Effects of Calcium on Alveolar Bone Loss and Periodontitis

Objectives: The objective of this study was to determine whether a high-calcium diet and a low-calcium diet results in a difference in age-related alveolar bone loss and ligature-induced periodontitis (LIP). Methods: 180 Sprague Dawley rats (90 M/90 F) were randomly assigned to a high (1%) or low (0.25%) calcium diet group at weaning. At 11 months half of the animals in each group were euthanized. The remaining animals were randomly divided into either a control or LIP group (ligature inserted around the mandibular first molar) and euthanized three months later. Hemi-mandibles were scanned and radiographed. Images were then analyzed to determine alveolar bone densities, and alveolar bone loss (linear measurement from contact point to alveolar bone crest, and surface area between first and second molars). Two-way t-tests were used to analyze differences in bone density and alveolar bone loss amongst the groups. Results: Significantly higher alveolar bone density was found for the high-calcium animals at 11 and 14 months, and for males and females (P-values ranged from <0.01 to 0.02) except for the LIP females (P=0.38). Age-related alveolar bone loss (at age 11 months) was less for the high calcium animals (P<0.01 for both linear and surface area measurements except for the surface area of the females: P=0.096). Alveolar bone loss in response to the LIP was less in the high calcium animals for both males and females (surface area P values <0.01 and for the linear measurement of bone loss P <0.01 for the females and P=0.39 for the males). Conclusion: A high-calcium diet results in greater alveolar bone density and less alveolar bone loss due to aging and LIP.

Acknowledgements: Supported by NIH/NIDCR T32DE007132.