Clinical and Histological Evaluation of Subepithelial Connective Tissue Graft Maturation at Different Healing Timepoints, With and Without Topical Application of a Polynucleotide- and Hyaluronic Acid-Based Gel

July 13, 2026 updated by: Marcella Kahn, University of Sao Paulo

Clinical and Histological Evaluation of Subepithelial Connective Tissue Graft Maturation at Different Healing Timepoints, With and Without Topical Application of a Polynucleotide- and Hyaluronic Acid-Based Gel: A Randomized, Blinded, Controlled Clinical Trial With a Split-Mouth Design

This study evaluates whether a 9-week healing interval is sufficient for subepithelial connective tissue graft (SCTG) maturation after palatal harvesting, and whether topical application of a polynucleotide and hyaluronic acid gel (Regenfast®) improves tissue quality. This is a randomized, blinded, controlled clinical trial with a split-mouth design involving 15 participants. Each participant undergoes bilateral SCTG harvesting from the palate in two surgical sessions 9 weeks apart. In the first session, one randomized side receives a single topical application of Regenfast® after graft removal; the contralateral side serves as control. Standardized tissue fragments (3×3 mm, 1.5 mm thickness) are collected from each graft for histological (HE, Picrosirius Red) and immunohistochemical analyses. Comparisons are made between grafts collected at baseline and after 9 weeks, and between sides treated with or without the gel.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Surgical procedures and sample collections will be performed at Instituto Kahn Odontologia (Rio de Janeiro, Brazil). Laboratory analyses will be conducted at the Histology Laboratory of the School of Dentistry of Ribeirao Preto, University of Sao Paulo (FORP-USP).

SCTG removal will be performed using the double incision technique (Harris, 2003) with a standardized 1.5 mm guide scalpel, under local anesthesia (2% lidocaine, 1:100,000 epinephrine). From each graft, a standardized fragment (3×3 mm, 1.5 mm thickness) will be collected from the distal portion and immediately fixed in 10% buffered formalin for 24-48 hours, then transferred to 70% alcohol.

Laboratory analyses will include: (1) Hematoxylin-eosin (HE) for general morphological assessment; (2) Picrosirius Red under polarized light for quantification of collagen density and proportion of type I and type III collagen fibers; (3) Immunohistochemistry for vascularization assessment, measuring microvessel density (n/mm²) and vascular area (%).

Statistical analysis will use paired Student's t-test or Wilcoxon test for paired samples, depending on data distribution (Shapiro-Wilk test), with significance level of 5% (p<0.05).

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Marcella Kahn, DDS, MS Candidate
  • Phone Number: +5521988483846
  • Email: mbkahn@usp.br

Study Contact Backup

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age between 18 and 60 years
  • Good general systemic health
  • Presence of multiple bilateral gingival recessions with indication for root coverage

Exclusion Criteria:

  • Smoking of any intensity
  • Pregnancy or lactation
  • Oral lesions or alterations in the palatal mucosa
  • Previous history of graft harvesting from the donor area
  • Continuous use of medications that interfere with the inflammatory response, such as corticosteroids or immunosuppressants
  • Autoimmune diseases, coagulation disorders, or other systemic conditions affecting wound healing

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Regenfast Gel Application Test Side
Palatal side randomized to receive a single topical application of polynucleotide and hyaluronic acid gel (Regenfast, 0.3 ml) immediately after subepithelial connective tissue graft (SCTG) harvesting in the first surgical session. The contralateral side receives no intervention. SCTG is harvested again from the same site after 9 weeks for histological and immunohistochemical analyses.
Drug: polynucleotide and hyaluronic acid gel
Single topical application of polynucleotide and hyaluronic acid gel (Regenfast, 0.3 ml) to the palatal donor site immediately after subepithelial connective tissue graft harvesting in the first surgical session, before suturing.
Procedure: subepithelial connective tissue graft harvesting
Bilateral subepithelial connective tissue graft harvesting from the palatal donor site using the double incision technique (Harris, 2003) with a standardized 1.5 mm guide scalpel, under local anesthesia (2% lidocaine with 1:100,000 epinephrine). Performed in two surgical sessions with a 9-week interval.
Active Comparator: No Intervention - Control Side
Contralateral palatal side receiving no topical intervention after SCTG harvesting in the first surgical session. SCTG is harvested again from the same site after 9 weeks. This arm serves as control for both the healing time comparison (baseline vs 9 weeks) and the biomaterial effect comparison.
Procedure: subepithelial connective tissue graft harvesting
Bilateral subepithelial connective tissue graft harvesting from the palatal donor site using the double incision technique (Harris, 2003) with a standardized 1.5 mm guide scalpel, under local anesthesia (2% lidocaine with 1:100,000 epinephrine). Performed in two surgical sessions with a 9-week interval.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Histological Tissue Architecture of the Subepithelial Connective Tissue Graft
Time Frame: Baseline and 9 weeks after initial graft harvesting
Morphological evaluation of tissue architecture using hematoxylin-eosin (HE) staining, assessing cellular organization, connective tissue maturation, and overall structural quality of grafts harvested at baseline and 9 weeks after initial harvesting, with and without topical application of polynucleotide and hyaluronic acid gel (Regenfast®).
Baseline and 9 weeks after initial graft harvesting
Collagen Density and Fiber Maturation of the Subepithelial Connective Tissue Graft
Time Frame: Baseline and 9 weeks after initial graft harvesting
Quantification of collagen density and proportion of type I and type III collagen fibers using Picrosirius Red staining under polarized light microscopy, comparing grafts harvested at baseline and 9 weeks after initial harvesting, with and without topical application of polynucleotide and hyaluronic acid gel (Regenfast®).
Baseline and 9 weeks after initial graft harvesting
Microvascular Density and Vascular Area of the Subepithelial Connective Tissue Graft
Time Frame: Baseline and 9 weeks after initial graft harvesting
Immunohistochemical evaluation of vascularization, assessing microvessel density (number/mm²) and vascular area (%) of grafts harvested at baseline and 9 weeks after initial harvesting, with and without topical application of polynucleotide and hyaluronic acid gel (Regenfast®).
Baseline and 9 weeks after initial graft harvesting

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Sao Paulo

Collaborators

Instituto Kahn Odontologia

Investigators

  • Principal Investigator: Marcella B Kahn, DDS, MS Candidate, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo (FORP-USP)
  • Study Chair: Michel Reis Messora, DDS, MS, PhD, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo (FORP-USP) Role: Study Chair
  • Study Director: Sergio Kahn, DDS, MS, PhD, Instituto Kahn Odontologia, Rio de Janeiro

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

October 31, 2026

Study Completion (Estimated)

February 27, 2027

Study Registration Dates

First Submitted

July 1, 2026

First Submitted That Met QC Criteria

July 13, 2026

First Posted (Actual)

July 16, 2026

Study Record Updates

Last Update Posted (Actual)

July 16, 2026

Last Update Submitted That Met QC Criteria

July 13, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 95625625.9.0000.5419 (Other Identifier: Plataforma Brasil)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared. Participant confidentiality is ensured through numerical coding, and all collected data will be used exclusively for scientific purposes within the scope of this study, in accordance with the ethical principles of the Declaration of Helsinki and the approved protocol.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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