Number Of Mutans Streptococci Research Articles

Oral health in young adults with long-term, controlled asthma

Objective. To study oral health in young adults with long-term, controlled asthma. Material and methods. Twenty 18- to 24-year-olds with a mean duration of asthma of 13.5 [standard deviation (SD) 5.4] years and 20 matched healthy controls were included. A clinical examination was performed and the prevalences of caries, erosions, gingival inflammation, cervicular fluid and periodontal pockets and the plaque formation rate were registered. The salivary flow rate and the numbers of mutans Streptococci and Lactobacilli in saliva were determined. Plaque pH was measured after a sucrose rinse for up to 40 min at two approximal sites. The participants were interviewed regarding dietary and oral hygiene habits. Results. The mean (SD) DFS, including manifest and initial caries, was 8.6 (10.6) in the asthma group and 4.0 (5.2) in the control group (P = 0.09). Initial caries lesions were more common in the asthma group than in the control group: 6.0 (8.1) and 1.3 (2.0), respectively (P = 0.02). The asthma group had more gingivitis (P = 0.01) and a lower stimulated salivary secretion rate than the controls (P = 0.01). The asthmatics also had a somewhat, although not statistically significant, lower initial pH value in plaque and a more pronounced pH drop compared with the controls. In the asthma group, 65% reported frequent mouthbreathing, compared with 10% of the controls (P = 0.01). No differences were found in tooth-brushing or dietary habits between the groups. Conclusion. Young adults with long-term, controlled asthma had more initial caries, more gingival inflammation and a lower stimulated salivary secretion rate than individuals without asthma.

Caries Prevalence, Caries-Related Factors and Plaque pH in Adolescents with Long-Term Asthma

The aim of the present case-control study was to investigate dental caries, various caries-related factors as well as gingival condition, in 12- to 16-year-olds with long-term asthma (n = 20) and a matched healthy control group (n = 20). Data on dietary and oral hygiene habits, numbers of mutans streptococci and lactobacilli in saliva were also obtained. The plaque pH drop after a sucrose rinse was measured up to 40 min at 2 approximal tooth sites. A lower salivary flow rate was found in the asthma group compared to the control group (p < 0.05). The mean (± SD) of DFS, including manifest and initial caries, was 4.9 ± 5.5 in the asthma and 1.4 ± 2.3 (p < 0.01) in the control group. Only 1 adolescent in the asthma group was caries free compared to 13 in the control group. Concerning pH in plaque, adolescents with asthma had a lower initial value (p < 0.01) and final pH (p < 0.05) than the control group. The Cariogram data showed that 55% of the subjects in the control group had ‘a high chance of avoiding caries’ compared to 10% in the asthma group (p < 0.01). The asthmatic adolescents had higher numbers of sites with gingival bleeding (p < 0.01). To conclude, adolescents with long-term asthma had a higher total DFS and caries risk (according to Cariogram), decreased salivary rate, more gingival bleeding and lower plaque pH than adolescents without asthma.

Effects of mucosal care on oral pathogens in professional oral hygiene to the elderly

To elucidate the effects of mucosal care on colonization of mutans streptococci and infection of Candida species, we randomized 50 functionally dependent nursing home residents, mean age 76.1 (±7.8 years), 76% females, to receive oral professional care with or without mucosal care. During 12 months of follow-up, significant reduction in the numbers of mutans streptococci in saliva and dental plaque samples were observed in both treatment groups. However, there was no reduction in the numbers of mutans streptococci in tongue samples in the non-mucosal group ( p = 0.150). In the comparison between the treatment with and without mucosal care, the treatment with mucosal care showed a significant inhibition effects on numbers of nutans streptococci on the tongue surface at 6 months after the treatment as compared with the treatment without mucosal care ( p = 0.043). Mucosal care was not associated with any significant reduction in the rate of opportunistic infection with Candida species in any of the three sites. However, more subjects without mucosal care had Candida infection in dental plaque during the follow-up ( p = 0.046). Professional dental care with (versus without) mucosal care had no effect on mutans streptococci colonization in saliva or plaque. Lack of mucosal care seemed to be associated with higher rates opportunistic infections with Candida species.

