title: Flexural bond strength of repaired composite resin restorations: influence of surface treatments and aging.
abstract: The objective of this study was to evaluate the effect of storage in deionized water at room temperature, for seven days and six months, on the flexural strength of a repaired photocured microhybrid composite resin, using different surface treatments. After each surface treatment, the adhesive interface was analyzed with a surface roughness tester. The flexural strength of samples from each group was determined by three-point bending in a testing machine at a crosshead speed of 0.5 mm/min with a 50 N load cell. Data were analyzed using ANOVA (p=0.0001) and compared with the Newman-Keuls multiple comparison test. It was verified that flexural strength of the unrepaired specimens, after both seven days and six months, was similar (p>0.05) and was in accordance with ISO specifications (minimum of 50 MPa), with values ranging from 52-63 MPa. The authors concluded that the use of an unfilled resin agent is necessary prior to the repair to increase the adhesive strength. Further, the use of a silane agent prior to use of the unfilled resin agent is unnecessary, since it does not increase the adhesive strength.
authors: Department of Operative Dentistry, School of Dentistry, Rio de Janeiro State University, RJ, Brazil.
authors: Angela Alexandre Meira
authors: AA
authors: Dias
authors: Marcos Oliveira
authors: MO
authors: Barceleiro
authors: Rogerio Luiz Oliveira
authors: RL
authors: Mussel
authors: Helio Rodrigues
authors: HR
authors: Sampaio-Filho
mesh_terms: D000096:Acetone / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D019245:Compressive Strength; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D017269:Dental Prosthesis Repair; D003799:Dental Stress Analysis / Q000295:instrumentation; D018130:Diamond / Q000737:chemistry; D055119:Elastic Modulus; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D055668:Photochemical Processes; D018583:Pliability; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D012821:Silanes; C467914:TPH spectrum; C444444:prime and bond 2.1; D014867:Water; D000096:Acetone; D018130:Diamond; C030242:phosphoric acid