EFFICACY OF MULTIVITAMINS AND LYSOZYME TABLETS IN COMPLEX MANAGEMENT OF PLAQUE-INDUCED GINGIVITIS IN CHILDREN: A COMPARATIVE BIOCHEMICAL STUDY

Although the pathogenesis of periodontal lesions has not been sufficiently studied, recent studies show that plaque formation and host immune response are important factors. The purpose of this study was improving efficiency of plaque-induced gingivitis treatment in children with immunological correction of saliva by administration of polyvitamins and lysozyme tablets. We have examined 60 12-year-old children diagnosed with plaque-induced gingivitis and divided them into the main and control groups consisted of 30 children in each accordingly. The children of both groups were treated by sanitation and professional oral hygiene. The children of the main group besides were prescribed with multivitamins complex "Supervit" and tablets "Lizak". The efficiency of the introduced complex we have assessed by contain of immunoglobulins A (IgA), immunoglobulins G (IgG), secretory immunoglobulin A (s-IgA), interleukin 1β (IL-1β), interleukin 4 (IL-4) and lysozyme in saliva. After 6 month the treatment children from the main group showed a decline in concentration of IL-1β by 30,06 % (р<0,01), IgA by 33,34 %, IgG by 12,5 % (р<0,05). The present data support the high efficiency of the introduced treatment that has been proved by positive progress of immunological indexes in saliva taken within six and 12 month since the research.

The adhesive PitA pilus protein from the early dental plaque colonizer Streptococcus oralis: expression, purification, crystallization and X-ray diffraction analysis

PitA is the putative tip adhesin of the pilus islet 2 (PI-2)-encoded sortase-dependent pilus in the Gram-positive Streptococcus oralis, an opportunistic pathogen that often flourishes within the diseased human oral cavity. Early colonization by S. oralis and its interaction with Actinomyces oris seeds the development of oral biofilm or dental plaque. Here, the PI-2 pilus plays a vital role in mediating adherence to host surfaces and other bacteria. A recombinant form of the PitA adhesin has now been produced and crystallized. Owing to the large size (∼100 kDa), flexibility and complicated folding of PitA, obtaining diffraction-quality crystals has been a challenge. However, by the use of limited proteolysis with α-chymotrypsin, the diffraction quality of the PitA crystals was considerably enhanced to 2.16 Å resolution. These crystals belonged to space group P1, with unit-cell parameters a = 61.48, b = 70.87, c = 82.46 Å, α = 80.08, β = 87.02, γ = 87.70°. The anomalous signal from the terbium derivative of α-chymotrypsin-treated PitA crystals prepared with terbium crystallophore (Tb-Xo4) was sufficient to obtain an interpretable electron-density map via terbium SAD phasing.

Composition and diversity of the subgingival microbiome and its relationship with age in postmenopausal women: an epidemiologic investigation

BACKGROUND

The extent to which the composition and diversity of the oral microbiome varies with age is not clearly understood.

METHODS

The 16S rRNA gene of subgingival plaque in 1219 women, aged 53-81 years, was sequenced and its taxonomy annotated against the Human Oral Microbiome Database (v.14.5). Composition of the subgingival microbiome was described in terms of centered log(2)-ratio (CLR) transformed OTU values, relative abundance, and prevalence. Correlations between microbiota abundance and age were evelauted using Pearson Product Moment correlations. P-values were corrected for multiple testing using the Bonferroni method.

RESULTS

Of the 267 species identified overall, Veillonella dispar was the most abundant bacteria when described by CLR OTU (mean 8.3) or relative abundance (mean 8.9%); whereas Streptococcus oralis, Veillonella dispar and Veillonella parvula were most prevalent (100%, all) when described as being present at any amount. Linear correlations between age and several CLR OTUs (Pearson r = - 0.18 to 0.18), of which 82 (31%) achieved statistical significance (P < 0.05). The correlations lost significance following Bonferroni correction. Twelve species that differed across age groups (each corrected P < 0.05); 5 (42%) were higher in women ages 50-59 compared to ≥70 (corrected P < 0.05), and 7 (48%) were higher in women 70 years and older.

CONCLUSIONS

We identified associations between several bacterial species and age across the age range of postmenopausal women studied. Understanding the functions of these bacteria could identify intervention targets to enhance oral health in later life.

Metabolic Profile of Supragingival Plaque Exposed to Arginine and Fluoride

Caries lesions develop when acid production from bacterial metabolism of dietary carbohydrates outweighs the various mechanisms that promote pH homeostasis, including bacterial alkali production. Therapies that provide arginine as a substrate for alkali production in supragingival oral biofilms have strong anticaries potential. The objective of this study was to investigate the metabolic profile of site-specific supragingival plaque in response to the use of arginine (Arg: 1.5% arginine, fluoride-free) or fluoride (F: 1,100 ppm F/NaF) toothpastes. Eighty-three adults of different caries status were recruited and assigned to treatment with Arg or F for 12 wk. Caries lesions were diagnosed using International Caries Detection and Assessment System II, and plaque samples were collected from caries-free and carious tooth surfaces. Taxonomic profiles were obtained by HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing), and plaque metabolism was assessed by the levels of arginine catabolism via the arginine deiminase pathway (ADS), acidogenicity, and global metabolomics. Principal component analysis (PCA), partial least squares-discriminant analysis, analysis of variance, and random forest tests were used to distinguish metabolic profiles. Of the 509 active lesions diagnosed at baseline, 70 (14%) were inactive after 12 wk. Generalized linear model showed that enamel lesions were significantly more likely to become inactive compared to dentin lesions (P < 0.0001), but no difference was found when treatment with Arg was compared to F (P = 0.46). Arg significantly increased plaque ADS activity (P = 0.031) and plaque pH values after incubation with glucose (P = 0.001). F reduced plaque lactate production from endogenous sources (P = 0.02). PCA revealed differences between the metabolic profiles of plaque treated with Arg or F. Arg significantly affected the concentrations of 16 metabolites, including phenethylamine, agmatine, and glucosamine-6-phosphate (P < 0.05), while F affected the concentrations of 9 metabolites, including phenethylamine, N-methyl-glutamate, and agmatine (P < 0.05). The anticaries mechanisms of action of arginine and fluoride are distinct. Arginine metabolism promotes biofilm pH homeostasis, whereas fluoride is thought to enhance resistance of tooth minerals to low pH and reduce acid production by supragingival oral biofilms.

Bacterial factors of cariogenicity (literature review)

OBJECTIVE

Introduction: According to the 2003 WHO report, dental caries affects from 60% to 90% of school-age children and adults that makes it one of the most common diseases worldwide. The aim was to systematize data about the modern conception of plaque formation and role of microorganisms in its development.

PATIENTS AND METHODS

Materials and methods: Biblosemantic, 50 medical literature sources were systematically reviewed as the material for the research.

RESULTS

Review: According to Miller's theory, oral microorganisms can decompose dietary carbohydrates into acids, which in turn dissolve the calcium phosphates found in the enamel, causing it demineralisation Along with Streptococcus mutans, nowadays some other bacteria as Streptococcus sorbinus, Lactobacillus spp. and Actinomyces spp. have been well studied as caries contributors. However, the disease is related to plaque-mediated, because a much larger number of normal oral microflora representatives are involved in creating favourable preconditions for its development. There are a lot of original research papers about a role of bacteria in caries decay but compositions and characters of oral microflora are changing nowadays. Therefore, authors show the main cariogenic bacteria and their factors of pathogenicity which create special conditions for caries lesions. Modern concepts of dental plaque formation and pathogenesis of plaque-assosiative diseases are presented according to the new actual dental research. A lot of attention is paid to the biochemical properties of cariogenic bacteria and chemical process in biofilm. Role of acid and alkali production by oral bacteria in caries decay are shown in this article. Moreover, mechanisms of bacterial acid-fast and acid-tolerance are presented.

CONCLUSION

Conclusions: Analysis of literature demonstrates a lot of bacterial pathogenicity factors which play key role in caries development.

Inhibitory Effects of Nitrite on Acid Production in Dental Plaque in Children

PURPOSE

To assess the inhibitory effects of nitrite on plaque acidogenicity and its relationship with caries experience.

MATERIALS AND METHODS

Plaque (2 μl) was collected from 76 children (age 5.8 ± 2.6 years, dmft 2.9 ± 3.5, DMTF 0.6 ± 1.4) and mixed with nitrite solution (final concentration = 0.63 mM) or distilled water (control). The initial pH (pH-0) of each sample was measured using a portable pH meter. The samples were incubated for 10 min, then their pH (pH-1) was measured again. Next, glucose (final concentration = 0.67%) was added to the samples, which were then incubated for a further 10 min before their pH was assessed for a third time (pH-2).

