Clinical trial NCT06261268: Strip Graft w/ Xenogeneic Matrix vs Free Gingival Graft for the Augmentation of Peri-implant Keratinized Mucosa
Official title: Strip Graft With Xenogeneic Matrix Versus Free Gingival Graft for the Augmentation of Peri-implant Keratinized Mucosa: A Randomized Clinical Trial With Vascular Analysis
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Peri-Implantational Loss
Surgical Wound
Healing Surgical Wounds
Thin-gingiva
Keywords: Strip graft
Free gingival graft
Peri-implant keratinized mucosa
Soft tissue augmentation
Early wound healing
Postoperative blood supply
Lead sponsor: Universidad Complutense de Madrid
Sponsor class: OTHER
First posted: 2024-02-15
Enrollment: 48
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A randomized controlled equivalence clinical trial will be performed, with two parallel groups, a 1:1 allocation ratio, and a 12-month follow-up.
Primary purpose: TREATMENT

Brief summary: The primary objective of this study is to compare changes in peri-implant keratinized mucosa (PIKM) following the application of apically repositioned flap (ARF) using a combination of a Strip graft and a Xenogeneic matrix, or with a free gingival graft (FGG), in implants in the second stage with \<2 mm of PIKM.

Additionally, as a secondary objective, the investigators compare postoperative blood supply in both recipient and donor sites based on the type of graft obtained. Meanwhile, the investigators evaluate differences between the two groups concerning microcirculation values (perfusion units, PU), soft tissue thickness (STT), volume change, vestibular depth, as well as clinical, aesthetic, and patient-reported outcome measures (PROMS).

Detailed description: 1. BACKGROUND The importance of keratinized tissue around teeth and dental implants is a frequently investigated topic in the literature. The need for an adequate amount of peri-implant keratinized mucosa (PIKM), which is defined as a minimum width of 2 mm is demonstrated according to a recently published systematic review and consensus report.

   The standard of care in the PIKM augmentation is the apically repositioned flap (ARF) combined with a free gingival graft (FGG), as it represents a predictable and documented strategy to gain KT width. However, such technique implies the harvest of abundant autogenous grafts, and is frequently associated to sub-optimal aesthetic results due to the poor color mimicry of the grafted tissue.

   In light of such limitations, some alternatives based on the use of soft tissue substitutes have been proposed, with the aim of reducing surgical invasiveness through the avoidance of large autogenous grafts and improving aesthetic outcomes.

   Among those, the sole use of as xenogeneic collagen matrices (XCM) has been associated with promising clinical outcomes albeit with lesser KT width gains as compared to autogenous FGGs.

   Recently, a novel approach called the Strip Technique (ST) has been introduced, where the exposed periosteal bed of a ARF is covered with the combination of a xenogeneic collagen matrix and a 2-3 mm wide strip of autogenous free gingival graft, sutured at the apical border of the matrix. The rationale for this "combined grafting technique" stands on reducing surgical invasiveness and improving color mimicry through the use of a XCM, while providing a source of autogenous keratinizing cells in the apical border of the grafted area to promote better PIKM gains. Albeit this new approach seems promising, there is limited evidence regarding its clinical efficacy and there is a lack of knowledge regarding how the adoption of such combined approach affects the re-perfusion of the grafted tissue and the overall microvascular healing of the surgical site.

   Furthermore, the pattern of the revascularization of both the autologous grafts and the XCM requires further understanding. Most of our recent knowledge comes from classical animal studies that evaluated the microvascularization of FGG when placed over periosteum with microscopy. The postoperative blood supply of these free grafts is of key importance to their survival.

   Recently a new non-invasive technique has been introduced in the field of medicine and dentistry the Laser Speckle Contrast Imaging (LSCI) system, that provides further understanding on the dynamics of postoperative blood supply of the applied grafts and elucidate regarding the healing pattern of the strip combination technique.
2. JUSTIFICATION There is a lack of knowledge regarding the clinical performance, the healing pattern and the dynamics of revascularization when performing apically repositioned flaps combined with either the autogenous strip-XCM technique or autogenous FGGs.

Results from this study could assess whether the strip-XCM technique represents a reliable, less invasive, and simplified alternative to autogenous FGGs for the increase of PIKM.

Moreover, it could provide additional knowledge regarding the healing and revascularization pattern of both strip-XCM and FGGs around dental implants, assessed through an innovative technology as Laser Speckle Perfusion.

Eligibility criteria: Inclusion Criteria:

* Patients older than 18 years
* Short-span dental implants in the mandible at second stage with inadequate PIKM (\<2 mm) with at least one adjacent tooth mesially
* Periodontally healthy patients with a pristine or reduced periodontium
* Plaque index (FMPS) less than 20%.

