Evaluation of the effect of surgical crown lengthening on periodontal parameters

Aims and Objectives: Biologic width (BW) as defined by Cohen is the part of the supracrestal gingival tissues that occupy the space between the base of the gingival crevice and the alveolar crest; it includes the junctional epithelium and the connective tissue element. The purpose of this study was to evaluate the positional changes of the periodontal tissues, particularly the biological width, following surgical crown lengthening in human subjects. Materials and Methods: A clinical trial study involving 15 patients was carried out for a period of 3 months. Sites were divided into3 groups: treated (TT) sites, adjacent (AD) sites and non-adjacent (NAD) sites. Free gingival margin (FGM), attachment level, pocket depth, bone level, biological width (BW) were recorded at baseline, 1 and 3 months. Direct bone level after flap reflection was recorded before and after osseous resection at baseline only. Level of osseous crest was lowered based on BW, and supracrestal tooth structure needed using a combination of rotary and hand instruments. Results: Overall, apical displacement of FGM at TT, AD and NAD sites was statistically significant compared to baseline. The apical displacement of FGM at TT site was more when compared to that at AD and NAD sites at 3 months. The BW at the TT site was smaller at 1 and 3 months compared to that at baseline.