Abstract
	Titanium and titanium alloys (especially Ti-6Al-4V) have been used for many years in medical practice thanks their mechanical and chemical properties. Their main advantages are biocompatibility, good resistance to corrosion and strength. But without any surface treatment (blasting, coating) titanium and its alloy do not form the strong bond with bone. The inert implant surface is bioactive only in case of its chemical treatment. Our previous study showed that titanium and titanium alloys form a calcium phosphate layer on its surface in supersaturated calcification solution (SCS2) when it was subjected to concentrated chloride acid and 10 mol.dm-3 NaOH treatments to form titanate hydrogel contained Na+ ions. Presence of this layer gives bioactive properties to titanium and its alloys. A uniform calcium phosphate (Ca-P) coating approximately 10 - 20 ?m thick was found on the substrates after 72 hours immersion. This layer can improve the bone – bonding interaction. The adhesion strength of the calcium phosphate layer to titanium and titanium alloy substrates was determined by tape test (ASTM D 3359), modified knife test (ASTM 6677-1) and modified pull test (STN EN 582). Calcium phosphate coatings were observed by scanning electron microscopy (SEM/EDS) and optical microscopy (OM). The coatings had a very good adhesion to titanium and titanium alloy substrate.