The influence of plasm ion nitriding of titanium surface and colagen type I on serum proteins adsorption on titanium surface, and its influence on adhesion, morphological structuration and bioactivity of human osteoblasts

Abstract

Titanium dental implants have been used with high clinical success on esthetic and functional rehabilitation of buccal cavity. After its bone insertion, the implants need 4 to 6 months of healing time to achieve its integration with host bone. New surfaces have been developed to improve the hydrophylic potential of titanium enhancing cell adhesion and consequently reducing the healing time needed and strengthening the osteointegration, by serum protein interaction. Therefore, the aim of this study is evaluate the effects on serum protein adsorption and bioactivity of human osteoblasts of the impregnation of amino radicals (NH2-) on titanium surface by plasm ion nitriding method and the collagen type I coverage. For this evaluation, titanium discs will be submitted to plasm ion nitriding treatment, with/without colagen type I coverage, and the hydrophilic potential will be evaluated by the surface free energy measure before and after human blood serum exposure. The protein profile adsorpted on titanium surface will be evaluated by mass spectrometry comparing to the control group (pure titanium). For the bioactivity evaluation, human osteoblasts will be cultured over titanium discs with one of the surface treatments (nitriding, collagen or pure titanium) after serum exposure. The adhesion evaluation will be done by counting at Neubauer chamber after cells enzymatic disaggregation. The morphological structuration will be evaluated by scan electronic microscopy and laser confocal microscopy. The bioactivity will be evaluated by the activity of alkaline phosphatase enzyme, by osteogenic proteins expression with real-time PCR, by mineral deposit level measurement. (AU)