Bone reactions to anorganic bovine bone (Bio-Oss) used in sinus augmentation procedures: A histologic long-term report of 20 cases in humans

Many materials are used for sinus augmentation procedures. Anorganic bovine bone (Bio-Oss) has been reported to be osteoconductive, and no inflammator y responses have been observed with the use of this biomaterial. One of the main questions pertaining to Bio-Oss concerns its biodegradation and subst itution by host bone. Some investigators have observed rapid replacement by host bone, while other researchers observed slow resorptive activity or no resorption at all. The aim of the present study was to conduct a long-term histologic analysis of retrieved specimens in humans where Bio-Oss was use d in sinus augmentation procedures. Specimens were retrieved from 20 patien ts after varying peri ods from 6 months to 4 years and were processed to ob tain thin ground sections. Bio-Oss particles were surrounded for the most p art by mature, compact bone. In some Haversian canals it was possible to ob serve small capillaries, mesenchymal cells, and osteoblasts in conjunction with new bone. No gaps were present at the interface between the Bio-Oss pa rticles and newly formed bone, in specimens retrieved after 18 months and 4 years, it was also possible to observe the presence of osteoclasts in the process of resorbing the Bio-Oss particles and neighboring newly formed bon e. Bio-Oss appears to be highly biocompatible and osteoconductive, is slowl y resorbed in humans, and can be used with success as a bone substitute in maxillary sinus augmentation procedures.