A HISTOLOGICAL AND HISTOMORPHOMETRICAL EVALUATION OF SCREW-TYPE CALCIUMPHOSPHATE (CA-P) COATED IMPLANTS - AN IN-VIVO EXPERIMENT IN MAXILLARY CANCELLOUS BONE OF GOATS

The bone response to different calcium phosphate (Ca-P) coated implant s was evaluated in a goat animal model. Two types of plasma spray coat ings were applied to a commercially pure titanium (cpTi) tapered, coni cal screw-design implant (BioComp(R)); hydroxyapatite (HA-PS) and a du al coating, consisting of FA and HA (FA/HA-PS). In addition an amorpho us RF magnetron sputter coating (Ca-P-a) and uncoated implants were in vestigated. Forty-eight implants were inserted in the maxilla of 12 ad ult female goats. After implantation periods of 3 and 6 months, the bo ne implant interface was evaluated histologically and histomorphometri cally. After both implantation periods all plasma spray coated implant s were maintained. On the other hand three Ca-P-a and two cpTi implant s were lost. Histological examination revealed a better bone response to both plasma spray coated implants. Histomorphometrical evaluation c onfirmed this finding. At 3 and 6 months significantly higher percenta ges of bone contact (p < 0.001, ANOVA) were measured for both plasma s pray coated implants than for the cpTi and Ca-P-a implants, while no s ignificant difference (p < 0.05) existed between both implantation per iods. Degradation of both plasma spray coatings was observed. Supporte d by the results, it is concluded that, although Ca-P coatings can imp rove the performance of dental implants, the presence of a Ca-P coatin g is not the only important factor for bone healing around implants pl aced in low density trabecular bone.