Influence of pore dimensions on bone ingrowth into porous hydroxylapatite blocks used as bone graft substitutes. A histometric study.

The aim of the present study was to determine the influence of pore dimensions of porous hydroxylapatite (HA) blocks on bone ingrowth when used as interposed grafts in alveolar ridge bone defects. HA blocks with pore diameters of 150 microns and 260 microns were used. Ten animals received one implant each with small pore sizes, whilst in 10 other animals blocks with larger pore sizes were used. The blocks were examined histometrically and spatially reconstructed for determination of 3-dimensional distribution of bone ingrowth. In the group of implants with 150 microns pore diameter a high rate of implant loss occurred. The blocks with 260 microns pore diameter had 3 times more bone ingrowth compared with the 150 microns group with uniform distribution.