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).