Desenvolvimento de um modelo in vitro de cárie recorrente utilizando biofilme de microcosmos e materiais resinosos contendo flavonoides

Abstract

Introduction: Recurrent caries is considered one of the main factors in the replacement of composite resin restorations. In an attempt to reduce recurrent caries at restoration margins and reduce the replacement of these restorations, resin materials containing antibacterials have been proposed. Antibacterials that have a specific action on the virulence factors of the cariogenic biofilm are more desirable. Because, in addition to having the potential to reduce caries formation, they are less likely to promote bacterial resistance or to alter the resident health-related oral microbiota. Objectives: to develop a new in vitro model of recurrent caries, with complexity similar to the oral environment, and to test new resin materials containing flavonoids that have specific antimicrobial activity on the virulence of Streptococcus mutans. At the same time, to assess whether the addition of these flavonoids negatively affects the flexural strength, degree of conversion and color of these materials. Material and methods: An in vitro model of recurrent caries with microcosm biofilm and cycling with artificial saliva was developed using bovine teeth restored with experimental resins. Experimental composite resins were manipulated and the flavonoids apigenin, pinocembrin and kaempferol were added, either alone or by combining apigenin with pinocembrin or kaempferol. After polymerization, the composites were evaluated for their ability to inhibit the growth of S. mutans and recurrent caries, as well as flexural strength, degree of conversion and color analysis. Results: There was no statistical difference in flexural strength. For the degree of conversion, no addition of flavonoids was able to reduce total conversion compared to the control group. There was no significant difference in the viability of S. mutans, however pinocenbrin and apigenin+pinocembrin reduced the dry weight of the biofilm. Only Pino did not affect composites color parameters compared to control group, except for L*. Conclusion: Although pinocembrin reduced biofilm dry weight and presented the least effect on color alteration, no experimental composite reduced visual demineralization in the proposed recurrent caries model.