Chronic exposure to lead acetate promotes changes in the alveolar bone of rats: microstructural and physical-chemical characterization

Abstract

There are a few data relating to the effects of lead (Pb) exposure on the alveolar bone, which has very distinct morphophysiological characteristics and is of great importance in the oral cavity. In this context, the aim of this study was to investigate the changes promoted after long-term exposure to Pb in the microstructure of the alveolar bone of rats. Twenty adult Wistar rats were exposed to 50 mg/kg/day of lead acetate for 55 days. These animals were euthanized and had their mandible removed. Each mandible was divided into hemimandibles, and the alveolar bone was used for bone lead quantification, crystallinity analysis, microstructure evaluation by the percentage of bone volume (BV/TV), number of trabeculae (Tb.N), thickness of the trabecular (Tb.Th), and trabecular space (Tb.Sp). Morphometric analysis of the exposed root area was also performed. Long-term exposure to Pb resulted in high levels of Pb in the alveolar bone but showed no changes in the organization of crystallinity. The microstructural analyses showed a reduction of BV/TV, Tb.Th, and Tb.N and increase of Tb.Sp parameters, resulting in an increase in the exposed root area and an alveolar bone loss in height. The findings of this study reveal the ability of Pb to alter the alveolar bone microstructure after long-term exposure to the metal, possibly due to changes in tissue homeostasis, contributing to the reduction of bone quality.

Keywords: Alveolar bone loss; Environmental exposure; Lead; MicroCT; Periodontium; Toxicology.