessary for its activity. The hydrolysis of N- l-prolyl-2-naphthylamine was found to be very characteristic of T. denticola ATCC 35405; out of 24 different N- l-aminoacyl-2-naphthylamines tested, only the proline derivative was hydrolyzed at a high rate. The substrate specificity of the enzymes discovered indicates that they may be important for the nutrition of T. denticola. The iminopeptidase activity may be related to the pathogenicity of this organism in periodontal disease. [ABSTRACT FROM AUTHOR]

Seven clinical isolates and the ATCC strain 35405 of Treponema denticola, obtained from human periodontal pockets, were studied for peptidase activity with several chromogenic compounds as substrates. The cell sonicates of all strains hydrolyzed phenylazobenzyloxycarbonyl- l-prolyl- l-leucyl-glycyl- l-prolyl- d-arginine (a collagenase substrate), azocasein, and the 2-naphthylamines of l-proline, l-hydroxyproline, l-pyrrolidine, and benzoyl- l-arginine, but the rates of hydrolysis varied considerably from strain to strain. Fast protein liquid chromatography on gel and anion exchange columns revealed further biochemical differences between the strains. The ATCC strain consistently produced several proline iminopeptidases, whereas four of the clinical isolates yielded high and three yielded low iminopeptidase activity. The ATCC strain and six clinical isolates displayed high benzoylarginine peptidase activity. The use of N- l-prolyl-2-naphthylamine as substrate revealed more differences between the strains than other substrates. The substrate specificity of the enzymes discovered suggests that they may be important for the nutrition of the organism or in the protection of the organism against chemical defense factors present in the gingival pocket. [ABSTRACT FROM AUTHOR]

Aim: To investigate the use of xylitol-containing chewing-gums in public elementary schools as a means to affect the growth of salivary and plaque mutans streptococci and salivary lactobacilli., Design: Over a period of 24 months, 750 8- to 9-year-old children chewed xylitol (X group; n = 255) or xylitol-sorbitol (XS group; n = 264) gum on school days (454 days over 2 years), or chewed no gum at all (C group; n = 231). Consumption of xylitol in the X and the XS groups was 6.6 and 5.4g per day, respectively. Use of gum took place at school in four daily episodes of which three were supervised by teachers. Following the 24-month chewing-gum period, the subjects were re-examined after 15 months (total follow-up period: 39 months) at which time an extraneous comparison group (ExC; n = 117) was also examined. The numbers of subjects examined after 39 months were: X, 239; XS, 248; C3 217., Methods: Salivary and plaque levels of mutans streptococci and the salivary levels of aerobically cultured aciduric bacteria (mostly representing lactobacilli) were determined using the Orion Diagnostica Dentocult SM and LB test kits, respectively., Results: There were statistically significant differences after 24 and 39 months between the two xylitol chewing-gum groups and the C group with regard to salivary and plaque mutans streptococci and salivary lactobacilli: the use of xylitol-containing chewing-gums significantly reduced these bacterial scores. The reductions were statistically more significant in the X group than in the XS group. The bacterial scores of groups C and ExC were similar., Conclusions: Long-term use of xylitol-containing chewing-gum can reduce the growth of mutans streptococci in saliva and dental plaque, and lactobacilli-type bacteria in saliva, even if xylitol is used only on school days. The results also suggest that xylitol gum use can have a long-term, delayed growth-retarding effect on these micro-organisms, since reduced bacterial growth was still observed 15 months following the termination of xylitol use. The results indicate a close biochemical relationship between xylitol and mutans streptococci, and suggest that a similar relationship may exist regarding aerobically cultured aciduric bacteria present in saliva.

Aim: To investigate the use of polyol-containing chewing gums in a day-care centre (kindergarten) setting as a means to affect the growth of mutans streptococci and dental plaque., Design: Over a period of six months, 123 five-year-old children chewed xylitol (X group), sorbitol (G group), or did not chew gum (C group). Consumption of xylitol, and sorbitol was 4.5 to 5.0 g per day and subjects consumed in five supervised daily chewing episodes four at the day-care centres and one at home., Methods: Interproximal dental plaque was sampled at baseline and after six months for a laboratory study of mutans streptococci counts. The Quigley & Hein plaque index procedure was used. Interviews and questionnaires elucidated the acceptability of the programme., Results: Parents and kindergarten personnel regarded the programme as an important, additional procedure to promote better oral health. The children regarded the use of chewing gum as a pleasurable experience. Compared with groups G and C, there was a statistically significant reduction of mutans streptococci in the interproximal plaque in the X group. The Quigley & Hein plaque index scores tended to decrease in the X group, while no such trend was observed in the G group., Conclusions: Habitual use of relatively small daily quantities of polyol-containing chewing gum by young children may be regarded as an important additional caries-preventive procedure in a combined day-care centre and home setting. Especially xylitol-containing chewing gum may significantly reduce the growth of mutans streptococci and dental plaque which may be associated with dental caries.