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Human milk oligosaccharides, such as 2′-fucosyllactose (2′-FL), and galacto-oligosaccharides (GOS), a prebiotic carbohydrate mixture, are being increasingly added to infant formulas, necessitating the understanding of their impact on the oral microbiota. Here, for the first time, the effects of 2′-FL and GOS on the planktonic growth and adhesion characteristics of the caries-associated oral pathogen Streptococcus mutans were assessed, and the results were compared against the effects of xylitol, lactose and glucose. There were differences in S. mutans growth between 2′-FL and GOS. None of the three S. mutans strains grew with 2′-FL, while they all grew with GOS as well as lactose and glucose. Xylitol inhibited S. mutans growth. The adhesion of S. mutans CI 2366 to saliva-coated hydroxyapatite was reduced by 2′-FL and GOS. Exopolysaccharide-mediated adhesion of S. mutans DSM 20523 to a glass surface was decreased with 2′-FL, GOS and lactose, and the adhesion of strain CI 2366 strain was reduced only by GOS. Unlike GOS, 2′-FL did not support the growth of any S. mutans strain. Neither 2′-FL nor GOS enhanced the adhesive properties of the S. mutans strains, but they inhibited some of the tested strains. Thus, the cariogenic tendency may vary between infant formulas containing different types of oligosaccharides.

Objectives A systematic review of published data was conducted with the aim of assessing the effects of sugar-free polyol chewing gums on gingival inflammation. Materials and methods Electronic and hand searches were performed to find clinical studies concerning the effects of sugar-free chewing gums on gingival scores. Prospective randomized controlled clinical trials published between 1971 and 2021 were included in the review. Results The initial search identified 46 erythritol, 102 xylitol, 23 sorbitol, and nine maltitol chewing gum articles. After applying inclusion and exclusion criteria, seven xylitol chewing gum studies, one sorbitol, and one maltitol chewing gum study with either high or fair quality were reviewed. In five out of the seven xylitol studies, xylitol gum decreased gingival scores. In two studies, xylitol decreased gingival scores compared to a polyol gum, and in three studies compared to no gum/gum base. As for sorbitol and maltitol, only sorbitol gum chewing showed a small decrease in gingival scores compared to the controls. Conclusions Habitual xylitol gum chewing may reduce gingival inflammation. The low number of studies and their heterogeneity provide clear indications that the effects of sugar-free polyol chewing gums on gingival inflammation need further, well-controlled studies. Clinical relevance Sugar-free chewing gums, especially xylitol gum, may function as adjuncts to toothbrushing for reducing gingival inflammation, but the evidence so far is inconclusive.

Streptococcus mutans is able to form a high-affinity biofilm on material surfaces. S mutans has also been detected around infected implants. Bioactive glasses (BAGs) have been shown to possess antibacterial effects against S mutans and other microorganisms. This in vitro study was performed to investigate the influence of BAG air abrasion on S mutans biofilm on sandblasted and acid-etched titanium surfaces. Sandblasted and acid-etched commercially pure titanium discs were used as substrates for bacteria (n = 107). The discs were immersed in an S mutans solution and incubated for 21 hours to form an S mutans biofilm. Twenty colonized discs were subjected to air abrasion with Bioglass 45S5 (45S5 BAG), experimental zinc oxide containing BAG (Zn4 BAG), and inert glass. After the abrasion, the discs were incubated for 5 hours in an anaerobic chamber followed by an assessment of viable S mutans cells. Surface morphology was evaluation using scanning electron microscopy (n = 12). The thrombogenicity of the glass particle–abraded discs (n = 75) was evaluated spectrophotometrically using whole-blood clotting measurement at predetermined time points. Air abrasion with 45S5 and Zn4 BAG eradicated S mutans biofilm. Significantly fewer viable S mutans cells were found on discs abraded with the 45S5 or Zn4 BAGs compared with the inert glass (P < .001). No significant differences were found in thrombogenicity since blood clotting was achieved for all substrates at 40 minutes. Air abrasion with BAG particles is effective in the eradication of S mutans biofilm from sandblasted and acid-etched titanium surfaces. Zn4 and 45S5 BAGs had similar biofilm-eradicating effects, but Zn4 BAG could be more tissue friendly. In addition, the steady release of zinc ions from Zn4 may enhance bone regeneration around the titanium implant and may thus have the potential to be used in the treatment of peri-implantitis. The use of either BAGs did not enhance the speed of blood coagulation.

Human milk oligosaccharides (HMOs), the third largest solid fraction in human milk, can modulate inflammation through Toll-like receptor signaling, but little is known about their immunomodulatory potential in the oral cavity. In this study, we determined whether the HMOs 2′-fucosyllactose (2′-FL) and 3-fucosyllactose (3-FL) regulate human-beta defensin (hBD)-2 and -3, cathelicidin (hCAP18/LL-37), and cytokine responses in human gingival cells using a three-dimensional oral mucosal culture model. The model was incubated with 0.1% or 1% 2′-FL and 3-FL, alone and in combination, for 5 or 24 h, and hBD-2, hBD-3, and hCAP18/LL-37 were analyzed by immunohistochemistry. The expression profiles of interleukin (IL)-1, IL-1RA, IL-8, and monocyte chemoattractant protein (MCP)-1 were determined by LUMINEX immunoassay. The combination of 1% 2′-FL and 1% 3-FL, and 1% 3-FL alone, for 24 h upregulated hBD-2 protein expression significantly (p < 0.001 and p = 0.016, respectively). No changes in the other antimicrobial peptides or proinflammatory cytokines were observed. Thus, 3-FL, alone and in combination with 2′-FL, stimulates oral mucosal secretion of hBD-2, without effecting a proinflammatory response when studied in an oral mucosal culture model.

