One‐ versus Two‐Stage Crown Lengthening Surgical Procedure for Aesthetic Restorative Purposes: A Randomized Controlled Trial

AIM This randomized controlled trial aimed to assess the efficacy of a two-stage crown lengthening intervention (SCL) in the aesthetic zone compared with a one-stage crown lengthening procedure (CCL). MATERIALS AND METHODS Thirty subjects were randomly assigned to either SCL (n = 15) or CCL (n = 15) groups. SCL consisted of full-thickness flaps followed by bone recontouring and gingivectomy 4 months postoperatively, if required. In CCL, osseous recontouring after submarginal incisions was performed, followed by flap repositioning. Records were obtained at baseline, 4 months (only in SCL), 6 months and 12 months. Primary outcome was the precision in achieving a pre-determined gingival margin position. Other outcomes considered were changes in the gingival margin position and keratinized tissue width (KTW) at 12 months, and patient-reported outcomes (PROMs). RESULTS Surgical precision was comparable between groups (0.2 ± 0.4 mm in the CCL group and -0.2 ± 0.5 mm in the SCL group). Four patients in the SCL group (27.7%) did not require a second-stage surgery. KTW was significantly higher in the SCL group (6.3 ± 1.4 mm versus 5.0 ± 1.4 mm, p = 0.017). SCL resulted in a lower impact on quality of life when compared to the CCL group. CONCLUSIONS Both approaches were highly accurate obtaining the desired crown length. SCL was associated with a lower reduction in KTW and more favourable oral health-related quality of life (OHIP-14).