title: Effects of mouthwashes on Knoop hardness and surface roughness of dental composites after different immersion times.
abstract: The aim of this in vitro study was to evaluate the effect of different mouthwashes on superficial roughness and Knoop hardness of two resin composites. Eighty specimens (6 mm Ø and 2 mm height) were prepared and divided into eight experimental groups (n = 10) according to the resin composites (4 Seasons and Esthet X), and storage solutions (G1 - Distilled water; G2 - Colgate Plax Overnight; G3 - Colgate Plax Alcohol Free; and G4 - Colgate Plax Whitening). The initial hardness and roughness readings (T1) were measured and then the specimens were stored in 2 mL of mouthwash for 12 h (T2) and 24 h (T3). The data were analyzed with repeat-measures two-way ANOVA and Tukey's test (α = 5%). Regardless of the type of solution and time of exposure, there was no statistical difference for roughness between the resins (p = 0.44). G4 and G8 presented higher roughness means than G1, G3, G5 and G7, after 12 and 24 hours of immersion. For Knoop microhardness analysis, there was a significant reduction for all groups after 12 hours and 24 hours. We conclude that the mouthwashes containing hydrogen peroxide and/or alcohol decrease the microhardness of the resins tested; however, the mouthwash containing hydrogen peroxide had a higher deleterious effect on roughness.
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Diogo de Azevedo
authors.initials: Dde A
authors.lastname: Miranda
authors.forename: Carlos Eduardo Dos Santos
authors.initials: CE
authors.lastname: Bertoldo
authors.forename: Flávio Henrique Baggio
authors.initials: FH
authors.lastname: Aguiar
authors.forename: Débora Alves Nunes Leite
authors.initials: DA
authors.lastname: Lima
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Lovadino
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D006245:Hardness Tests; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007101:Immersion; D008422:Materials Testing; D009067:Mouthwashes / Q000494:pharmacology*; D018709:Statistics, Nonparametric; D013499:Surface Properties / Q000187:drug effects; D013997:Time Factors
chemical_list: D003188:Composite Resins; D009067:Mouthwashes; D006861:Hydrogen Peroxide