Objectives A systematic review of published data was conducted with the aim of assessing the effects of xylitol consumption on the amount of dental plaque. Materials and methods Electronic and hand searches were performed to find clinical studies concerning the effects of xylitol chewing gum or candies on dental plaque. Prospective randomized controlled clinical trials published between 1971 and 2020 conducted in healthy subjects were included in the review. Results The initial search identified 424 xylitol articles. After applying inclusion and exclusion criteria, altogether 14 articles (16 studies) were reviewed. The review identified 12 of the total of 14 xylitol chewing gum studies as having fair or high quality. In 13 of the 14 chewing gum studies, xylitol gum decreased plaque accumulation. In six studies, xylitol gum chewing decreased plaque compared to sorbitol gum, and in three studies compared to gum base/no gum. In three fair-quality studies conducted with xylitol candies, plaque accumulation did not change. Conclusions Habitual xylitol gum chewing appears to show plaque-reducing effects that differ from those of sorbitol gum. This suggests specific effects for xylitol on plaque accumulation. Xylitol candies appear not to decrease plaque. The heterogeneity of the studies warrants further research. Clinical relevance Habitual xylitol gum chewing is likely to decrease plaque.

A systematic review of published data was conducted with the aim of assessing effects of xylitol and erythritol consumption on levels of mutans streptococci (MS) and the oral microbiota.Electronic and hand searches were performed to find clinical microbiological studies concerning the consumption of xylitol and erythritol chewing gum or candies, and published between 2000 and 2019. Prospective randomized controlled clinical trials conducted in healthy subjects were included in the review.The initial search identified 561 xylitol and 83 erythritol studies. After applying inclusion and exclusion criteria, 21 xylitol studies and one erythritol study were reviewed. The review identified nine xylitol studies with a fair or high quality, four conducted in children and five in adults, all demonstrating a decrease in MS levels in association with habitual consumption of xylitol. The three microbiota studies employing multispecies probe approaches revealed no effects for xylitol on the microbiota. The only erythritol study fulfilling the inclusion criteria showed no consistent effects on MS levels.Xylitol consumption is likely to decrease MS counts but it may not change the overall microbiota. Xylitol shows thus properties of an oral prebiotic. More studies are needed to demonstrate the effects of erythritol on MS.

To determine the effect of a probiotic combination of Lactobacillus rhamnosus GG (LGG) and Bifidobacterium lactis BB-12 on the gingival health, dental plaque accumulation, and the oral carriage of four putative periodontal pathogens in healthy adolescents. 108 schoolboys, aged 13-15 years, participated in this study. They were divided into two groups: probiotics (n=54) and placebo (n=54). Both groups received two probiotic-laced or placebo lozenges twice a day during a four-week period. Plaque Index (PI) and Gingival Index (GI) were recorded at baseline and after four weeks. Salivary and plaque carriage of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum were also monitored likewise. 101 subjects completed the study. A statistically significant reduction in GI was seen in the probiotic group as compared to the placebo group (P=0.012). A reduction in PI was found for both groups, with no difference observed between the groups after intervention (P=0.819). Probiotic lozenges significantly reduced levels of A. actinomycetemcomitans and F. nucleatum in saliva and plaque (P

Few laboratory methods exist for evaluating the cariogenicity of food ingredients. In this study, a dental simulator was used to determine the effects of commercial sucrose and xylitol mint products on the adherence and planktonic growth of Streptococcus mutans. Solutions (3% w/v) of sucrose, xylitol, sucrose mints, xylitol mints, xylitol with 0.02% peppermint oil (PO), and 0.02% PO alone were used to test the levels of planktonic and adhered S. mutans. A dental simulator with continuous artificial saliva flow, constant temperature, and mixing was used as a test environment and hydroxyapatite (HA) discs were implemented into the model to simulate the tooth surface. Bacterial content was quantified by qPCR. Compared with the artificial saliva alone, sucrose and sucrose mints increased the numbers of HA-attached S. mutans, whereas xylitol decreased them. Similarly, planktonic S. mutans quantities rose with sucrose and declined with xylitol and xylitol mints. Versus sucrose mints, xylitol mints significantly reduced the counts of HA-bound and planktonic S. mutans. Similar results were observed with the main ingredients of both types of mints separately. PO-supplemented artificial saliva did not influence the numbers of S. mutans that attached to HA or planktonic S. mutans compared with artificial saliva control. In our dental simulator model, xylitol reduced the counts of adhering and planktonic S.mutans. The mints behaved similarly as their pure, main ingredients—sucrose or xylitol, respectively. PO, which has been suggested to have antimicrobial properties, did not influence S. mutans colonization.

This study investigated the antimicrobial efficacy and mechanical strength of hard and soft denture liners modified with benzalkonium chloride (BAC). The specimens (1 mm thickness, 8 mm diameter) were prepared by mixing 0.5, 1, 2 and 5 wt% BAC with soft (Sofreliner Medium, Tokuyama) and hard (Rebase II, Tokuyama) denture liners (n = 5/group). BAC was not added to the controls. Candida albicans ATCC 28366 (A 550 = 0.5) and Streptococcus mutans Ingbritt suspensions (A 550 = 0.35) were pipetted onto the specimens, and incubated for 4 h. The viable cells were collected, and determined by plate-culturing (CFU). The tests were repeated after the specimens were soaked in distilled water for 7 days. The mechanical strengths were evaluated by tear and 4-point flexural strength tests for soft and hard liners, respectively. The data were analyzed with ANOVA and Tukey's HSD tests at p = 0.05. C. albicans viability was lost in all groups of BAC-modified soft liners (p 0.05). For the hard liner, BAC 5 wt% killed the C. albicans and S. mutans cells both before and after soaked in water (p 0.05). BAC did not reduce the flexural strength of the hard liner (p > 0.05), except of BAC 5 wt% group (p

