title: Surface roughness of composite resins subjected to hydrochloric acid.
abstract: The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, Universide de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Ana Carolina Cabral
authors.initials: AC
authors.lastname: Roque
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, Universide de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Lauren Oliveira Lima
authors.initials: LO
authors.lastname: Bohner
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, Universide de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Ana Paula Terossi
authors.initials: AP
authors.lastname: de Godoi
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Colucci
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Silmara Aparecida Milori
authors.initials: SA
authors.lastname: Corona
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, Universide de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: Alma Blásida Concepción Elizaur Benitez
authors.initials: AB
authors.lastname: Catirse
mesh_terms: D003188:Composite Resins; D006851:Hydrochloric Acid / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D012463:Saliva; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D006851:Hydrochloric Acid