title: The effect of preheating and opacity on the sorption and solubility of a composite resin.
abstract: This study evaluated the influence of material opacity and preheating on the sorption and solubility of a composite resin material. A commercially available composite resin and an 8 × 2-mm circular metallic matrix were used to fabricate a total of 60 specimens in 6 shades, of which 3 had conventional opacity (CA2, CA3, and CA3.5) and 3 were opaque (OA2, OA3, and OA3.5). Specimens were prepared at a room temperature of 25°C or preheated to 60°C (n = 5 per shade at each temperature). The specimens were weighed 3 times: M1, dried for 24 hours at 37°C; M2, stored for 7 days in 75% ethanol at 37°C; and M3, dried for an additional 24 hours at 37°C. The weights were used to calculate the sorption and solubility of the composite resin and were analyzed using 2-way analysis of variance and Tukey tests (α = 5%). Composite resin specimens heated at 60°C yielded lower values of sorption and solubility than did specimens prepared at 25°C (P < 0.05). The sorption and solubility of conventional and opaque composite shades were found to be similar (P > 0.05), except for shade CA2, which presented a greater mean solubility value than OA2 (P = 0.004). Therefore, preheating was beneficial, as it lowered both the sorption and solubility of the evaluated composite resin, but opacity had little effect on these properties.
authors.forename: Fabrício Luscino Alves de
authors.initials: FL
authors.lastname: Castro
authors.forename: Flávia Bittencourt
authors.initials: FB
authors.lastname: Pazinatto
authors.forename: Érick
authors.initials: É
authors.lastname: de Lima
authors.forename: Paulo Francisco
authors.initials: PF
authors.lastname: Cesar
authors.forename: Rogério Vieira
authors.initials: RV
authors.lastname: Reges
mesh_terms: D003116:Color; D003188:Composite Resins / Q000737:chemistry* / Q000627:therapeutic use; D006358:Hot Temperature; D008422:Materials Testing; D012995:Solubility
chemical_list: D003188:Composite Resins
keywords: absorption; composite resins; heat; solubility