Correlations between periodontal tissue breakdown and cell populations

The present study evaluated correlations between periodontal breakdown and cell populations during an experimental periodontitis. Periodontitis was induced by tying plaque retentive silk ligatures at the gingival margins of maxillary and mandibular bicuspids and molars of 4 squirrel monkeys. Periodontal destruction was evaluated at baseline, and 3, 7 and 14 days after ligature placement by measuring loss of connective tissue attachment and crestal alveolar bone. Cell populations were characterized at corresponding time points by counting polymorphonuclear leucocytes (PMNs), plasma cells and the total number of cells. At baseline, levels of connective tissue attachment and crestal alveolar bone were normal. At 3, 7 and 14 days, loss of attachment and loss of bone were statistically significant. At baseline PMNs and plasma cells were sparse. At 3, 7 and 14 days, the total number of cells and PMNs were statistically significantly increased compared to baseline. Periodontal tissue destruction was positively and strongly correlated with the number of PMNs. These correlations emphasize the potential role of PMNs during acute bursts of periodontal tissue destruction.