RESUMO
PURPOSE: To evaluate the effect of cavity preparation device (i.e. carbide bur, diamond bur, air abrasive, Sonicsys, and Er:YAG laser) on microleakage of Class V resin-based composite (RBC) restorations, the tooth restoration interface and dentin ultrastructure. MATERIALS AND METHODS: Eight groups (n=18) of 9 human molars each were prepared on the buccal and lingual surfaces for Class V RBC restorations using five preparation devices: Group 1: carbide bur #8 round; Group 2: diamond bur #801; Group 3: KCP 1000 air abrasion unit; Group 4: Sonicsys Approx.; Group 5: Er:YAG laser; Group 6: carbide bur plus air abrasive; Group 7: carbide bur plus laser, and Group 8: laser without etching. Circular cavity preparations, 3 mm diameter and 1.5 mm deep, were cut at the CEJ on the buccal and lingual surfaces of each tooth. A bevel was placed on the enamel margin. All cavities were restored using Single Bond adhesive system and Silux Plus according to manufacturer's directions, with the exception that no etchant was used with Group 8. After thermocycling, specimens were tested for microleakage using silver nitrate methodology. Dye penetration data was collected and subjected to non-parametric statistical analysis. SEM analysis of the dentin-RBC interface, as well as the effect of each cavity preparation device on the surface of dentin was performed. RESULTS: Microleakage did not occur in enamel for any method of cavity preparation when the enamel was etched prior to adhesive application. Kruskal-Wallis One-way ANOVA revealed differences in dentin microleakage among the tested groups at alpha=0.05. Mann-Whitney Test for Paired Comparisons at alpha=0.01 demonstrated significantly greater dentin microleakage in Groups 5 and 7 compared to all groups except Group 3 (air abrasive). Although Group 8 had the least microleakage in dentin, this was not significantly different from Groups 1, 2, 4 and 6. SEM observation revealed hybridization at the dentin-resin interface for all groups except for Group 8 (laser prepared, non-etched). Surface analysis showed differences related to the operating mode of each preparation device. CLINICAL SIGNIFICANCE: The method of cavity preparation did not affect microleakage in etched enamel. When using a laser for cavity preparation, enamel should be etched although not etching dentin may help to improve marginal seal.
Assuntos
Resinas Compostas/química , Preparo da Cavidade Dentária/instrumentação , Infiltração Dentária/classificação , Restauração Dentária Permanente/classificação , Condicionamento Ácido do Dente , Ar , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato/química , Compostos Inorgânicos de Carbono , Colagem Dentária , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Adesivos Dentinários/química , Diamante , Desenho de Equipamento , Humanos , Lasers , Microscopia Eletrônica de Varredura , Coloração pela Prata , Estatísticas não Paramétricas , Propriedades de Superfície , Termodinâmica , Colo do Dente/ultraestruturaRESUMO
Recently, simple radiometers for measuring the intensity of dental curing lights have been introduced. This study examined the relationship among light intensity measurements by three radiometers, distance of curing tip from composite resin, and resin polymerization (as indicated by microhardness). Light intensity measurements, which decreased with increasing distance from the curing tip, were strongly correlated with composite resin hardness. Reduced light intensity produced softer composite resin, particularly on the bottom of specimens (2-mm depth). The different radiometers provided similar indications of the changes in light intensity at various curing distances.
Assuntos
Resinas Compostas/química , Análise de Variância , Dureza , Luz , Teste de Materiais , RadiometriaRESUMO
When restoring dentition compromised by periodontal treatment, good aesthetics must be achieved without compromising the periodontal health. Improved composite resin systems and new dentin bonding agents offer excellent restorative options. The learning objective of this article is a review of composite resins and direct bonding for aesthetic restorations. Two cases are presented to illustrate the procedure.
Assuntos
Resinas Compostas , Colagem Dentária/métodos , Restauração Dentária Permanente/métodos , Retração Gengival/etiologia , Curetagem Subgengival/efeitos adversos , Adulto , Diastema/etiologia , Diastema/terapia , Estética Dentária , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Periodontais/terapiaRESUMO
El bruñido no asegura necesariamente una amalgama de calidad y de larga duración. Hay muchos otros factores que también son muy importantes y deben tomarse en consideración. Es esencialmente que el odontólogo prepare correctamente la cavidad para recibir el material restaurador. También debe mantener actualizados sus conocimientos sobre los avances en los materiales de amalgama y seleccionar la mejor aleación disponible. La amalgama debe ser colocada y tallada correctamente para corregir la forma anatómica y la función. Sin embargo, al combinar el bruñido con los anteriores factores, pueden mejorarse las propiedades físicas y el odontólogo puede sentirse seguro de proporcionar el mejor servicio posible a su paciente