Influence of zoledronic acid in the development of apical periodontitis in rats with osteoporosis and association of oxidative stress with bone mineral content

The present thesis was structured in two studies presented as two articles, that investigated the association between the parameters of Oxidative Stress (OS) and osteoporosis and the systemic and local effects of the osteoporosis treatment with Zoledronic Acid (ZOL). The first paper evaluated the association between OS markers and Bone Mmineral Content (BMC) of the femur, as well as determined the presence of these markers in the liver of rats with osteoporosis treated and untreated with ZOL. Wistar rats were divided into 4 groups (n = 10): OVX - ovariectomy surgery and vehicle treatment; OVX + ZOL - ovariectomy surgery and ZOL treatment; SHAM - sham surgery and vehicle treatment; SHAM + ZOL - sham surgery and ZOL treatment. Twenty-one days after surgery, vehicle or ZOL were administered in a single application. After 35 days the animals were euthanized. Oxidative damage and antioxidant defenses in the liver were evaluated by measuring the levels of Lipid Peroxidation (LP), Reactive Oxygen Species (ROS), Nitric Oxide (NOx), non-protein thiol groups and vitamin C. From multivariate regression it was observed that markers of oxidative damage (LP, ROS, NOx) were associated with reduction of BMC in both cancellous and cortical bone (P .05). Local and systemic inflammatory infiltrate were not affected by treatment with ZOL (P > .05). The OVX and OVX + ZOL groups presented higher levels of ROS than SHAM groups (P 0,05). O infiltrado inflamatório local e sistêmico não foram afetados pelo tratamento com ZOL (P > 0,05). Os grupos OVX e OVX + ZOL apresentaram maiores níveis de ROS que os grupos SHAM (P < 0,05). O ZOL diminuiu os níveis de ROS nas ratas ovariectomizadas (P < 0,05). Concluiu-se que a terapia com ZOL não interfere na perda óssea periapical e nos parâmetros inflamatórios. Contudo, o ZOL reduziu um marcador de dano oxidativo