title: Effect of chemical and microwave disinfection on the surface microhardness of acrylic resin denture teeth.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of simulated disinfections (2% glutaraldehyde, 1% sodium hypochlorite, and microwave energy) on the surface hardness of Trilux, Biocler, Biotone, New Ace, and Magister commercial artificial teeth.
  
  
  METHODS
  Specimens (n = 10) were made with the teeth included individually in circular blocks of acrylic resin, leaving the labial surface exposed. Cycles of simulated chemical disinfection were accomplished with the specimens immersed in the solutions at room temperature for 10 minutes, followed by tap water washing for 30 seconds and storage in distilled water at room temperature for 7 days until the next disinfection. Simulated disinfection by microwave energy was carried out in a domestic oven with 1300 W at a potency of 50% for 3 minutes with the specimens individually immersed in 150 ml of distilled water. Control (no disinfection) and the experimental groups (first and third disinfection cycles) were submitted to Knoop hardness measurements with indentations at the center of the labial tooth surface. Data were submitted to repeated measure two-way ANOVA and Tukey's test (α = 0.05).
  
  
  RESULTS
  Biocler, Magister, and Trilux showed lower surface microhardness when submitted to microwave. Lower microhardness for Biotone was promoted by hypochlorite, while no significant difference was shown for New Ace. The third disinfection cycle significantly decreased the tooth surface hardness only for microwave.
  
  
  CONCLUSIONS
  Different disinfection methods promoted different effects on the microhardness of different types of artificial teeth. Surface microhardness of the teeth was less affected by the simulated chemical disinfections when compared to microwaved specimens.
authors: Amazonas State University Dentistry Clinics, Manaus, Amazonas, Brazil.
authors: Ligia Regina
authors: LR
authors: Vasconcelos
authors: Rafael Leonardo Xediek
authors: RL
authors: Consani
authors: Marcelo Ferraz
authors: MF
authors: Mesquita
authors: Mário Alexandre Coelho
authors: MA
authors: Sinhoreti
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry; D019551:Dental Disinfectants / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D004203:Disinfection / Q000379:methods*; D005976:Glutaral / Q000737:chemistry; D006244:Hardness; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D008872:Microwaves / Q000627:therapeutic use*; D063225:Organically Modified Ceramics / Q000737:chemistry; D058105:Polymerization; D012973:Sodium Hypochlorite / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014093:Tooth, Artificial; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D003188:Composite Resins; D019551:Dental Disinfectants; D003764:Dental Materials; D063225:Organically Modified Ceramics; D014867:Water; D012973:Sodium Hypochlorite; D005976:Glutaral