There is growing interest in the use of probiotic bifidobacteria for enhancement of the therapy, and in the prevention, of oral microbial diseases. However, the results of clinical studies assessing the effects of bifidobacteria on the oral microbiota are controversial, and the mechanisms of actions of probiotics in the oral cavity remain largely unknown. In addition, very little is known about the role of commensal bifidobacteria in oral health. Our aim was to study the integration of the probiotic Bifidobacterium animalis subsp. lactis Bb12 and of oral Bifidobacterium dentium and Bifidobacterium longum isolates in supragingival and subgingival biofilm models and their effects on other bacteria in biofilms in vitro using two different in vitro biofilms and agar-overlay assays. All bifidobacteria integrated well into the subgingival biofilms composed of Porphyromonas gingivalis, Actinomyces naeslundii, and Fusobacterium nucleatum and decreased significantly only the number of P. gingivalis in the biofilms. The integration of bifidobacteria into the supragingival biofilms containing Streptococcus mutans and A. naeslundii was less efficient, and bifidobacteria did not affect the number of S. mutans in biofilms. Therefore, our results suggest that bifidobacteria may have a positive effect on subgingival biofilm and thereby potential in enhancing gingival health; however, their effect on supragingival biofilm may be limited.

Specific probiotic bacteria have proven to be effective in the prevention and treatment of infectious diseases in early life in at-risk populations. The impact of administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on the risk of acute infectious diseases was studied in healthy children. In this double-blind, placebo-controlled study, 109 1-mo-old infants were assigned randomly to a probiotic group receiving a BB-12–containing tablet (n = 55) or a placebo (n = 54). Test tablets were administered to the infants twice a day (daily dose of BB-12 10 billion colony-forming units) until the age of 2 y with a novel slow-release pacifier or a spoon. Breastfeeding habits, pacifier use, dietary habits, medications, and all signs and symptoms of acute infections were registered in diaries by parents and in questionnaires by trained professionals. The infants receiving BB-12 were reported to have experienced fewer respiratory tract infections (RTIs; 87 vs. 100%; risk ratio: 0.87; 95% confidence interval: 0.76, 1.00; P = 0.033) than the controls. No significant differences between the groups were observed in reported gastrointestinal symptoms, otitis media, or fever. The baseline characteristics of the two groups were similar, as was the duration of breastfeeding. Administration of BB-12 in early childhood may reduce RTIs.

Biostable fiber-reinforced composite (FRC) implants prepared from bisphenol-A-dimethacrylate and triethyleneglycoldimethacrylate resin reinforced with E-glass fibers have been successfully used in cranial reconstructions in 15 patients. Recently, porous FRC structures were suggested as potential implant materials. Compared with smooth surface, porous surface allows implant incorporation via bone ingrowth, but is also a subject to bacterial attachment. Non-cytotoxic silver-polysaccharide nanocomposite coatings may provide a way to decrease the risk of bacterial contamination of porous FRC structures. This study is focused on the in vitro characterization of the effect porosity on the antimicrobial efficiency of the coatings against Staphylococcus aureus and Pseudomonas aeruginosa by a series of microbiological tests (initial adhesion, antimicrobial efficacy, and biofilm formation). Characterization included confocal laser scanning microscopy and scanning electron microscopy. The effect of porosity on the initial attachment of S. aureus was pronounced, but in the case of P. aeruginosa the effect was negligible. There were no significant effects of the coatings on the initial bacterial attachment. In the antimicrobial efficacy test, the coatings were potent against both strains regardless of the sample morphology. In the biofilm tests, there were no clear effects either of morphology or of the coating. Further coating development is foreseen to achieve a longer-term antimicrobial effect to inhibiting bacterial implant colonization.

The purpose of this study was to evaluate blood and platelet response to nanostructured TiO2 coatings and to investigate the effect of Ultraviolet (UV) light treatment on blood clotting ability, platelet activation and protein adhesion. Ti-6Al-4V titanium alloy plates (n = 138) were divided into three groups; a sol–gel derived MetAliveTM coating (MA); hydrothermal coating (HT); and a non-coated group (NC). Sixty nine titanium substrates were further treated with UV light for 1 h. The thrombogenicity of the titanium substrates was assessed using fresh human blood with a whole blood kinetic clotting time method. The platelet adhesion test was conducted to evaluate the morphology and adhesion behavior of the platelets on the titanium substrates. Human diluted plasma and bovine fibronectin were used to evaluate protein adsorption. Total clotting time for the UV treated HT, MA and NC titanium substrates was almost 40 min compared to 60 min for non-UV substrates, the total clotting time for the UV treated groups were significantly lower than that of the non UV NC group (p

Biofilm formation and dipeptidyl peptidase IV (DPPIV) enzyme activity contribute to the virulence of oral bacteria, and these virulence factors are partly regulated by quorum sensing signaling system. We recently demonstrated that estradiol regulates growth properties and DPPIV activity of Prevotella intermedia, Prevotella nigrescens, and Prevotella pallens. Here, we examined the DPPIV dependency of biofilm formation of Prevotella aurantiaca. Three strains (two clinical strains AHN 37505 and 37552 and the type strain CCUG 57723) were incubated in three estradiol concentrations (30, 90, and 120 nmol/L). Regulation of DPPIV activity, biofilm and fimbria formation, and coaggregation of bacterial strains were analyzed after incubation with four concentrations (10 nM, 100 nM, 1 μM, 10 μM) of dihydroxy-2,3-pentaedione (DPD), the universal precursor of autoinducer -2 (AI-2), and analogs (ethyl-DPD, butyl-DPD, and isobutyl-DPD) for 24 h. Estradiol enhanced the planktonic growth, coaggregation, and biofilm formation of P. aurantiaca strains. The whole cell extract of AHN 37505 had the highest DPPIV activity, followed by CCUG 57723 and AHN 37552. Inhibition of DPPIV activity with di-isopropylfluorophosphate suppressed the effect of estradiol on biofilm formation. At 100 nM and 10 μM concentrations of DPD, butyl DPD, and isobutyl DPD, biofilm formation of P. aurantiaca was significantly inhibited. Fimbriae formation was enhanced up to concentrations of 100 nM and 1 μM followed by a significant inhibition at higher concentrations of DPD and all analogs. A slight but significant inhibitory effect of DPD and analogs on DPPIV activity was observed. Our results indicate that DPPIV plays a key role in the estradiol-regulated biofilm formation of P. aurantiaca. Quorum sensing autoinducer DPD and C1-alkyl analogs could inhibit biofilm-related virulence of P. aurantiaca.

