Plasma‐sprayed coatings of tetracalciumphosphate, hydroxyl‐apatite, and α‐TCP on titanium alloy: An interface study

Abstract

In order to study the interaction of calcium phosphate coatings with bone tissue, coated titanium cylinders with a standard size were implanted in dog femora. Coatings were made by plasma spraying powders of hydroxylapatite, β‐whitlockite, and tetracalciumphosphate particles. The plasma spraying process tuns β‐whitlockite into α‐TCP. Bone bonding and bone formation were evaluated by mechanical push‐out tests and histological observations. Hydroxylapatite and tetracalciumphosphate coatings show an interface strength after 3 months of implantation of 34.3 ± 6.5 MPa and 26.8 ± 3.9 MPa, respectively, while α‐TCP and blanco titanium lead to an interface strength of 10.0 ± 3.5 MPa and 9.7 ± 1.3 MPa, respectively. Histological examinations revealed that hydroxylapatite and tetracalciumphosphate give rise to an excellent bone formation, while α‐TCP and blanco titanium evoked remodeling and less bone contact.