Autogenous vs. Xenogeneic Peri-implant Soft Tissue Grafts Placed in Full vs. Split Thickness Flaps
- Conditions
- Thin Gingiva
- Interventions
- Procedure: Split thickness flapProcedure: Full thickness flapProcedure: Autogenous sub epithelial connective tissue graftProcedure: Volume stable collagen matrix
- Registration Number
- NCT05211115
- Lead Sponsor
- Universidad Complutense de Madrid
- Brief Summary
Randomized, outcome assessor and data analyst blinded, single center trial with four parallel arms and a 1:1:1:1 allocation ratio, with the aim of comparing which combination of bilaminar technique (split vs. full thickness flap) and graft type (autogenous or xenogeneic) provides better clinical, aesthetic, morphological, vascular and patients related outcomes, when augmenting the buccal peri-implant mucosa at the reopening of submerged implant fixtures
- Detailed Description
This randomized four parallel arms controlled clinical trial with blinded outcome assessment and data analysis aims to establish which combination of bilaminar technique (split vs. full thickness flap) and graft type (autogenous subepithelial connective tissue graft vs. volume stable collagen matrix) provides better clinical, aesthetic, morphological, vascular and patients related outcomes, when augmenting the buccal peri-implant mucosa at the reopening of submerged implant fixtures. The primary outcome is the gain in soft tissue thickness (standardised measurement at baseline, after surgery, at 1m and 6m). Secondary outcomes include changes in tissue volume (intraoral scans at baseline, post-op, 14d, 1m, 6m), RAL and KTW (clinical measurements at baseline, 1m, 6m), tissue color integration (∆E at 1m and 6m), and PROMS (7d, 14d, 30d). Exploratory outcomes include tissue morphology (histology at 1m,2m,4m,6m), microcirculation (Doppler flowmetry at pre-op, 7d, 14d, 1m) and revascularization (IHC at 1m,2m,4m,6m). A figure of 10 subjects per group was obtained for a 0,3mm difference in tissue thickness increase (SD 0,23mm), using 80% power, alpha 0.05, and a 10% drop-out rate. Patients will be randomly allocated to four groups: test (STF+VCM), control 1 (FTF+VCM), control 2 (SFT+CTG), control 3 (FTF+CTG). Patients will be the unit of analysis and ANOVA (normality) or Kruskall-Wallis (no normality) tests will be performed setting the significance level at p \< 0.05.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 40
Any male or female adult (≥ 18 year old) patient from the University Complutense of Madrid, being able to sign an informed consent form, presenting a submerged dental implant scheduled to undergo a second stage surgery, which is bounded mesially or distally by a remaining natural tooth, and exhibits a lack of buccal soft tissue volume, will be potentially eligible for this trial.
The case definition for a lack of buccal soft tissue volume will be the presence of a thin buccal mucosa (< 2mm) or a minor volumetric contraction of the alveolar process (flat or concave buccal mucosal profile at the edentulous area).
Patients fitting to all the above inclusion criteria will be not included in the study if unable to attend to the study-related procedures (including the follow-up visits) or if one or more of the following systemic or local exclusion criteria will be found during enrolment or through the study:
Systemic primary exclusion criteria:
- Compromised general health status contraindicating the study procedures (≥ASA IV);
- Drug abuse, alcohol abuse, or smoking > 10 cigarettes a day;
- Chronic use of corticosteroids, NSAIDs, or immune-modulators (any type, any dose);
- Assumption of bisphosphonates (any type, any dose, past or present);
- Pregnant or nursing women;
- Hypersensitivity to paracetamol;
Local primary exclusion criteria
- History of previous mucogingival surgeries in the area of interest;
- Lack of adequate vestibule depth to perform a bilaminar procedure;
- Lack of osseointegration at the time of implant reopening;
- Need for additional bone grafting at the time of implant reopening;
- Intraoperative evidence of a flap thickness < 0,5mm or > 2mm.
