Caries-preventive and remineralizing effect of fluoride gel in orthodontic patients after 2 years.

Patients with orthodontic appliances exhibit a higher caries risk, but they are often excluded from preventive studies. Thus, the aim of this observational study was to assess the caries-preventive and remineralizing effect of a high-fluoride gel in orthodontic patients. Two hundred twenty-one orthodontic patients (age, 6-19 years; mean, 13.1 ± 2.3; n = 104 with use of a 1.25% fluoride gel weekly at home, 117 participants without) were recruited and followed for 2 years, recording caries (decayed/missing/filled teeth (DMFT)/decayed/missing/filled surface (DMFS), active/inactive lesions), orthodontic treatment, use of fluorides, plaque and gingivitis. Baseline values regarding demographic and clinical parameters were equivalent for the 75 participants using fluoride gel and the 77 individuals of the control group who completed the study. The initial plaque and gingivitis values (approximal plaque index (API), 37% ± 34 and 42% ± 39, resp.; papillary bleeding index (PBI), 19% ± 28 and 22% ± 27, resp.) deteriorated slightly during the 2-year study (API, 54%/56%; PBI, 25%/28%). The increase in carious defects or fillings was minimal in both groups (fluoride, 0.75 DMFT ± 1.2, 1.27 DMFS ± 1.9; control, 0.99 ± 1.3 and 1.62 ± 2.6, resp.) without reaching statistical significance (p = 0.12 for DMFT, 0.44 for DMFS). The main statistically significant effect of the fluoride use was the reversal of active initial lesions diagnosed (fluoride group, -0.96 ± 1.82; control, -0.19 ± 2.0, p = 0.004), while the number of inactive initial lesions increased (2.3 ± 2.1 and 1.7 ± 2.1, resp.; p = 0.02). In conclusion, the weekly application of a fluoride gel in orthodontic patients can reduce their caries activity. Initial caries lesions in orthodontic patients can be inactivated by weekly fluoride gel use at home.

Efficacy of semiannual topical fluoride application in schoolchildren.

OBJECTIVE: Fluoride is the most important factor in the decline of caries in children and adolescents. The aim of this observational study, begun in 2000, was to assess the effect of semiannual topical fluoride application in schoolchildren. METHOD AND MATERIALS: Due to limited resources, only 334 of all first and second grade schoolchildren (6 to 8 years of age, 0.32 ± 1.02 decayed/missing/filled surface [DMFS], schools randomly selected) in Greifswald received a semiannual application of elmex fluid, while the remaining 442 children served as the control group (0.36 ± 1.15 DMFS). In 2002 and 2004, 230 and 349 of these children were re-examined according to WHO criteria by one calibrated examiner (DMFT/S). The parents filled out questionnaires on additional fluoride use, which was summarized as fluoride scores. In the dropout analysis, a selection bias among the dropout, fluoride, and control group regarding age, baseline caries prevalence, additional fluoride use, and sealants was excluded. RESULTS: During the entire study, no adverse effects were recorded with the use of elmex fluid. The caries increment was almost identical in the intervention and control groups (0.81 ± 1.74 and 0.78 ± 1.81 DMFS) with 72% and 69% of the children, respectively, showing no caries increment. The effect of only two applications of elmex fluid might have been overridden by the high background fluoride use. The participants had high mean values of the fluoride scores, reflecting the regular use of fluoride toothpaste and additional fluoride sources, without a polarization within the sample (intervention, 1.40 ± 0.60; control, 1.33 ± 0.60). CONCLUSION: Further studies should examine the effect of semiannual topical fluoride applications after caries decline.

Sealing proximal surfaces with polyurethane tape: three-year evaluation.

The purpose of this investigation was to test the safety and clinical effect of a new material for the treatment of proximal caries. In 50 patients with two proximal initial lesions, one of the lesions was randomly chosen and sealed with a thin polyurethane-dimethacrylate foil using bonding. The other lesion received oral home care and was left as the control. In clinical follow-ups after 6 and 12 months and X-ray evaluation after 2 and 3 years, the sealants showed good retention, marginal adaptation, and color. No relevant significant differences in plaque accumulation or gingival status were found between sealed and control teeth. On the radiographs, almost all sealed and control lesions appeared stable, indicating an arrest of the lesion. In conclusion, sealing initial proximal lesions showed no clinical problems and mostly arrest of caries on bitewing radiographs.

Sealing of proximal surfaces with polyurethane tape: a two-year clinical and radiographic feasibility study.