Exclusion Criteria:

* Compromised general health status that contraindicates study procedures (≥ASA III);
* Drug or alcohol abuse;
* Smoking of \> 10 cigarettes per day;
* Chronic use of corticosteroids, NSAIDs or immunomodulators (any type or dose);
* Pregnant or lactating women;
* History of previous mucogingival surgeries in the area of interest

Primary outcomes:
measure: Changes in peri-implant keratinized mucosa width (mm)
timeFrame: Baseline, 1, 3, 6 and 12 months
Secondary outcomes:
measure: Vascularization (in Laser Speckle perfusion units [LSPU])
timeFrame: pre-surgically, post-surgically at 4, 7, 10, 14 and 30 days, and at 3-6 and 12 months
measure: Changes in soft tissue thickness (STT) (mm)
timeFrame: Baseline, post-op, 1, 3, 6 and 12 months
measure: Vestibule depth (VD) (mm)
timeFrame: Pre-surgically, and at 30 days, 3-6 and 12 months
measure: Probing pocket depth (PPD) (mm)
timeFrame: pre-surgically, at 3, 6 and 12 months after surgery
measure: Dehiscence (mm)
timeFrame: post-surgically, at 3, 6 and 12 months after surgery
measure: Full-mouth plaque score (FMPS)
timeFrame: Baseline, 1 month, 3 months, 6 and 12 months
measure: Volumetric changes
timeFrame: Baseline, 14 days, 1 month, 3, 6 and 12 months
measure: Patient reported outcome measures (PROMS)
timeFrame: immediately after the surgery, 12 hours after the surgery, 1 day, 2, 3, 4, 5, 6, 7 days and 2 weeks after the surgery
measure: Esthetic analysis
timeFrame: 30-day, 3-, 6- and 12-month
measure: Intra-surgical parameters
timeFrame: During surgery
measure: Intra-surgical time
timeFrame: During the surgery
measure: Demographic data
timeFrame: Baseline
measure: Anamnesis data
timeFrame: Baseline, through study completion, an average of 1 year
measure: Smoking habit
timeFrame: Baseline, through study completion, an average of 1 year
measure: Full-mouth bleeding score (FMBS) (%)
timeFrame: Baseline, 1 month, 3 months, 6 and 12 months
Other outcomes:
Locations:
city: Madrid
country: Spain
facility: Complutense University
Study officials:
affiliation: Universidad Complutense de Madrid
name: Mariano Sanz Alonso
role: STUDY_DIRECTOR
References:
citation: Ramanauskaite A, Schwarz F, Sader R. Influence of width of keratinized tissue on the prevalence of peri-implant diseases: A systematic review and meta-analysis. Clin Oral Implants Res. 2022 Jun;33 Suppl 23:8-31. doi: 10.1111/clr.13766.
citation: Sanz M, Schwarz F, Herrera D, McClain P, Figuero E, Molina A, Monje A, Montero E, Pascual A, Ramanauskaite A, Renouard F, Sader R, Schiegnitz E, Urban I, Heitz-Mayfield L. Importance of keratinized mucosa around dental implants: Consensus report of group 1 of the DGI/SEPA/Osteology Workshop. Clin Oral Implants Res. 2022 Jun;33 Suppl 23:47-55. doi: 10.1111/clr.13956.
citation: Montero E, Molina A, Matesanz P, Monje A, Sanz-Sanchez I, Herrera D. Efficacy of soft tissue substitutes, in comparison with autogenous grafts, in surgical procedures aiming to increase the peri-implant keratinized mucosa: A systematic review. Clin Oral Implants Res. 2022 Jun;33 Suppl 23:32-46. doi: 10.1111/clr.13751.
citation: Solonko M, Regidor E, Ortiz-Vigon A, Montero E, Vilchez B, Sanz M. Efficacy of keratinized mucosal augmentation with a collagen matrix concomitant to the surgical treatment of peri-implantitis: A dual-center randomized clinical trial. Clin Oral Implants Res. 2022 Jan;33(1):105-119. doi: 10.1111/clr.13870. Epub 2021 Oct 21.
citation: Urban IA, Lozada JL, Nagy K, Sanz M. Treatment of severe mucogingival defects with a combination of strip gingival grafts and a xenogeneic collagen matrix: a prospective case series study. Int J Periodontics Restorative Dent. 2015 May-Jun;35(3):345-53. doi: 10.11607/prd.2287.
citation: Molnar E, Molnar B, Lohinai Z, Toth Z, Benyo Z, Hricisak L, Windisch P, Vag J. Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study. Biomed Res Int. 2017;2017:4042902. doi: 10.1155/2017/4042902. Epub 2017 Jan 23.