The potential use of glycosyl-transferase inhibitors for targeted reduction of S. mutans biofilms in dental materials.

Streptococcus mutans is the primary oral caries-forming bacteria, adept at producing "sticky" biofilms via the synthesis of insoluble extracellular polysaccharides (EPS), catalyzed by glucosyltransferases (GTFs). To circumvent the use of broad-spectrum antibiotics to combat these bacteria, this study sought to modify existing EPS-targeting small molecules with the ultimate goal of producing anti-biofilm polymer surfaces specifically targeting S. mutans. To achieve this, a known GTF inhibitor (G43) was modified with methoxy or tetraethyleneglycol substitutions in different positions (nine derivatives, tested at 50-µM) to pinpoint potential sites for future methacrylate functionalization, and then assessed against single-species S. mutans biofilms. As expected, the compounds did not diminish the bacterial viability. In general, the compounds with methoxy substitution were not effective in reducing EPS formation, whereas the tetraethyleneglycol substitution (G43-C3-TEG) led to a decrease in the concentration of insoluble EPS, although the effect is less pronounced than for the parent G43. This aligns with the reduced GTF-C activity observed at different concentrations of G43-C3-TEG, as well as the consequent decrease in EPS formation, and notable structural changes. In summary, this study determined that G43-C3-TEG is non-bactericidal and can selectively reduce the biofilm formation, by decreasing the production of EPS. This molecule will serve to functionalize surfaces of materials to be tested in future research.

Associação terapêutica conservadora para o tratamento das manchas de fluorose dental / Conservative treatment therapy for dental fluorosis staining

O excesso de ingestão de flúor durante o desenvolvimento do órgão dental pode resultar em alterações estruturais tanto em esmalte quanto em dentina. No esmalte, observa-se um aumento de porosidades causadas pela interação do flúor com os prismas em desenvolvimento, tanto na superfície quanto em profundidade. Clinicamente essas alterações são visíveis como manchas com aspecto que vai do branco opaco ao amarelo amarronzado. A presença de manchas no esmalte dental leva ao comprometimento estético do sorriso tão valorizado atualmente. Para a homogeinização de cor, nos casos mais brandos, recomenda-se a realização do tratamento clareador com agentes oxidantes de baixa concentração (clareamento caseiro). Em casos mais severos a associação do clareamento caseiro com o procedimento de microabrasão é indicada para remoção das manchas de fluorose. Na microabrasão, o uso simultâneo da abrasão e da erosão ácida é capaz de remover as manchas decorrentes de alterações superficiais em esmalte. Portanto, utilizando tratamentos conservadores é possível devolver a autoestima do paciente de forma bastante satisfatória.

The excess fluoride intake during dental organ development may result structural changes in enamel and dentin. Increase porosity was observed by fluorine interaction with enamel prisms development, both on surface and in depth. Clinically these changes are visible as spots with aspect that goes from opaque white to brownish yellow. The enamel spots leads to unpleasant smile. In mild cases, for color homogenization, it is recommended bleaching treatment with low concentration oxidizing agents (home bleaching). In more severe cases, the home bleaching and microabrasion procedure association are indicated for fluorosis stains removal. In microabrasion, the association of abrasion and acid erosion remove stains from changes on enamel surface. Thus conservative treatments can successfully restore patient's self- esteem.