RESULTS

The pH-0, pH-1, and pH-2 values of the control samples were 7.25 ± 0.16, 6.07 ± 0.44, and 5.11 ± 0.48, respectively, and those of the nitrite-treated samples were 7.26 ± 0.16, 6.37 ± 0.45, and 5.34 ± 0.48, respectively. The pH-1 and pH-2 values of the nitrite-treated samples were higher than those of the control samples (p < 0.005). Greater plaque acid production was associated with stronger inhibition of plaque acid production by nitrite (p < 0.005). No relationship was detected between the inhibition by nitrite and caries experience.

CONCLUSIONS

Nitrite inhibited both endogenous and exogenous plaque acid production. Nitrite inhibited acid production more markedly in plaque that exhibited greater acid production, suggesting that nitrite might be effective at preventing caries, as it contributes to pH homeostasis in plaque by countering excess acidification.

Amino acid composition and amino acid-metabolic network in supragingival plaque

Dental plaque metabolizes both carbohydrates and amino acids. The former can be degraded to acids mainly, while the latter can be degraded to various metabolites, including ammonia, acids and amines, and associated with acid-neutralization, oral malodor and tissue inflammation. However, amino acid metabolism in dental plaque is still unclear. This study aimed to elucidate what kinds of amino acids are available as metabolic substrates and how the amino acids are metabolized in supragingival plaque, by a metabolome analysis. Amino acids and the related metabolites in supragingival plaque were extracted and quantified comprehensively by CE-TOFMS. Plaque samples were also incubated with amino acids, and the amounts of ammonia and amino acid-related metabolites were measured. The concentration of glutamate was the highest in supragingival plaque, while the ammonia-production was the highest from glutamine. The obtained metabolome profile revealed that amino acids are degraded through various metabolic pathways, including deamination, decarboxylation and transamination and that these metabolic systems may link each other, as well as with carbohydrate metabolic pathways in dental plaque ecosystem. Moreover, glutamine and glutamate might be the main source of ammonia production, as well as arginine, and contribute to pH-homeostasis and counteraction to acid-induced demineralization in supragingival plaque.

Ca, Pi, and F in the Fluid of Biofilm Formed under Sucrose

Calcium (Ca), inorganic phosphorus (Pi), and fluoride (F) concentrations are low in the whole plaque biofilm formed under exposure to sucrose. It was hypothesized that this would be reflected in the biofilm fluid, where these low values should greatly influence the de/remineralization process. Dental biofilms were formed in situ over enamel blocks mounted in palatal appliances and exposed 8 times/day to distilled water, glucose+fructose, or sucrose solutions for 14 days. While Ca, Pi, and F concentrations in the whole biofilms were significantly lower in the glucose+fructose and sucrose groups, no effect on biofilm fluid was observed, even after a cariogenic challenge. An increase in whole biofilm mineral ions was observed 24 hrs after the carbohydrate treatments were suspended, but this effect was also not observed in the fluid. These results suggest that there is a homeostatic mechanism that maintains biofilm fluid mineral ion concentration, regardless of its total concentration in the whole biofilm.

[The Role of HMGN2 in the Development of Periodontitis Dental Plaque]

OBJECTIVES

To determine the role of high mobility group chromosomal protein N2 (HMGN2) in the development of periodontitis plaque biofilm.

METHODS

Saliva samples were collected before clinical interventions in patients with periodontitis (25 Mild periodontitis, 25 Moderate periodontitis and 25 Severe periodontitis) and healthy controls ( n=25).Following an estimation of dental plaque index, the level of HMGN2 in saliva was determined by enzyme-linked immunosorbent assay (ELISA).The recombinant human HMGN2 protein was purified and tested, its inhibitive effects on Porphyromonas gingivalis (P.g)growth and formation of P.g bioflim were detected by K-B antibacterial annulus and crystal violet staining, respectively.

RESULTS

The healthy controls had lower levels of HMGN2 in saliva than those with periodontitis, especially those with severe periodontitis ( P<0.01).The level of HMGN2 was negatively correlated with dental plaque index ( r=-0.363, P<0.05). HMGN2 inhibited the development of main periodontal bacteria biofilm ( P<0.05).

CONCLUSIONS

HMGN2 is involved in the development of periodontitis plaque biofilm and plays an important role in the development of periodontitis.

Chlorhexidine--pharmaco-biological activity and application

OBJECTIVES

Chlorhexidine (CHX) is one of the most widely used antiseptic, especially in dentistry. At low concentrations CHX is bacteriostatic and at high concentrations acts bactericidal causing cell death by cytolysis. In this study, we performed a systematic review of pharmaco-biological activity and application of CHX.

MATERIALS AND METHODS

Articles for inclusion in this review were retrieved from online databases PubMed/Medline. The selected papers were included in the present manuscript according to their relevance for the topic.

RESULTS

Totally 75 papers were enrolled in this research. CHX has strong biocidal activity against Gram-positive bacteria and weaker activity against Gram-negative bacteria. It is also active against yeasts, some dermatophytes and some lipophilic viruses. The most widely application CHX has found in dentistry and antisepsis. Numerous studies have confirmed the beneficial effects of CHX in reducing of plaque accumulation, in tooth caries, gingivitis, periodontitis and in alveolar osteitis. Unfortunately, CHX exhibits cytotoxic activity on human cells, can cause colorization of teeth and fillings, and its activity depends on the pH of the environment and the presence of organic substances.

CONCLUSIONS

CHX play a valuable role in the dentistry and antisepsis. However, it can also cause side effects, limiting its application time.

Influence of matrix and filler fraction on biofilm formation on the surface of experimental resin-based composites

The aim of this study was to investigate the impact of resin matrix chemistry and filler fraction on biofilm formation on the surface of experimental resin-based composites (RBCs). Specimens were prepared from eight experimental RBC formulations differing in resin matrix blend (BisGMA/TEGDMA in a 7:3 wt% ratio or UDMA/aliphatic dimethacrylate in a 1:1 wt% ratio) and filler fraction (no fillers; 65 wt% dental glass with an average diameter of 7 or 0.7 µm or 65 wt% SiO2 with an average diameter of 20 nm). Surface roughness, surface free energy, and chemical surface composition were determined; surface topography was visualized using atomic force microscopy. Biofilm formation was simulated under continuous flow conditions for a 48 h period using a monospecies Streptococcus mutans and a multispecies biofilm model. In the monospecies biofilm model, the impact of the filler fraction overruled the influence of the resin matrix, indicating lowest biofilm formation on RBCs with nano-scaled filler particles and those manufactured from the neat resin blends. The multispecies model suggested a more pronounced effect of the resin matrix blend, as significantly higher biofilm formation was identified on RBCs with a UDMA/dimethacrylate matrix blend than on those including a BisGMA/TEGDMA matrix blend but analogous filler fractions. Although significant differences in surface properties between the various materials were identified, correlations between the surface properties and biofilm formation were poor, which highlights the relevance of surface topography and chemistry. These results may help to tailor novel RBC formulations which feature reduced biofilm formation on their surface.

A 12-week clinical study assessing the clinical effects on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride

PURPOSE

To evaluate the clinical effect on plaque metabolism of a dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride compared to a commercially available dentifrice containing 1,450 ppm fluoride in a silica base.

METHODS

A 12-week, parallel, randomized, double-blind study using 48 subjects was conducted at the Colgate-Palmolive Technology Center (Piscataway, NJ, USA). One group used a test dentifrice containing 1.5% arginine, an insoluble calcium compound and 1,450 ppm fluoride as sodium monofluorophosphate (MFP), and the other group used a commercial silica dentifrice with 1,450 ppm fluoride as sodium fluoride (NaF) as a control. Plaque metabolism analyses were conducted at baseline and after 2, 4, 6, 8, and 12 weeks of assigned product use. The plaque analyses included pH measurements before and after a sucrose rinse, ammonia production and lactic acid production.

RESULTS

Subjects using the test dentifrice had significantly higher plaque pH values before (P< or = 0.01) and after (P< or = 0.045) a sucrose challenge than those using the commercially available control dentifrice. Subjects using the test dentifrice also produced higher levels of ammonia and lower levels of lactic acid compared to subjects using the control dentifrice.

