Subcutaneous evaluation of RF magnetron-sputtered calcium pyrophosphate and hydroxylapatite-coated Ti implants.
The in vivo behavior of infrared-heated, RF magnetron-sputtered hydroxylapatite (HA) and calcium pyrophosphate (DCPP) coated titanium discs was investigated. The discs were implanted subcutaneously in the back of six goats for 2, 4, 8 and 12 weeks. At the end of the study, coated discs were removed and examined on their physicochemical properties by X-ray diffraction (XRD) and scanning electron microscopy (SEM), including energy dispersive spectroscopy (EDS). Also, implants were prepared for light microscopical evaluation of the tissue response. The results showed that heat-treated HA coatings showed a stable behavior, i.e. no changes in the XRD pattern occurred during implantation. Also, no dissolution of the coating was observed by SEM. EDS revealed that the Ca/P ratio of the HA coatings remained stable during implantation. In contrast, heat-treated DCPP coatings showed a compositional change into apatite and tricalcium phosphate (TCP) during implantation. This was confirmed by the SEM and EDS analysis. The Ca/P ratio of the DCPP coatings changed from 0.8 to 1.52 during implantation. Finally, histology showed that both heat-treated HA and DCPP coatings showed no adverse tissue response, as characterized by the presence of thin, dense fibrous tissue capsule. Consequently, it can be concluded that 2 mum thick heat-treated, RF magnetron-sputtered HA and DCPP coatings are of sufficient thickness to withstand dissolution during 12 weeks of implantation in a subcutaneous location in goats. In addition, both coatings showed a biocompatible tissue behavior. Further, heat-treated DCPP coatings revealed a gradual compositional change into apatite and TCP.
Department of Periodontology and Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
Yan
Y
Yonggang
J G C
JG
Wolke
Li
L
Yubao
J A
JA
Jansen
D000818:Animals; D002131:Calcium Pyrophosphate; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D006041:Goats; D008297:Male; D019736:Prostheses and Implants; D040521:Subcutaneous Tissue; D014025:Titanium
D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium; D002131:Calcium Pyrophosphate