Introduction:
Ceramic coatings on titanium endoosseous implants are known for their osteoinductive and osteoconductive properties. Unfortunately, such coating, especially one obtained during plasma spraying technique, can detach itself and impair the osseointegration process of the titanium implant.

Aim of the study:
To assess the influence of laser modification of electrochemically deposited hydroxyapatite coating on titanium.

Material and methods:
Hydroxyapatite coating on titanium was prepared by means of electrodeposition. The coating was then modified with a femtosecond laser irradiation in two different regimes (varied power, speed, frequency) (1-1, 2-2). Two different surface modifications thus obtained were analysed in terms of topography, roughness, chemical composition and hydrophilicity.

Results:
Two different morphologies of hydroxyapatite coating could be observed on the SEM micrographs. 2-2 laser modification did not change the coating morphology while 1-1 processing resulted in creation of laserinduced periodic surface structures (LIPSS) with characteristic parallel microgroves and hydroxyapatite crystals sintered into spherical structures. 1-1 laser processing changed the concentration of O, Ca and P on the sample surface. The roughness of both samples was comparable relative to the Ra parameter. Both surfaces were hydrophilic with sample modified with 1-1 processing had contact angle two times smaller than for 2-2 processing.

Conclusions:
1-1 laser-modified hydroxyapatite coating presents surface properties potentially favourable for biological reaction. Further studies on animal models are necessary to verify this conclusion in vivo.