PURPOSE: Proximal carious lesions comprise a constant clinical problem. The aim of this investigation was to test the safety and clinical effect of a new treatment for proximal caries. MATERIALS AND METHODS: In 50 patients with two proximal initial lesions (D1-3 without cavitation, bitewing radiograph), orthodontic rubber rings were applied to gain access to the interproximal space. One of the lesions was sealed with a thin polyurethane-dimethacrylate foil using a bonding agent; the other lesion received oral home care with dental floss and fluoridated toothpaste, and was left as control. RESULTS: In clinical follow-ups after 6 and 12 months and radiographic evaluation after two years, clinical retention of proximal tape and the underlying sealant, marginal adaptation, discoloration, tooth vitality, proximal plaque, and gingivitis were checked. In addition, carious lesions were assessed clinically and radiographically. The sealants showed good retention, marginal adaptation, and color. After two years, vitality of all teeth was still positive and no relevant differences in plaque accumulation or gingival status were found between sealed and control teeth. Nine sealed lesions showed caries regression and 2 progression. In contrast, only 4 control lesions regressed and also 2 showed progression. The loss of tape had no significant influence on the lesion progression, indicating the effect of the underlying bond. All other sealants and control lesions were stable, indicating an arrest of the lesion. CONCLUSION: Sealing initial proximal lesions showed no clinical problems and mostly arrest of initial carious lesions on bitewing radiographs.

Effect of xylitol and sorbitol on plaque acidogenesis.

OBJECTIVE: To evaluate the in vivo potential of xylitol to reduce plaque acidogenicity in comparison to sorbitol. METHOD AND MATERIALS: After completing a questionnaire on general health, smoking, diet, and oral hygiene habits, 61 dentate adults refrained from oral hygiene for 3 days before the clinical baseline examination, which included decayed, missing, and filled teeth (DMFT) index, mutans streptococci and lactobacilli counts, and plaque acidogenicity (cH) index after a sucrose rinse. Then the participants were randomly allocated to consume either sorbitol or xylitol lozenges (5 pieces/day, 2 g each) for 4 weeks and were asked to refrain from oral hygiene for the 3 days prior to the final examination (cH, area < pH 7, bacterial counts). RESULTS: The variation of acidogenicity in different individuals was considerable at baseline (range: 0.2 to 446.6 min micromol/L) with a mean value of 37.9 +/- 58.9 min micromol/L for the sorbitol group and 60.6 +/- 87.6 min micromol/L for the xylitol group. At the end of the study, the reduction in the xylitol group (42.9 +/- 80.6 min micromol/L) was statistically significantly higher than in the sorbitol group (6.0 +/- 69.4 min micromol/L, P = .034), which was also confirmed in an additional analysis excluding 2 participants with extreme values (reduction for xylitol: 29.5 +/- 36.9 min micromol/L; sorbitol: 1.7 +/- 57.0 min micromol/L; P = .019). Statistically significant differences were also found for the area below pH 7 (reduction for xylitol: 10.8 min pH; sorbitol, 0.2 min pH; P = .0025). CONCLUSION: The regular consumption of xylitol lozenges modifies dental plaque, resulting in a marked reduction in the plaque acidogenicity, which could not be detected using sorbitol lozenges. Therefore, xylitol could have an additional benefit in caries prevention.

Influence of cytoplasmic deletions on the filopodia-inducing effect of syndecan-3.

Syndecans, transmembrane heparan sulfate proteoglycans (HSPG), mediate cell-cell and cell-matrix adhesion thereby controlling cell movement and shape. Syndecan cytoplasmic domains are very short (ca. 30 amino acids) and divided into two constant regions (C1 and C2) separated by one variable (V) region. Here we attempted to map the cytoplasmic region responsible for the filopodia-inducing effect of syndecan-3. We found that only the C1-region was necessary for this effect. In addition, the deletion of the C2-region led to extensive membrane blebbing. Nevertheless, the elimination of the entire cytoplasmic region did not affect delivery of syndecan-3 to the plasma membrane. These results indicate that the different regions of syndecan-3 cytoplasmic domain have different functions probably by binding to distinct proteins.

Syndecan-2 expression enhances adhesion and proliferation of stably transfected Swiss 3T3 cells.

Syndecans (heparan sulfate proteoglycans) participate in cell-cell and cell-matrix adhesion and are co- and low-affinity receptors for growth factors and enzymes, respectively. We examined the influence of stable syndecan-2 expression in Swiss 3T3 cells on cell-adhesion and proliferation. Higher syndecan-2 expression changed cell morphology and increased spreading and adhesion in these cells and proliferation induced by FCS and FGF-2. This emphasizes the role of syndecan-2 in the integration of signals from soluble and insoluble factors.

Identification of a novel Ezrin-binding site in syndecan-2 cytoplasmic domain.

ERM (Ezrin/Radixin/Moesin) proteins are crosslinkers between plasma membrane proteins and the actin cytoskeleton, thereby involved in the formation of cell adhesion sites. Earlier work showed that Ezrin links syndecan-2 to the actin cytoskeleton. Here we provide evidence that the Ezrin N-terminal domain binds to the syndecan-2 cytoplasmic domain with an estimated K(D) of 0.71 microM and without the requirement of other proteins. We also studied the regions in the syndecan-2 cytoplasmic domain implicated in the binding to Ezrin. By truncating the syndecan-2 cytoplasmic domain and by oligopeptide competition assays we show that the Ezrin-binding sequence is not located in the positively charged juxtamembrane region (RMRKK), but in the neighboring sequence DEGSYD. We therefore conclude that the consensus sequence for Ezrin binding is unique among membrane proteins, suggesting a distinct regulation.