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Completed

NCT Number: NCT04409366

One- Versus Two-Stage Aesthetic Crown Lengthening

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).

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Conventional Crown Lengthening (CCL)

Other

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

Two-stage Crown Lengthening (SCL)

Other

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.

Primary outcomes

  1. T1-T4

    Time frame: Baseline-12 months

    The difference in mm between the ideal gingival margin (T1) and the position of the gingival margin at 12 months (T4).

Secondary outcomes

  1. Clinical Crown Length

    Time frame: At baseline, 6- and 12-month

    Distance from the gingival margin to the incisal edge on the midbuccal.Measured in mm.

  2. Amount of keratinized tissue

    Time frame: At baseline, 6- and 12-month

    Distance from the gingival margin to the mucogingival junction on the midbuccal.Measured in mm.

  3. Gingival display upon smiling

    Time frame: At baseline, 6- and 12-month

    Distance from the gingival margin of the central incisors to the lower edge of the upper lip. Measured in mm.

  4. Supracrestal tissue dimension

    Time frame: At baseline, 6- and 12-month

    Distance from the gingival margin to the alveolar bone crest (GM-ABC) as determined by bone sounding following local anesthesia. Measured in mm.

Sponsors and collaborators

Lead sponsor

Universidad Complutense de Madrid

Other

Registry information

Official study title

One- Versus Two-Stage Aesthetic Crown Lengthening for Restorative Purposes: A Randomized Controlled Trial.

Important dates

Study start
2013
Primary completion
2018
Study completion
2018
First posted
Jun 1, 2020
Registry last updated
Jun 1, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.