Oral Bone Grafting in a Rat Model and the Use of Scanning Electron Microscopy for Tissue Morphology Evaluation

Abstract

Oral bone grafting is a procedure widely performed in current dentistry. Several biomaterials fit this purpose.  The aim of this study was to use scanning electron microscopy (SEM) to evaluate the ultrastructural  aspects of bone repair in a rat model, with periodontal tissues involved. Two groups (I and II) of 20 animals  each were operated on to create a surgical defect with a round carbide burr (3mm) on the right side  of their mandible, anterior to the mental foramen. Both groups were evenly divided with 5 animals each to  receive the application of either bifasic calcium phosphate bioceramic (B), lyophilized deproteinated  bovine bone (L), bifasic bioceramic associated with lyophilized deproteinated bovine bone (BL), or no biomaterial  (control or C). Group I was monitored for one week and group II for three weeks prior to euthanasia.  Hemi-mandibles were prepared for SEM analysis. Parameters such as exposure of incisive root surface,  width of the cross-section of filiform structures and presence of mineralized-like globuli (area) were evaluated.  The findings of this study suggested that surgical procedures for introduction or not of biomaterial  did not cause problems with normal feeding to the animals. Both of the biomaterials used promoted a periodontal  ligament involvement. Fibers (single filiform structures) could be detected in a range from 0.07 to  0.18μm of diameter, except for L that was larger – considered to be due to residual fibers of bovine origin.  C bundles (groups of fibers) showed larger width of cross-section than with the use of biomaterials.  Globuli areas (mineralization) were smaller to C than with the biomaterials use. B showed larger globuli  areas, suggesting slow incorporation. It was concluded that the use of these biomaterials favored maintenance  of tissue volume although slowing remodeling, and the combination (BL) presented the best performance.