IMPACTO DA MODELAGEM ADESIVA E DO TIPO DE LUVA NAS PROPRIEDADES MECÂNICAS DE UMA RESINA COMPOSTA: Um Estudo In Vitro

Abstract

Restorative materials, such as composite resins, are widely used due to their esthetics, functionality, and preservation of dental structure. Their properties include strength, homogeneity, and ease of handling; however, these characteristics can be compromised by contamination during manipulation. Handling techniques vary according to the material's features, and the use of adhesives as lubricants and/or digital modeling can negatively impact the longevity of restorations due to the formation of defects at the adhesive interface. This study aimed to evaluate the influence of physical-mechanical properties of composite resins manipulated with latex and latex-free gloves, followed by modeling with two different adhesive systems. Nine groups were evaluated: (G1) Control group, (G2) Conventional adhesive group, (G3) Universal adhesive group, (G4) Latex gloves group, (G5) Latex gloves + conventional adhesive group, (G6) Latex gloves + universal adhesive group, (G7) Nitrile gloves group, (G8) Nitrile gloves + conventional adhesive group, and (G9) Nitrile gloves + universal adhesive group. Flexural strength, elastic modulus, water sorption, and Vickers microhardness were assessed. The results revealed that manipulation with adhesives significantly altered the physicochemical properties of the composites, except for water sorption and solubility tests, which showed no statistical variations among groups (). In the flexural strength test, group G9 (Nitrile + Universal Adhesive) showed the best median performance, while G3 (Universal Adhesive alone) exhibited the lowest values. Regarding the elastic modulus, groups G6, G7 and G9 demonstrated higher stiffness, whereas G2 presented the lowest stability. Vickers microhardness was severely negatively impacted in groups G2 and G3, evidencing that the use of adhesives as modelers, regardless of the glove type, reduces surface hardness. It is concluded that digital manipulation with nitrile gloves, especially when associated with universal adhesive, presents superior performance compared to latex manipulation, whose residues and sulfides tend to compromise the polymerization and the final mechanical strength of the resin.