Secondary exclusion criteria:
- Non compliant patients: poor oral hygiene at 2 consecutive visits.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Split thickness flap + Autogenous connective tissue Autogenous sub epithelial connective tissue graft A split thickness flap will be raised with a micro-blade, keeping a flap thickness \>0,5mm. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 1,5mm thick autogenous sub epithelial connective tissue graft will be stabilised at the inner aspect of the flap. Split thickness flap + Autogenous connective tissue Split thickness flap A split thickness flap will be raised with a micro-blade, keeping a flap thickness \>0,5mm. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 1,5mm thick autogenous sub epithelial connective tissue graft will be stabilised at the inner aspect of the flap. Split thickness flap + Volume stable collagen matrix Split thickness flap A split thickness flap will be raised with a micro-blade, keeping a flap thickness \>0,5mm. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 6mm thick volume stable collagen matrix will be stabilised at the inner aspect of the flap. Split thickness flap + Volume stable collagen matrix Volume stable collagen matrix A split thickness flap will be raised with a micro-blade, keeping a flap thickness \>0,5mm. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 6mm thick volume stable collagen matrix will be stabilised at the inner aspect of the flap. Full thickness flap + Autogenous connective tissue Autogenous sub epithelial connective tissue graft A full thickness flap will be raised with a periosteal elevator. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 1,5mm thick autogenous sub epithelial connective tissue graft will be stabilised at the inner aspect of the flap. Full thickness flap + Volume stable collagen matrix Full thickness flap A full thickness flap will be raised with a periosteal elevator. The healing abutment will be connected to the implant, and a 10mm wide by 6-8mm high volume stable collagen matrix will be stabilised at the inner aspect of the flap. Full thickness flap + Volume stable collagen matrix Volume stable collagen matrix A full thickness flap will be raised with a periosteal elevator. The healing abutment will be connected to the implant, and a 10mm wide by 6-8mm high volume stable collagen matrix will be stabilised at the inner aspect of the flap. Full thickness flap + Autogenous connective tissue Full thickness flap A full thickness flap will be raised with a periosteal elevator. The healing abutment will be connected to the implant, and a 10mm wide, 6-8mm high, 1,5mm thick autogenous sub epithelial connective tissue graft will be stabilised at the inner aspect of the flap.
- Primary Outcome Measures
Name Time Method Buccal soft tissue thickness before surgery, after surgery, 1 month after surgery, 6 months after surgery Changes in the thickness of the buccal peri-implant mucosa, measured with trans-gingival probing.
- Secondary Outcome Measures
Name Time Method Morphology of the grafted area 1 month after surgery or 2 months after surgery or 4 months after surgery or 6 months after surgery Descriptive histology performed on paraffin embedded sections from buccal gingival specimens, stained with hematoxylin-eosin.
Full mouth Bleeding score baseline, after surgery, 1 month after surgery, 6 months after surgery Full mouth bleeding score measured with a standardised UNC-15 probe.
Microcirculation of the grafted area before surgery, after surgery, 7 days after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery Microcirculation of the treated area evaluated with a laser Doppler flowmeter.
Full mouth Plaque score baseline, after surgery, 1 month after surgery, 6 months after surgery Full muouth plaque score measured with a standardised UNC-15 probe.
Volume changes before surgery, after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery Changes in the size of the buccal peri-implant tissues and in their volume distribution, measured with a digital volumetric analysis.
Colorimetric integration 1 month after surgery, 6 months after surgery Colorimetric integration of the augmented buccal peri-implant mucosa, relative to the buccal attached gingiva of the mesial and distal adjacent tooth, quantified throughout the ∆E score, calculated on standardised digital photographs.
Modified Plaque index baseline, after surgery, 1 month after surgery, 6 months after surgery Presence/absence of plaque at the treated implant
Attachment level baseline, after surgery, 1 month after surgery, 6 months after surgery Relative attachment level (implant) and clinical attachment level (adjacent tooth) measured with a standardised UNC-15 probe.
Patients related outcome measures 7 days after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery Patients pain and discomfort with respect to the procedure evaluated with the short form of the McGill pain questionnaire (SF-MPQ).
Revascularization and reinnervation of the grafted area 1 month after surgery or 2 months after surgery or 4 months after surgery or 6 months after surgery Immune histochemistry performed on paraffin embedded, hematoxylin-eosin stained sections using markers of tissue revascularization and reinnervation.
Keratinised tissue width baseline, after surgery, 1 month after surgery, 6 months after surgery Keratinised tissue width measured with a standardised UNC-15 probe.
Bleeding on probing baseline, after surgery, 1 month after surgery, 6 months after surgery Presence/absence of bleeding on probing at the treated implant measured with a standardised UNC-15 probe.
Trial Locations
- Locations (1)
Department of Periodontology, University Complutense Madrid, Spain
🇪🇸Madrid, Spain