Abstract:We examined the effects of calcium gluconate, an anti-inflammatory calcium salt, on ligature-induced experimental periodontitis and related alveolar bone loss. Calcium gluconate was orally administered daily for 10 days at 250, 125 or 62.5 mg ⁄ kg, beginning 1 day after ligation. We recorded changes in body-weight and alveolar bone loss and quantified the anti-inflammatory effects of calcium gluconate by measuring levels of myeloperoxidase (MPO), IL-1b and TNF-a. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentration as a measure of antioxidant effects. Ligature placement produced a marked decrease in body-weight, increased alveolar bone loss, and led to increased MPO, IL-1b, TNF-a and MDA concentrations, as well as elevated iNOS activity, increased inflammatory cell infiltration and decreased collagen fibre content in gingival tissue. Histopathology revealed decreased alveolar bone volume, increased osteoclast cell numbers and activity, and an elevated percentage of osteclasts on the alveolar bone surface. The effects of ligature placement were significantly and dose-dependently inhibited by 10 days of daily oral treatment with 250 and 125 mg ⁄ kg of calcium gluconate. The results suggest that 10 days daily oral treatment with calcium gluconate effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via antioxidant effects.