Efeito remineralizador e protetor de dentifrícios com tecnologia Refix® em lesões cariosas : um estudo in vitro

Abstract

Introduction: The REFIX® technology, incorporated into toothpaste, consists of fluoride, silica, and phosphates, forming stable complexes that act in the remineralization of carious dental tissues in acidic environments, such as saliva. Objective: To evaluate, in vitro, the remineralizing and protective effects of toothpaste containing REFIX® technology, with or without fluoride, on bovine enamel with and without initial caries lesions. Materials and Methods: Two independent pH cycling models were performed: one for the remineralizing effect (with initial caries lesions) and the other for the protective effect (without initial caries lesions). For each model, 60 blocks of bovine incisor enamel (4x4x2mm) were used, distributed into five groups (n=12/group): DRS1 - Regenerating + Sensitive Toothpaste - (1450 ppm NaF + silicate - REFIX® Technology); DRS2 - (1100 ppm NaF + silicate - REFIX® Technology); DRS3 - (silicate - REFIX® Technology without fluoride); CN – Negative Control (Toothpaste without fluoride and without REFIX® Technology); and CP - Positive Control (Oral B Toothpaste - 1450 ppm NaF without REFIX® Technology). In the remineralizing model, the enamel surface was divided into three parts: (1) sound area, (2) demineralized area, and (3) test area. For the protective model, the enamel surface was divided into two areas: (1) sound and (2) test area. The specimens were subjected to two models of cariogenic remineralizing pH cycling for six days (remineralizing effect) and five days (protective effect). The blocks were treated with toothpaste slurries (1:3 ratio) in a standardized brushing machine for two minutes, before and after the cariogenic challenge. At the end, the blocks were analyzed by Quantitative Light-induced Fluorescence (QLF) to evaluate the protection/remineralization variables (ΔF) and lesion depth (ΔFmax). The data showed normal distribution and were analyzed using ANOVA, followed by Tukey's test, and Pearson correlation, with p<0.05. Results: Significant differences were observed between the groups in both models studied, for both variables. In the remineralizing model, analyzing the ΔFRE variable, the DRS2 and DRS3 groups showed the best efficacy in caries remineralization, followed by DRS1 and CP. The groups treated with REFIX® Technology showed a substantial reduction in lesion depth (ΔFmaxRE), comparable to CP. The CN group showed mineral loss and increased lesion depth after treatment. A significant positive correlation was observed between the ΔFRE and ΔFmaxRE variables (p<0.05). In the protective effect, analysis of the ΔF variable showed that the DRS1, DRS2, and CP groups (p>0.05) were more effective in protecting enamel after the cariogenic challenge, while DRS3 and CN differed significantly from the first groups (p<0.05) and showed the greatest mineral loss. For the ΔFmax variable, in the same model, the efficacy in protecting against the formation of less deep lesions can be classified as DRS1= DRS2> CP>DRS3=CN. Conclusion: REFIX® technology combined with fluoride demonstrated efficacy in both remineralizing carious lesions and protecting against cariogenic acidic challenges. In the protective model, fluoride concentration had a greater influence on the formation of more resistant enamel, while in the remineralizing model, mineral gain was also observed in toothpastes with REFIX® technology without fluoride. These findings highlight the potential of REFIX® technology as an additional therapeutic option for the prevention and remineralization of dental caries.