title: Effects of Different Radiation Doses on the Bond Strengths of Two Different Adhesive Systems to Enamel and Dentin.
abstract: OBJECTIVE
  To evaluate the effects of three different radiation doses on the bond strengths of two different adhesive systems to enamel and dentin.
  
  
  METHODS
  Eighty human third molars were randomly divided into four groups (n = 20) according to the radiation dose (control/no radiation, 20 Gy, 40 Gy, and 70 Gy). The teeth were sagittally sectioned into three slices: one mesial and one distal section containing enamel and one middle section containing dentin. The sections were then placed in the enamel and dentin groups, which were further divided into two subgroups (n = 10) according to the adhesive used. Three restorations were performed in each tooth (one per section) using Adper Single Bond 2 (3M ESPE) or Universal Single Bond (3M ESPE) adhesive system and Filtek Z350 XT (3M ESPE) resin composite and subjected to the microshear bond test. Data were analyzed using a two-way ANOVA followed by Tukey's test. Failure modes were examined under a stereoscopic loupe.
  
  
  RESULTS
  Radiotherapy did not affect the bond strengths of the adhesives to either enamel or dentin. In dentin, the Universal Single Bond adhesive system showed higher bond strength values when compared with the Adper Single Bond adhesive system. More adhesive failures were observed in the enamel for all radiation doses and adhesives.
  
  
  CONCLUSIONS
  Radiotherapy did not influence the bond strength to enamel or dentin, irrespective of the adhesive or radiation dose used.
authors.forename: Sandra Ribeiro de Barros
authors.initials: SR
authors.lastname: da Cunha
authors.forename: Pedro Augusto Minorin Mendes
authors.initials: PA
authors.lastname: Ramos
authors.forename: Cecília Maria Kalil
authors.initials: CM
authors.lastname: Haddad
authors.forename: João Luis Fernandes
authors.initials: JL
authors.lastname: da Silva
authors.forename: Eduardo Rodrigues
authors.initials: ER
authors.lastname: Fregnani
authors.forename: Ana Cecília Corrêa
authors.initials: AC
authors.lastname: Aranha
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D055117:Curing Lights, Dental / Q000145:classification; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry / Q000528:radiation effects; D003743:Dental Enamel / Q000528:radiation effects*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000528:radiation effects*; D006801:Humans; D010756:Phosphoric Acids / Q000737:chemistry; D011829:Radiation Dosage; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: C554641:Adper single bond 2; D003188:Composite Resins; D003738:Dental Cements; C444701:Filtek Z250; D010756:Phosphoric Acids; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid