An interventional study of Free gingival graft with apical flap repositioning and Free gingival graft with vestibular mucosa excision in Keratinized Mucosa Deficiency, Peri-implant Soft Tissue and Dental Implants, sponsored by University of Barcelona. Not yet recruiting at 1 site in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-19.
Sponsored by University of Barcelona · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to learn which surgical technique works better to increase the amount of firm gum tissue (called keratinized mucosa) around dental implants in adults.
The main question it aims to answer is:
-Does repositioning the gum flap upward with stitches lead to a greater gain in firm gum tissue width at 6 months compared to simply removing the extra gum tissue, when both techniques are combined with a free gum graft?
Researchers will compare two techniques used during the second stage of implant surgery to see which one produces a greater gain in firm gum tissue around the implant.
Participants will:
This superiority multicenter randomized clinical trial is coordinated by the Universitat de Barcelona (UB) and includes the Universidad Complutense de Madrid (UCM) as a collaborating center.
Participant selection Adults with osseointegrated implants in the posterior maxilla or mandible presenting keratinized mucosa width of 2 mm or less and/or vestibular depth less than 4 mm will be screened for eligibility. Participants must be in periodontal and peri-implant health and have a plaque index of 15% or less.
Randomization Eligible participants will be randomly assigned (1:1) to one of two treatment groups using an Interactive Web Response System (IWRS) provided by Sealed Envelope Ltd. Randomization will take place intraoperatively, once the partial-thickness mucosal flap has been prepared.
Interventions
Group 1 (Control): Free gingival graft with apical repositioning and suturing of the vestibular mucosal flap to the periosteum Group 2 (Experimental): Free gingival graft with excision of the vestibular mucous tissue
Outcome assessment Soft tissue changes will be assessed at 5 timepoints (T0, Tim, T6w, T3m, T6m) using intraoral scans (TRIOS 3®, 3Shape) analyzed with Geomagic Control X® software through three-dimensional digital superimposition. Clinical measurements will also be performed using a calibrated periodontal probe and a customized thermoplastic stent to standardize the measurement point across visits.
Participants will complete a pain diary during the first 7 postoperative days recording pain intensity (100 mm visual analogue scale), analgesic consumption, and days with limited activity.
Sample size A total of 46 participants (23 per group) are required, accounting for a minimum clinically relevant difference of 1 mm in KTW gain, a standard deviation of 1.3 mm, 80% statistical power, 5% significance level, an intraclass correlation coefficient of 0.30 for multiple implants per patient, and a 15% dropout rate.
Statistical analysis The primary outcome will be analyzed in the intention-to-treat population using a generalized linear mixed model (GLMM), with patient as a random effect, adjusted for baseline KTW and study center.
Exclusion Criteria:
Free gingival graft with apical repositioning and suturing of the vestibular mucosal flap to the periosteum during second-stage implant surgery.
Procedure: Free gingival graft with apical flap repositioning
Free gingival graft with excision of the vestibular mucous tissue during second-stage implant surgery.
Procedure: Free gingival graft with vestibular mucosa excision
Autologous free gingival graft harvested from the palate and placed at the recipient site. The vestibular mucosal flap is repositioned apically and sutured to the periosteum during second-stage implant surgery.
Autologous free gingival graft harvested from the palate and placed at the recipient site. The vestibular mucous tissue is excised during second-stage implant surgery.
Peri-implant keratinized tissue width (KTW) gain
Absolute change in KTW, measured digitally as the linear distance between the mucosal margin and the mucogingival junction on the vestibular aspect of the implant, using Geomagic Control X® software on intraoral scan models (TRIOS 3®, 3Shape).
Time frame: Baseline (T0) to 6 months (T6m)
Clinical gain in peri-implant keratinized tissue width (KTW)
Absolute change in KTW, measured clinically with a calibrated periodontal probe using a customized thermoplastic stent.
Time frame: Baseline (T0) to 6 months (T6m)
Change in graft height
Change in graft height, measured in millimeters (mm), between immediate postoperative and 6 months, assessed by 3D digital superimposition.
Time frame: Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Change in graft width
Change in graft width, measured in millimeters (mm), between immediate postoperative and 6 months, assessed by 3D digital superimposition.
Time frame: Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Graft area contraction
Percentage of graft area reduction between immediate postoperative and 6 months, assessed by 3D digital superimposition.
Time frame: Immediate postoperative (Tim) to 6 months (T6m)
Change in graft volume
Change in graft volume, measured in cubic millimeters (mm³), between immediate postoperative and 6 months, assessed by 3D digital superimposition.
Time frame: Immediate postoperative (Tim), 6 weeks (T6w), 3 months (T3m), 6 months (T6m)
Vestibular depth
Change in vestibular depth from baseline to 6 months, assessed both digitally and clinically.
Time frame: Baseline (T0) to 6 months (T6m)
Surgical time
Time in minutes from anesthesia administration to placement of the last suture.
Time frame: Intraoperative (Tim)
Adverse events
Incidence and nature of postoperative adverse events related to the free gingival graft procedure.
Time frame: Immediate postoperative (Tim) to 6 months (T6m)
Clinician-perceived surgical difficulty
Degree of surgical difficulty perceived by the clinician at the end of the procedure, evaluated using a 100 mm visual analogue scale (0 = no difficulty, 100 = maximum imaginable difficulty).
Time frame: Intraoperative (Tim)
Postoperative pain
Pain intensity recorded at the end of the procedure and at 2, 6, 12 and 24 hours, and daily for 7 days, using a 100 mm visual analogue scale (0 = no pain, 100 = worst imaginable pain).
Time frame: Up to 7 days postoperat
Analgesic consumption
Number of doses of ibuprofen 600 mg and paracetamol 1 g consumed during the first 7 postoperative days.
Time frame: Up to 7 days postoperative
Patient global satisfaction
Overall satisfaction with the intervention evaluated at 7 days postoperative using a 100 mm visual analogue scale (0 = completely dissatisfied, 100 = completely satisfied).
Time frame: 7 days postoperative
Days with limitation of daily activity
Number of days with total or partial limitation of usual daily activity during the first 7 postoperative days.
Time frame: Up to 7 days postoperative
Plan to share: No
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University of Barcelona