Antibacterial activity of composite resin with glass-ionomer filler particles

The purpose of this study was to examine the antibacterial activity of composite resin with glass-ionomer filler particles versus that of contemporary commercial composite resins. Three composite resins were used: Beautifil II (containing S-PRG filler), Clearfil AP-X, and Filtek Z250. Resin blocks were bonded to maxillary first molars, and plaque accumulation on the resin block surface was examined after 8 hours. For the antibacterial test, the number of Streptococcus mutans in contact with the composite resin blocks after incubation for 12 hours was determined, and adherence of radiolabeled bacteria was evaluated. Less dental plaque was formed on Beautifil II resin block as compared to the other two materials. Antibacterial test revealed that there were no significant differences in the number of Streptococcus mutans among the three composite resins. However, the adherence of radiolabeled bacteria to the saliva-treated resin surface was significantly (p<0.01) lower in Beautifil II than in the other two materials. These results suggested that Beautifil II could reduce dental plaque formation and bacterial adherence, leading to prevention of secondary caries.

Risk profile of adults with several dental restorations using the Cariogram model

Objective. The aims of the study were: 1) to evaluate the caries profile in a group of Saudi adults with several dental restorations by assessing various caries-related factors using the Cariogram model, and 2) to correlate the Cariogram data, expressed as “the chance of avoiding caries”, with initial caries lesions (DiS), total initial and manifest caries lesions (Di+mS), and filled surfaces (FS). Material and Methods. 175 individuals in Saudi Arabia, aged between 18 and 56 years, were included. All were interviewed about their oral health, dietary habits, and use of fluoride, and were examined for dental caries, both clinically and radiographically. Salivary and microbiological factors, including the number of mutans streptococci and lactobacilli, buffer capacity, and secretion rate, were obtained using chair-side tests. Results. The number of teeth, total Di+mMFS, Di+mS, and FS were 26.0, 53.8, 19.3, and 22.6, respectively. The mean chance of avoiding caries was 31%±19.7. The individuals were divided according to Cariogram data “the chance of avoiding caries” into four risk groups: 0–20% (n=66) “high-risk”, 21–40% (n=43) “medium-risk”, 41–60% (n=50) “low-risk”, and 61–100% (n=16) “very low-risk”. ANOVA revealed statistically significant differences between the high-risk group and the other three groups with respect to Di+mS (p<0.01) and FS (p<0.05). The mean DiS of the high-risk group differed significantly from that of the low-risk group (p<0.05). Conclusions. The Cariogram model can identify the caries-related factors that could be the reasons for the estimated future caries risk. There is a direct association between the categorized outcomes of the Cariograms and the DiS and Di+mS indices.

Hop Bract Polyphenols Reduced Three-day Dental Plaque Regrowth

Previous research has shown the inhibitory effects of hop bract polyphenols (HBP) on cariogenic streptococci in vitro, but their effects in humans have not been investigated. This double-blind, crossover clinical study tested the hypothesis that HBP delivered in a mouthrinse suppresses plaque regrowth in humans. Twenty-nine healthy male volunteers had all plaque removed, and refrained from all oral hygiene for 3 days, except for rinsing with a mouthrinse containing 0.1% HBP or a placebo. The results showed that the mean amount of plaque assessed by the Patient Hygiene Performance score after the volunteers used the HBP mouthrinse was significantly less than that after they used the placebo (p < 0.001). The number of mutans streptococci in the plaque samples after volunteers used the HBP mouthrinse was significantly lower than that after they used the placebo (p < 0.05). These findings suggested that HBP, delivered in a mouthrinse, successfully reduced dental plaque regrowth in humans.

