Table 3.

In vitro and in vivo studies of CaP coatings on metallic implants for osteointegration.

CaPs	Substrates	Techniques	In vitro and in vivo performances	Ref
DCPD	Mg–1.2Mn–1Zn alloy	Chemical conversion	Fibroblast cells: improved cell adhesion, growth, and proliferation; femoral shaft of rabbits: significantly enhanced osteoconductivity and osteogenesis (4 weeks).	[115]
	Ti–6Al–4V	Electro-deposition	Human fetal osteoblasts cells: supported the osteogenic function and the expression of extracellular matrix.	[116]
	Pure Ti	Plasma spray	Distal femur of rabbits: improved in vivo stability and early stage bone formation (6 weeks).	[117]
	Porous Ti	Plasma spray	Femur and tibia of sheep: improved cancellous bone ingrowth in the early stage (4 weeks) but decreased mechanical stability (12 weeks).	[118]
OCP	Ti–6Al–4V	Biomimetic	Mouse bone-marrow cell: cell-mediated degradation in osteoclast-enriched cell cultures.	[119]
	pure Ti	Electro-deposition	Human osteosarcoma-derived osteoblast-like cells: improved cell attachment and coverage; Femur of rabbits: osteoconductive and improved the bone growth (6 weeks).	[120]
α-TCP	Pure Ti	Magnetron sputtering	Femur of rabbits: increased bone-implant contact and peri-implant bone volume with increasing coating dissolution: α-TCP > TTCP > HA (6 weeks).	[121]
	Ti–6Al–4V	Plasma spray	Femur of dogs: similar bone response to TTCP and HA coatings, with a small increase in bone contact and remodeling lacunae after 5 months implantation.	[122]
β-TCP	pure Ti	Electrospray	Subcutaneous implantation in goats: gradual degradation (12 weeks);	[123]
α+β-TCP	Ti–6Al–4V	PLD	Rat bone marrow cells: bone matrix formation on remaining porous β-TCP coating with osteoclastic cellular resorption in the potentially osteogenic cell culture.	[124]
TCP + HA	Ti alloy	Plasma spray	Human total hip arthroplasty: reduced femoral bone loss after 2 years of implantation.	[125]
ACP	Ti–6Al–4V	Biomimetic	Mouse bone-marrow cells: no cell-mediated degradation in osteoclast-enriched cell cultures.	[119]
	Ti–6Al–4V	PLD	Rat bone marrow cells: bone matrix delaminated in the potentially osteogenic primary cell culture.	[124]
	pure Ti	Electrospray	Subcutaneous implantation in goats: gradual degradation (12 weeks).	[123]
CDHA	Ti–6Al–4V scaffolds	Electro-deposition	Human periosteum-derived cells: showed spreading and interactions on the stable coating, with an inverted relationship between the cell viability and the current density applied for coating deposition.	[126]
	Mg–2.0Zn–0.2Ca	Electro-deposition	Femur of rabbits: coating is valid for 8 weeks and could accelerate the new bone formation and transformation 24 weeks postoperatively.	[127]
HA + OCP	Mg–2.0Zn–0.2Ca	Electro-deposition	Femur of rabbits: induced more new bone formation and faster bone response (18 weeks).	[128]
HA	Pure Ti	Plasma spray	Adult human gingiva fibroblasts: lower crystallinity helps cell attachment, while higher medium pH inhibits cell proliferation.	[129]
	Pure Ti	Magnetron sputtering	Rat femora bone marrow cells: crystalline coatings stimulate cell proliferation and differentiation, while the amorphous coatings showed adverse and negative effects.	[130]
	Ti–6Al–4V	PLD	Rat bone marrow cells: osteoconductive and strong bone bonding without osteoclastic cellular resorption in the potentially osteogenic cell culture.	[124]
	Pure Ti	Magnetron sputtering	Femur of osteoporotic rats: enhanced bone/implant interface in both osteoporotic and normal conditions (12 weeks).	[131]
	Pure Ti	Biomimetic	Femur of rabbits: significantly higher bone-to-implant contact and promoted new bone formation (4 weeks).	[132]
	Ti–6Al–4V	Electro-deposition	Canine trabecular bone: induced the mineralized tissue apposition ratio and microstructure, with better mechanical integration (14 days).	[133]
	Ti–6Al–4V	Plasma spray	Canine trabecular bone: accelerate early stage (7 days) mineralization of bone tissue formation.	[133]
	Ti–13Nb–11Zr	Biomimetic	Rabbit cortical bone: significantly higher bone mineralization index than that of HA-coated Ti6Al4V surface (12 weeks).	[134]
	Stainless steel	ASTM F1185 commercial	Wrist of patients: showed not obviously superior clinical performance and not recommended for the external fixation for unstable wrist fractures (5 weeks).	[135]
fluoridated HA (FHA)	Mg–6Zn alloy	Electro-deposition	Human bone marrow stromal cells: enhanced cellular proliferation and differentiation. Femur of rabbits: better interface contacts with slow degradation (1 month).	[114] [136]
	AZ91	Electro-deposition	Greater trochanter of rabbits: increased new bone formation and decreased inflammation around the implant (2 months).	[137]
	Pure Ti	Electro-deposition	MC3T3-E1 osteoblast-like cell line: improved biological affinity including cell proliferation and alkaline phosphatase activity; higher bonding strength and lower dissolution rate than HA coating.	[138]
	Ti–6Al–4V	Sol-gel	Osteoblast-like cells of rabbits: increasing percentage of cells in S period but slightly decreasing cell proliferation rate when increasing F content in the FHA coatings.	[139,140]
	Ti–6Al–4V	Plasma spray	Jaws of Dogs: good bone integration and much slower degradation than HA coating (12 months).	[141]
carbonated apatite (CA)	Ti–6Al–4V	Biomimetic	Bone marrow stromal cells of goats: polygonal shape with extending cytoplasmic processes, and better cell attachment than OCP coating and electro-deposited CA coating.	[142]
	Ti–6Al–4V	Biomimetic	Mouse bone-marrow cell: cell-mediated degradation with numerous resorption lacunae in osteoclast-enriched cell cultures.	[119]
	Ti–6Al–4V	Biomimetic	Subcutaneous implantation in rats: calcified after 1 week of implantation.	[143]
	Pure Ti	Electrospray	Subcutaneous implantation in goats: gradual degradation (12 weeks).	[123]
	Pure Ti scaffolds	Electro-deposition	Dorsal subcutaneous pouches of rats: a mineralized collagen tissue formation around the implants, without new bone formation (4 weeks).	[73]