This longitudinal study of 194 very-low birthweight (VLBW) and 184 normal birthweight (NBW) infants hypothesized that the causal pathway between birth group (VLBW or NBW) and mutans streptococci (MS) acquisition (presence) at 18-20 months is mediated by biological, behavioral, and caregiver MS levels. Biological (number of teeth at 8 and 18-20 months and enamel hypoplasia) and behavioral (brushing/cleaning, sweet snacks, breastfeeding, and dental access) factors were assessed using dental examinations and caregiver questionnaire responses at 8 and 18-20 months. Infant MS acquisition and caregiver MS levels were assessed from saliva and plaque samples collected at 8 and 18-20 months. Structural equation modeling evaluated the causal pathway with latent variables for biology and behavior. Mutans streptococci presence was similar between birth groups at 18-20 months (40% in VLBW infants and 49% in NBW infants), but was significantly higher for NBW infants at 8 months. Increased number of teeth at 8 and 18-20 months was associated with biological risk. Infants whose caregivers had a 1-point higher score on MS had a significantly (1.5) higher odds of MS presence. Caregiver behavior was not associated with MS presence. Early-intervention efforts should focus on delaying initial acquisition and improving caregiver awareness of taking care of erupting primary teeth.

Background Prevalence and risk factors for human papillomavirus (HPV) persistence in oral mucosa are largely unknown. Furthermore, the antiviral effects of saliva in the outcome of oral HPV infections are unexplored. Objectives To compare the levels of selected salivary defence proteins in women with a persistent oral HPV infection and in those without any signs of oral HPV. Lifestyle factors including the use of oral contraceptives, oral sex, smoking and alcohol drinking habits were also assessed. Study design This nested case–control study of the Finnish Family HPV Study included 60 women with a persistent oral HPV infection and 117 women who remained HPV DNA negative throughout a 6-year follow-up. Whole saliva samples and oral scrapings for HPV testing were collected at the same visit. The oral HPV status was related to salivary concentrations of lactoferrin, lysozyme, IgA, IgG, total protein and sodium as well as to the use of oral contraceptives, oral sex, smoking and alcohol drinking habits. Results Women with a persistent oral HPV infection had higher salivary levels of IgG ( p = 0.007) and lysozyme ( p = 0.002, when adjusted to the total protein concentration), than those without an HPV infection. Lactoferrin and IgA concentrations were not related to the HPV-status. Smoking increased the risk of a persistent oral HPV infection ( p = 0.020), but the oral HPV status was not related to other life-style factors studied. Conclusions Smoking is a risk factor for a persistent oral HPV infection. Oral HPV infection may be associated with increased concentrations of salivary IgG and lysozyme.

The aim of this study was to determine the effects of short-term xylitol gum chewing on the salivary microbiota of children. The study was a randomised, controlled, double-blind trial. Healthy children used xylitol chewing gum (xylitol group, n = 35) or sorbitol chewing gum (control group, n = 38) for 5 weeks. The daily dose of xylitol/sorbitol was approximately 6 g/day. At baseline and at the end of the test period, unstimulated and paraffin-stimulated saliva were collected. The microbial composition of the saliva was assessed using human oral microbe identification microarray (HOMIM). Mutans streptococci (MS) were plate cultured. As judged by HOMIM results, no xylitol-induced changes in the salivary microbiota took place in the xylitol group. In the control group, Veillonella atypica showed a significant decrease (p = 0.0001). The xylitol gum chewing decreased viable counts of MS in both stimulated (p = 0.006) and unstimulated (p = 0.002) saliva, but similar effects were also seen in the control group. The use of xylitol gum decreased MS, in general, but did not change the salivary microbial composition. Short-term consumption of xylitol had no impact on the composition of the salivary microbiota, but resulted in a decrease in the levels of MS.

Four novel quaternary ammonium dimethacrylate monomers named IMQ (side alkyl chain length from 12 to 18) were synthesized with the aim to synthesize dental resin with antibacterial activity. All of IMQs were added into bis-GMA/TEGDMA dental resin system with a series of mass ratio (5, 10, and 20 wt%), double bond conversion (DC), flexural strength (FS), modulus of elasticity (FM) and biofilm formation inhibitory effect were studied. According to the results of DC, FS, FM, and the biofilm inhibitory effect, IMQ-16 containing polymer had the best comprehensive properties, and the optimal concentration of IMQ-16 in bis-GMA/TEGDMA dental resin would be in the range of 5-10 wt%.

Alterations in the quantity and quality of biofilms at gingival margin are considered to play a role in the initiation and development of pregnancy-related gingivitis. Prevotella intermedia sensu lato is able to consume estradiol, the major sex hormone secreted during pregnancy, in the absence of vitamin K. The aim of the study was to examine the effect of estradiol on the planktonic growth, coaggregation, polysaccharide production, and biofilm formation of the P. intermedia group bacteria, namely P. intermedia , Prevotella nigrescens , and Prevotella pallens . In all experiments, the type strain (ATCC) and a clinical strain (AHN) of P. intermedia , P. nigrescens , and P. pallens were incubated with the concentrations of 0, 30, 90, and 120 nmol/L of estradiol. Planktonic growth was assessed by means of the colony forming unit method, while coaggregation and biofilm formation were assessed by spectrophotometric methods. In the determination of protein and polysaccharide levels, the Bradford and phenol–sulfuric acid methods were used, respectively. P. pallens AHN 9283 and P. nigrescens ATCC 33563 increased their numbers at planktonic stage with increasing estradiol concentrations. In 48-h biofilm tests, elevated protein levels were found for both strains of P. intermedia , and the strains P. nigrescens ATCC 33563 and P. pallens AHN 9283 in the presence of estradiol. The P. intermedia strains also increased the levels of polysaccharide formation in the biofilm. Coaggregation of the P. intermedia group organisms with Fusobacterium nucleatum was enhanced only in P. intermedia AHN 8290. In conclusion, our in vitro experiments indicate that estradiol regulates planktonic growth, coaggregation, polysaccharide production, and biofilm formation characteristics of P. intermedia , P. nigrescens , and P. pallens differently. These results may, at least partly, explain the differences seen in their contribution to the pathogenesis of pregnancy-related gingivitis.