A study on changes in caries risk and microbial flora with the placement of edgewise appliance

The aim of this study was to evaluate the changes of caries risk and oral microbial flora in the patients having edgewise appliance. Forty-two patients treated at the Orthodontic Clinic of Niigata University Hospital participated. Using a caries risk examination kit by Bio Medical Laboratory (BML, Tokyo), stimulated saliva test was performed to investigate the salivary flow rate, pH of saliva, buffer capacity, and the levels of lactobacilli. Modified Mitis–Salivarius–Bacitracin (MSB) agar plates were used to detect and count Streptococcus mutans and S. sobrinus. Furthermore, the members of commensal bacteria and transient bacteria in aerobic culture medium were examined in salivary level to investigate the alterations in oral microbial flora. The number of mutans streptococci and lactobacilli decreased after 1 month of treatment, and then increased to reach the initial level at 3 months. While the amount of plaque increased and saliva pH deteriorated after the onset of treatment, the salivary flow rate improved. The number of transient bacteria showed a tendency toward an increase. These results demonstrate that both caries risk and oral microbial flora balance possibly change with the placement of appliances. Therefore, caries risk test should be performed before and during orthodontic treatment to monitor alterations in intraoral environment of the orthodontic patients not to cause an iatrogenic caries.

Diet Intake and Caries Prevalence in Four-Year-Old Children Living in a Low-Prevalence Country

Preventive measures have dramatically decreased the prevalence of dental caries in children. However, risk factors for the disease in children living in low-prevalence areas remain elusive. In the present study we evaluated associations between dental caries, saliva levels of mutans streptococci and lactobacilli, and diet with special emphasis on the intake of fermentable carbohydrates and dairy products in 4-year-old children living in an area where the overall caries prevalence was low. Dietary intake was recorded in 234 infants as part of the Study of Infant Nutrition in Umeå, Sweden (SINUS). Of these the parents of 124 children gave consent to participate in a follow-up at 4 years of age. Dietary intake, height and weight, dental caries, oral hygiene, including tooth brushing habits, presence of plaque and gingival inflammation, fluoride habits and numbers of mutans streptococci and lactobacilli in saliva were recorded. Using multivariate stepwise logistic regression, caries experience was negatively associated with intake frequency of cheese (OR = 0.67; 95% CI = 0.44–0.98) and positively associated with the salivary level of mutans streptococci (OR = 1.57; 95% CI = 1.21–2.03). Caries experience was not correlated with intake frequency or amounts of carbohydrate-containing foods, with any other particular food, or with daily intake of energy, carbohydrate or any other macro- or micronutrient. We conclude that cheese intake may have a caries-protective effect in childhood populations where the overall caries prevalence and caries experience are low and the children are regularly exposed to fluoride from toothpaste.

Establishing a genetic system for ecological studies ofStreptococcus oligofermentans

Streptococcus oligofermentans is a newly characterized species belonging to the mitis group of oral streptococci. So far no correlation has been demonstrated between S. oligofermentans and dental caries. Furthermore, a reverse correlation has been observed between the number of S. oligofermentans and the number of Streptococcus mutans, a major cariogenic pathogen, in the oral cavity. These properties suggest that S. oligofermentans may have a potential to be used as a 'probiotics' for caries prevention. In this study, we aim to establish a genetic system in S. oligofermentans to further study the biology of this new species. Using homologous regions of the comCDE locus in other streptococci, the comC gene was isolated and sequenced. A synthetic competence-stimulating peptide (CSP) was synthesized and shown to be able to effectively induce competence in S. oligofermentans. This CSP-induced transformation system in S. oligofermentans was used to construct green fluorescent protein (gfp) and luciferase (luc) reporter systems, both of which are driven by the lactate dehydrogenase (ldh) promoter. These reporter systems were further shown to be highly expressed in planktonic and biofilm cells, suggesting that these reporter systems can be used in future ecological studies of S. oligofermentans.

