One- Versus Two-Stage Aesthetic Crown Lengthening

Universidad Complutense de Madrid

Status: Completed

Conditions: Patients in Need of Surgical CL in the Anterior Maxillary Sextant for Restorative Purposes

Treatments: Other: Conventional Crown Lengthening (CCL); Other: Two-stage Crown Lengthening (SCL)

Study type: Interventional

Funder types: Other

Identifiers

NCT04409366

Crown Lengthening RCT

Details and patient eligibility

About

This randomized controlled trial was aimed at assessing the efficacy of a two-stage crown lengthening intervention (SCL) for restorative purposes in the aesthetic zone compared with a one-stage crown lengthening procedure (CCL).

Full description

Subjects were randomly allocated to receive SCL or CCL. SCL consisted of full thickness flaps followed by bone recontouring and minor gingivectomy 4 months postoperatively, if required. In CCL, osseous recontouring after sub-marginal incisions was performed, followed by flap repositioning. Records were obtained at baseline, 4 months (only in SCL), 6 and 12 months. Primary outcome was the precision in achieving a predetermined gingival margin position. Other outcomes were changes in the gingival margin position and keratinized tissue width (KTW) at 12 months, and patient-reported outcomes (PROMs) using the OHIP-14 tool.

Enrollment: 30 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• older than eighteen years of age;
• more than 20 teeth in the mouth;
• with full mouth plaque and bleeding scores lower than 15%; and
• without probing pocket depth and/or attachment loss >4 mm

Exclusion criteria

• Pregnant women or breastfeeding
• smokers
• treated with antimicrobial and/or anti-inflammatory drugs within two months prior to entering the study
• currently undergoing orthodontic therapy

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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30 participants in 2 patient groups

Conventional Crown Lengthening; CCL

Active Comparator group

Description:

Using the surgical guide, submarginal internal bevel incisions were performed on the buccal aspect of the affected teeth. A full-thickness flap was raised up to the mucogingival junction (Dominguez et al., 2020). Ostectomy and osteoplasty were carried out by means of rotatory instruments and surgical chisels, as necessary, to achieve the necessary space between the bone crest and the restorative margin according to the presurgical plan. The CEJ was not the reference point since, in many cases, the position of the final margin of the restoration was planned apical to the actual position of the CEJ. Exposed root surfaces were carefully instrumented manually with curettes and, finally, vertical internal mattress sutures were placed to position the gingival margin at the level of the margin of the planned restoration. Sutures were removed after 7 days.

Treatment:

Other: Conventional Crown Lengthening (CCL)

Two-stage Crown Lengthening (SCL)

Experimental group

Description:

In the first surgical intervention, intrasulcular incisions were performed and a full thickness flap was raised up to the mucogingival junction. Ostectomy and osteoplasty were performed to establish the space for supracrestal tissue attachment, following the restorative plan and using the presurgical blueprint as the reference to determine the final position of the restoration margin, instead of the CEJ (Lee, 2004). Then the flaps were repositioned and secured with internal mattress sutures, placing the gingival margin at the original level. Sutures were removed at 7 days. In the second stage, after 3-4 months, minor gingival recontouring was performed, if necessary, to attain the desired gingival margin position according to the presurgical plan

Treatment:

Other: Two-stage Crown Lengthening (SCL)