Review of casein phosphopeptides-amorphous calcium phosphate

Casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) is a bioactive agent with a base of milk products, which has been formulated from two parts: casein phosphopeptides (CPP) and amorphous calcium phosphate (ACP). CPP was produced from milk protein casein and has a remarkable ability to stabilize calcium phosphate in solution and to substantially increase the level of calcium phosphate in dental plaque. CPP-ACP buffers the free calcium and phosphate ion activities, thereby helping to maintain a state of supersaturation with respect to tooth enamel, reducing demineralisation and promoting remineralisation. The free calcium and phosphate ions move out of the CPP, enter the enamel rods and reform onto apatite crystals. Laboratory, animal and human studies have shown that CPP-ACP inhibits cariogenic activity. CPP-ACP is useful in the treatment of white spot lesions, hypomineralised enamel, mild fluorosis, tooth sensitivity and erosion, and prevents plaque accumulation around brackets and other orthodontic appliances. CPP-ACP also facilitates a normal post-eruptive maturation process and is ideal for protecting primary teeth at a time when oral care is difficult. CPP-ACP has commercial potential as an additive to foods, soft drinks and chewing gum, as well as additive to toothpastes and mouthwashes to control dental caries.

Purification and properties of an α-(1 → 3)-glucanase (EC 3.2.1.84) from Trichoderma harzianum and its use for reduction of artificial dental plaque accumulation

Extracellular α-(1 → 3)-glucanase (mutanase, EC 3.2.1.84) produced by Trichoderma harzianum CCM F-340 was purified to homogeneity by ultrafiltration followed by ion exchange and hydrophobic interaction chromatography, and final chromatofocusing. The enzyme was recovered with an 18.4-fold increase in specific activity and a yield of 4.3%. Some properties of the α-(1 → 3)-glucanase were investigated. The molecular mass of the enzyme is 67 kDa, as estimated by SDS/PAGE, its isoelectric point 7.1, and the carbohydrate content 3%. The pH and temperature optima are 5.5 and 45°C, respectively. The enzyme is stable over a pH range of 4.5-6.0 and up to 45°C for 1 h. The Km and Vmax under standard assay conditions are 0.73 mg/ml and 11.39 x 10(-2) µmol/min/mg protein, respectively. The enzyme activity is stimulated by addition of Mg(2+) and Na(+), and significantly inhibited by Hg(2+). The α-(1 → 3)-glucanase preparation preferentially catalyzed the hydrolysis of various streptococcal mutans and fungal α-(1 → 3)-glucans. The 20-residue N-terminal sequence of the enzyme is identical with those of other α-(1 → 3)-glucanases from the genus Trichoderma, and highly similar to those from other fungi. The purified α-(1 → 3)-glucanase was effective in preventing artificial dental plaque formation. The easy purification from fermentation broth and high stability, and the effective inhibition of oral biofilm accumulation make this α-(1 → 3)-glucanase highly useful for industrial and medical application.

In vivo effects of a new dentifrice containing 1.5% arginine and 1450 ppm fluoride on plaque metabolism

OBJECTIVE

This paper presents the results of a clinical study assessing the in vivo effects on plaque metabolism of a new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride compared to a commercially available dentifrice containing 1450 ppm fluoride alone.

METHODS

A four-week, parallel, randomized, double-blind clinical study using 54 subjects was conducted at the New York University College of Dentistry Bluestone Center for Clinical Research. Two study groups used the following products for two weeks: 1) a dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride as sodium monofluorophosphate (MFP; test); and 2) a commercial silica dentifrice with 1450 ppm fluoride as sodium fluoride (NaF; control). In the following two-week period, all subjects used the control product. The effects of product use on plaque metabolism in vivo were assessed by conducting ex vivo analyses at baseline, after two weeks of assigned product use, and after two weeks of control product use. These plaque analyses comprised pH measurements before and after an in vivo sucrose rinse, and measurements of ammonia production and lactate production.

RESULTS

The study showed that subjects using the test dentifrice, containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride, had significantly higher plaque pH values before the sucrose challenge than those using the commercially available control dentifrice (p < or = 0.01). Plaque samples from subjects using the arginine-containing dentifrice also produced significantly higher levels of ammonia (p < or = 0.01). Subjects using the arginine-containing dentifrice also had a directionally higher plaque pH after the sucrose challenge, and their plaque samples produced a directionally lower level of lactate during the two-week treatment period compared to subjects using the control dentifrice. Following two weeks of subsequent use of the control product, there were no significant differences in plaque metabolism measures between groups.

CONCLUSION

A new dentifrice containing 1.5% arginine, an insoluble calcium compound, and 1450 ppm fluoride has been shown in this study to modulate plaque metabolism, increasing ammonia production and decreasing lactate production, thereby increasing plaque pH to help restore a pH-neutral environment.

In situ clinical effects of new dentifrices containing 1.5% arginine and fluoride on enamel de- and remineralization and plaque metabolism

OBJECTIVE

The primary objective of the three studies reported in this paper was to evaluate the effects of new dentifrices containing 1.5% arginine, an insoluble calcium compound, and fluoride for their ability to promote remineralization of demineralized enamel, and to prevent mineral loss from sound enamel specimens. A secondary objective was to determine the effects on plaque metabolism with respect to the conversion of arginine to ammonia and sucrose to lactic acid.

METHODS

In Study 1, an intraoral remineralization/demineralization clinical model was used to assess the ability to promote remineralization of enamel of two dentifrices containing 1.5% arginine and 1450 ppm fluoride, as sodium monofluorophosphate (MFP), relative to a positive control with dicalcium phosphate dihydrate (Dical) and 1450 ppm fluoride, and a negative control with Dical and 250 ppm fluoride. One of the arginine-containing dentifrices contained Dical, and the other contained calcium carbonate as the source of insoluble calcium. Microradiography and image analysis were used to measure mineral changes. The study used a double-blind crossover design with a two-week treatment period. Each treatment period was preceded by a one-week washout period. Each product was used twice a day for two weeks. In the two other studies, the ability of dentifrices containing 1.5% arginine and fluoride to prevent demineralization of sound enamel blocks was assessed using an intraoral demineralization/remineralization clinical model and a double-blind crossover design with a five-day treatment period. A one-week minimum washout period preceded each treatment phase. Microhardness was used to assess mineral changes. Cariogenic challenges were administered by dipping each intraoral retainer into a 10% sucrose solution four times per day. Each product was used twice per day during the treatment period. Plaque was harvested from the specimens to measure the ability of the plaque to convert arginine to ammonia (Studies 2 and 3) and sucrose to lactic acid (Study 3) at the end of each treatment period. In Study 2, a dentifrice containing 1.5% arginine, Dical, and 1450 ppm fluoride as MFP was compared to a matched positive control containing 1450 ppm fluoride and to a matched negative control containing 250 ppm fluoride. In Study 3, a dentifrice containing 1.5% arginine, calcium carbonate, and 1000 ppm fluoride as MFP was compared to a matched positive control containing 1000 ppm fluoride and to a matched negative control containing 0 ppm fluoride.

RESULTS

In Study 1, the percent mineral changes were +18.64, +16.77, +4.08, and -24.95 for the 1.5% arginine/Dical/1450 ppm fluoride, the 1.5% arginine/calcium carbonate/1450 ppm fluoride, the positive control, and negative control dentifrices, respectively. Study validation was successfully achieved by showing that the positive control was statistically significantly better that the negative control in promoting remineralization (p = 0.0001). The two arginine-containing test products were statistically significantly better than the positive control (p < 0.05). No significant difference was observed in efficacy between the two arginine-containing products, indicating that efficacy in promoting remineralization was independent of the choice of Dical or calcium carbonate as the source of insoluble calcium. In Study 2, the percent demineralization values were -8.50, +1.67, and +12.64 for the 1.5% arginine/Dical/1450 ppm fluoride, the positive control, and negative control dentifrices, respectively. Study validation was successfully achieved by showing that the positive control was statistically significantly better at preventing demineralization than the negative control (p < 0.0001). The arginine-containing dentifrice was shown to be statistically significantly better at preventing enamel demineralization than the positive control (p < 0.0001). Plaque metabolism measures for plaque exposed to the three treatments gave the following values for ammonia production after an arginine-sucrose challenge, expressed in nanomoles per milligram plaque: 162.7; 105.4; and 115.9 for the 1.5% arginine/Dical/1450 ppm fluoride, positive control, and negative control dentifrices, respectively. No statistically significant differences were observed between the three treatments, but the arginine-based dentifrice showed directionally higher ammonia production than both the positive and negative controls In Study 3, the percent demineralization values were +1.16, +4.96, and +15.34, for the 1.5% arginine/calcium carbonate/1 000 ppm fluoride, the positive control, and negative control dentifrices, respectively. Study validation was successfully achieved by showing that the positive control was statistically significantly better at preventing demineralization than the negative control (p < 0.0001). The arginine-containing dentifrice was shown to be statistically significantly better at preventing enamel demineralization than the positive control (p < 0.05). Plaque metabolism measures for plaque exposed to the three treatments gave the following values for ammonia production after an arginine-sucrose challenge, expressed in nanomoles per milligram plaque: 99.6; 56.2; and 42.2 for the 1.5% arginine/calcium carbonate/1000 ppm fluoride, the positive control, and negative control dentifrices, respectively. Plaque treated with the arginine- containing dentifrice produced significantly more ammonia than the positive and negative control dentifrices (p < 0.05). No significant difference in ammonia production was observed between the two controls. Lactic acid production after a sucrose challenge gave the following values, expressed as nanomoles per milligram plaque: 4.06; 5.12; and 4.64 for the 1.5% arginine/calcium carbonate/1000 ppm fluoride, the positive control, and negative control dentifrices, respectively. No significant difference was observed between the three treatments, but the arginine-based treatment showed directionally lower lactic acid production.