Aktivitas antibakteri flavonoid propolis Trigona sp terhadap bakteri Streptococcus mutans (in vitro) (In vitro antibacterial activity of flavonoids Trigona sp propolis against Streptococcus mutans)

A number of investigations have shown a positive correlation between the number of Streptococcus mutans (S. mutans) in dental plaque and the prevalence of dental caries. Consequently, this microorganism has been the prime target for the prevention of dental caries. Propolis being a substance made by the honeybee, is a potent antibacterial agent. The main chemical class present in propolis is flavonoids. Flavonoids are well-known plant compounds that have antibacterial property. Because S. mutans is accepted to be one of the microorganisms responsible for dental caries and flavonoids in propolis are antibacterial, the purpose of this study was to evaluate in vitro the antibacterial activity of flavonoids Trigona sp propolis against S. mutans as a first step in its possible use as an alternative anticaries agent. Extract flavonoids was purified from ethanol extract of propolis which was obtained from Bulukumba Regency South Sulawesi using thin layer chromatography. The purification of flavonoids was carried-out by UVradiation at λ max 254 nm and λ max 366 nm and treatment with ammonia. Extract flavonoids was diluted in aquadest to 0.05%; 0.075%; 0.1%; 0.25%; 0.5%; 0.75% concentrations. Aquadest and 10% Povidone iodine were also used as control solution. S mutans were grown in medium glucose nutrient agar and incubated with flavonoids for 24 and 48 hours, at 37° C. Antibacterial activity was reflected by the diameter of the inhibition zones around the stainless steel cylinder. The data were analyzed by using ANOVA followed by LSD test with significance level of 5%. The results of this study showed that after being incubated for 24 and 48 hours, all flavonoid concentrations significantly (p < 0.05) inhibited the growth of S mutans. 0.1% flavonoid was the most effective concentration to inhibit the growth of S mutans after 24 hours of incubation and 0.5% flavonoid after 48 hours of incubator.

Levels of mutans streptococci and lactobacilli in plaque on aged restorations of an ion-releasing and a universal hybrid composite resin

The purpose of this in vivo study was to evaluate the cariogenic microflora of plaque on aged restorations of a hydroxyl, fluoride, and calcium ion-releasing composite resin (IRCR) (Ariston pHc), and to compare it intra-individually with a universal hybrid composite resin and enamel. Each of 19 subjects received one proximal restoration of the IRCR, one proximal universal hybrid composite resin restoration (CR) and each subject had one non-filled proximal enamel control surface to make intra-individual comparisons possible. To avoid peak ion releases from the materials, aged restorations were studied. Plaque was collected from 57 surfaces using sterile applicator tips. Samples were cultured to determine the numbers of mutans streptococci, lactobacilli, and total microorganisms. The relative numbers for mutans streptococci (% of total bacteria) were: IRCR 0.59%, CR 0.40%, enamel 0.22%. Two outliers were found in the IRCR group. Excluding these outliers resulted in a relative number of 0.33%. Lactobacilli were detected in the plaque from only 9 surfaces and at very low relative proportions for all three surfaces: 0.01%. The enamel surfaces showed the lowest relative numbers of mutans streptococci and lactobacilli, but the differences were not significant. It can be concluded that the ion release of the IRCR did not influence the growth of cariogenic microorganisms in dental plaque.

Effect of different frequencies of preventive maintenance treatment on dental caries: five-year observations in general dentistry patients

A long-term study in adults at a public dental clinic in Sweden was initiated to evaluate the relative effectiveness of prophylactic treatments on the progression of dental caries and periodontal disease. With treatments scheduled every 3rd, 6th, 12th or 18th month, this report presents results on caries for the 3-month, 6-month and 18-month groups, and evaluates the impact of various caries-related risk factors. Caries increment over approximately 5 years was determined by adding clinical and radiographic findings of manifest primary and secondary caries during the study. Overall caries activity among all 105 participating individuals was low to moderate. No significant differences for caries on any of the various tooth surfaces or for total caries were observed among the three groups. Multiple regression analysis with 5-year caries increment as dependent variable showed that the following factors had a statistically significant association with caries increment: percentage filled surfaces at baseline examination, dietary score, plaque score, and number of mutans streptococci and lactobacilli in saliva. Non-significant factors included number of preventive treatments provided during the 5-year interval. The results of this long-term trial suggest that preventive treatments as often as every 3-6 months may not be justified in the case of patients with low to moderate caries activity.

