Synthesis of Ordered and Disordered Nanofluorapatite Biomimetic Surfaces

Osteointegration and osteocondution of implants is dependent to a large degree on the biomimetic characteristic of the implant surfaces. It has been suggested in the literature (Chen F. et al, 2006 ) that ordered fluorapatite (FA) surfaces may be more biocompatible than hydroxyapatite (HA) and disordered fluorapatite surfaces. Objective: To create ordered and disordered FA films grown on metal subtracts. Materials and Methods: The stainless steel /titanium discs were acid-etched in 50% hydrogen peroxide and 50% sulfuric acid overnight. The discs were held at a 15^o angle and placed in a flask containing 200 ml of 9.36 g EDTA-Ca-Na₂, 2.07 g NaH₂ PO₄ and 0.21 g NaF, pH 6.0. The flask was then autoclaved for 10 hours at 2 atm and 121^oC condition and examined under Philips XL 30 scanning electron microscope (SEM). Results: The SEM results show that the undersurface side of the disc was covered with a layer of uniformly distributed, vertically arranged FA crystals. The reverse side of disc was covered with randomly distributed FA crystals which uniformly covered the discs. Both surfaces support dental pulp stem cell and osteoblast cell growth. We speculate that the ordered FA surfaces will be more biocompatible than the disordered surfaces. Conclusions: We are able to create an ordered and disordered FA crystal layer on stainless steel/titanium discs consistently using hydrothermal method. This study is supported by NIDR grant #: DE 015599.