RESULTS

The results of these three studies show that dentifrices containing 1.5% arginine, an insoluble calcium compound, and fluoride have a significantly improved ability to promote remineralization and prevent demineralization of enamel relative to dentifrices containing the same level of fluoride alone. Two different sources of insoluble calcium were evaluated, Dical and calcium carbonate. Dentifrices with Dical and with calcium carbonate, each in combination with 1.5% arginine and fluoride, provided superior efficacy as compared to matched dentifrices with fluoride alone, and the two products demonstrated comparable efficacy in promoting remineralization. The results of these studies demonstrate that the addition of 1.5% arginine to Dical-and calcium carbonate-based fluoride dentifrices provides superior efficacy in preventing demineralization and promoting remineralization, and, further, indicate that he arginine-containing dentifrices enhance the ability of plaque to metabolize arginine to ammonia.

Fluoride toothpaste containing 1.5% arginine and insoluble calcium as a new standard of care in caries prevention

In spite of obvious achievements in prevention, caries remains a prevalent disease. Fluorides are effective by inhibiting enamel and dentin demineralization and enhancing remineralization, but have little or no influence on bacterial processes in dental plaque. Dental caries is a continuum of stages from reversible, early lesions to irreversible, pre-cavitated lesions and, ultimately, to cavities. Prevention should focus on strengthening protective and reducing pathological factors, and careful monitoring of the disease state. While fluoride and the mineral aspects of caries have been in focus for decades, new insights into the etiology of caries have generated novel concepts and approaches to its prevention and treatment. The observation that some plaque bacteria can produce alkali metabolites and, thus, raise pH or neutralize acid formed in plaque has long been known. Such pH rise factors are related to caries susceptibility. Nourishing the plaque with substrates that encourage alkali-producing reactions is a protective factor in the caries continuum. This article reviews the results of clinical studies with a novel toothpaste containing 1.5% arginine, an insoluble calcium compound, and fluoride which have demonstrated superior remineralization of white spot enamel lesions and rehardening of root surface lesions, favorable effects on the de-/remineralization balance, as well as superior cavity prevention efficacy compared to toothpaste with fluoride alone. Studies have also confirmed formation of ammonia and elevated pH levels in subjects using the arginine-containing toothpaste. This novel toothpaste effectively combines the established effects of fluoride on de- and remineralization with reduction of caries-inducing pathological factors resulting from plaque metabolism.

pH of tooth surface in healthy adolescents at rest and after a glucose rinse: effect of 72 hours of plaque accumulation

AIM

This study was performed to evaluate the effect of a glucose rinse and of plaque accumulation on pH of tooth surface in healthy adolescents with a device used in gastroenterology and never tested in the oral cavity.

MATERIALS AND METHODS

Values of pH were monitored in 12 adolescents using a portable device (pH-day 2® Menfis, bioMedica S.r.l., Bologna, Italy) with a disposable antimonium electrode kept in contact with the interproximal surface of the upper molars for 40 minutes respectively before and after a one-minute rinse with 10 ml of a 10% glucose solution. The same procedure was repeated in the same subjects after 72 hours of plaque accumulation.

RESULTS

The device tested resulted difficult to use on the tooth surface because of the size of the active part of the probe. The glucose rinse caused a statistically significant decrease of the mean pH, restrained in basal conditions (d = -0.16, p <0.05), clinically relevant after plaque accumulation (d = -1.24, p <0.05). Time in minutes of pH < 6 grew considerably only in case of combination of plaque accumulation and glucose rinse (d = 20.90, p <0.05). A Stephan's curve of drop and recover of the pH values was not recorded.

CONCLUSIONS

The continuous recording of pH of natural plaque present on the tooth could represent an alternative to other techniques found in literature. More studies are necessary to verify the suitability of this new device for the monitoring of pH in the oral cavity.

Effect of the presence of dental plaque on oral sugar clearance and salivary pH: an in vivo study

BACKGROUND

Fermentable carbohydrates and microorganisms in the plaque play a significant role in the pathogenesis of dental caries. Oral clearance of sugars and salivary pH is affected by the presence of plaque.

AIMS AND OBJECTIVES

This study was conducted to study the effect of the presence of plaque on the salivary clearance of sucrose and on salivary pH.

MATERIALS AND METHODS

The study design was of a randomized controlled parallel group clinical trial and included two groups: The control group and plaque group, as follows: Control group--subjects without plaque and plaque group--subjects with plaque. Salivary sucrose determination was done by using the anthrone technique. A digital pH meter estimated the salivary pH. The Student's t test and Mann-Whitney test was employed to compare the intergroup differences. Pearson's correlation coefficient was used for analysis.

RESULTS

The salivary sucrose clearance time was increased by presence of plaque.

CONCLUSION

The presence of plaque led to increased salivary sucrose concentrations and increased the salivary sucrose clearance time.

CLINICAL SIGNIFICANCE

The dental caries is the dynamic relationship among the dental plaque microbiota, dietary carbohydrates, saliva and cariogenic potential of the dental plaque. Caries occur preferentially in the dentition sites characterized by high exposure to carbohydrate and diminished salivary effect.

Effect of quaternary ammonium and silver nanoparticle-containing adhesives on dentin bond strength and dental plaque microcosm biofilms

OBJECTIVE

Antibacterial bonding agents are promising to hinder the residual and invading bacteria at the tooth-restoration interfaces. The objectives of this study were to develop an antibacterial bonding agent by incorporation of quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effect of QADM-NAg adhesive and primer on dentin bond strength and plaque microcosm biofilm response for the first time.

METHODS

Scotchbond Multi-Purpose adhesive and primer were used as control. Experimental adhesive and primer were made by adding QADM and NAg into control adhesive and primer. Human dentin shear bond strengths were measured (n = 10). A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, lactic acid production, and live/dead staining assay (n = 6).

RESULTS

Adding QADM and NAg into adhesive and primer did not compromise the dentin shear bond strength which ranged from 30 to 35MPa (p>0.1). Scanning electron microscopy (SEM) examinations revealed numerous resin tags, which were similar for the control and the QADM and NAg groups. Adding QADM or NAg markedly reduced the biofilm viability, compared to adhesive control. QADM and NAg together in the adhesive had a much stronger antibacterial effect than using each agent alone (p<0.05). Adding QADM and NAg in both adhesive and primer had the strongest antibacterial activity, reducing metabolic activity, CFU, and lactic acid by an order of magnitude, compared to control.

SIGNIFICANCE

Without compromising dentin bond strength and resin tag formation, the QADM and NAg containing adhesive and primer achieved strong antibacterial effects against microcosm biofilms for the first time. QADM-NAg adhesive and primer are promising to combat residual bacteria in tooth cavity and invading bacteria at the margins, thereby to inhibit secondary caries. QADM and NAg incorporation may have a wide applicability to other dental bonding systems.

Dental plaque microcosm biofilm behavior on calcium phosphate nanocomposite with quaternary ammonium

OBJECTIVES

Half of dental restorations fail in 10 years, with secondary caries as the main reason. Calcium phosphate composites could remineralize tooth lesions. The objectives of this study were to: (1) impart antibacterial activity to a composite with nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate the effect of quaternary ammonium dimethacrylate (QADM) on mechanical and dental plaque microcosm biofilm properties for the first time.

METHODS

The NACP and glass particles were filled into a dental resin that contained bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM. NACP nanocomposites containing 0%, 7%, 14%, and 17.5% of QADM by mass, respectively, were photo-cured. A commercial composite with no antibacterial activity was used as control. Mechanical properties were measured in three-point flexure. A human saliva microcosm model was used to grow biofilms on composites. Live/dead assay, metabolic activity, colony-forming unit (CFU) counts, and lactic acid production of biofilms on the composites were measured.

