Zur kariesprotektiven Wirkung einer Zahnpaste mit bioaktivem Glas im Vergleich zu Zahnpasten mit unterschiedlichen Fluoridverbindungen

Objective: Caries as a localized, multifactorial disease begins with an initial carious lesion of the enamel. To counteract a progression of this initial lesion, there are, among other measures, various toothpastes on the market with caries-protective effects. A toothpaste with bioactive glass and sodium fluoride that appeared on the market in 2016 promises to incorporate to the tooth surface due to the bioactive glass and release calcium, phosphate and fluoride ions over a longer period of time. This is said to lead to an improved remineralizing effect. Aim: In the present study, the remineralizing behaviour of the toothpaste with bioactive glass and sodium fluoride was investigated in-vitro in comparison with toothpastes containing the different fluoride compounds sodium fluoride and stannous fluoride. This study aimed to determine whether differences exist in the remineralizing efficacy of the toothpaste with bioactive glass and sodium fluoride and the comparative toothpastes. One hypothesis focussed on the comparison of the remineralizing effect of the toothpaste with bioactive glass and sodium fluoride and the toothpaste with sodium fluoride based on the fluorescence loss (∆F) and the volume of the lesion (∆Q). The other hypothesis focussed on the comparison of the remineralizing effect of the toothpaste with bioactive glass and sodium fluoride and the toothpaste with stannous fluoride based on the fluorescence loss (∆F) and the volume of the lesion (∆Q). Material and Method: Forty-five tooth specimens of extracted human teeth were used for the study. An area was polished on all specimens (n = 45), 15 specimens each were randomly assigned to three groups (test group, control group I, control group II) and artificially demineralized for 14 days using a methylcellulose-lactic acid system (pH = 4.6). A toothpaste with a different fluoride compound was selected for each group: Test group = BioMinTM F (bioactive glass and 530 ppm sodium fluoride), control group I = Signal Kariesschutz (1450 ppm sodium fluoride) and control group II = Sensodyne Repair*&Protect (1100 ppm stannous fluoride). Over a period of 90 days, the samples were stored in a remineralization solution at 37 °C in an incubator. All samples were treated in the sense of a pH cycling model to simulate the phases of demineralization and remineralization. For this purpose, they were soaked every day twice for two minutes in 0.1 M lactic acid (pH = 4.6), rinsed with distilled water and then placed in a toothpaste suspension of the respective toothpaste for two minutes. Quantitative light-induced fluorescence (QLFTM) measurements were performed before and after demineralization and after 7, 30, 60 and 90 days. The mineralization behaviour was assessed using the parameters of fluorescence loss (∆F in %) and volume of lesion (∆Q in % x px2). Subsequent statistical analysis was performed using MedCalc software, version 19.3.1. The Shapiro-Wilk test was used to examine the measurements for normal distribution (p < 0.001). The Kruskal-Wallis test was carried out to examine the independent data, the Friedman test was used for the dependent data and for further analysis the Conover's post-hoc was used. The significance level was set at α = 0.05. Results: After 7 days, significant differences were observed for fluorescence loss ∆F in % (p = 0.019) and lesion volume ∆Q in % x px2 (p = 0.011). For both parameters, the test group (bioactive glass and sodium fluoride) showed lower remineralizing efficacy after 7 days compared to both control groups. After 90 days, a significant difference in remineralizing effect was observed for ∆F (p = 0.041). Accordingly, the test group (bioactive glass and sodium fluoride) showed a greater loss of fluorescence and thus a lower remineralizing effect than the control group II (stannous fluoride). Disucussion and Conclusion: The results of this in-vitro-study show that after 7 days, the test toothpaste and both reference toothpastes, as well as over a period of 90 days, the test toothpaste and the reference toothpaste with stannous fluoride do not have the same remineralizing efficacy. The comparative toothpaste with stannous fluoride showed the highest remineralizing effect regarding the ∆F parameter. Further studies are needed to verify the results obtained in this study in-vivo.