Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo deste trabalho foi avaliar o efeito de um diodo emissor de luz (LED) Smart Lite PS (Dentsply) e da lâmpada halógena convencional Curing Light XL 3000 (3M) na efetividade de polimerização do compômero Dyract Ap (Dentsply) e da resina composta TPH Spectrum (Dentsply) por meio de testes de microdureza Knoop, resistência à compressão e resistência flexural e caracterização dos materiais. Foram confeccionadas 100 amostras e divididas em 12 grupos de acordo com o teste aplicado, a luz de polimerização e o material utilizado. A lâmpada halógena convencional selecionada, Curing Light XL 3000 (3M), tinha intensidade de 470mW/cm2 e comprimento de onda entre 400 e 510nm; o LED Smart Lite PS (Dentsply) tinha intensidade de 950mW/cm2 e comprimento de onda entre 450 e 490nm. O tempo de fotopolimerização para cada incremento com 2mm de espessura foi de 40 s. para a lâmpada halógena convencional e 10 s. para o LED. Para os testes de microdureza Knoop foram confeccionadas 20 amostras numa matriz cilíndrica com 8,0mm de diâmetro e 2,0mm de altura. As leituras da microdureza foram realizadas nas superfícies superiores e inferiores das amostras utilizando um microdurômetro Micromet 2003, com uma carga de 50 gf por 15 s. Para o teste de resistência à compressão foram confeccionadas 40 amostras numa matriz cilíndrica com 4,0mm de diâmetro e 8,0mm de altura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 500Kgf e velocidade de carregamento de 0,5 mm/min. Para o teste de resistência flexural foram construídas 40 amostras numa matriz em forma de caixa com 25,0mm de comprimento, 2,0mm de altura e 2,0mm de largura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 50Kgf e velocidade de carregamento de 0,5 mm/min. Cada material foi caracterizado pela termogravimetria, espectrometria no infravermelho, espectrometria de ressonância magnética nuclear, teor de cinzas, fluorescência de raios-X e microscopia eletrônica de varredura. Os resultados foram tratados por ANOVA e teste de SNK (p<0,05). Os resultados de microdureza Knoop, resistência à compressão e resistência flexural providos pela luz halógena foram melhores que os dos LED. A resina composta apresentou melhor performance que o compômero em todos os testes. / The goal of this work was to evaluate the effects of the blue light emitting diodes (LEDs) Smart Lite PS (Dentsply) and the conventional halogen lamp Curing Light XL 3000 (3M) on the polymerization effectiveness of the Dyract Ap compomer (Dentsply) and the TPH Spectrum composite resin (Dentsply) by the Knoop microhardness, compressive strength, flexural strength and material characterization tests. A hundred samples were prepared and divided into 12 groups according to the test applied, the polymerization light and the material. The conventional halogen lamp light had power of 470mW/cm and wavelength between 400 and 510nm; the LED light had power of 950mW/cm and wavelength between 450 and 490nm. The polymerization time for each material 2mm buildup was 40 seconds for the conventional halogen lamp and 10 seconds for LED. For the Knoop microhardness tests the 20 samples were cylinder shaped, 8mm diameter and 2mm height. The hardness was read in the upper and lower side of the samples by a micrometer (Micromet 2003), with 50 gf for 15 seconds. For the compressive strength test the 40 samples were cylinder shaped, 4mm diameter and 8mm height. The strength was measured in an universal testing machine Emic DL 10.000 with 500Kgf and cross-head speed of 0,5 mm/min. For the flexural strength test the 40 samples were box shaped, 25mm length, 2mm width and 2mm height. The strength was measured in an universal testing machine Emic DL 10.000 machine with 50Kgf and cross-head speed of 0,5 mm/min. Each material was characterized by Thermogravimetry, FT-IR analysis, Nuclear Magnetic Resonance, Ash Content Test, X-Ray Fluorescence and Scanning Electron Microscopy. The results were treated by ANOVA and SNK tests (p<0,05). The Knoop microhardness, compressive strength and flexural strength results provided by the halogen light lamp were better than the LED ones. The composite resin performed better than the compomer in all mechanical tests.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo deste trabalho foi avaliar o efeito de um diodo emissor de luz (LED) Smart Lite PS (Dentsply) e da lâmpada halógena convencional Curing Light XL 3000 (3M) na efetividade de polimerização do compômero Dyract Ap (Dentsply) e da resina composta TPH Spectrum (Dentsply) por meio de testes de microdureza Knoop, resistência à compressão e resistência flexural e caracterização dos materiais. Foram confeccionadas 100 amostras e divididas em 12 grupos de acordo com o teste aplicado, a luz de polimerização e o material utilizado. A lâmpada halógena convencional selecionada, Curing Light XL 3000 (3M), tinha intensidade de 470mW/cm2 e comprimento de onda entre 400 e 510nm; o LED Smart Lite PS (Dentsply) tinha intensidade de 950mW/cm2 e comprimento de onda entre 450 e 490nm. O tempo de fotopolimerização para cada incremento com 2mm de espessura foi de 40 s. para a lâmpada halógena convencional e 10 s. para o LED. Para os testes de microdureza Knoop foram confeccionadas 20 amostras numa matriz cilíndrica com 8,0mm de diâmetro e 2,0mm de altura. As leituras da microdureza foram realizadas nas superfícies superiores e inferiores das amostras utilizando um microdurômetro Micromet 2003, com uma carga de 50 gf por 15 s. Para o teste de resistência à compressão foram confeccionadas 40 amostras numa matriz cilíndrica com 4,0mm de diâmetro e 8,0mm de altura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 500Kgf e velocidade de carregamento de 0,5 mm/min. Para o teste de resistência flexural foram construídas 40 amostras numa matriz em forma de caixa com 25,0mm de comprimento, 2,0mm de altura e 2,0mm de largura. A resistência foi medida na máquina de teste universal de ensaios Emic DL 10.000 com uma célula de carga 50Kgf e velocidade de carregamento de 0,5 mm/min. Cada material foi caracterizado pela termogravimetria, espectrometria no infravermelho, espectrometria de ressonância magnética