In this study, three dimethacrylate quaternary ammonium compounds N,N-bis[2-(3-(methacryloyloxy)propanamido)ethyl]-N-methyldodecyl ammonium iodide (QADMAI-12), N,N-bis[2-(3-(methacryloyloxy)propanamido)ethyl]-N-methylhexadecyl-ammonium iodide (QADMAI-16), and N,N-bis[2-(3-(methacryloyloxy)propanamido)ethyl]-N-methyloctadectyl ammonium iodide (QADMAI-18) were synthesized and proposed to be used as antibacterial and radio-opaque agents in dental resin.All QADMAIs were synthesized through a 2-steps reaction route, and their structures were confirmed by FT-IR and 1H NMR spectra. Antibacterial activities against Streptococcus mutans (S. mutans) of QADMAIs were measured by agar diffusion test. Each QADMAI was mixed with TEGDMA (50/50, w/w) and photoinitiation system (0.7 wt% of CQ and 0.7 wt% of DMAEMA) to form resin system. Degree of monomer conversion (DC) was determined by FT-IR analysis. The flexural strength (FS) and modulus (FM) of the polymer were measured using a three-point bending set up. Radiograph was taken to determine the radio-opacity of the polymer, and aluminum step-wedge (0.5-4 mm) was used as calibration standard. Surface charge density was measured using fluorescein binding. A single-species biofilm model with S. mutans as the tests organism was used to evaluate the antibacterial property of the polymer. Bis-GMA/TEGDMA resin system was used as control material in all of the tests.FT-IR and 1H NMR spectra showed that the structures of QADMAIs were the same as designed. ANOVA analysis revealed that antibacterial activity of QADMAI decreased with the increasing of alkyl chain length (p0.05). QADMAI containing polymers had higher DC (p0.05) but lower FS and FM (p0.05) than control polymer. Alkyl chain length had no influence on DC (p0.05), but FS and FM of QADMAI-12 containing polymer were better than those of QADMAI-16 and QADMAI-18 containing polymers (p0.05). QADMAI containing polymers had much better radio-opacity than control polymer (p0.05), and the radio-opacity of polymer decreased with the increasing of alkyl chain length (p0.05). All of QADMAIs containing polymers had higher surface charge density than control polymer (p0.05), and surface charge densities of QADMAI-12 and QADMAI-16 containing polymers were nearly the same (p0.05) which were higher than that of QADMAI-18 containing polymer (p0.05). All of QADMAI containing polymers had good inhibitory effect on biofilm formation.QADMAIs had no miscibility problem with TEGDMA, and QADMAIs could endow dental resin with both antibacterial activity and radio-opacity. Formulation of QADMAI containing resin should be optimized in terms of mechanical stregth to satisfy the requirements of dental resin for clinical application.

The purpose of this study was to examine the associations between daily habits, Streptococcus mutans, and caries using International Caries Detection and Assessment System Caries Index (ICDAS CI); and compare it to the DMF index.Altogether 122 children were examined and interviewed. Saliva and plaque samples were collected and analyzed by Dentocult SM(®) Strip Mutans test. ICDAS CI was calculated by counting all ICDAS caries scores of all surfaces divided by total number of carious teeth.ICDAS CI was significantly (p0.01) and strongly associated with DMFT/dmft (ρ=0.72), DMFS/dmfs (ρ=0.72), total number of carious teeth (DT/dt) (ρ=0.77), enamel caries surfaces (ρ=0.61) and dentine caries surfaces (ρ=0.75). Plaque S. mutans was significantly (p0.05) correlated with ICDAS CI and DT/dt. Children who brushed once a day or more had significantly lower ICDAS CI (p0.01). Children who consumed sweets or drank soft drinks more than once a day had significantly higher ICDAS CI (p0.05). No significant association was found between ICDAS CI and frequency of flossing, use of mouthrinse, or gum chewing.ICDAS CI seems to have similar trends as DMF indices, but includes more information about the stage, severity, and progress of the caries lesions of the patient.

Objectives In a Finnish study carried out in 1990s, high-caries-risk mothers used xylitol gum on daily basis when their child was 3–24-month old, whereas the high-risk control mothers received biannual fluoride or chlorhexidine treatments. The maternal prevention reduced colonization of mutans streptococci and early childhood caries in children. The present retrospective study aimed to extend the post-trial follow-up to 10-year-old children (n = 148). Additionally, the dental health of these high-caries-risk children was compared with a reference group comprising the rest of the children in the same age cohort (n = 359). Methods The annual data on dental health and treatments were gathered from public dental care registers. Results The median caries-free age (dmft = 0 and DMFT = 0) was 8.2 in the xylitol, 5.8 in the control, and 8.1 in the reference group (xylitol versus control, P = 0.005, HR = 1.75; 95% CI 1.18–2.60, reference versus xylitol, P = 0.410, HR = 1.13; 95% CI 0.84–1.51 Cox regression). Thus, the children in the xylitol group had caries-free teeth longer than the control group. Compared to the reference group, the xylitol group did not show notable difference. Up to 4 years of age, figures for cumulative restorative treatment visits were 0.2 in the xylitol, 0.7 in the control, and 0.4 in the reference group (xylitol versus control P = 0.006, Student's t-test). Conclusions The reduced mother–child transmission of mutans streptococci seems to have long-term effects on children's dental health. The maternal use of xylitol reduces caries occurrence and need for restorative treatment in assumed high-caries-risk children to the average level of the whole age cohort.