Antibacterial activity of bactericide-immobilized filler for resin-based restoratives

This study examined the antibacterial activity of prepolymerized resin filler, in which the bactericide quaternary ammonium was immobilized. The experimental filler was prepared by grinding prepolymerized resin blocks of methacrylate monomers, silica particles, and the antibacterial monomer methacryloyloxydodecylpyridinium bromide (MDPB). The number of Streptococcus mutans after incubation for 18 h in contact with the experimental filler with or without protein adsorption by saliva treatment was determined, and adherence of bacteria to the filler surface was evaluated by scanning electron microscopy. Elution of unpolymerized MDPB from the filler and its influence on bacterial growth were also investigated. The growth of S. mutans was completely inhibited by contact with the experimental filler without saliva treatment. Although the effects were attenuated, the saliva-treated filler still exhibited growth inhibition at >99.9%. Less bacteria attached to the experimental filler than the control filler without MDPB, indicating that the reduction in bacterial number after contact with the experimental filler was not due to bacterial adherence to the particles. Unpolymerized MDPB at 1 μg/ml was eluted from the filler particles but was confirmed to have little effect on bacterial growth. The results indicate that the bactericide-immobilized filler containing MDPB shows significant bacteriostatic effects without releasing antibacterial components, and is useful for incorporation into various resin-based restoratives.

Mutans streptococci in subgingival plaque of treated and untreated patients with periodontitis.

The etiology of root caries is thought to be identical to coronal caries, though root caries seem to be more complicated because of the higher susceptibility of exposed roots (dentin) by periodontal therapy to demineralization than intact enamel. This implies that mutans streptococci are the most likely pathogens in the development of root caries. Although it is known that both the numbers of mutans streptococci and the frequency of isolation in root caries lesions are negatively correlated with the distance from the gingival margin, the subgingival sulcus has not been considered a possible habitat for mutans streptococci. However, subgingival occurrence of mutans streptococci in both untreated and treated periodontal patients has not been documented well in the literature. To investigate the presence and levels of mutans streptococci in the subgingival plaque of patients (n=154) in different stages of periodontal therapy. The subgingival sulcus may be a possible habitat for mutans streptococci. This localisation of mutans streptococci may be of importance in the development of root caries after periodontal surgery. In this cross-sectional study, subgingival plaque samples from 154 consecutive adult periodontitis patients were tested for presence and levels of mutans streptococci and putative periodontal pathogens by anaerobic cultures. These patients were divided into 4 groups based on their stage of periodontal treatment: (1) untreated patients; (2) patients after initial periodontal therapy only; (3) patients in the maintenance phase who not underwent periodontal surgery; (4) patients after periodontal surgery. The prevalence of mutans streptococci in the 4 study groups varied from 82% in untreated patients to 94% in maintenance patients. The mean proportion of mutans streptococci was 6.65% in maintenance patients versus 1.86% in untreated patients (p=0.005) and 2.51% in patients after scaling and root planing (p=0.041). The subgingival area is a microbial habitat for mutans streptococci that may be of importance in the development of root caries in periodontitis patients.

Effects of Dental Treatment and Single Application of a 40% Chlorhexidine Varnish on Mutans Streptococci in Young Children under Intravenous Anaesthesia

Clinical studies suggest that application of a highly concentrated chlorhexidine varnish results in a decrease in the number of mutans streptococci and thereby a decrease in the caries risks. The aim of this study was to determine the effect of dental treatment on the levels of mutans streptococci (MS) and lactobacilli (LB) and the additional effect of a single application of 40% chlorhexidine varnish (EC40) on the level of MS. Twenty–three children under the age of 5 years scheduled for full dental treatment were selected. Of these 23 children (mean dmf–s 27.1, SD 19.3), 11 children had nursing bottle caries. The mean sugar exposure was 6.4. Subjects were randomly distributed into two groups of approximately equal size. One group received an EC40 application after dental treatment, while the other group received only full dental treatment, both with intravenous anaesthesia with propofol as a single drug. An unstimulated saliva sample and a plaque sample were taken prior to dental treatment. The saliva and plaque sampling of the subjects was repeated after 6 weeks. MS and LB were isolated and counted. The number of children harbouring more than 10⁶ MS in a pooled plaque sample decreased significantly from 8 to 2 children 6 weeks after dental treatment. No additional effect of EC40 was found. The number of salivary MS did not change significantly between the groups or before and after treatment. The figures for LB remained at a high level of more than 10⁴/ml saliva before (21 children) and 6 weeks after treatment (17 children). The results of this study indicate that dental treatment results in a significant suppression of plaque MS, while a single application of EC40 showed no significant additional suppression after 6 weeks.

