In vitro analysis of different properties of acrylic resins for ocular prosthesis submitted to accelerated aging with or without photopolymerized glaze

Abstract

The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008h). Data were submitted to the ANOVA and Tukey Test (p<0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins.

Effect of photopolymerized glaze application on bacterial adhesion on ocular acrylic resin surfaces submitted to accelerated ageing

“…A previous study of Santos et al . () related that the surface energy of the ocular acrylic resins submitted to glaze application did not differ from the groups which received mechanical polishing, but an increase in surface energy was observed only on N1 acrylic resin after ageing. Thus, we believe that these two studies can be considered complementary, since this study showed the greater roughness value for the N1 AR group with glaze after ageing, and the previous one showed greater surface energy values for this group, independent of the treatment.…”

“…First, the groups had showed similar contact angles in our previous study (Santos et al . ). Second, the surface roughness values of acrylic resins submitted to Staph.…”

“…The greater roughness and lower surface free energy of this group (Santos et al . ) may have influenced the greater bacterial adhesion, and consequently, may have led to a rapid maturation of the biofilm at 24‐h of bacterial growth, with a subsequent detachment of the cells at 48‐h.…”

“…Two hundred eighty‐eight heat‐polymerized N1 (white colour) and colourless AR (Artigos Odontologicos Classico Ltda., Sao Paulo, Brazil) samples were fabricated (10 mm diameter × 3 mm height) according to a previous protocol (Santos et al . ). For each micro‐organism, the samples were randomly distributed in eight groups ( n = 9), being G1 to G4 before ageing, and G5 to G8 after accelerated ageing: N1 AR without photopolymerized glaze (G1 and G5); colourless AR without photopolymerized glaze (G2 and G6); N1 AR with photopolymerized glaze (G3 and G7); and colourless AR with photopolymerized glaze (G4 and G8).…”

“…The AR samples were submitted to polishing using metallographic sandpaper of different granulations (400, 600 and 800) (Buehler, Lake Bluff, IL) in a universal semiautomatic polisher (Ecomet 300PRO; Buehler) under constant irrigation (Santos et al . ). Additional sandpaper of 1000 and 1200 grains was used, and the final polishing was performed with a diamond solution on a felt disc (Buehler) on the groups that did not receive a layer of photopolymerized glaze (G1, G2, G5 and G6).…”