title: Effect of carbamide peroxide bleaching gel on composite resin flexural strength and microhardness.
abstract: This study investigated the effect of 16% carbamide peroxide (Whiteness Perfect/FGM) on the Vickers microhardness and flexural strength of the restorative composites Filtek Z100 (hybrid), Filtek Z350 (nanofill), Brilliant (micro-hybrid) and Opallis (micro-hybrid). Disc-shaped (4x2 mm; n=5) and bar-shaped (12x2x1 mm; n=10) specimens of each restorative material were randomly divided into 2 groups: (G1) 16 weeks stored in distilled water; (G2) 16 weeks stored in distilled water, with 16% carbamide peroxide application during 6 h per day for the last 4 weeks. The mechanical properties were evaluated using a Vickers microhardness tester and a mechanical testing machine. Data were analyzed by two-way ANOVA and Tukey's (HSD) post-hoc test (α=0.05). Filtek Z100 presented the highest microhardness value, followed by Filtek Z350 and finally by Brilliant and Opallis (p=0.00). Filtek Z100 and Brilliant exhibited the highest flexural strength value, followed by Filtek Z350 and Opallis (p=0.00). Bleaching treatment decreased significantly microhardness of Brilliant and Opallis (p=0.00). The flexural strength of all studied materials was not affected by the home bleaching (p=0.28).
authors: Department of Dental Materials and Prosthodontics, Araraquara Dental School, Univ Estadual Paulista, Araraquara, SP, Brazil.
authors: Gabriel Rodrigues
authors: GR
authors: Hatanaka
authors: Filipe de Oliveira
authors: Fde O
authors: Abi-Rached
authors: Antonio Alves de
authors: AA
authors: Almeida-Júnior
authors: Carlos Alberto dos Santos
authors: CA
authors: Cruz
mesh_terms: D000077463:Carbamide Peroxide; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010545:Peroxides / Q000737:chemistry*; D018583:Pliability; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors; D058205:Tooth Bleaching Agents / Q000737:chemistry*; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D010545:Peroxides; D011109:Polymethacrylic Acids; D058205:Tooth Bleaching Agents; C083568:Z100 composite resin; C533204:filtek Z350; D014867:Water; C069353:Brilliant Dentin resin; C020946:triethylene glycol dimethacrylate; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D000077463:Carbamide Peroxide; D011092:Polyethylene Glycols; D012822:Silicon Dioxide; D014508:Urea; D015040:Zirconium