Soluções de fluoreto de prata associadas ou não ao iodeto de potássio: eficácia in vitro na prevenção da perda de dureza de esmalte bovino e e-book instrucional

Abstract

The present dissertation consists of two products: (1) a laboratory study and (2) an ebook. The aim of the in vitro study was to evaluate the efficacy of 38% ammonia-free silver fluoride solution (SFS), with and without subsequent application of potassium iodide (KI), as a second step in preventing the prevention of surface microhardness loss of bovine enamel surfaces. For the study, bovine enamel blocks (4×4×2 mm) were prepared and randomly allocated into 4 groups (n = 10 per group): G1 - sterility control, G2 - growth control, G3 - SFS (Riva Star Aqua® 38%) without KI application, and G4 - SFS (Riva Star Aqua® 38%) with KI application. All blocks (n=40) were analyzed for initial Knoop surface microhardness (50g for 5s) and were subsequently adhered to 24- well culture plates, with G3 and G4 treated according to the manufacturer’s guidelines. The blocks were then covered with Brains-Heart Infusion culture medium enriched with 5% sucrose (1000μl/well), and except for G1, a mixed inoculum (20ul/well) of Streptococcus mutans (ATCC 25175) and Candida albicans (ATCC 10231) was added to the wells. The plates/blocks system was incubated for 24 and 48 hours in microaerophilia at 37°C. During the cariogenic challenge, 20 blocks (n=5 per group) were removed after 24 hours (moment 1) and 20 (n=5 per group) after 48 hours (moment 2). After each time point of the study, the blocks were evaluated for final surface microhardness to assess the percentage of surface microhardness loss (%SML). The pH of the culture medium was also measured using a pH meter at moments 1 and 2. The data were analyzed using ANOVA, followed by Tukey’s test (p<0.05). Similar initial microhardness values were observed among the groups (p>0.05). There was no difference (p>0.05) between G3 and G4 at both time points regarding the %SML. However, G3-48h (-3.39±6.76) was similar to G1-24h (0.60±9.34; p=1,00) and G1-48h (12.31±8.59; p=0,53), and different from G2-24h (22.77±10.35; p=0,05) and G2-48h (31.40±13.25; p=0,03), still demonstrating a gain in enamel hardness. The groups without (G3) and with KI (G4) showed no difference in pH between them (p>0,05), but had higher values than the controls (G1 and G2) at both time points (p<0.05). Regarding the e-book, the aim was to develop educational material to guide dentists and dental students on the indications for use, concentrations, advantages, and disadvantages, as well as the step-by-step application of silver diamine fluoride (SDF) and ammonia-free SFS available in the domestic market, considering caries and hypersensitivity outcomes. The e-book, created on the Canva® platform, includes illustrations and citizen language, and its content was based on scientific literature, current guidelines, and recommendations from pediatric dentistry societies. It consists of 24 pages, with 15 sections and is hosted on the Pantheon platform (https://pantheon.ufrj.br). Considering the limitations of the in vitro study, it is concluded that after 48 hours in cariogenic challenge, the SFS without KI presented potential for the prevention of dental enamel demineralization, with more studies needed to contribute to the evidence base. Furthermore, as an important advancement in disseminating scientific knowledge about SDF and SFS available in the domestic market, the e-book has been published in the UFRJ repository.