In vivo reactions to particulate rhenanite and particulate hydroxylapatite after implantation in tooth sockets

To gain more information on the in vivo behaviour of rhenanite (CaNaPO sub(4)), particles of this material and of hydroxylapatite were mixed with gelatine or saline and inserted in tooth sockets of beagle dogs for periods of 3 and 6 months. Rhenanite appeared to transform into an apatite containing carbonate, sodium and magnesium. Resorption of both calcium phosphate particles was not observed histologically and was not shown histomorphometrically. Calcium phosphates were not found in lymph node tissue. The presence of particles in the sockets gave rise to new bone formation. Histomorphometry demonstrated that statistically significant more bone deposition occurred on rhenanite particles than on hydroxylapatite particles. Also gelatin, meant as a spacer, contributed to new bone formation.