title: Effect of the curing conditions on the properties of an acrylic denture base resin microwave-polymerised.
abstract: OBJECTIVE
  The aim of this study is to evaluate the effect of the different conditions of curing on the residual monomer levels, hardness and impact strength of a microwave-polymerised acrylic resin.
  
  
  METHODS
  The material was polymerised in a microwave oven in four different conditions of power and curing time. The kinetics of release of residual monomer in water was evaluated by spectrophotometric method up to 24 h. The hardness of the sample was determined by the Rockwell method and the impact strength tested by the Charpy method. The results were subjected to statistical analysis using ANOVA and Tukey's test for comparison.
  
  
  RESULTS
  The levels of residual monomer were found dependent upon the curing conditions and they were correlated with the values of impact strength. Significant differences were observed in this property regarding the analysed conditions (p<0.001).
  
  
  CONCLUSIONS
  From the appropriate selection of power and time of curing of the resin, it is possible to optimise the level of residual monomer and a low cytotoxicity keeping at the same time the best mechanical properties.
authors.affiliation: Facultad de Ciencias Exactas, Instituto de Investigaciones Fisicoqui;micas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata-CONICET, Casilla de Correo 16, Sucursal 4, 1900, La Plata, Argentina.
authors.forename: M J
authors.initials: MJ
authors.lastname: Azzarri
authors.forename: M S
authors.initials: MS
authors.lastname: Cortizo
authors.forename: J L
authors.initials: JL
authors.lastname: Alessandrini
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D000704:Analysis of Variance; D003819:Denture Bases; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008872:Microwaves; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D019904:Polymethyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D013053:Spectrophotometry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D011108:Polymers; D019904:Polymethyl Methacrylate