In order to endow dental resin with antibacterial activity, a series of antibacterial quaternary ammonium methacrylate monomers (QAM) with different substituted alkyl chain length (from 10 to 18) were incorporated into commonly used 2,2-bis[4-(2'-hydroxy-3'-methacryloyloxy-propoxy)-phenyl]propane (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50 wt/50 wt) dental resin as immobilized antibacterial agents. Double bond conversion (DC), flexural strength (FS) and modulus (FM), and young and mature biofilms inhibition effectiveness of prepared dental resins were studied and Bis-GMA/TEGDMA without QAM was used as reference. Results showed that there was no significant difference on DC, FS, and FM between copolymer with and without 5 wt% QAM. Substituted alkyl chain length of QAM had no influence on DC, FS, and FM of copolymer, but had influence on antibacterial activity of copolymer. Antibacterial activity of copolymer increased with increasing of substituted alkyl chain length of QAM, and the sequence followed as 5%C105%C11 ≈ 5%C125%C16 ≈ 5%C18. Copolymers containing C18 and C16 had the best inhibition effectiveness on both young biofilm and mature biofilm, copolymers containing C12 and C11 only had inhibition effectiveness on young biofilm and copolymer containing C10 had none inhibition effectiveness on neither young biofilm nor mature biofilm.

Probiotic bifidobacteria are widely used in the prevention of childhood diseases. These bacteria are also associated with caries occurrence. The present secondary analysis in a low-caries population evaluated the effect of early administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on caries occurrence and identified markers of dental decay in early childhood. In the original randomized, double-blind, placebo-controlled study (NCT00638677, http://www.clinicaltrials.gov), infants (n = 106) received BB-12, xylitol or sorbitol tablets from the age of 1-2 months to 2 years with a slow-release pacifier or a spoon (daily dose of BB-12 1010 colony-forming units, polyol 200-600 mg). The present data were collected using clinical examinations and questionnaires at the age of 4 years. The occurrence of dental caries was assessed using the International Caries Detection and Assessment System. Oral hygiene status and mutans streptococci (MS) levels were also determined. No differences were detected between the study groups in the occurrence of enamel caries (p = 0.268) or obvious dentinal caries (p = 0.201). The occurrence of caries was associated with daily consumption of sweet drinks (p = 0.028), visible plaque observed (p = 0.002) and MS detected in the dental plaque (p = 0.002). Administration of BB-12 in infancy does not seem to increase or decrease the occurrence of caries by 4 years of age in a low-caries population.

The purpose of this study was to prepare antibacterial and radiopaque dental resin through adding one polymerizable quaternary ammonium compound with iodine as counter anion into Bis-GMA/TEGDMA (50/50, wt/wt) dental resin system, and evaluate the degree of monomer conversion, mechanical properties, radiopacity, and antibacterial effectiveness of the polymer.2-Dimethyl-2-dodecyl-1-methacryloxyethyl ammonium iodine (DDMAI) (3 wt.% and 5 wt.%) was added into a Bis-GMA/TEGDMA (50/50, wt/wt) resin system with CQ (0.7 wt.%) and DMAEMA (0.7 wt.%) as photoinitiation system. Degree of monomer conversion (DC) was determined by FT-IR analysis. The flexural strength (FS) and flexural modulus (FM) of the polymer were measured using a three-point bending set up. Radiographs were taken to determine the radiopacity of the polymer, and aluminum step-wedge (0.5-4mm) was used as calibration standard. A single-species biofilm model with Streptococcus mutans as the tests organism was used to evaluate the antibacterial property of the polymer. Bis-GMA/TEGDMA without DDMAI was used as control material in all of the tests.ANOVA analysis revealed that there was no significant difference in DC between polymer with and without DDMAI (p0.05). Polymer with 3 wt.% DDMAI had higher FS than the control material (p0.05), while polymer with 5 wt.% DDMAI had comparable FS with the control material (p0.05). Though average FM of control material was lower than that of 3 wt.% DDMAI containing polymer and higher than 5 wt.% DDMAI containing polymer, but the differences were statistically insignificant. By increasing the quantity of DDMAI, the radiopacity of the polymer increased. Of the three formulations, the polymer with 5 wt.% DDMAI inhibited biofilm the formation of the clinically relevant young biofilm.Incorporation of DDMAI into resin system could endow it with radiopacity and antibacterial effectiveness, and these two properties seem to be improved with increasing the quantities of DDMAI.

We studied the effects of xylitol on biofilms containing xylitol-resistant (Xr) and xylitol-sensitive (Xs) Streptococcus mutans, Actinomyces naeslundii and S. sanguinis. The biofilms were grown for 8 and 24 h on hydroxyapatite discs. The viable microorganisms were determined by plate culturing techniques and fluorescence in situ hybridization (FISH) was performed using a S. mutans-specific probe. Extracellular cell-bound polysaccharides (EPS) were determined by spectrofluorometry from single-species S. mutans biofilms. In the presence of 5 % xylitol, the counts of the Xs S. mutans decreased tenfold in the young (8 h) biofilm (p\0.05) but no effect was seen in the mature (24 h) biofilm. No decrease was observed for the Xr strains, and FISH confirmed these results. No differences were detected in the EPS production of the Xs S. mutans grown with or without xylitol, nor between Xr and Xs S. mutans strains. Thus, it seems that xylitol did not affect the EPS synthesis of the S. mutans strains. Since the Xr S. mutans strains, not inhibited by xylitol, showed no xylitol-induced decrease in the biofilms, we conclude that growth inhibition could be responsible for the decrease of the counts of the Xs S. mutans strains in the clinically relevant young biofilms. © 2012 Springer Science+Business Media, LLC., The work done at IPLA-CSIC (Spain) was funded by the project AGL2009-09445 (Spanish Ministry of Science and Innovation).

