Effect of a daily dose of <i>Lactobacillus brevis</i> CD2 lozenges in high caries risk schoolchildren

Objectives A double-blind, randomised, placebo-controlled clinical trial was performed to validate the hypothesis that the use of lozenges containing Lactobacillus brevis CD2 (Inersan®, CD Investments srl) may reduce plaque pH, salivary mutans streptococci (ms) and bleeding on probing, during a 6-week period, in a sample of high caries risk schoolchildren. Methods A total of 191 children (aged 6–8 years), presenting two to three carious lesions and a salivary ms concentration of ≥105 CFU/ml, were enrolled and divided into two groups, an L. brevis CD2 lozenge group and a no L. brevis lozenge group, and examined at baseline (t0), after 3 weeks (t1), after 6 weeks of lozenge use (t2) and 2 weeks after the cessation of lozenge use (t3). Plaque pH was assessed using the microtouch technique following a sucrose challenge. The area under the curve (AUC5.7 and AUC6.2) was recorded. Salivary ms were counted, and bleeding on probing was assessed. Results At t0, the plaque-pH and ms concentration values were similar in both groups. Mean areas (AUC5.7 and AUC6.2) were significantly greater in the control group at t1, t2 and t3. L. brevis CD2 lozenges significantly reduced salivary ms concentrations and bleeding. The subjects from the test group showed a statistically significant decrease (p=0.01)in salivary ms concentration. At t2, a statistically significantly lower bleeding value was recorded in the test group compared with the control group (p=0.02). Conclusions Six weeks’ use of lozenges containing L. brevis CD2 had a beneficial effect on some important variables related to oral health, including a reduction in plaque acidogenicity, salivary ms and bleeding on probing.</br

Six months of high-dose xylitol in high-risk caries subjects—a 2-year randomised, clinical trial

Objectives The hypothesis was that the daily use of a high dose of a xylitol chewing gum for 6 months would reduce the increment of decayed permanent first molar surfaces (ΔD6S) in high-risk schoolchildren after 2 years. Methods In this randomised, clinical trial, 204 schoolchildren with a high caries risk were assigned to two experimental groups, xylitol and non-xylitol. Caries status, salivary mutans streptococci, and lactobacilli were re-evaluated 2 years later in 74 xylitol-treated and 83 non-xylitol-treated schoolchildren. Differences in mean ∆D6S between groups registered at baseline and at follow-up were evaluated using the nonparametric Mann–Whitney U test. Results Outcome was the development of detectable carious lesions initial (D1–D2) and manifest (D3) in the permanent first molars. In the xylitol group, the difference in proportion of children with decayed first permanent molars at baseline and follow-up was 1.43 % for manifest lesion and 2.86 % for initial lesions; while in the non-xylitol group was 10.26 % (p &lt; 0.01) and 16.66 % (p &lt; 0.01), respectively. A statistically significant difference regarding means was also observed in the non-xylitol group: the ∆D6S for manifest lesion was 0.18 (p = 0.03) and 0.67 (p = 0.02) for initial lesion. Conclusion The use of a chewing gum containing a high dose of xylitol for a period of 6 months has been shown to produce a long-term effect on caries development in high caries-risk children. Clinical relevance A school-based preventive programme based on 6 months’ administration of a high dose of xylitol via chewing gum proved to be efficacious in controlling caries increment in high-risk children

Opportunities for caries prevention using an ion-releasing coating material: a randomised clinical study

Ion-releasing materials (containing fuoride and boron, for example) have shown caries-preventive efects in vitro. The purpose of the present study was to investigate the impact of multi-ion-releasing coating material on pH stabilisation, plaque accumulation and the bacterial composition of dental plaque during a time period of 90 days. The null hypothesis tested here was that the evaluated material would not show any diferences in pH stabilisation, plaque accumulation or bacterial composition compared with control material. The study was carried out as a double-blind, split-mouth, randomised, controlled clinical trial in 28 volunteers. Over the evaluation period (days 4, 30, 60 and 90), pH measurements, plaque index and plaque sampling for bacterial analyses were conducted in a calibrated, standardized manner. The study received ethical permission and was carried out in accordance with the Helsinki Declaration. A signifcant diference was observed, with less plaque accumulation over time in the subjects in whom the ion-releasing material was applied in comparison to the non-active group. No signifcant diference was evident in terms of either pH stabilisation or plaque levels of mutans streptococci. The null hypothesis relating to plaque accumulation was rejected, with a lower plaque index shown for the test group up to 60–90 days. No adverse efects during the observation period were observed. Since the studied cohort was healthy from a caries perspective, more clinical studies are needed to further evaluate the caries-prevention potential of the ion-releasing material in other patient groups

The Influence of Sweet Taste Perception on Dietary Intake in Relation to Dental Caries and BMI in Saudi Arabian Schoolchildren

