Der remineralisierende Effekt von Silberdiaminfluorid auf artifizielle initiale Läsionen an Glattflächen – Eine in-vitro Studie

Objektive: Every caries starts as an initial carious lesion. In contrast to later stages, an exclusively non-invasive therapy can lead to the complete reversion of the caries. There are a large number of different active substances on the market for this purpose, mainly fluoride-based. A sollution with silver diamine fluoride introduced in Germany in 2020 represents an expansion to the products available to date. Aim: This study compared several dental varnishes in terms of their remineralisation performance. Particular attention was paid to silver diamine fluoride. The aim was to find out whether silver diamine fluoride can achieve or even exceed the caries-inhibiting effect of established dental varnishes. Material and Method: 45 tooth samples from extracted human permanent teeth were cleaned and ground so that a plane smooth surface was formed in the enamel. The tooth samples were demineralised with lactic acid (pH = 4.6) for 2 weeks. They were divided into 3 groups of 15 teeth each and treated once with I: Riva Star (SDF), II: Bifluorid 12 (NaF, CaF2), III: Cervitec F (CHX, CPC, NH4F). Afterwards, the teeth were exposed to a pH-cycling regime for 28 days to model the stress placed on teeth in an oral cavity. The tests were carried out immediately after demineralisation and on a weekly basis after the start of pH-cycling. Quantitative light-induced fluorescence was chosen as the measurement method to collect data on average and maximum fluorescence loss (∆F, ∆Fmax), as well as lesion volume (∆Q). The results were examined for their normal distribution using the Shapiro-Wilks test and for their variance using ANOVA and the Levene test. The post-hoc analysis was carried out with the Mauchly test. The significance level was defined as α = 0.05. Result: After demineralisation, all samples showed a mean value of ∆F of -16.53 ± 4.29%, without significance differences between the mineralisation of the groups (p = 0.393). After varnish applikation the mean value increased to ∆F = -13.73 ± 4.75% (p = 0.77). After 14 days, the samples of Group I (Riva Star) were on average the most mineralised with ∆F = -15.53 ± 4.42%. This was followed by the samples of group III (∆F = -15.97 ± 4.56%) and II (∆F = -19.4 ± 5.19%). The differences between the groups were not statistically significant (p = 0.06). After 28 days, the samples of group III (Cervitec F) were the most mineralised with ∆F = -11.71 ± 4.83%. These were followed at some distance by Groups II (∆F = -15.53 ± 2.15%) and I (∆F = -16.47 ± 6.08%). The mineralisation of the groups among each other varied significantly (p = 0.018). By measuring the tooth samples several times over time, trends for the de- and remineralisation processes of the different varnishes could be observed: The mineralisation of groups II (Bifluorid 12) and III (Cervitec F) decreased from day 1 to day 14 and subsequently increased after that. In group I (Riva Star), mineralisation decreased less until the 14th day, but there was no subsequent increase. In addition to the measurements of the QLF, a slight yellow colouration could be detected on the tooth samples of group I after the application of the varnish, which did not change over the course of the experiment. Conclusion: In the first 2 weeks, the demineralisation-inhibiting effect of the SDF varnish exceeds that of the other dental varnishes. However, in the 3rd and 4th week, this was more than compensated by a higher remineralisation rate of these. The best remineralising of the varnishes used after 4 weeks was the CHX, CPC and NH4F-based Cervitec F varnish. Due to the recognised trends, the seemingly contradictory results in the existing literature, when comparing SDF with conventional fluoride varnishes, can be reconciled with the help of the categorisation of the time period of the pH cycling carried out. Due to its strong demineralisation-inhibiting effect in the first 14 days, the SDF varnish seems to be predestined for patients with a temporary deterioration of oral hygiene, such as patients after oral surgery, while the Cervitec-F varnish is suitable for patients who are compromised for a longer period of time, such as wearers of orthodontic appliances.