RESULTS

Increasing QADM mass fraction monotonically reduced the biofilm viability, CFU and lactic acid. Biofilms on NACP nanocomposite with 17.5% QADM had metabolic activity that was 30% that on a commercial composite control (p<0.05). Total microorganisms, total streptococci, and mutans streptococci CFU counts (mean ± sd; n = 6) on composite control was 6-fold those on NACP +17.5% QADM nanocomposite. Composite control had long strings of bacterial cells with normal short-rod shapes, while some cells on NACP-QADM nanocomposites disintegrated into pieces. Adding QADM to NACP did not decrease the composite strength and elastic modulus, which matched (p>0.1) those of a commercial composite without Ca-PO(4) or antibacterial activity.

SIGNIFICANCE

A dental plaque microcosm model was used to evaluate the novel NACP-QADM nanocomposite. The nanocomposite greatly reduced the biofilm viability, metabolic activity and lactic acid, while its mechanical properties matched those of a commercial composite. NACP-QADM nanocomposite with calcium phosphate fillers, good mechanical properties and a strong antibacterial activity may have potential for anti-biofilm and anti-caries restorations.

Changes of four proinflammatory proteins in whole saliva during experimental gingivitis

OBJECTIVE

To examine changes of four proinflammatory proteins in whole saliva in the early stage of plaque-induced experimental gingivitis.

METHODS

Eleven young male volunteers were recruited following the cessation of all oral hygiene measures for a period of 21 days. The levels of Interleukin-6 (IL-6), Interleukin-1ß (IL-1ß), calprotectin in saliva were determined with enzyme linked immunosorbent assay. The activity of elastase in saliva was examined.

RESULTS

IL-1ß, IL-6 and calprotectin in saliva increased gradually as plaque accumulated and peaked on the 14th and 21st day respectively. Moreover, the three proinflammatory proteins showed good correlations with clinical parameters, with IL-1ß correlating with clinical parameters more closely in particular. The activity of elastase in saliva elevated rapidly and peaked on the second day (P < 0.01). However, after the seventh day, elastase activity declined slowly continuously. The change of IL-6 and IL-1ß in saliva showed a similar tendency throughout the experiment, the correlation coefficient was r = 0.687 (P < 0.01), but there was no obvious correlation between calprotectin and elastase, even though both mainly come from neutrophils.

CONCLUSION

Our study demonstrated that IL-6, IL-1ß and calprotectin concentrations in saliva could reflect the degree of gingival inflammation. The longitudinal change of elastase activity in saliva during the experimental gingivitis period was quite different from that of other pro-inflammatory proteins; reasons for the decrease of elastase activity in the late gingivitis period need further study.

Oral findings and salivary parameters in children with celiac disease: a preliminary study

OBJECTIVE

The aim of this study was to investigate the prevalence of dental enamel defects, recurrent aphthous stomatitis (RAS) and caries experience and to measure salivary flow rate, buffer capacity, saliva and plaque pH and salivary cariogenic microflora in patients with celiac disease (CD) compared to healthy subjects.

SUBJECTS AND METHODS

Thirty-five patients, aged 6-19 years, with a diagnosis of CD and 35 healthy children of the same age participated in the study. Enamel defects were diagnosed and classified using Aine's classification. The patients with RAS and dental caries were recorded using WHO criteria. The parents were interviewed about various oral health-related factors. Saliva samples were collected to measure the stimulated salivary flow rate, buffer capacity and pH values of saliva and plaque. Salivary mutans streptococci and lactobacilli were counted.

RESULTS

The enamel defects and RAS prevalence were statistically higher (40 and 37.1%, respectively) in the CD group, and the prevalence of salivary mutans streptococci (48 and 14%) and lactobacilli (51 and 34%) colonization was statistically lower (p = 0.012, p = 0.010) in the CD group; the DMFS and dfs values were similar in both groups.

CONCLUSION

CD appeared to be associated with a significantly higher prevalence of developing enamel defects and RAS, but a lower prevalence of salivary mutans streptococci and lactobacilli colonization, and the diagnosis of these oral manifestations might be helpful for an early diagnosis of CD.

Zinc in the mouth, its interactions with dental enamel and possible effects on caries; a review of the literature

Zinc is an essential trace element. In the mouth, it is present naturally in plaque, saliva and enamel. Zinc is formulated into oral health products to control plaque, reduce malodour and inhibit calculus formation. It has good oral substantivity, and elevated concentrations can persist for many hours in plaque and saliva following delivery from mouthrinses and toothpastes. Although low concentrations of zinc can both reduce enamel demineralisation and modify remineralisation, during caries clinical trials, the addition of zinc to fluoride toothpastes has not affected their ability to reduce caries. Mechanistic studies may help explain this apparent contradiction. Zinc is readily desorbed from hydroxyapatite by calcium, which is plentiful in plaque and saliva. Where crystal-growth sites remain occupied by zinc despite this, they may simply be 'over-grown' by remineralisation initiated at unoccupied sites. Further, under certain conditions, low concentrations of zinc can enhance remineralisation of enamel lesions, by retarding lesion arrestment. Although this may help to explain the apparent lack of an overall zinc effect on caries, it seems unlikely that any negative effects would be countered exactly by positive effects. Further mechanistic studies, complementing well-designed in vitro and in situ caries studies, should lead to further understanding of the zinc-enamel interactions relevant to demineralisation and remineralisation.

Fluoride varnish: the top choice for professionally applied fluoride

Although various modes of delivery for professionally applied fluoride exist, one form has emerged that combines caries prevention efficacy with safety and versatility. The American Dental Association Council on Scientific Affairs recommends fluoride varnish as the only professionally applied fluoride for moderate to high risk patients of all age groups. In addition to demonstrating effectiveness equivalent to fluoride gels, fluoride varnish provides improved safety and acceptability. Furthermore, fluoride varnish has shown promise in preventing dental caries in special groups, such as orthodontic patients and the elderly.

Application of adenosine triphosphate-driven bioluminescence for quantification of plaque bacteria and assessment of oral hygiene in children

PURPOSE

Dentistry has undergone a shift in caries management toward prevention and improved oral hygiene and diagnosis. Caries prevention now represents one of the most important aspects of modern dental practice. The purpose of this cross-sectional study was to demonstrate the use of adenosine triphosphate- (ATP-) driven bioluminescence as an innovative tool for the rapid chairside enumeration of oral bacteria (including plague streptococci) and assessment of oral hygiene and caries risk.

METHODS

Thirty-three pediatric patients (7- to 12-year-old males and females) were examined, and plague specimens, in addition to stimulated saliva, were collected from representative teeth within each quadrant. Oral specimens (n=150 specimens) were assessed by plating on enriched and selective agars, to enumerate total bacteria and streptococci, and subjected to adenosine triphosphate- (ATP-) driven bioluminescence determinations using a luciferase-based assay system.

RESULTS

Statistical correlations, linking ATP values to numbers of total bacteria, oral streptococci and mutans streptococci, yielded highly significant r values of 0.854, 0.840, and 0.796, respectively

CONCLUSIONS

Our clinical data is consistent with the hypothesis that ATP measurements have a strong statistical association with bacterial number in plague and saliva specimens, including numbers for oral streptococci, and may be used as a potential assessment tool for oral hygiene and caries risk in children.

Effect of xylitol and sorbitol on plaque acidogenesis

OBJECTIVE

To evaluate the in vivo potential of xylitol to reduce plaque acidogenicity in comparison to sorbitol.

METHOD AND MATERIALS

After completing a questionnaire on general health, smoking, diet, and oral hygiene habits, 61 dentate adults refrained from oral hygiene for 3 days before the clinical baseline examination, which included decayed, missing, and filled teeth (DMFT) index, mutans streptococci and lactobacilli counts, and plaque acidogenicity (cH) index after a sucrose rinse. Then the participants were randomly allocated to consume either sorbitol or xylitol lozenges (5 pieces/day, 2 g each) for 4 weeks and were asked to refrain from oral hygiene for the 3 days prior to the final examination (cH, area < pH 7, bacterial counts).

RESULTS

The variation of acidogenicity in different individuals was considerable at baseline (range: 0.2 to 446.6 min micromol/L) with a mean value of 37.9 +/- 58.9 min micromol/L for the sorbitol group and 60.6 +/- 87.6 min micromol/L for the xylitol group. At the end of the study, the reduction in the xylitol group (42.9 +/- 80.6 min micromol/L) was statistically significantly higher than in the sorbitol group (6.0 +/- 69.4 min micromol/L, P = .034), which was also confirmed in an additional analysis excluding 2 participants with extreme values (reduction for xylitol: 29.5 +/- 36.9 min micromol/L; sorbitol: 1.7 +/- 57.0 min micromol/L; P = .019). Statistically significant differences were also found for the area below pH 7 (reduction for xylitol: 10.8 min pH; sorbitol, 0.2 min pH; P = .0025).