Mutans streptococci and lactobacilli on healthy and carious teeth in the same mouth of children with and without dental caries

Interactions between mutans streptococci and lactobacilli contribute towards the microbial challenge of dental caries. A comparison was made between numbers of mutans streptococci and lactobacilli in plaque from primary teeth in healthy children and between caries-free teeth and carious lesions in the same mouth of children with caries. The study group comprised 107 nursery-school children with a clinically healthy dentition and 117 children with caries. After a dental examination with mirror only, plaque was sampled from molar tooth 84 in caries-free children. An untreated carious lesion and a healthy tooth contralateral to the lesion was sampled in children with caries. Plaque was collected using a sterile wooden toothpick, inoculated into reduced transport fluid and processed for microbiology. Results showed no relationship between mutans streptococci, lactobacilli counts and dmft in children with caries. Yet, statistically significant correlation was found in counts of mutans streptococci (r=0.46, P=0.0001) between caries-free teeth and carious lesions in the same mouth. Mutans streptococci and lactobacilli numbers were significantly higher in caries-free teeth in children with caries than in healthy children (P=0.05; P=0.01). Mutans streptococci comprised 4.3% of total viable count in caries-free children, 8.2% in caries-free teeth and 14.4% in carious lesions, while lactobacilli composed 0.02%, 0.12% and 1.2% respectively. To conclude, high mutans streptococci counts in carious lesions causes an increase of these bacteria in caries-free teeth contralateral to the lesion in the same mouth, while caries-free teeth have statistically higher numbers than healthy teeth in children without caries in which the numbers are low. Keywords: mutans streptococci, lactobacilli, carious lesions, caries-free teeth, caries-free children.

Níveis de infecção de estreptococos do grupo mutans em gestantes

Considerando que a aquisição precoce dos estreptococos do grupo mutans é um fator de risco para o desenvolvimento de lesões cariosas nas crianças e que a transmissão desses microrganismos é dependente do nível de colonização apresentado pelas mães, procurou-se analisar a situação bucal de gestantes residentes na cidade de Bauru-SP-Brasil. Foram amostradas 50 gestantes na faixa etária de 16 a 37 (média de 22,8 ± 5,5 anos) de baixo nível sócio-econômico que faziam acompanhamento pré-natal no Núcleo de Assistência às Gestantes (NAG-7). A condição bucal foi avaliada pelo índice CPO-S, realizado com o auxílio de sonda exploradora e espelho, sem o uso de tomadas radiográficas. Amostras de saliva estimulada foram obtidas e manipuladas de acordo com as especificações do fabricante do Caritest-SM (HERPO), para pesquisa do grupo mutans. Entre as 50 gestantes examinadas, o índice CPO-S variou de 5 a 114 (média de 37,1), sendo que 8 (16%) possuíam todos os dentes; 39 (78%) haviam perdido de 1 a 10 dentes e 4 (8%), de 13 a 22 dentes. O grupo mutans foi detectado em 48 (96%) amostras de saliva, das quais 4 (8%) apresentavam nível de infecção de 1 x 104 UFC/ml; 10 (20%), 5 x 104 UFC/ml e 4 (8%), 1 x 105 UFC/ml. Níveis de infecção mais favoráveis para a transmissão mãe-filho foram encontrados em 30 (60%) gestantes, das quais 10 (20%) mostraram 2,5 x 105 UFC/ml; 12 (24%), 5 x 105 UFC/ml e 8 (16%), 1 x 106 UFC/ml. Esses resultados demonstram que as gestantes albergam elevados níveis salivares de estreptococos do grupo mutans e que um programa preventivo direcionado ao grupo urge ser desenvolvido, a fim de reduzir ou protelar a transmissão intrafamilial desses microrganismos.

