title: Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions.
abstract: This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.
authors.affiliation: Department of Dental Materials and Prosthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil. helenpar@forp.usp.br
authors.forename: Helena de Freitas Oliveira
authors.initials: Hde F
authors.lastname: Paranhos
authors.forename: Letícia Resende
authors.initials: LR
authors.lastname: Davi
authors.forename: Amanda
authors.initials: A
authors.lastname: Peracini
authors.forename: Rafael Bellini
authors.initials: RB
authors.lastname: Soares
authors.forename: Cláudia Helena da Silva
authors.initials: CH
authors.lastname: Lovato
authors.forename: Raphael Freitas de
authors.initials: RF
authors.lastname: Souza
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000287:Administration, Topical; D003116:Color; D019551:Dental Disinfectants / Q000008:administration & dosage / Q000009:adverse effects*; D003799:Dental Stress Analysis; D003819:Denture Bases; D004305:Dose-Response Relationship, Drug; D006801:Humans; D018583:Pliability / Q000187:drug effects; D017797:Prosthesis Coloring; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000009:adverse effects*; D013314:Stress, Mechanical; D013499:Surface Properties / Q000187:drug effects
chemical_list: D000180:Acrylic Resins; D019551:Dental Disinfectants; C539103:onda cryl; D012973:Sodium Hypochlorite