|Nielsen, Forrest - Frosty|
Submitted to: The Anatomical Record
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2008
Publication Date: 3/15/2008
Citation: Gorustovich, A.A., Steimetz, T., Nielsen, F.H., Guglielmotti, M.B. 2008. Histomorphometric Study of Alveolar Bone Healing in Rats Fed a Boron-Deficient Diet. The Anatomical Record. 291:441-447. Interpretive Summary: Alveolar bone is found in a specialized part of the jaw that forms the support structure for teeth. Tooth extraction damages this bone. The bone repair process that begins immediately after tooth extraction requires nutritional factors including mineral elements. Emerging evidence indicates that boron plays a role in bone formation and maintenance. Thus, an experiment was performed with rats to determine whether the mineral element boron is a factor in bone healing after tooth extraction. Male rats were fed either a boron-deficient or a boron-adequate diet. Bone healing 7 and 14 days after a tooth was extracted was determined by microscopic measurements of stained sections of the alveolus. The boron-deficient rats showed a reduction in bone forming cells (osteoblasts) and an increase in quiescent bone forming surfaces in the alveolus after tooth extraction. As a result, the boron-deficient rats did not have as much new alveolar bone as the boron-adequate rats at both 7 and 14 days. The findings suggest that boron helps in alveolar bone formation and healing after tooth extraction.
Technical Abstract: Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. Weanling Wistar rats were divided into two groups: control (+B; 3 mg B/kg diet), and boron-deficient (-B; 0.07 mg/kg diet). At t0 the first molar was extracted under anesthesia. The animals in both groups were killed in groups of 10 at 7 and 14 days post-surgery. The guidelines of the NIH for the care and use of laboratory animals were observed. The mandibles were resected, fixed, decalcified and embedded in paraffin. Buccolingually oriented sections were obtained at the level of the mesial alveolus and stained with H-E. Total alveolar volume (TV) and bone volume fraction (TbV/TV) in the apical third of the alveolus were determined. Percentages of osteoblast surface (ObS), eroded surface (ES), and quiescent surface (QS) were determined. No statistical significance in food intake and body weight were observed. Histomorphometric evaluation found -B rats had 36% and 63% reductions in TbV/TV at 7 and 14 days, respectively. When compared to +B rats, -B rats had significant reductions (57% and 87%) in ObS concomitantly with increases (120% and 126%) in QS at 7 and 14 days, respectively. The findings show that boron deficiency results in altered bone healing because of a marked reduction in osteogenesis.