Periodontal status of teeth facing extraction sites long-term after orthodontic treatment.

The present study was undertaken to examine the long-term periodontal status of teeth orthodontically moved into extraction sites. Patients were examined 14 to 34 years after active orthodontic treatment involving extraction of four first premolars. Three groups were established: one with closed tooth contacts and parallel adjacent teeth, one with closed tooth contacts and tipped adjacent teeth, and one with open contacts between adjacent teeth. Within each group accumulation of plaque, gingival health status, probing pocket depth, and probing attachment level of interproximal tooth surfaces, facing extraction sites and adjacent control sites between canine and lateral incisor were compared. Significantly more probing attachment loss was found in extraction sites with open tooth contacts (P less than 0.01) and with parallel adjacent teeth and closed tooth contacts (P less than 0.05) than in control sites. However, the mean differences were less than 0.5 mm, which may not be considered clinically significant. Tipping of teeth into the extraction sites had no long-term detrimental effect on the probing attachment level. No differences in accumulation of plaque and in gingival health status were observed.