CONCLUSION

The regular consumption of xylitol lozenges modifies dental plaque, resulting in a marked reduction in the plaque acidogenicity, which could not be detected using sorbitol lozenges. Therefore, xylitol could have an additional benefit in caries prevention.

Dental plaque as a biofilm: the significance of pH in health and caries

Dental plaque is an example of a biofilm; its presence is natural and it supports the host in its defense against invading microbes. In health, the microbial composition of dental plaque is diverse and remains relatively stable over time (microbial homeostasis). The predominant microorganisms prefer host molecules (eg, salivary mucins) and a neutral pH for growth. Under certain circumstances, this microbial homeostasis can break down and diseases such as caries can occur. In dental caries, there is a shift toward increased proportions of acid-producing and acid-tolerating species, such as mutans streptococci and Lactobacilli, although other species with relevant traits can participate in demineralization. Strategies to control caries include effective oral hygiene practices to reduce biofilm development, and adoption of a low-sugar diet to restrict periods of acidic challenge to teeth. These conventional approaches also should be augmented by interference with the factors that enable the cariogenic bacteria to outcompete the organisms associated with health. Evidence suggests that regular conditions of low pH in plaque select for mutans streptococci and Lactobacilli. Therefore, the suppression of sugar catabolism and acid production by the use of metabolic inhibitors in oral care products, the consumption of nonfermentable sweeteners in snacks, the stimulation of saliva flow, and/or other strategies that maintain supragingival plaque at a pH around neutrality will assist in the maintenance of microbial homeostasis in plaque.

Fluoride and casein phosphopeptide-amorphous calcium phosphate

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) slows the progression of caries and remineralizes enamel subsurface lesions. The aim of this study was to determine the ability of CPP-ACP to increase the incorporation of fluoride into plaque and to promote enamel remineralization in situ. Randomized, double-blind, cross-over studies involved mouthrinses and dentifrices containing CPP-ACP and fluoride. The mouthrinses were used for 60 sec, three times/day for 5 days, and supragingival plaque was collected and analyzed for F. The dentifrices were rinsed as a water slurry for 60 sec four times/day for 14 days in an in situ model. The addition of 2% CPP-ACP to the 450-ppm-F mouthrinse significantly increased the incorporation of fluoride into plaque. The dentifrice containing 2% CPP-ACP produced a level of remineralization similar to that achieved with a dentifrice containing 2800 ppm F. The dentifrice containing 2% CPP-ACP plus 1100 ppm F was superior to all other formulations.

Chairside evaluation of pH-lowering activity and lactic acid production of dental plaque: correlation with caries experience and incidence in preschool children

OBJECTIVES

Because caries activity may be related to dental plaque acidogenicity, a method was developed for chairside evaluation of pH-lowering activity and lactic acid production by dental plaque. Moreover, this study examined the association of these 2 factors with caries experience on oral examination and with caries activity by following caries incidence for 4 years in a group of preschool children.

METHOD AND MATERIALS

A dental plaque sample (2.4 microL) was collected from sound buccal surfaces of maxillary primary second molars using a spoon excavator and placed onto the sensor area of a portable pH meter. Sucrose (30 microL, 228 mmol) was mixed with the plaque sample, and pH changes were monitored for 10 minutes. After pH determination, lactic acid concentration in the plaque-sucrose mixture was measured using a portable lactate meter.

RESULTS

Caries experience of subjects correlated with minimum pH (at 10 minutes after sucrose addition) ( r = -0.53, P < .001) and lactic acid production ( r = 0.38, P < .001). In addition, increments of both primary tooth caries (Delta dft) and permanent tooth caries (Delta DFT) for 4 years correlated with minimum pH ( r = -0.47, P < .005 and r = -0.38, P < .05, respectively). Setting cutoff values of pH and lactic acid concentration at 5.0 and 7.0 mmol/L for DELTA dft allows screening for caries-susceptible subjects (sensitivity = 0.950 and 0.800, specificity = 0.391 and 0.783, respectively).

CONCLUSION

Plaque in caries-susceptible preschool children displays greater pH-lowering activity and lactic acid production. This method can be applied as a chairside screening test for caries activity and susceptibility for preschool children in dental clinics.

Inflammatory mediator release following bone grafting in humans: a pilot study

AIM

The aim of this pilot study was to track markers of periodontal inflammation and bone resorption associated with decalcified freeze-dried bone allografts.

MATERIAL AND METHODS

Eleven subjects completed standardized treatment of intrabony defects > or =3 mm with allografts. Gingival crevicular fluid was collected from the defect site and an adjacent interproximal site within the surgical field at baseline, 2, 4, and 8 weeks post-operatively, and analysed for biochemical markers of inflammation/bone resorption. Probing depth, recession, bleeding on probing, plaque, and 6-month radiographic bone height change were measured.

RESULTS

Both prostaglandin E(2) (p=0.007) and bone-specific type 1 collagen (p=0.01) increased in crevicular fluid after 2 weeks in the bone graft sites. Matrix metalloproteinase-9 levels remained constant over time. There were positive correlations between prostaglandin levels during the first 8 weeks and bone height change over 6 months.

CONCLUSIONS

Periodontal bone grafts stimulate an inflammatory response during the first 2 weeks post-operatively, and the potential negative effects of inhibiting prostaglandins post-operatively should be investigated further.

Plaque formation and lactic acid production after the use of amine fluoride/stannous fluoride mouthrinse

The aim of this study was to determine the effects of 3 wk of daily rinsing with amine fluoride/stannous fluoride (AmF/SnF(2)) mouthrinse on plaque formation at buccal and interproximal sites, and on the acid production in plaque, in a randomized clinical trial with 30 participants. The amount of plaque was scored according to Turesky's modification of the Quigley and Hein index. Plaque samples were collected, before and after sucrose rinsing, from the buccal and interproximal surfaces of upper (pre)molars at two baseline visits and on days 2 and 7 after the discontinuation of 3 wk of daily rinsing. Metabolic acid ions were determined by capillary electrophoresis. The results at baseline showed higher lactic acid concentrations in resting interproximal plaque than in buccal plaque, and a higher acid production in response to sucrose challenge in buccal plaque than in interproximal plaque. After 3 wk of use of the AmF/SnF(2) mouthrinse, no significant differences in plaque scores were observed, and the alleged reduction in acidogenicity of dental plaque was not significant on the second day after the last mouthrinse. We conclude that 3 wk of use of AmF/SnF(2) rinse once daily does not result in a reduction of plaque formation or in a reduction of sucrose metabolism in buccal and interproximal plaque after discontinuing the rinse.

[Human salivary mucins--their role and meaning]

PURPOSE

The aim of this work is to present the current views concerning the role and the meaning of human salivary mucins.

MATERIAL AND METHODS

A review of works dealing with basic information regarding mucins, their role and use in the diagnosis of some of the systematic diseases.

RESULTS

Human salivary mucins are glycoproteins secreted through epithelial cells of the salivary glands of the oral cavity. Those molecules should not only be linked with the forming of dental plaque or their function of lining the oral cavity with a protective layer. The so far carried out investigations show that apart from lactoferrin, amylases or peroxidases those salivary proteins can be used in the diagnosis of many disease entities.

Fluoride concentrations in dental plaque and saliva after the use of a fluoride dentifrice preceded by a calcium lactate rinse

Plaque fluoride concentrations ([F]) are directly related to plaque calcium concentrations [Ca]. Attempts to increase plaque F uptake from dentifrices or rinses have used methods designed to increase plaque [Ca] but with inconsistent results. This double-blind, double-crossover study tested the effect of a 150 mM calcium lactate rinse used prior to brushing with placebo or fluoridated dentifrices (1030 p.p.m. as NaF) on plaque and salivary [F] and [Ca]. Sixteen children (8-10 yr of age) were randomly assigned to four different groups according to the four treatments (placebo dentifrice or fluoridated dentifrice preceded by calcium lactate or deionized water prerinses). Plaque and saliva were collected 1 and 12 h after brushing on day 7 after starting to use the dentifrices. F was determined using the electrode and Ca was determined using atomic absorption spectrometry. Plaque and salivary [Ca] were not significantly increased after use of the calcium lactate prerinse, except for plaque [Ca] 1 h after the use of the placebo dentifrice. A significant increase in salivary [F] was associated with the calcium lactate prerinse only at 1 h after the use of the fluoridated dentifrice. The the calcium lactate prerinse did not significantly affect plaque [F] under any condition.

