ABSTRACT
The effect of restoration depth on the curing time of a conventional and two bulk-fill composite resins by measuring microhardness and the respective radiosity of the bottom surface of the specimen was investigated. 1-, 3- and 5-mm thick washers were filled with Surefil SDR Flow-U (SDR), Tetric EvoCeram Bulk Fill-IVA (TEC) or Esthet-X HD-B1 (EHD), and cured with Bluephase® G2 for 40s. Additional 1-mm washers were filled with SDR, TEC or EHD, placed above the light sensor of MARC®, stacked with pre-cured 1-, 3- or 5-mm washer of respective material, and cured for 2.5~60s to mimic 2-, 4- and 6-mm thick composite curing. The sensor measured the radiosity (EB) at the bottom of specimen stacks. Vickers hardness (VH) was measured immediately at 5 locations with triplicate specimens. Nonlinear regression of VH vs EB by VH=α[1-exp(-EB/ß)] with all thickness shows that the values of α, maximum hardness, are 21.6±1.0 kg/mm2 for SDR, 38.3±0.6 kg/mm2 for TEC and 45.3±2.6 kg/mm2 for EHD, and the values of ß, rate parameter, are 0.40±0.06 J/cm2 for SDR, 0.77±0.04 J/cm2 for TEC and 0.58±0.09 J/cm2 for EHD. The radiosity of the bottom surface was calculated when the bottom surface of each material attained 80% of α of each material. The curing times for each material are in agreement with manufacturer recommendation for thickness. It is possible to estimate time needed to cure composite resin of known depth adequately by the radiosity and microhardness of the bottom surface.
Subject(s)
Composite Resins/chemistry , Composite Resins/radiation effects , Curing Lights, Dental , Light-Curing of Dental Adhesives/methods , Analysis of Variance , Hardness Tests , Linear Models , Materials Testing , Polymerization , Polymethyl Methacrylate/chemistry , Polymethyl Methacrylate/radiation effects , Radiation Dosage , Reference Values , Resin Cements/chemistry , Resin Cements/radiation effects , Surface Properties/radiation effects , Time FactorsABSTRACT
Abstract The effect of restoration depth on the curing time of a conventional and two bulk-fill composite resins by measuring microhardness and the respective radiosity of the bottom surface of the specimen was investigated. 1-, 3- and 5-mm thick washers were filled with Surefil SDR Flow-U (SDR), Tetric EvoCeram Bulk Fill-IVA (TEC) or Esthet-X HD-B1 (EHD), and cured with Bluephase® G2 for 40s. Additional 1-mm washers were filled with SDR, TEC or EHD, placed above the light sensor of MARC®, stacked with pre-cured 1-, 3- or 5-mm washer of respective material, and cured for 2.5~60s to mimic 2-, 4- and 6-mm thick composite curing. The sensor measured the radiosity (EB) at the bottom of specimen stacks. Vickers hardness (VH) was measured immediately at 5 locations with triplicate specimens. Nonlinear regression of VH vs EB by VH=α[1-exp(-EB/β)] with all thickness shows that the values of α, maximum hardness, are 21.6±1.0 kg/mm2 for SDR, 38.3±0.6 kg/mm2 for TEC and 45.3±2.6 kg/mm2 for EHD, and the values of β, rate parameter, are 0.40±0.06 J/cm2 for SDR, 0.77±0.04 J/cm2 for TEC and 0.58±0.09 J/cm2 for EHD. The radiosity of the bottom surface was calculated when the bottom surface of each material attained 80% of α of each material. The curing times for each material are in agreement with manufacturer recommendation for thickness. It is possible to estimate time needed to cure composite resin of known depth adequately by the radiosity and microhardness of the bottom surface.
Subject(s)
Composite Resins/radiation effects , Composite Resins/chemistry , Light-Curing of Dental Adhesives/methods , Curing Lights, Dental , Radiation Dosage , Reference Values , Surface Properties/radiation effects , Time Factors , Materials Testing , Linear Models , Analysis of Variance , Resin Cements/radiation effects , Resin Cements/chemistry , Polymethyl Methacrylate/radiation effects , Polymethyl Methacrylate/chemistry , Polymerization , Hardness TestsABSTRACT
A etapa de cimentação é de fundamental importância para o tratamento restaurador usando laminados cerâmicos. É nessa etapa que normalmente são verificados os erros e acertos nas etapas anteriores de planejamento, preparo e moldagem dos laminados. É fundamental que o dentista conheça essa etapa, desde o tratamento da superfície interna da restauração cerâmica até o preparo do substrato dental para a técnica adesiva. Dessa forma, o objetivo desse artigo é mostrar de forma segura a cimentação de laminados cerâmicos reforçados por dissilicato de lítio, o que garante um resultado final satisfatório do tratamento conservador estético
Subject(s)
Humans , Male , Female , Adhesiveness , Cementation , Ceramics , Composite Resins , Dental Cements , Dental Materials , Dental Veneers , Dentin-Bonding Agents , Resin CementsABSTRACT
A etapa de preparo é de fundamental importância para o tratamento restaurador usando laminados cerâmicos. É nessa etapa que normalmente são verificados os espaços existentes para a futura restauração, bem como o eixo de inserção, irregularidades e erros de inclinação axial. As preparações dentais praticamente garantem o sucesso da restauração, pois este pode ser influenciado pelo planejamento, e seu erro influencia a moldagem e a cimentação das peças cerâmicas. É fundamental que o dentista realize ainda o polimento dos preparos para uma melhor cópia na etapa de moldagem e futura adaptação das lâminas de cerâmica. Dessa forma, o objetivo desse artigo é mostrar de forma segura preparos conservadores para laminados cerâmicos reforçados por dissilicado de lítio, o que garante um resultado final satisfatório do tratamento estético
