The effect of oestrogen deficiency on the alveolar bone resorption caused by traumatic occlusion

Abstract

This study, using 132 female rats, was designed to investigate whether oestrogen loss facilitates alveolar bone alterations induced by traumatic occlusion. Rats were ovariectomized (OVX) or underwent sham-operation (Sham). Seven days after surgery, half of the rats in each group were subjected to experimental traumatic occlusion (trauma), and the other half were left untreated. Thus, there were four groups: OVX+trauma, Sham+trauma, OVX, and Sham. Rats in each group were killed 1, 3, 5, 7, or 10 days after the introduction of occlusal trauma. The resected mandibles were processed without decalcification, and histomorphometric measurements were performed in the alveolar bone adjacent to the periodontal ligament of the first molar. The statistical assessment of the time- and group-specific differences by analysis of variance revealed significant differences between the OVX+trauma and Sham+trauma groups in the resorption parameters, but not in the formation parameters. The results show that the alveolar bone dynamics induced by traumatic occlusion are enhanced by oestrogen deficiency.

Evaluation of bone loss due to primary occlusal trauma in two experimental models of occlusal overload

“…Due to ethical limitations on prospective evaluation of OT in humans, 2 experimental models in rats were developed for the present study, with the goal of evaluating the consequence of the type of occlusion on the development of bone loss in primary OT. In one of the models, occlusal interference 7,8,11 was created to imitate experimentally the occlusal interferences and premature occlusal contacts that lead to the increase in the vertical dimension of occlusion, leading to occlusal instability by altering the force vectors and changing the magnitude of the applied forces to one tooth. In the other model, the unilateral vertical dimension was reduced, creating occlusion on only one of the first molars, with the goal of reproducing experimentally the cases of partial edentulism 15 , also creating occlusal overload experimentally.…”

“…Several studies have been conducted with the aim of understanding the cellular, molecular and genetic mechanisms involved in occlusal trauma [7][8][9][10][11] . Clinically, however, there is an ethical implication that limits the conduct of prospective studies on occlusal trauma in humans, making it difficult to measure occlusal overload and its implications on bone, cementum and the periodontal ligament 12,13 .…”

Role of Nitric Oxide in Inflammatory Periodontal Diseases:

“…49 The biological properties of NO is related with its unpaired electron, which makes NO a free and stable radical. NO is a lipophilic and high diffusible solute whose actions are dependent on both its concentration and form with in the cell.…”

A influência da deficiência estrogênica no processo de remodelação e reparação óssea

“…A influência da deficiência estrogênica na reparação óssea alveolar foi investigada por Kawamoto e Nagaoka (31) , que observaram que as alterações ósseas alveolares induzidas por oclusão traumática são agravadas pelos baixos níveis de estrógeno de ratas ovariectomizadas. Eles verificaram que a dinâmica óssea alveolar induzida pelo trauma oclusal foi aumentada pela deficiência estrogênica conseqüente à remoção dos ovários.…”