The role of sucrose in cariogenic dental biofilm formation--new insight

Dental caries is a biofilm-dependent oral disease, and fermentable dietary carbohydrates are the key environmental factors involved in its initiation and development. However, among the carbohydrates, sucrose is considered the most cariogenic, because, in addition to being fermented by oral bacteria, it is a substrate for the synthesis of extracellular (EPS) and intracellular (IPS) polysaccharides. Therefore, while the low pH environment triggers the shift of the resident plaque microflora to a more cariogenic one, EPS promote changes in the composition of the biofilms' matrix. Furthermore, it has recently been shown that the biofilm formed in the presence of sucrose presents low concentrations of Ca, P(i), and F, which are critical ions involved in de- and remineralization of enamel and dentin in the oral environment. Thus, the aim of this review is to explore the broad role of sucrose in the cariogenicity of biofilms, and to present a new insight into its influence on the pathogenesis of dental caries.

In vitro anti-cariogenic activity of dichloromethane fraction from Rheum undulatum L. root

This study aimed to evaluate in vitro effects of Rheum undulatum L. root on the development of dental caries, especially its effects on viability, dental plaque formation, and glycolytic acid production of Streptococcus mutans and Streptococcus sobrinus. Methanol extract of Rheum undulatum L. root and its fractions were prepared and tested. Among the test extract and fractions, dichloromethane fraction (DF) showed the most active antibacterial activity (inhibition zone: 13-17 mm) against S. mutans and S. sobrinus in a disc diffusion method. Minimal inhibitory concentrations (MICs) of DF against these bacteria ranged from 0.25 to 0.5 mg/mL. Furthermore, DF significantly inhibited the caries-inducing factors of these bacteria. At sub-MIC levels, DF inhibited in vitro dental plaque formation by S. mutans and S. sobrinus (IC50= 0.079 and 0.142 mg/mL, respectively), which was caused, in part, by the inhibitory effect on the activity of glucosyltransferases. A significant reduction of glycolytic acid production was found at the concentration as low as 0.032 mg/mL for S. mutans and 0.063 mg/mL for S. sobrinus. The possible bioactive compounds that are inducing in vitro anti-cariogenic activity of DF are unknown. Based on the preliminary phytochemical analysis, the activity of DF may be related to the presence of anthraquinones, cardiac glycosides, coumarines, sterols/terpenes, and phenolics. These results indicate that DF is probably useful for the control of dental plaque formation and subsequent dental caries development.

Effect of iron on bovine enamel and on the composition of the dental biofilm formed “in situ”

OBJECTIVES

This study investigated in situ the effect of iron (Fe) on the reduction of demineralization of bovine enamel, as well as on the composition of dental biofilm.

DESIGN AND METHODS

Twelve volunteers were included in this blind crossover study, which was conducted in two stages of 14 days each. For each stage, the volunteers received palatal appliances containing four blocks of bovine enamel (4 mm x4 mm x 2.5 mm). Six volunteers dripped a solution of 15 mmol L(-1) ferrous sulphate onto the fragments and the remaining six dripped deionized water (eight times per day). After five minutes, a fresh 20% (w/v) sucrose solution was dripped onto all enamel blocks. During the experimental period the volunteers brushed their teeth with non-fluoridated dentifrice. After each stage, the percentage of surface microhardness change (%SMHC) and area of mineral loss (DeltaZ) were determined on enamel and the dental biofilm formed on the blocks was collected and analysed for F, P, Ca, Fe and alkali-soluble carbohydrates. The concentrations of F, Ca and Fe in enamel were also analysed after acid biopsies.

RESULTS

There was a statistically significant increase in the P and Fe concentrations in the biofilms treated with ferrous sulphate (p<0.05), which was not observed for F, Ca and alkali-soluble carbohydrates. The group treated with ferrous sulphate had significantly lower %SMHC and DeltaZ when compared to control (p<0.05).

CONCLUSIONS

These results showed that ferrous sulphate reduced the demineralization of enamel blocks and altered the ionic composition of the dental biofilm formed in situ.

Effects of Various Rinsing Protocols after the Use of Amine Fluoride/Stannous Fluoride Toothpaste on the Acid Production of Dental Plaque and Tongue Flora

The aim of this clinical study was to evaluate the effect of various rinsing protocols on oral acid production 6 h after tooth brushing with an amine fluoride/stannous fluoride (AmF/SnF2) toothpaste. After a 14-day period of using F-free toothpaste, 30 participants followed three experimental protocols each, followed by F-free washout periods in a randomized crossover trial. They used AmF/SnF2 toothpaste twice daily for 1 week, and after brushing, they either rinsed with tap water, omitted the post-brush rinse, or rinsed with an AmF/SnF2 mouthwash. In the F-free washout periods, the participants brushed their teeth without further instructions. Six hours after the last brushing (+/-rinsing) of each period, subjects rinsed with 10 ml 10% sucrose solution for 2 min. A tongue film sample and a buccal plaque sample were taken 4 and 8 min after the sucrose challenge, respectively. Metabolic acid ions were determined by capillary electrophoresis. The results show that (1) omitting the post-brush water rinse did not reduce the production of lactic, acetic or minor acids in plaque, nor on the tongue, and that (2) the additional use of AmF/SnF2 mouthwash after brushing reduced the acid production in plaque and tongue samples for at least 6 h. The distributions of acids produced in the plaque or tongue samples were not statistically different between experimental periods. It is concluded that an increase in the antimetabolic effect of AmF/SnF2 toothpaste in between two daily brushing exercises is not achieved by omitting the post-brush water rinse. The additional use of AmF/SnF2 mouthwash after brushing is effective in reducing the acid metabolism in dental plaque and tongue flora.

The complex oral microflora of high-risk individuals and groups and its role in the caries process

The involvement of the oral biofilm in the caries process requires re-evaluation. The essential role of mutans streptococci (Streptococcus mutans and Streptococcus sobrinus) in the caries process is not proven. Acid production by dental plaque is not dependent upon the presence of mutans streptococci; caries occurs in the absence of these species and their presence does not necessarily indicate caries activity. Other oral bacteria, non-mutans streptococci, Actinomyces spp. and Bifidobacterium spp., are acidogenic and aciduric. They outnumber mutans streptococci in dental plaque, and there are data which support a role for these bacteria in the initiation and progression of caries. Molecular studies demonstrate the great diversity and complexity of the flora associated with caries. Many taxa identified have not been cultured and the role of these taxa is not known. We have, in mutans streptococci, good markers of disease but not necessarily the aetiological agents of the disease. Considerably more research is required to investigate the transition of tooth surfaces from being intact and sound to the white spot lesion stage. A combination of conventional and molecular approaches are required to elucidate the involvement of an individual taxon and of microbial populations with particular traits in the caries process.

Penetration of fluoride into natural plaque biofilms

Caries occurs at inaccessible stagnation sites where plaque removal is difficult. Here, the penetration through plaque of protective components, such as fluoride, is likely to be crucial in caries inhibition. We hypothesized that topically applied fluoride would readily penetrate such plaque deposits. In this study, plaque biofilms generated in vivo on natural enamel surfaces were exposed to NaF (1000 ppm F-) for 30 or 120 sec (equivalent to toothbrushing) or for 30 min. Biofilms were then sectioned throughout their depth, and the fluoride content of each section was determined with the use of a fluoride electrode. Exposure to NaF for 30 or 120 sec increased plaque fluoride concentrations near the saliva interface, while concentrations near the enamel surface remained low. Fluoride penetration increased with duration of NaF exposure. Removal of exogenous fluoride resulted in fluoride loss and redistribution. Penetration of fluoride into plaque biofilms during brief topical exposure is restricted, which may limit anti-caries efficacy.

A role of salivary carbonic anhydrase VI in dental plaque

OBJECTIVE

Carbonic anhydrase (CA) VI is a unique secreted isozyme of CA, which catalyzes the reversible reaction CO2 +H2O<-->H+ +HCO3-. CA VI has been thought to provide a greater buffering capacity to fluids into which it is secreted. This study was performed to confirm this in saliva.

DESIGN

Nine healthy subjects participated in the study. The pH of the dental plaque from each subject was monitored after a mouth rinse with 10% sucrose with or without 10(-5)M acetazolamide, a specific inhibitor of CA. Also CA was examined in plaque by enzyme histochemistry, immunohistochemistry and Western blot analysis.

RESULTS

Though sucrose and sucrose plus inhibitor yielded Stephan curves with a similar temporal pattern, the pH values of the latter were significantly lower than those of the former. Plaque exhibited CA activity by enzyme histochemistry. Immunohistochemistry and Western analysis demonstrated that the activity was due to CA VI but not to CA I or CA II.

CONCLUSIONS

The results indicate that CA VI in saliva penetrates plaque and facilitates acid neutralization by salivary bicarbonate. Therefore, CA VI may be considered an anti-caries protein in saliva.

