Deproteinized bovine bone used as an adjunct to guided bone augmentation: an experimental study in the rat.

Abstract

Promising results have been reported following treatment of periodontal and peri-implant bone defects with deproteinized bovine bone grafts, but their influence on bone formation has not been clarified. The goal of this study was to examine whether implantation of deproteinized bovine bone (Bio-Oss, Geistlich AG, Wolhusen, Switzerland) influences bone formation when used as an adjunct to guided bone augmentation (GBA). A rigid, hemispherical, Teflon capsule was loosely packed with a standardized quantity of Bio-Oss and placed with its open part facing the lateral surface of the mandibular ramus (test) in 30 rats. At the contralateral side of the jaw, an empty capsule was placed (control). Groups of 10 animals were sacrificed after 1, 2, and 4 months. The volumes of the space created by the capsule and of the (1) newly formed bone, (2) remaining Bio-Oss particles, (3) soft connective tissue, and (4) acellular space in the capsule were estimated by a point-counting technique in three or four histologic sections, taken by uniformly random sampling. Bone formation at 1 month was limited in both tests and controls. After 2 months, the mean volume of the newly formed bone occupied 9.0% of the space created by the capsule in the test specimens compared with 23.8% in the control specimens (p < .01). After 4 months, the respective figures were 11.6% (tests) versus 38.7% (controls) (p < .01). It can be concluded that Bio-Oss, used as an adjunct to GBA, interferes with bone formation.