Effect of NaF-, SnF2-, and chlorhexidine-impregnated birch toothpicks on mutans streptococci and pH in approximal dental plaque

The antimicrobial effect of birch toothpicks impregnated with 4% NaF, 8% SnF2, or 2% chlorhexidine was studied both in vitro and in vivo. A non-impregnated toothpick served as a control. In vitro, suspensions of Streptococcus mutans were exposed to the various toothpicks for 20 min and then cultured on blood agar. The results of this susceptibility test revealed the following ranking order with respect to inhibition: chlorhexidine > SnF2 > NaF and non-impregnated; with significant differences in colony-forming units (CFU) between these three groups. In vivo, 12 individuals used the 4 types of toothpick 3 times a day for 5 days in a procedure with a crossover design. Saliva and approximal plaque samples were collected at baseline and on various occasions up to 23 days after the treatment. At the same time, plaque-pH was measured at approximal sites 10 min after rinsing with 10% sucrose. The results of these in vivo experiments revealed lower proportions of mutans streptococci after using all four types of toothpick, but the reduction was significant only after 2 days for the toothpicks impregnated with SnF2 and chlorhexidine (P < 0.05). On the sampling occasions 9 and 23 days after the treatment, the mutans streptococci were more or less back to baseline levels again. In saliva no significant differences in the number of mutans streptococci were found either within or between the four treatments. No significant differences were found regarding decline in the plaque-pH between the NaF-, SnF2-, chlorhexidine-, and non-impregnated toothpicks on any of the sampling occasions.

Effects of xylitol, xylitolsorbitol, and placebo chewing gums on the plaque of habitual xylitol consumers

Xylitol reduces plaque but the reduction mechanism is largely unknown. The main aim of the present study was to determine whether the xylitol-induced reduction in the amount of plaque and the number of mutans streptococci could be demonstrated in subjects with (presumably) high levels of xylitol-resistant (XR; not inhibited by xylitol) mutans streptococci acquired following previous xylitol consumptions. 37 healthy dental students participated in the double-blind study. All subjects had been uncontrolled, habitual consumers of xylitol-containing products for at least 1 yr before the study. A 1-month washout period was followed by a 2-week test period during which either xylitol, xylitol-sorbitol or unsweetened chewing gum base was chewed 3-5 x a day. Plaque and saliva samples were collected at baseline and at the 2-week point for determination of the amount of plaque, microbiological variables, and hydrolytic enzymes. Mixtures of xylitol and sorbitol seemed to perform equally well with respect to reduction in the amount of plaque but not the number of mutans streptococci. Thus, polyols were the active ingredients of chewing gums able to modulate the amount of plaque and its microbial composition. Xylitol reduced plaque with a mechanism which appeared not to be associated with the study-induced changes in the proportion (%) of mutans streptococci in plaque, the number of salivary mutans streptococci, the proportion of XR strains in plaque or saliva, or the hydrolytic enzyme activities of plaque.

Oral Sugar Clearance and Other Caries-Related Factors in Patients with Myotonic Dystrophy

Engvall M, Birkhed D. Oral sugar clearance and other caries-related factors in patients with myotonic dystrophy.The aim of the investigation was to try to explain why patients with myotonic dystrophy (MD) have a high canes prevalence. Seventeen MD patients, 15 of whom had been examined 8 years earlier, and 17 matched, healthy controls participated. In connection with this follow-up examination, the oral sugar clearance was evaluated after chewing a glucose tablet. A paraffin-stimulated whole saliva sample was collected for determination of secretion rate, buffer capacity, and numbers of mutans streptococci and lactobacilli. Dietary score, plaque index, oral muscular coordination, and self-cleaning ability were also recorded. For all factors, the MD patients showed less favorable mean values than the controls; the differences between the groups were statistically significant, except for the bacterial counts and the salivary buffer capacity. Thus, the high caries prevalence in MD patients may be explained by longer oral sugar clearance time, lower salivary secretion rate, higher intake frequency of sugar-containing products, higher plaque index, and less pronounced oral muscular coordination and self-cleaning ability than in healthy individuals.