Bone regeneration: molecular and cellular interactions with calcium phosphate ceramics.

Calcium phosphate bioceramics are widely used in orthopedic and dental applications and porous scaffolds made of them are serious candidates in the field of bone tissue engineering. They have superior properties for the stimulation of bone formation and bone bonding, both related to the specific interactions of their surface with the extracellular fluids and cells, ie, ionic exchanges, superficial molecular rearrangement and cellular activity.

Bone tissue engineering on amorphous carbonated apatite and crystalline octacalcium phosphate-coated titanium discs.

Poor fixation of bone replacement implants, e.g. the artificial hip, in implantation sites with inferior bone quality and quantity may be overcome by the use of implants coated with a cultured living bone equivalent.

Calcium phosphate interactions with titanium oxide and alumina substrates: an XPS study.

Besides the excellent mechanical properties of titanium and alumina (Al(2)O(3)) in the case of load bearing applications, their bone-bonding properties are very different. In osseous environment, Al(2)O(3) ceramic is encapsulated by fibrous tissues, whereas bone can bind directly to titanium, via its natural titanium dioxide (TiO(2)) passivation layer. So far, this calcification dissimilarity between TiO(2) and Al(2)O(3) was attributed to respectively their negative and positive surface charge under physiological conditions.

Nano-scale study of the nucleation and growth of calcium phosphate coating on titanium implants.

The nucleation and growth of a calcium phosphate (Ca-P) coating deposited on titanium implants from simulated body fluid was investigated by using atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM). Forty titanium alloy plates were assigned into two groups. One group with a smooth surface having a maximum roughness R(max) < 0.

Osteogenecity of octacalcium phosphate coatings applied on porous metal implants.

The biomimetic route allows the homogeneous deposition of calcium phosphate (Ca-P) coatings on porous implants by immersion in simulated physiologic solution. In addition, various Ca-P phases, such as octacalcium phosphate (OCP) or bone-like carbonated apatite (BCA), which are stable only at low temperatures, can be deposited. In this pilot study, experiments were designed with a twofold-purpose: (1) to investigate the osteoinduction of OCP-coated and noncoated porous tantalum cylinders and of dense titanium alloy cylinders (5 mm in diameter and 10 mm in length) in the back muscle of goats at 12 and 24 weeks (n = 4); and (2) to compare the osteogenic potentials of BCA-coated, OCP-coated, and bare porous tantalum cylinders in a gap of 1 mm created in the femoral condyle of a goat at 12 weeks (n = 2).