Surgical lengthening of the clinical crown.

The aim of the present study was to assess the changes in the periodontal tissue levels as an immediate result of the surgical crown lengthening procedure and over a 6-months healing period. 25 patients ranging between 20 to 81 years of age were included in the study. A total of 85 teeth (43 test and 42 control teeth not exposed to surgery) were evaluated over 6 months. After initial therapy, the indication for crown lengthening comprised need for increased retention and accessibility to deep subgingival preparation margins hampering impression taking. During surgery, the alveolar crest was reduced, thereby creating a distance of 3 mm to the future reconstruction margin. The results of this study demonstrated that the mean probable changes in the levels of the periodontal tissues from those defined after surgery were minimal, resulting in changes comparable to the shifts observed at control teeth not exposed to any surgical procedures. Frequency analysis of the number of sites with dislocation of the free gingival margin demonstrated that 12% of the sites with crown lengthening procedure showed 2-4 mm recession of the free gingival margin between 6 weeks and 6 months postoperatively. In esthetically critical, visible areas of the dentition, recessions must be closely observed in the healing period after surgical crown lengthening, when prosthetic reconstructions are planned on such teeth.