Artificial periodontal defects in beagle dogs. A clinical evaluation during 24 months

Artificial periodontal defects were evaluated clinically for 24 months in six beagle dogs. Defects were created bilaterally around the lower second, third and fourth premolars. The gingiva was separated from the teeth by intrasulcular incisions and copper bands were cemented around the teeth as far apically as possible. After 3 weeks the bands were replaced by cotton ligatures, which were kept in place deep subgingivally for 11 weeks. The dogs were placed on a soft diet, allowing plaque accumulation throughout the study. One week after removal of the ligatures, probing depths of around 4.5 mm were recorded. During the evaluation period of 24 months, plaque accumulation was abundant and subsequently the gingiva was heavily inflamed. However, a distinct healing tendency was evident clinically. Two years after removal of the ligatures, probing depth was reduced to approximately 3.5 mm and the attachment level as assessed clinically had changed in a coronal direction. Part of this recorded increase in periodontal attachment may have been the result of changes in composition and condition of the periodontal tissues resulting in differences in probing depths.