title: Nanohybrid versus nanofill composite in class I cavities: margin analysis after 12 months.
abstract: This study evaluates the margin of a nanofill, a nanohybrid, and a conventional microhybrid composite in restorations in occlusal cavities of posterior teeth after 12 months. Forty-one patients, each with three molars affected by primary caries or the need to replace restorations, participated in this research. The teeth were restored with a nanofill (Filtek Z350), a nanohybrid (Esthet-X), and a microhybrid as a control (Filtek Z250). Ten patients were selected randomly, and the three restorations were molded with a low-viscosity polyvinyl siloxane material. The molds were poured with epoxy resin, gold-sputter coated, observed by scanning electron microscopy, and classified as: "perfect margin," "marginal irregularity," "marginal gap," "marginal fracture," or "artifact." For statistical analysis, the Wilcoxon and Friedman nonparametric tests and paired-samples t-test were used (significance level of 5%). The performance of the three materials was compared after 1 week and 12 months. No statistically significant differences were detected for all criteria (P > 0.05). When each composite was compared over time, statistically significant differences were found for the criterion, perfect margins (Esthet-X and Filtek Z350, P < 0.05). The materials performed satisfactorily over the 12-month-observation period, but all composites under investigation showed a certain amount of deterioration relating to marginal quality over time.
authors.affiliation: Department of Restorative Dentistry, Federal University of Paraíba-UFPB, Brazil. kamandrade@hotmail.com
authors.forename: Ana Karina Maciel
authors.initials: AK
authors.lastname: de Andrade
authors.forename: Rosângela Marques
authors.initials: RM
authors.lastname: Duarte
authors.forename: Severino Jackson
authors.initials: SJ
authors.lastname: Guedes Lima
authors.forename: Tibério Andrade
authors.initials: TA
authors.lastname: Passos
authors.forename: Kenio Costa
authors.initials: KC
authors.lastname: Lima
authors.forename: Marcos Antônio Japiassú Resende
authors.initials: MA
authors.lastname: Montes
mesh_terms: D003737:Dental Cavity Preparation / Q000295:instrumentation*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000032:analysis*; D003793:Dental Restoration, Permanent / Q000295:instrumentation*; D005500:Follow-Up Studies; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000601:surgery; D053761:Nanocomposites / Q000032:analysis*; D049329:Nanostructures / Q000032:analysis*; D014076:Tooth Diseases / Q000601:surgery / Q000628:therapy*
chemical_list: D003764:Dental Materials