In children, a strong relationship between the timing of colonisation of mutans streptococci (MS) and future caries risk has been shown to exist. The aim of the study was to examine the association of early MS colonisation with dental decay and the need for restorative treatment. The subjects had been participants in an earlier Finnish mother-child study and assumed to be high-caries-risk subjects due to their mothers’ high MS levels. The information on MS colonisation at 2 years of age was available for 164 children. Of them, comprehensive data on dental health, visits and treatments until 10 years of age were found in the registers for 147 subjects. The children who had not been colonised by MS at 2 years of age (n = 118) maintained their teeth caries-free longer than the MS-colonised (n = 29) children. The median value for the caries-free time for MS-colonised children was 4.6 years, in comparison with 8.0 years for non-MS-colonised children (p < 0.001, hazard ratio 2.70; 95% CI 1.72–4.25, Cox regression). Until 10 years of age, the MS-colonised children had made on average 4.6 visits for restorative treatment, while the non-MS-colonised had made 2.8 visits (p = 0.005, Student’s t test). The results suggest that the avoided early MS colonisation may lead to favourable long-term effects on caries experience and need for restorative treatment.

A randomized clinical trial studied the effects of early ad-ministration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on oral colonization of (1) mutans streptococci (MS), and (2) BB-12. In this double-blind, placebo-controlled study, infants (n = 106) received probiotic bacteria (BB-12 group), xylitol (X group), or sorbitol (S group). Test tablets were administered twice a day (from the age of 1-2 months) with a novel slow-release pacifier or a spoon (daily dose of BB-12 1010 CFU, polyol 200-600 mg). Samples were collected from mucosa/teeth at the age of 8 months and 2 years for BB- 12 determination (qPCR) and plate culturing of MS (MSB, TYCSB), lactobacilli (Rogosa) and yeasts (Sabouraud). The MS levels of the mothers were determined (Dentocult SM Strip Mutans). The baseline characteristics of the three groups were similar. Mean duration of tablet delivery was 14.9 ± 6.7 months. In all groups, >90% of the mothers showed high MS counts (log CFU ≧5). MS colonization percentages of the children at the age of 2 years were rather low (BB-12 group: 6%; X group: 31%; S group: 10%; p < 0.05). The levels of lactobacilli and yeasts did not differ between the groups. BB-12 cell counts barely exceeding the detection limit were found in three of the oral samples of the 8-month-old children; however, the 2-year samples did not contain BB-12. The early administration of BB-12 did not result in permanent oral colonization of this probiotic or significantly affect MS colonization in the children.

Objectives: Our aim was to investigate the effect of short-term xylitol consumption on the microbial composition of plaque and saliva. Methods: Twelve volunteers (22-38 yrs) harboring mutans streptococci (MS) participated in the randomized, double-blind, cross-over study. The experimental chewing gum contained 65% xylitol while the control gum contained 63% sorbitol and 2% maltitol w/w. The polyol dose was approximately 6 g/day. Stimulated saliva and plaque samples were collected before and after the two four-week test periods. The samples were cultured for MS, total streptococci, lactobacilli, and total facultatives. A part of the samples were subjected to DNA-DNA hybridizations of 14 microbial plaque species: Actinomyces naeslundii, A. viscosus, Fusobacterium nucleatum, Lactobacillus acidophilus, L. fermentum, L. paracasei, L. rhamnose, L. plantarum, Streptococcus gordonii, S. oralis, S. parasanguis, S. salivarius, S. sanguinis, Veillonella parvula. Results: The MS counts of the plaque samples collected from “caries-prone” tooth sites decreased significantly (P

This study investigated salivary cholesterol of children from 6 to 16 years of age in response to dietary intervention. One thousand sixty-two infants started in the prospective, randomized project. At 3 years of age, every fifth child was invited into the study (n = 178). Of these, 148 enrolled, and 86 completed the oral sub-study at 16 years of age. The intervention aimed at restricting the child’s saturated fat and cholesterol intake. Control children received no special recommendations. Every third year, paraffin-stimulated saliva samples (10.0 mL) were collected for cholesterol assays. Nutrient intakes and serum total cholesterol concentrations were regularly followed up by means of 4-day food records and blood samples. Intake of saturated fatty acids (SAFA) was lower in the intervention than in the control group (p < 0.001). Salivary cholesterol concentration increased from 1.9 (± 1.1) µmol/L at 6 years of age to 16.0 (± 9.0) µmol/L at 16 years of age. The increase was smaller in the intervention than in the control group (p < 0.001). The ratios of salivary to serum cholesterol concentrations tended to be higher in boys than in girls (p = 0.07). Thus, dietary intervention was reflected in children’s salivary cholesterol values more sensitively than in serum cholesterol values. (clinicaltrials.gov NCT00223600).

The impact of controlled administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on the risk of acute infectious diseases was studied in healthy newborn infants. In this double-blind, placebo-controlled study, 109 newborn 1-month-old infants were assigned randomly to a probiotic group receiving a BB-12-containing tablet (n 55) or to a control group receiving a control tablet (n 54). Test tablets were administered to the infants twice a day (daily dose of BB-12 10 billion colony-forming units) from the age of 1–2 months to 8 months with a novel slow-release pacifier or a spoon. Breastfeeding habits, pacifier use, dietary habits, medications and all signs and symptoms of acute infections were registered. At the age of 8 months, faecal samples were collected for BB-12 determination (quantitative PCR method). The baseline characteristics of the two groups were similar, as was the duration of exclusive breastfeeding. BB-12 was recovered (detection limit log 5) in the faeces of 62 % of the infants receiving the BB-12 tablet. The daily duration of pacifier sucking was not associated with the occurrence of acute otitis media. No significant differences between the groups were observed in reported gastrointestinal symptoms, otitis media or use of antibiotics. However, the infants receiving BB-12 were reported to have experienced fewer respiratory infections (65 v. 94 %; risk ratio 0·69; 95 % CI 0·53, 0·89; P = 0·014) than the control infants. Controlled administration of BB-12 in early childhood may reduce respiratory infections.

