RESUMEN
The aim of this study was to evaluate the reliability of the impression replica technique with a four-unit zirconia fixed dental prosthesis (FDP). Marginal and internal fit were measured by repeatedly placing the FDP on an epoxy cast using light-body silicone material corresponding to cement. All measured marginal and internal fit points showed varying values. The greatest variations were seen at the most distal margin (33 µm) and at the distal abutment of the FDP (77 µm). The results showed that the technique gives moderate variations and is a useful method to evaluate marginal and internal fit.
Asunto(s)
Técnica de Impresión Dental/estadística & datos numéricos , Adaptación Marginal Dental , Dentadura Parcial Fija , Sulfato de Calcio/química , Diseño Asistido por Computadora , Revestimiento para Colado Dental/química , Técnica de Colado Dental , Materiales de Impresión Dental/química , Materiales Dentales/química , Diseño de Dentadura , Resinas Epoxi/química , Humanos , Modelos Dentales , Reproducibilidad de los Resultados , Siliconas/química , Propiedades de Superficie , Itrio/química , Circonio/químicaRESUMEN
PURPOSE: To measure the horizontal machining tolerances of the interface between internal- and external-hexagon implants and analogs with corresponding components after delivery from the manufacturer. These values may be a valuable tool for evaluating increasing misfit caused by fabrication, processing, and wear. MATERIALS AND METHODS: Seven implants and seven analogs with external- and internal-hexagon connections (Biomet 3i) with corresponding prefabricated gold cylinders and gold screws, prefabricated cylindric plastic cylinders, and laboratory screws were studied. One set of components from the external and internal groups was measured manually and digitally. Measurements from the test subjects were compared with identical measurements from the virtual model to obtain threshold values. The virtual model was then used to obtain optimally oriented cuts. RESULTS: The horizontal machining tolerances for castable plastic abutments on external implants were 12 ± 89 µm, and for internal implants they were 86 ± 47 µm. Tolerance measurements on prefabricated gold abutments for external implants were 44 ± 9 µm, and for internal implants they were 58 ± 28 µm. CONCLUSION: The groups with metallic components showed the smallest tolerance at < 50 µm for the external group and < 90 µm for the internal group. The prefabricated plastic cylinder groups ranged from < 100 µm for external and < 130 µm for internal connection.
