RESUMO
The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.
Assuntos
Resinas Compostas/efeitos da radiação , Metacrilatos/efeitos da radiação , Radiografia Dentária Digital , Resinas Sintéticas/efeitos da radiação , Resinas de Silorano/efeitos da radiação , Esmalte Dentário/efeitos da radiação , Dentina/efeitos da radiação , Humanos , Teste de MateriaisRESUMO
OBJECTIVE: The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. MATERIAL AND METHODS: Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's post hoc test (α=0.05). RESULTS: KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p<0.05) after 24 h of incubation. KaloreTM stimulated the early production of TNF-α in comparison with control (p<0.05), whereas FiltekTM Silorane did not affect TNF-α levels after 6 and 12 h (p>0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). CONCLUSIONS: KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.
Assuntos
Resinas Compostas/toxicidade , Metacrilatos/toxicidade , Resinas de Silorano/toxicidade , Fator de Necrose Tumoral alfa/análise , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Resinas Compostas/efeitos da radiação , Lâmpadas de Polimerização Dentária , Ensaio de Imunoadsorção Enzimática , L-Lactato Desidrogenase , Teste de Materiais , Metacrilatos/efeitos da radiação , Camundongos , Valores de Referência , Reprodutibilidade dos Testes , Resinas de Silorano/efeitos da radiação , Fatores de TempoRESUMO
ABSTRACT The successful use of composite resins in Dentistry depends on physicochemical properties, but also on the biological compatibility of resins, because of the close association between pulp and dentin. Objective The aim of this study was to evaluate cytotoxicity and cytokine production induced by light-cured or non-light-cured methacrylate-based and silorane composite resins in RAW 264.7 macrophages. Material and Methods Cells were stimulated with the extracts from light-cured or non-light-cured composite resins. After incubation for 24 h, cytotoxicity was assessed with the lactate dehydrogenase (LDH) and methyl thiazolyl tetrazolium (MTT) assays, and total protein was quantified using the Lowry method. TNF-α detection was examined with an enzyme-linked immunosorbent assay (ELISA) conducted with cell supernatants after cell stimulation for 6, 12, and 24 h. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test (α=0.05). Results KaloreTM and FiltekTM Silorane were cytotoxic with or without light curing (p<0.05) after 24 h of incubation. KaloreTM stimulated the early production of TNF-α in comparison with control (p<0.05), whereas FiltekTM Silorane did not affect TNF-α levels after 6 and 12 h (p>0.05). However, after 24 h FiltekTM Silorane inhibited the production of TNF-α (p<0.05). Conclusions KaloreTM and FiltekTM Silorane were cytotoxic regardless of light curing. The extract obtained from KaloreTM after 15 days of incubation stimulated the production of TNF-α, unlike that obtained from FiltekTM Silorane.
Assuntos
Animais , Camundongos , Fator de Necrose Tumoral alfa/análise , Resinas Compostas/toxicidade , Resinas de Silorano/toxicidade , Metacrilatos/toxicidade , Valores de Referência , Fatores de Tempo , Teste de Materiais , Ensaio de Imunoadsorção Enzimática , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Reprodutibilidade dos Testes , Resinas Compostas/efeitos da radiação , Lâmpadas de Polimerização Dentária , Resinas de Silorano/efeitos da radiação , L-Lactato Desidrogenase , Metacrilatos/efeitos da radiaçãoRESUMO
The aim of this study was to examine the effect of the light source on the microshear bond strength of different composite resins repaired with the same substrate. Thirty cylindrical specimens of each composite resin--Filtek Silorane, Filtek Z550 (3M ESPE), Gradia Direct Anterior (GC), and Aelite Posterior (BISCO)--were prepared and light-cured with a QTH light curing unit (LCU). The specimens were aged by thermal cycling and divided into three subgroups according to the light source used--QTH, LED, or PAC (n = 10). They were repaired with the same substrate and a Clearfil Repair Kit (Kuraray). The specimens were light-cured and aged for 1 week in distilled water at 37 °C. The microshear bond strength and failure modes were assessed. There was no significant difference in the microshear bond strength values among the composite resins, except for the Filtek Silorane group that showed significantly lower bond strength values when polymerized with the PAC unit compared to the QTH or LED unit. In conclusion, previously placed dimethacrylate-based composites can be repaired with different light sources; however, if the composite to be repaired is silorane-based, then using a QTH or LED device may be the best option.
Assuntos
Resinas Compostas/efeitos da radiação , Lâmpadas de Polimerização Dentária , Cimentos Dentários/efeitos da radiação , Cura Luminosa de Adesivos Dentários/métodos , Resistência ao Cisalhamento/efeitos da radiação , Resinas Compostas/química , Cimentos Dentários/química , Falha de Restauração Dentária , Testes de Dureza , Lasers Semicondutores , Teste de Materiais , Quartzo/química , Valores de Referência , Resinas de Silorano/química , Resinas de Silorano/efeitos da radiação , Estatísticas não Paramétricas , Propriedades de Superfície , Fatores de Tempo , Tungstênio/químicaRESUMO
PURPOSE: To evaluate the Knoop hardness (KH) and the bond strength (BS) at the tooth/restoration interface of conventional methacrylate- (Filtek Supreme) and silorane-based (Filtek P90) composites photoactivated by different methods using an LED Freelight 2. MATERIALS AND METHODS: Bond strength was tested in a universal testing machine by the "push-out" test in restored cavities measuring 2 × 1.5 × 2 mm with a C-factor of 2.2, prepared in 60 bovine teeth. To restore the cavities, the respective adhesive system of each composite was used (Single Bond 2 and P90 system adhesives). The composites were photoactivated by 3 different methods: continuous light: 40 s at 1000 mW/cm²; soft-start: 10 s at 150 mW/cm² + 38 s at 1000 mW/cm²; pulse delay: 5 s at 150 mW/cm², followed by a 3-min wait (without photoactivation) and 39 s at 1000 mW/cm². Before the push-out test was performed, the KH was analyzed at the top and bottom of the restorations. Data were statistically anaylzed using ANOVA and Tukey's test. RESULTS: The photoactivation methods produced no differences in BS or KH in the same composite, while Filtek P90 (28.0 MPa) showed higher BS values than Filtek Supreme (22.3 MPa) and a lower KH. CONCLUSION: The composite Filtek P90 was capable of increasing bond strength, but presented lower Knoop hardness.