Morphology of perimplant regenerated bone, in sheep’s tibia, by means of guided tissue regeneration.

No data on the resistance to functional loads of bone regenerated by means of guided tissue regeneration, can be found. In this paper the new-formed bone is analyzed, in cases that see the surgical creation of defects in testing animals. The morphological aspects of perimplant bone, regenerated by means of bone substitutes or not, were evaluated. A coronal defect was created by means of a counter-sink bur. The following step provided for osseointegrated fixtures, with a machined or blasted (TiOblast) surface, to be installed. Some bone defects were filled with Bio-Oss®, and covered with resorb-able membrane (Vycril®), others were left unfilled. The animals were sacrificed after different periods of time (24 and 45 days). Some thick sections (200 µm) underwent then microradiography and were examined with a microscope, under transmitted and polarized light. Other sections, thin (5 µm), were coloured with toluidine blue, Gomori's Stain and Soloch-rome Cyanine/Congo red. Data confirm the excellent behaviour of bovine bone and of TiO blasted fixtures. The experimental results bring into evidence that, in cases of Guided Bone Regeneration (GBR) by means of membrane, the use of fixtures with a blasted surface (TiOblast), and of Bio-Oss® as bone substitute, made osseointegration easier. Results, moreover, suggest that in case of implant surgery with GBR, in order to allow the maturation of regenerated bone, it's healing time must be prolonged.