Abstract
Objective The present study aims to analyze histomorphometrically the repair of a non-critical
bone defect after implantation of hydroxyapatite (HA) microspheres substituted by
magnesium (Mg).
Methods Thirty rats were distributed into 3 experimental groups, evaluated at 15 and 45 days
postoperatively: HAG (bone defect filled with HA microspheres); HAMgG (bone defect
filled with HA microspheres replaced with 1 mol% Mg), and CG (bone defect without
implantation of biomaterials).
Results After 15 days, the biomaterials filled the entire defect extent, forming a new osteoid
matrix between the microspheres. In the CG, this neoformation was restricted to the
edges with the deposition of loose connective tissue with reduced thickness. At 45
days, new bone formation filled almost the entire extension of the bone defect in
the 3 groups, with statistically significant osteoid deposition in the CG despite
the reduced thickness compared with the HAG and HAMgG. The groups with biomaterial
implantation displayed a more abundant osteoid matrix than at 15 days.
Conclusion The biomaterials studied showed biocompatibility, osteoconductivity, and bioactivity.
The Mg concentration in the substituted HA did not stimulate more significant bone
formation than HA without this ion.
Keywords
biomaterials - bone and bones - bone regeneration - hydroxyapatite - magnesium
