A HISTOLOGICAL AND HISTOMORPHOMETRICAL EVALUATION OF THE APPLICATION OF SCREW-DESIGNED CALCIUMPHOSPHATE (CA-P)-COATED IMPLANTS IN THE CANCELLOUS MAXILLARY BONE OF THE GOAT
H. Caulier et al., A HISTOLOGICAL AND HISTOMORPHOMETRICAL EVALUATION OF THE APPLICATION OF SCREW-DESIGNED CALCIUMPHOSPHATE (CA-P)-COATED IMPLANTS IN THE CANCELLOUS MAXILLARY BONE OF THE GOAT, Journal of biomedical materials research, 35(1), 1997, pp. 19-30
Various studies already have shown that the occurrence of oral implant
failure is higher in the maxilla than in the mandible. To learn wheth
er Ca-P coatings can improve the success rate of oral implants in the
maxilla, three different plasma-sprayed, Ca-P-coated, self-tapping Bra
nemark(R) implants were inserted in the trabecular bone of the maxilla
. Before the insertion of the implants, the two first upper premolars
of 16 goats were bilaterally extracted. Four months later, each animal
received four types of implants: three different Ca-P-coated types an
d one uncoated. After an endosseous period of 6 months, the implants w
ere provided with permucosal abutments. Four months later the animals
were killed. At the end of the experiment, it appeared that 10 of the
16 installed noncoated implants had failed while of the 48 Ca-P-coated
implants, only 6 had failed. All successful implants were retrieved a
nd prepared for histomorphometrical evaluation of the bone and gingiva
response. The Ca-P-coated implants showed a significantly greater per
centage of bone in contact with the implant surface compared with the
uncoated implants. The length of the epithelium was not significantly
different for the coated compared to the uncoated implants, but the co
nnective tissue was significantly thicker for the noncoated implants t
han for the Ca-P-coated implants. Also, measurements revealed that all
coatings showed reduction in thickness. On the basis of these finding
s, we concluded that the application of Ca-P coatings (1) improves the
bone-implant reaction, although all coatings reduced in thickness, an
d (2) is of benefit during the healing period in less mineralized trab
ecular bone. (C) 1997 John Wiley & Sons, Inc.