title: The Effect of Disinfection Techniques on the Flexural Strength of Thermopolymerisable Acrylic Resins With or Without Pigment Addition.
abstract: OBJECTIVE
  The aim of this study was to assess the flexural strength of two brands of thermopolymerisable acrylic resins (Onda Cryl, Artigos Odontológicos Clássico Ltda, São Paulo, SP, Brazil; and Lucitone 550, Dentsply, York, PA, USA) with varying concentrations of pigment (Poli-Côr, Artigos Odontológicos Clássico Ltda, São Paulo, SP, Brazil) under the influence of thermocycling, storage and disinfection.
  
  
  METHODS
  A total of 210 samples were manufactured (105 for each acrylic resin brand), with dimensions of 64 x 10 x 3.3 mm. The samples were divided into 30 subgroups (n = 7) according to the proportion of pigment used (without pigment, 3% and 7%), the assessment period (initial or thermocycling for 2000 cycles) and disinfection method (immersion in 1% sodium hypochlorite, (Apothicário, Araçatuba, SP, Brazil), microwave energy or immersion in alkaline peroxide (Efferdent, Pfizer, Morris Plains, NJ, USA). The samples were submitted to the flexural strength test before and after thermocycling, and after storage with disinfection. The disinfection process was performed every 3 days, for 60 days. Data were submitted to analysis of variance (ANOVA) and Tukey test (p < 0.05).
  
  
  RESULTS
  The factors that provided statistical alteration in flexural strength values were resin type and assessment period. The Onda Cryl resin and the period after disinfection (126 ± 25 MPa) exhibited the higher values of flexural strength.
  
  
  CONCLUSIONS
  Following disinfection, Onda-Cryl resin exhibited the highest values of flexural strength. All the samples obtained are considered clinically acceptable.
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.forename: Bruna Carolina Rossatti
authors.initials: BC
authors.lastname: Zuccolotti
authors.forename: Marcela Filié
authors.initials: MF
authors.lastname: Haddad
authors.forename: Amália
authors.initials: A
authors.lastname: Moreno
authors.forename: Aldiéris Alves
authors.initials: AA
authors.lastname: Pesqueira
authors.forename: Humberto Filho
authors.initials: HF
authors.lastname: Gennari
authors.forename: Daniela Micheline
authors.initials: DM
authors.lastname: Dos Santos
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D004202:Disinfectants / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D008872:Microwaves / Q000627:therapeutic use; D010545:Peroxides / Q000737:chemistry; D018583:Pliability; D058105:Polymerization; D012973:Sodium Hypochlorite / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D004396:Coloring Agents; D003764:Dental Materials; D004202:Disinfectants; D010545:Peroxides; C539103:onda cryl; D014867:Water; C040291:Lucitone; D012973:Sodium Hypochlorite