Objectives. The aim of the study was to evaluate the influence of sweet taste perception on dietary habits in Saudi schoolchildren. In addition, the relationship between dietary habits and both caries and BMI was studied. Methods. A cross-sectional observational study comprising 225 schoolchildren aged 13–15 years from Jeddah, Saudi Arabia, was conducted. The consumption frequency of certain food items was analysed from a beverage and snack questionnaire and a three-day estimated dietary record was obtained. The sweet taste perception level was determined as sweet taste threshold (TT) and sweet taste preference (TP). Children were grouped into low, medium, and high, according to their sweet taste perception level. ICDAS and DMFS indices were used for caries registration and anthropometric measurements using BMI were collected. Results. Sweet taste perception was found to be negatively correlated to the number of main meals and positively correlated to both snack and sweet intake occasions. Statistically significant differences were found between the TT and TP groups with regard to the number of main meals and sweet intake (p≤0.01). No significant correlation between the dietary variables and caries or BMI was found. Conclusions. The dietary habits and sweet intake were found to be influenced by the sweet taste perception level, while the relation between the dietary habits and the caries and BMI was found insignificant

Effect of fluoridated toothpicks and dental flosses on enamel and dentine and on plaque composition in situ

The aim was to evaluate the effect of two toothpicks and two dental flosses on demineralized enamel and dentine and on plaque composition, using an in situ model with simulated approximal spaces within dentures. Fifteen subjects with full dentures were recruited and 14 completed the study. It consisted of two crossover periods, the first comparing a birch toothpick with AmF and a birch toothpick with NaF, and the second comparing a dental floss with AmF + NaF and a dental floss without F. Between these four periods, there was a control period without any approximal cleaning. In small, rectangular sample holders, one enamel and one dentine specimen were embedded, forming a triangular, approximal-like space. Two sample holders were mounted in the premolar-molar region of the upper or lower dentures. The subjects used the toothpicks or dental flosses 3 times/day for 4 weeks. The results showed that all toothpicks and dental flosses inhibited further demineralization compared to the control period ( p <0.001). The dental flosses were somewhat more effective in this respect than the toothpicks, especially in dentine. There were relatively small numerical differences between AmF and NaF toothpicks, but in favour of NaF regarding mineral gain ( p <0.05). The fluoridated floss gave somewhat less lesion depth in dentine than the non-fluoridated floss ( p <0.01). Toothpicks and flosses resulted in lower counts of microorganisms in plaque compared to the control period ( p <0.001); the AmF toothpick gave a more pronounced reduction than the NaF toothpick ( p <0.001). Copyright (C) 2005 S. Karger AG, Basel

Supragingival plaque microbial analysis in reflection to caries experience

Background: Dental caries develops as a result of the metabolism of carbohydrates by cariogenic bacteria present in a complex biofilm. The present study aimed to examine if bacteria in pooled supragingival plaque samples quantified using a “checkerboard DNA-DNA hybridization” based panel of caries-related bacteria, could reflect the caries experience in a manner similar to saliva samples analysed using a chair-side method in a previous investigation. Methods: A total of 86 mothers and their children aged 4–6 years and 12–16 years old participated. Caries experience (DMFT/dmft; Decayed, Missing and Filled Teeth for permanent and primary teeth) was registered clinically and radiographically. Caries was recorded at the D3 level (caries into dentine). The D/d component was divided into three categories. A pooled supragingival plaque sample per participant was obtained from posterior approximal sites. Analyses of 15 bacterial species were performed using the checkerboard DNA-DNA hybridisation technique. Results: No significant relationships were found between the bacterial scores and DMFT/dmft nor D/d groups. Conclusions: Unlike the saliva samples and the chair-side method, interproximal pooled plaque samples analysed using the “checkerboard DNA-DNA hybridization technique” did not reveal any significant relations between the bacterial counts and the caries experience.</br

In Vitro Assessment of Shiitake Mushroom (Lentinula edodes) Extract for Its Antigingivitis Activity

Gingivitis is a preventable disease characterised by inflammation of the gums due to the buildup of a microbial biofilm at the gingival margin. It is implicated as a precursor to periodontitis, a much more serious problem which includes associated bone loss. Unfortunately, due to poor oral hygiene among the general population, gingivitis is prevalent and results in high treatment costs. Consequently, the option of treating gingivitis using functional foods, which promote oral health, is an attractive one. Medicinal mushrooms, including shiitake, have long been known for their immune system boosting as well as antimicrobial effects; however, they have not been employed in the treatment of oral disease. In the current study, the effectiveness of shiitake mushroom extract was compared to that of the active component in the leading gingivitis mouthwash, containing chlorhexidine, in an artificial mouth model (constant depth film fermenter). The total bacterial numbers as well as numbers of eight key taxa in the oral community were investigated over time using multiplex qPCR. The results indicated that shiitake mushroom extract lowered the numbers of some pathogenic taxa without affecting the taxa associated with health, unlike chlorhexidine which has a limited effect on all taxa

Algebraic analysis of a model of two-dimensional gravity

An algebraic analysis of the Hamiltonian formulation of the model two-dimensional gravity is performed. The crucial fact is an exact coincidence of the Poisson brackets algebra of the secondary constraints of this Hamiltonian formulation with the SO(2,1)-algebra. The eigenvectors of the canonical Hamiltonian $H_{c}$ are obtained and explicitly written in closed form.Comment: 21 pages, to appear in General Relativity and Gravitatio