RESUMEN

OBJECTIVES: This retrospective longitudinal study investigated the longevity of posterior restorations placed in a single general practice using 2 different composites in filler characteristics and material properties: P-50 APC (3M ESPE) with 70vol.% inorganic filler loading (midfilled) and Herculite XR (Kerr) with 55vol.% filler loading (minifilled). METHODS: Patient records were used for collecting data. Patients with at least 2 posterior composite restorations placed between 1986 and 1990, and still in the practice for regular check-up visits, were selected. 61 patients (20 male, 41 female, age 31.2-65.1) presenting 362 restorations (121 Class I, 241 Class II) placed using a closed sandwich technique were evaluated by 2 operators using the FDI criteria. Data were analyzed with Fisher's exact test, Kaplan-Meier statistics, and Cox regression analysis (p<0.05). RESULTS: 110 failures were detected. Similar survival rates for both composites were observed considering the full period of observation; better performance for the midfilled was detected considering the last 12 years. There was higher probability of failure in molars and for multi-surface restorations. SIGNIFICANCE: Both evaluated composites showed good clinical performance over 22 years with 1.5% (midfilled) and 2.2% (minifilled) annual failure rate. Superior longevity for the higher filler loaded composite (midfilled) was observed in the second part of the observation period with constant annual failure rate between 10 years and 20 years, whereas the minifilled material showed an increase in annual failure rate between 10 years and 20 years, suggesting that physical properties of the composite may have some impact on restoration longevity.

Asunto(s)

Resinas Compuestas/química , Fracaso de la Restauración Dental , Restauración Dental Permanente/métodos , Adulto , Diente Premolar , Distribución de Chi-Cuadrado , Restauración Dental Permanente/clasificación , Análisis del Estrés Dental , Módulo de Elasticidad , Femenino , Humanos , Estimación de Kaplan-Meier , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Diente Molar , Modelos de Riesgos Proporcionales , Cementos de Resina/química , Estudios Retrospectivos

RESUMEN

OBJECTIVE: Characterize the microstructure, composition and some physical properties of a glass-infiltrated alumina/zirconia-reinforced ceramic (IZ) and the effect of surface treatment on topography. METHODS: IZ ceramic specimens were fabricated according to ISO6872 instructions and polished through 1 microm alumina abrasive. Quantitative and qualitative analyses were performed using scanning electron microscopy (SEM), backscattered imaging (BSI), electron dispersive spectroscopy (EDS) and stereology. The elastic modulus (E) and Poisson's ratio (nu) were determined using ultrasonic waves, and the density (rho) using a helium pycnometer. The following ceramic surface treatments were used: AP-as-polished; HF-etching with 9.5% hydrofluoric acid for 90 s; SB-sandblasting with 25 microm aluminum oxide particles for 15s and SC-blasting with 30 microm aluminum oxide particles modified by silica (silica coating) for 15s. An optical profilometer was used to examine the surface roughness (Ra) and SEM-EDS were used to measure the amount of silica after all treatments. RESULTS: The IZ mean property values were as follows: rho=4.45+/-0.01 g/cm(3); nu=0.26 and E=245 GPa. Mean Ra values were similar for AP- and HF-treated IZ but significantly increased after either SC or SB treatment (p

Asunto(s)

Óxido de Aluminio , Materiales Biocompatibles Revestidos , Porcelana Dental , Circonio , Óxido de Aluminio/química , Cristalización , Grabado Dental/métodos , Pulido Dental/métodos , Porcelana Dental/química , Análisis del Estrés Dental , Elasticidad , Microanálisis por Sonda Electrónica , Vidrio/química , Ácido Fluorhídrico , Lantano , Microscopía Electrónica de Rastreo , Óxidos , Dióxido de Silicio/análisis , Propiedades de Superficie , Circonio/química