Surface design using laser technology for Ti6Al4V-hydroxyapatite implants

Although hydroxyapatite coatings have been proven effective for obtaining uniform and continuous coatings on metallic endosseous implants, the detachment of these coatings during implantation can critically compromise the hydroxyapatite bioactive role. In order to overcome this problem, this work proposes a new integrated approach, starting with the laser machining of the Ti6Al4V implant, followed by the allocation of the hydroxyapatite and its subsequent laser sintering. In this study two different powder compaction/laser sintering methods were tested. Hydroxyapatite sinterability and adhesion to the metal was assessed for both methods, considering several conditions. Hydroxyapatite possible degradation due to the temperatures achieved during this process was also evaluated by means of Energy Dispersive Spectrometry (EDS) and X-ray diffraction (XRD). The better solution assured a significant retained volume of non-degraded hydroxyapatite. This work proves that laser technology is a promising approach for the manufacturing of implants with improved bioactivity sites that can overcome the detachment problems of coating-based solutions.