Biocompatibilidade de superf?cies de implantes dent?rios tratadas com ?cido fosf?rico.

Programa de P?s-Gradua??o em Engenharia de Materiais. Departamento de Engenharia Metal?rgica, Escola de Minas, Universidade Federal de Ouro Preto.As modifica??es nas superf?cies de implantes dent?rios podem, quando intra?sseo, acelerar a ades?o, migra??o e prolifera??o celular, e desta maneira acelerar o processo de osseointegra??o e quando estas s?o feitas na superf?cie supra ?ssea favorecem a fixa??o das pr?teses implanto suportadas. Os tratamentos superficiais s?o realizados com o objetivo de aumentar as liga??es qu?micas e mec?nicas entre o implante e osso e quando supra ?ssea aumentar o embricamento mec?nico com o cimentante. Uma superf?cie com aumento de sua rugosidade ? a almejada para que ocorra a deposi??o de matriz e crescimento do tecido ?sseo, outro desejo ? aumentando as rugosidades na superf?cie supra?ssea, facilitando a fixa??o das pr?teses sobre implantes. O objetivo deste trabalho foi caracterizar superf?cies de implantes dent?rios tratadas com ?cido fosf?rico ? 37%, bem como avaliar seus efeitos sobre c?lulas sangu?neas e correlacionar com os n?veis de citocinas. Foram avaliadas superf?cies de implantes divididas em grupos com 50 amostras sendo distribu?dos em: amostras de porcelana, sem tratamento; amostras de metal sem tratamento; amostras de porcelana com tratamento com ?cido fosf?rico a 37% por 30 segundos; amostras de metal com tratamento ?cido fosf?rico a 37% por 30 segundos; amostras de porcelana com tratamento com ?cido fosf?rico a 37% por 60 segundos; amostras de metal com tratamento com ?cido fosf?rico a 37% por 60 segundos. As amostras foram caracterizadas por Microscopia Eletr?nica de Varredura (MEV) e por reometria. Os ensaios biol?gicos foram realizados com c?lulas mononucleares sangu?neas de doadores humanos. As amostras foram incubadas por 24 horas na presen?a ou aus?ncia de enxague das superf?cies. A viabilidade celular foi determinada por m?todos colorim?tricos e a quantifica??o de citocinas no sobrenadante pelo m?todo de citometria de fluxo. Ap?s o tratamento com ?cido fosf?rico foram observadas modifica??es de porosidade, amplia??o da ?rea de contato e presen?a de placas cobrindo a superf?cie. Independente do tipo de tratamento, a an?lise das curvas de fluxo de sangue e de viscosidade foram similares tanto nas superf?cies com tratamento como nas n?o tratadas e altos ?ndices de viabilidade celular foram observados na an?lise das superf?cies de implantes, determinando sua biocompatibilidade. Houve aumento das interleucinas (IL); IL-2, IL-4, IL-6, IL-10 e do fator de necrose tumoral (TNF-?), quando as c?lulas foram incubadas com enxague das superf?cies tratadas com ?cido e com cimento. Obteve-se tamb?m correla??o positiva entre as concentra??es das IL-10 com IL -2 e IL-10 com IL-4 em sobrenadantes de culturas de c?lulas incubadas na presen?a do ?cido. Os resultados encontrados sugerem que os tratamentos de superf?cies de implantes com ?cido fosf?rico a 37% foram capazes de ativar a produ??o de citocinas inflamat?rias. Portanto, o aumento de citocinas pode atuar modulando a reposta imunol?gica e resultando em melhora de processos de biofuncionalidades garantindo desta forma o sucesso das pr?teses implanto suportadas de uso odontol?gico.Changes in the surfaces of dental implants can, when intraosseous, accelerate the adhesion, migration and cell proliferation, and in this way accelerate the osseointegration process and when these are made on the supra bone surface favor the fixation of the supported implant prostheses. Surface treatments are performed with the aim of increasing the chemical and mechanical bonding between the implant and bone and when supra-bone increase mechanical bonding with the cement. A surface with increased roughness is the aim for the matrix deposition and growth of the bone tissue, another desire is to increase the roughness on the supraosseous surface, these facilitate the fixation of the prosthesis on implants. The objective of this study was to characterize surfaces of dental implants treated with phosphoric acid at 37%, as well as to evaluate its effects on blood cells and correlate with cytokine levels. Implant surfaces were divided into groups with 50 samples being distributed in: porcelain samples, without treatment; Untreated metal samples; Porcelain samples treated with phosphoric acid at 37% for 30 seconds; Samples of metal with phosphoric acid treatment at 37% for 30 seconds; Porcelain samples treated with phosphoric acid at 37% for 60 seconds; Samples of metal treated with phosphoric acid at 37% for 60 seconds. The samples were characterized by Scanning Electron Microscopy (SEM) and by rheometry. Biological assays were performed with blood mononuclear cells from human donors. The samples were incubated for 24 hours in the presence or absence of surface rinsing. Cell viability was determined by colorimetric methods and the quantification of cytokines in the supernatant by the flow cytometry method. After treatment with phosphoric acid, porosity changes, contact surface magnification and presence of plaques covering the surface were observed. Regardless of the type of treatment, the analysis of blood flow and viscosity curves were similar on both treated and untreated surfaces and high cell viability indices were observed in the analysis of the implant surfaces, determining their biocompatibility. There was an increase in interleukins (IL); IL-2, IL-4, IL-6, IL-10 and tumor necrosis factor (TNF-?), when cells were incubated with rinsed acid and cement treated surfaces. There was also a positive correlation between IL-10 concentrations with IL-2 and IL-10 with IL-4 in supernatants from cultures of cells incubated in the presence of the acid. The results suggest that surface treatments of implants with phosphoric acid at 37% were able to activate the production of inflammatory cytokines. Therefore, the increase of cytokines can act by modulating the immunological response and resulting in improved biofunctional processes, thus guaranteeing the success of supported implant prostheses for dental use