title: Effect of radiotherapy on the radiopacity and flexural strength of a composite resin.
abstract: The aim of this study was to evaluate the effect of radiotherapy on the radiopacity and flexural strength of composite resin. Forty Z250 composite resin specimens were polymerized using a halogen light-curing unit and divided into 5 groups, in accordance with the radiotherapy dose: G1- without irradiation, G2- 30 Gy, G3- 40 Gy, G4- 50 Gy and GS- 60 Gy Digital images were obtained using a GE 100 X-ray. Radiopacity values were obtained with the Digora digital imaging system and the flexural strength was evaluated with an EMIC universal testing machine. Data were submitted to ANOVA and Tukey 's test. G1 presented the highest radiopacity value, followed by G3, G5, G4 and G2. For flexural strength, G1 presented the lowest value, followed by G2, G5, G3 and G4. Differences were no significant (p>0.05). The commonly used dosage of radiotherapy treatment, did not cause alteration in the radiopacity and flexural strength of resin-based composites.
authors.affiliation: Department of Restorative Dentistry, Araçatuba School of Dentistry, UNESP, Araçatuba, Brazil.
authors.forename: Anderson
authors.initials: A
authors.lastname: Catelan
authors.forename: Ana C S
authors.initials: AC
authors.lastname: Padilha
authors.forename: Leda M P
authors.initials: LM
authors.lastname: Salzedas
authors.forename: Gilberto A
authors.initials: GA
authors.lastname: Coclete
authors.forename: Paulo H
authors.initials: PH
authors.lastname: dos Santos
mesh_terms: D015502:Absorptiometry, Photon; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D003287:Contrast Media / Q000737:chemistry / Q000528:radiation effects; D055117:Curing Lights, Dental; D003764:Dental Materials / Q000737:chemistry / Q000528:radiation effects*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D018583:Pliability; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D019252:Radiography, Dental, Digital / Q000295:instrumentation; D011878:Radiotherapy; D011879:Radiotherapy Dosage; D013314:Stress, Mechanical
chemical_list: D003188:Composite Resins; D003287:Contrast Media; D003764:Dental Materials; C444701:Filtek Z250; D011108:Polymers