Gary Brierly

Critical Sized Mandibular Defect Regeneration in Preclinical In Vivo Models

Restoration of critical sized defects of the mandible still poses a major problem in the field of Oral and Maxillofacial Surgery. The current gold standard of treatment relies on the use of autologous grafts and therefore, has associated disadvantages such as donor site morbidity and insufficient bone for prosthetic rehabilitation. Recent advances in the fields of bone tissue engineering and distraction osteogenesis provide an alternative treatment modality to restore the aforementioned critical sized defects. These alternative modalities offer patients and clinicians multiple advantages such as decreased morbidity and increased volume of bone for prosthetic restoration. The aim of this review was to evaluate the bone regeneration capacity of bone tissue engineering and distraction osteogenesis in preclinical in vivo animal models against the current gold standard.

Comparison of Different Decalcification Methods Using Rat Mandibles as a Model

Selection of decalcification agents is an essential consideration when processing mineralized tissues because the integrity and immunohistochemical characteristics of the tissues may be affected. Here, we report results obtained from the decalcification of rat mandibles using 10% ethylenediaminetetraacetic acid (EDTA) at room temperature (RT), 10% EDTA at 37C, 5% nitric acid, and 10% formic acid at RT. Decalcification endpoints were determined by microcomputed tomography. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry. Decalcification of the anterior and posterior portions of the mandible took 220 and 191 hr in 10% EDTA RT, 102 and 73 hr in 10% EDTA 37C, 13.5 and 4.3 hr in 5% nitric acid, and 140 and 36 hr in 10% formic acid, respectively. Decalcification in 10% EDTA at 37C was accelerated, but 10% EDTA at RT provided optimal results for immunohistochemistry and cellular and structural details. Decalcification using 5% nitric acid was accomplished in the shortest time and exhibited good cellular and architectural morphology, whereas 10% formic acid was suboptimal with respect to tissue and cellular morphology. Despite being the slowest method, EDTA at RT is still the recommended method for decalcifying mineralized tissues; however, if rapid decalcification is needed, 5% nitric acid is the best option, yielding acceptable tissue integrity and speed.