nuclear, teor de cinzas, fluorescência de raios-X e microscopia eletrônica de varredura. Os resultados foram tratados por ANOVA e teste de SNK (p<0,05). Os resultados de microdureza Knoop, resistência à compressão e resistência flexural providos pela luz halógena foram melhores que os dos LED. A resina composta apresentou melhor performance que o compômero em todos os testes. / The goal of this work was to evaluate the effects of the blue light emitting diodes (LEDs) Smart Lite PS (Dentsply) and the conventional halogen lamp Curing Light XL 3000 (3M) on the polymerization effectiveness of the Dyract Ap compomer (Dentsply) and the TPH Spectrum composite resin (Dentsply) by the Knoop microhardness, compressive strength, flexural strength and material characterization tests. A hundred samples were prepared and divided into 12 groups according to the test applied, the polymerization light and the material. The conventional halogen lamp light had power of 470mW/cm and wavelength between 400 and 510nm; the LED light had power of 950mW/cm and wavelength between 450 and 490nm. The polymerization time for each material 2mm buildup was 40 seconds for the conventional halogen lamp and 10 seconds for LED. For the Knoop microhardness tests the 20 samples were cylinder shaped, 8mm diameter and 2mm height. The hardness was read in the upper and lower side of the samples by a micrometer (Micromet 2003), with 50 gf for 15 seconds. For the compressive strength test the 40 samples were cylinder shaped, 4mm diameter and 8mm height. The strength was measured in an universal testing machine Emic DL 10.000 with 500Kgf and cross-head speed of 0,5 mm/min. For the flexural strength test the 40 samples were box shaped, 25mm length, 2mm width and 2mm height. The strength was measured in an universal testing machine Emic DL 10.000 machine with 50Kgf and cross-head speed of 0,5 mm/min. Each material was characterized by Thermogravimetry, FT-IR analysis, Nuclear Magnetic Resonance, Ash Content Test, X-Ray Fluorescence and Scanning Electron Microscopy. The results were treated by ANOVA and SNK tests (p<0,05). The Knoop microhardness, compressive strength and flexural strength results provided by the halogen light lamp were better than the LED ones. The composite resin performed better than the compomer in all mechanical tests.

Pathological processes in the alveolar and facial bones can lead to bone loss that may not heal with complete regeneration. Biomaterials can be used to facilitate the healing process and/or as a bone substitute, but the mechanisms are not fully understood. Persistent leakage of bacteria/bacterial toxins, after root canal treatment, may lead to a residual bone defect. The healing is dependent on a placed dental biomaterial providing a tight seal. The composition of the filling material may also influence the healing process. The general aim of this study is to investigate surface properties and biological interactions of biomaterials used in dento-alveolar surgery. A dental biomaterial, a bonded compomer (DAP) containing a corroding glass filler, was used as a root end filling material, promoting a new operation technique. The healing (assessed according to Molven´s x-ray criteria) demonstrates a significant improvement in healing results for the compomer group, compared to a commonly used technique. The surface properties and biological interactions of DAP were analyzed. ICP-OES of DAP cell culture medium extract demonstrated a significant release of Sr, Si and F from the dental biomaterial. Human periodontal ligament (PDL) cells grew on and around DAP specimens without any sign of toxic reactions. DAP extract stimulated proliferation of PDL cells, but caused an inhibition of osteoblastic gene expression in mouse bone marrow cells. The surface properties of the glass containing compomer may contribute to improved healing of the periapical lesions. A bovine inorganic bone graft substitute (BO) is commonly used as a treatment option in dento-alveolar surgery with new bone formation in immediate close contact with BO material. ICP-OES dissolution analysis of cell culture media, after incubation with BO particles, demonstrated a dosedependent release of Si and a decrease of Ca and P. An uptake of Ca from the medium to the BO particle was demonstrated with calcium-45 labeling. The Si dissolution varied between different batches, possibly reflecting a variation in food intake in the animals. Stimulated osteogenic response was seen in close contact to the BO particles in cell cultures. Furthermore, it was clearly demonstrated that the study design is a critical factor for correctly understanding biomaterials’ biological interactions. The surface properties of three bone graft substitutes reported to have good results in dento-alveolar surgery were investigated, in order to establish whether or not dissolution-precipitation reactions could contribute to the bone healing. Dissolution-precipitation extracts of BO, bioactive glass 45S5 (BG) and a marine algae hydroxyl apatite (AP) in cell culture media were analyzed. Dissolution of Si at significant levels was detected for BO and 45S5 over time. Significant uptake levels of Ca and P from the culture were seen for both 45S5, BO and AP but at different times. Surface analysis of the biomaterials with SEM/EDAX, before and after immersion in cell culture media, revealed a smoothing of the surface morphology for 45S5 over time. No obvious alterations for BO and AP were detected. Ca/P ratio decreased significantly for 45S5, but no major changes were detected by XPS for BO or AP. XPS further demonstrated a surface charge for BO, changing from negatively to positively charged when exposed to serum. 45S5 and AP had positive surface charges, both in the absence and the presence of serum. These demonstrated surface changes in biomaterials could contribute to adherence of cells and subsequently affect bone healing. Conclusion: Biomaterials used in dento-alveolar surgery interact with biological surroundings through surface and dissolution-precipitation reactions which may have implications for bone healing.

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