Objectives. The aim was to investigate the adhesion of Streptococcus mutans (S. mutans) to a short glass fibers reinforced semi-IPN polymer matrix composite resin. The effect of surface roughness on adhesion was also studied. For comparison, different commercial restorative materials were also evaluated. Materials and Methods. Experimental composite FC resin was prepared by mixing 22.5 wt% of short E-glass fibers, 22.5 wt% of IPN-resin and 55 wt% of silane treated silica fillers using high speed mixing machine. Three direct composite resins (Z250, Grandio and Nulite), resin-modified glass ionomers (Fuji II LC), amalgam (ANA 2000), fiber-reinforced composite (FRC) (everStick and Ribbond), and pre-fabricated ceramic filling insert (Cerana class 1) were tested in this study. Enamel and dentin were used as controls. The specimens (n=3/group) with or without saliva were incubated in a suspension of S. mutans allowing initial adhesion to occur. For the enumeration of cells on the disc surfaces as colony forming units (CFU) the vials with the microbe samples were thoroughly Vortex-treated and after serial dilutions grown anaerobically for 2 days at +37°C on Mitis salivarius agars (Difco) containing bacitracin. Bacterial adhesion was also evaluated by using scanning electron microscopy. Surface roughness (Ra) of the materials was also determined using a surface profilometer. All results were statistically analyzed with one-way analysis of variance (ANOVA). Results. Composite FC resin and other commercial restorative materials showed similar adhesion of S. mutans, while adhesion to dentin and enamel was significantly higher (p Conclusions. Short fiber-reinforced composite with semi-IPN polymer matrix revealed similar S. mutans adhesion than commercial restorative materials.

doi:10.1111/j.1741-2358.2009.00329.x Experiments on in vivo biofilm formation and in vitro adhesion of Candida species on polysiloxane liners Objectives: Microorganisms may colonise polysiloxane soft liners leading to bio-deterioration. The aim of this study was to investigate in vitro adhesion and in vivo biofilm formation of Candida species on polysiloxane surfaces. Methods: The materials used in this study were Molloplast B, GC Reline soft, Mollosil Plus, Silagum Comfort and Palapress Vario. The in vitro retention of clinical isolates of Candida albicans to the relining and denture-base materials by microscopic (scanning electron microscopy, SEM), conventional culturing methods and antimicrobial properties of these materials were studied. Candida found on materials and mucosa following long-term use were identified and quantified, and biofilms covering the surfaces were investigated by SEM. Results: There was a significant decrease in the number of cells attached in vitro to saliva-coated surfaces compared with non-treated surfaces. An oral Candida carriage of 78% was found. Candida albicans, C. glabrata, C. intermedia and C. tropicalis were identified. In vivo biofilm formation on the liners appeared as massive colonisation by microorganisms. Conclusions: The results of the in vitro experiments suggest that salivary film influences early colonisation of different C. albicans strains. The film layer also minimises the differences among different strains. The Candida carriage of these patients was similar to denture-wearing patients without soft liners.

Xylitol consumption decreases counts of mu- tans streptococci. However, the mechanism behind this decrease is not well understood. We studied not only type strains and clinical isolates of mutans streptococci, but also other polysaccharide-forming oral streptococci. Growth inhibition and adherence of cells to a smooth glass sur- face—reflecting synthesis of water-insoluble polysaccha- rides were studied in the presence of 2% (0.13 mol/l) and 4% (0.26 mol/l) xylitol. The effect of xylitol was compared to a novel polyol sweetener, erythritol. Except for Strep- tococcus mutans 10449 and S. sobrinus OMZ 176, the glass surface adhesion of most polysaccharide-forming strepto- cocci was reduced by the presence of both 4% xylitol and erythritol. For the S. mutans and S. sobrinus type strains, the growth inhibition with 4% xylitol and erythritol was 36-77% and for the clinical S. mutans isolates 13-73%. Of the other oral streptococci, only S. sanguinis was inhibited with 4% xylitol (45-55%). For both polyols, the magnitude of the growth inhibition observed was not associated with the magnitude of the decrease in adherence (xylitol: r = -0.18; erythritol: r = 0.49). In conclusion, both xylitol and erythritol can decrease polysaccharide-mediated cell adherence contributing to plaque accumulation through a mechanism not dependent on growth inhibition.

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; C 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.

The aim of this study was to investigate the impact of daily chewing, for 12 weeks, of 2 different probiotic gums compared with placebo on saliva flow rate, saliva IgA levels and saliva pH. The intervention study included 54 adult volunteers with hyposalivation in a double-blind, randomised and placebo-controlled design with three parallel groups. Volunteers were randomly assigned to 3 different groups: subjects in group A (n = 19) were given placebo chewing gum, group B (n = 17) received Bifidobacterium animalis ssp. lactis Bb12 (ATCC 27536) and group C (n = 18) received Lactobacillus rhamnosus LGG (ATCC 53103), Bifidobacterium longum 46 (DSM 14583) and Bifidobacterium longum 2C (DSM 14579) gums, during 3 months. Two volunteers from group B left the study for personal reasons leaving 19, 15 and 18 volunteers, respectively, for analyses. Clinical examinations, personal interviews, sialometries and saliva sampling were conducted at baseline and after 1, 2, 3 and 4 months. No statistically significant differences were found between probiotic and placebo groups for any of the parameters analysed. No side effects of probiotic or placebo chewing gums were observed. Chewing gum, with and without probiotics, had a positive impact on salivary flow rate and saliva pH and IgA levels., This study was funded by the STABPRO project from the TEKES (the Finnish Funding Agency for Technology and Innovation) of Finland.