Preparation of sodium fluoride-loaded gelatin microspheres, characterization and cariostatic studies

Sodium fluoride-loaded gelatin microspheres (NaF-GMS) were prepared using double-phase emulsified condensation polymerization. The average diameter of microspheres was (11.33+/-5.56) microm. The drug content and encapsulation efficiency were 8.80% and 76.73%, respectively. The fluoride releasing profiles of NaF-GMS in physiological saline and artificial saliva (pH 4.5, pH 6.8) showed that NaF-GMS had a sustained-release property and fluoride release rate was increased in pH 4.5 artificial saliva. Experiments conducted in rabbits' oral cavity using NaF-GMS and NaF solution as control revealed NaF-GMS could maintain oral fluoride retention longer than NaF solution. Cariostatic abilities of NaF-GMS including demineralization prohibition in vitro, fluoride deposition in artificial dental plaque and the ability of targeting to cariogenic bacteria were investigated in artificial dental plaque. The results indicated NaF-GMS with lower fluoride concentrations could achieve equivalent cariostatic effect to the concentrated NaF solution, at the same time, could prolong fluoride retention in dental plaque. Microscopic observation showed that NaF-GMS carrying fusion protein of glucan-binding domain could adhere more bacteria than NaF-GMS and this might indicate the possibility of targeting to cariogenic bacteria when NaF-GMS were properly modified.

Clinical trial of a plant-derived antibody on recolonization of mutans streptococci

OBJECTIVE

This double-blinded, placebo-controlled clinical trial tested the safety and efficacy of a topical secretory IgA antibody manufactured in tobacco plants (plantibody) in preventing recolonization of mutans streptococci (MS) in human plaque as measured by whole stimulated saliva samples.

METHODS

Following a 9-day antimicrobial treatment with chlorhexidine (CHX), 56 eligible adults (enrollment salivary MS > or = 10(4) CFU/ml; no current caries) were randomized equally to a group receiving 0, 2, 4, or 6 topical applications of plantibody followed by 6, 4, 2, or 0 applications of placebo, respectively, over a 3-week period.

RESULTS

Among the 54 subjects who completed the trial, the CHX regimen eliminated salivary MS in 69%. After 6 months, there were no significant differences in MS levels by number of applications, relative to placebo (p > 0.43). No adverse effects were observed.

CONCLUSION

Plantibody is safe but not effective at the frequency, concentration, and number of applications used in this study.

Effect of an Essential Oil Mouthrinse, with and without Fluoride, on Plaque Metabolic Acid Production and pH after a Sucrose Challenge

This clinical study evaluated the effect of rinsing with an essential oil-containing antiseptic mouthrinse, with or without 100 mg/kg fluoride ion, on the plaque metabolic acid production and plaque pH response after a sucrose challenge. This observer-blind, randomized study used a three-way crossover design. Twenty-four subjects rinsed with 20 ml of one of the following rinses: (1) essential oil (EO) mouthrinse, (2) essential oil mouthrinse plus 100 mg/kg fluoride, or (3) negative control, for 30 s, twice daily for 16 days. On day 17, 1 h after the last mouthrinse, subjects rinsed with 20 ml of mass fraction 10% sucrose solution for 1 min. Seven minutes after the sucrose challenge, supragingival plaque was collected from molar and premolar teeth. Plaque pH and metabolic acid ions were analyzed using a micro pH electrode and capillary electrophoresis, respectively. The results showed that after EO mouthrinse dental plaque produced 36% less lactate, 36% less acetate and 44% less propionate than after the negative control rinse. The dental plaque also exhibited a pH 0.42 unit higher after EO rinse than after the negative control rinse. These results were not affected by the addition of 100 mg/kg fluoride to the EO mouthrinse. From these results we concluded that this EO antiseptic mouthrinse, with or without fluoride ion, is effective in reduction of plaque acidogenicity after a sucrose challenge.

Effects of mouthrinses with triclosan, zinc ions, copolymer, and sodium lauryl sulphate combined with fluoride on acid formation by dental plaque in vivo

Bacteriological tests demonstrated a slight synergistic effect of triclosan and sodium lauryl sulphate (SLS) on the growth of Streptococcus mutans NCTC 10449 and Streptococcus sanguis ATCC 10556 in vitro. A single mouthrinse with SLS (17.4 mM) or SLS plus triclosan (3.5 mM) significantly decreased the number of salivary mutans streptococci in a group of 12 subjects up to 90 min after rinsing. The effect on plaque pH of a mouthrinse with either 12.0 mM NaF, NaF plus 10.0 mM zinc acetate, NaF plus 17.4 mM SLS, or NaF plus SLS plus 3.5 mM triclosan with or without the addition of zinc ions or 0.65% w/v of a polyvinylmethyl ether/maleic acid copolymer was investigated. The plaque pH responses to a 10% w/v sucrose mouthrinse were measured in 2-day-old plaque with microtouch pH electrodes in six groups of 10 subjects 90 min after a single mouthrinse with test solution. There was no significant difference in plaque pH between the various mouthrinses. In conclusion, triclosan enhanced the growth-inhibitory activity of SLS against oral streptococci in vitro but not against salivary mutans streptococci in vivo. Neither triclosan incorporated into a mouthrinse containing SLS plus fluoride, nor the addition of zinc ions or copolymer affected acid formation by dental plaque in vivo.

Evaluation of the dental plaque pH recovery effect of a xylitol lozenge on patients with fixed orthodontic appliances

The purpose of this study was to evaluate the influence of a xylitol lozenge on the dental plaque pH profile of fixed orthodontic patients. Twelve volunteers participated in this study. Before the measurement of plaque pH, subjects were asked to refrain from brushing their teeth for 48 hours and from eating and drinking for two hours. The subjects' baseline dental plaque pH was recorded using the touch technique. It was followed by a one-minute rinse with 15 ml of a 10% solution of sucrose, and subsequent plaque pH measurements were carried out during the next one hour. Xylitol lozenges were taken five times a day during a 14-day period. The variables of resting-plaque pH, minimum-plaque pH (MP pH), time required to reach MP pH (TMP), last-plaque (LP) pH at the end of one hour, cH area (CH), and pH at each test time were calculated for each pH test of the subjects. The paired sample t-test was used for statistical comparison. The mean MP pH values increased from 4.81 to 5.09 in the experimental measurement (P < .05). The mean TMP was not affected by the use of xylitol (P > .05). Although the LP pH showed an increase during the experimental period, the difference between control and experimental periods was not statistically significant (P > .05). The CH of the experimental period was significantly less than that of the control period (P < .05). As a result, the use of a xylitol lozenge after a sucrose challenge can be an advisable practice for fixed orthodontic patients to prevent future dental caries.

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.

How ‘Clean’ Must a Cavity Be before Restoration?

The metabolic activity in dental plaque, the biofilm at the tooth surface, is the driving force behind any loss of mineral from the tooth or cavity surface. The symptoms of the process (the lesion) reflect this activity and can be modified by altering the biofilm, most conveniently by disturbing it by brushing with a fluoride-containing toothpaste. The role of operative dentistry in caries management is to restore the integrity of the tooth surface so that the patient can clean. Thus, the question, 'how clean must a cavity be before restoration?' may be irrelevant. There is little evidence that infected dentine must be removed prior to sealing the tooth. Leaving infected dentine does not seem to result in caries progression, pulpitis or pulp death. However, some of the bacteria survive. What is their fate and if they are not damaging, why is this?

Sulphur by-product: the relationship between volatile sulphur compounds and dental plaque-induced gingivitis

The purpose of this study was to evaluate the relationship between volatile sulphur compounds (VSC) and gingival health status, and to monitor the changes in VSC in early dental plaque-induced gingivitis. Using an experimental gingivitis model, twelve subjects between 19 and 28 years old, with a healthy gingival status, refrained from brushing and flossing one randomly selected half of the mandibular arch for two weeks. At baseline and during six subsequent appointments, gingival inflammation (GI), bleeding on probing (BOP), and sulfide levels (SUL) were measured using the Gingival Index and the Diamond Probe/Perio 2000 System. The Spearman correlation was used to compare the relationships between SUL, GI, and BOP on the brushing (B) and non-brushing (NB) sides. Data on the NB side revealed a stronger correlation than on the B side. Wilcoxon rank sum was used to evaluate the differences between mean SUL, GI, and BOP scores on the B and NB sides over time. Results indicate that SUL were the first periodontal parameter to show a significant difference between sides. SUL were significantly higher on the NB side at 4 of the 6 data collection intervals; therefore, SUL may be associated with the initiation and progression of early plaque-induced gingivitis.