<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT04409366</url>
  </required_header>
  <id_info>
    <org_study_id>Crown Lengthening RCT</org_study_id>
    <nct_id>NCT04409366</nct_id>
  </id_info>
  <brief_title>One- Versus Two-Stage Aesthetic Crown Lengthening</brief_title>
  <official_title>One- Versus Two-Stage Aesthetic Crown Lengthening for Restorative Purposes: A Randomized Controlled Trial.</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Universidad Complutense de Madrid</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>Universidad Complutense de Madrid</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      This randomized controlled trial was aimed at assessing the efficacy of a two-stage crown&#xD;
      lengthening intervention (SCL) for restorative purposes in the aesthetic zone compared with a&#xD;
      one-stage crown lengthening procedure (CCL).&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Subjects were randomly allocated to receive SCL or CCL. SCL consisted of full thickness flaps&#xD;
      followed by bone recontouring and minor gingivectomy 4 months postoperatively, if required.&#xD;
      In CCL, osseous recontouring after sub-marginal incisions was performed, followed by flap&#xD;
      repositioning. Records were obtained at baseline, 4 months (only in SCL), 6 and 12 months.&#xD;
      Primary outcome was the precision in achieving a predetermined gingival margin position.&#xD;
      Other outcomes were changes in the gingival margin position and keratinized tissue width&#xD;
      (KTW) at 12 months, and patient-reported outcomes (PROMs) using the OHIP-14 tool.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">April 1, 2013</start_date>
  <completion_date type="Actual">October 1, 2018</completion_date>
  <primary_completion_date type="Actual">October 1, 2018</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Treatment</primary_purpose>
    <masking>Single (Outcomes Assessor)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>T1-T4</measure>
    <time_frame>Baseline-12 months</time_frame>
    <description>The difference in mm between the ideal gingival margin (T1) and the position of the gingival margin at 12 months (T4).</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Clinical Crown Length</measure>
    <time_frame>At baseline, 6- and 12-month</time_frame>
    <description>Distance from the gingival margin to the incisal edge on the midbuccal.Measured in mm.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Amount of keratinized tissue</measure>
    <time_frame>At baseline, 6- and 12-month</time_frame>
    <description>Distance from the gingival margin to the mucogingival junction on the midbuccal.Measured in mm.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Gingival display upon smiling</measure>
    <time_frame>At baseline, 6- and 12-month</time_frame>
    <description>Distance from the gingival margin of the central incisors to the lower edge of the upper lip. Measured in mm.</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Supracrestal tissue dimension</measure>
    <time_frame>At baseline, 6- and 12-month</time_frame>
    <description>Distance from the gingival margin to the alveolar bone crest (GM-ABC) as determined by bone sounding following local anesthesia. Measured in mm.</description>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">30</enrollment>
  <condition>Patients in Need of Surgical CL in the Anterior Maxillary Sextant for Restorative Purposes</condition>
  <arm_group>
    <arm_group_label>Conventional Crown Lengthening; CCL</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <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.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Two-stage Crown Lengthening (SCL)</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <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</description>
  </arm_group>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Conventional Crown Lengthening (CCL)</intervention_name>
    <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</description>
    <arm_group_label>Conventional Crown Lengthening; CCL</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Other</intervention_type>
    <intervention_name>Two-stage Crown Lengthening (SCL)</intervention_name>
    <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.</description>
    <arm_group_label>Two-stage Crown Lengthening (SCL)</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  older than eighteen years of age;&#xD;
&#xD;
          -  more than 20 teeth in the mouth;&#xD;
&#xD;
          -  with full mouth plaque and bleeding scores lower than 15%; and&#xD;
&#xD;
          -  without probing pocket depth and/or attachment loss &gt;4 mm&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Pregnant women or breastfeeding&#xD;
&#xD;
          -  smokers&#xD;
&#xD;
          -  treated with antimicrobial and/or anti-inflammatory drugs within two months prior to&#xD;
             entering the study&#xD;
&#xD;
          -  currently undergoing orthodontic therapy&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <verification_date>May 2020</verification_date>
  <study_first_submitted>May 26, 2020</study_first_submitted>
  <study_first_submitted_qc>May 26, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">June 1, 2020</study_first_posted>
  <last_update_submitted>May 26, 2020</last_update_submitted>
  <last_update_submitted_qc>May 26, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">June 1, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT04409366
org study id: Crown Lengthening RCT
nct id: NCT04409366
lead sponsor: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
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).
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.
allocation: Randomized
intervention model: Parallel Assignment
primary purpose: Treatment
masking: Single (Outcomes Assessor)
measure: T1-T4
time frame: Baseline-12 months
description: The difference in mm between the ideal gingival margin (T1) and the position of the gingival margin at 12 months (T4).
measure: Clinical Crown Length
time frame: At baseline, 6- and 12-month
description: Distance from the gingival margin to the incisal edge on the midbuccal.Measured in mm.
measure: Amount of keratinized tissue
time frame: At baseline, 6- and 12-month
description: Distance from the gingival margin to the mucogingival junction on the midbuccal.Measured in mm.
measure: Gingival display upon smiling
time frame: At baseline, 6- and 12-month
description: Distance from the gingival margin of the central incisors to the lower edge of the upper lip. Measured in mm.
measure: Supracrestal tissue dimension
time frame: At baseline, 6- and 12-month
description: Distance from the gingival margin to the alveolar bone crest (GM-ABC) as determined by bone sounding following local anesthesia. Measured in mm.
arm group label: Conventional Crown Lengthening; CCL
arm group type: Active Comparator
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.
arm group label: Two-stage Crown Lengthening (SCL)
arm group type: Experimental
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
intervention type: Other
intervention name: Conventional Crown Lengthening (CCL)
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
arm group label: Conventional Crown Lengthening; CCL
intervention type: Other
intervention name: Two-stage Crown Lengthening (SCL)
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.
arm group label: Two-stage Crown Lengthening (SCL)
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
responsible party type: Sponsor