Study of Hyaluronic Acid Used With Gum Surgery to Treat Gum Recession in Adults

April 14, 2026 updated by: Universidade do Porto

Effectiveness of Hyaluronic Acid Application in Coronally Advanced Flap Combined With a Subepithelial Connective Tissue Graft Versus Coronally Advanced Flap Combined With a Subepithelial Connective Tissue Graft Alone: A Clinical Trial

Gingival recession is a common condition in which the gum tissue recedes, exposing the root surface of the tooth. This can lead to tooth sensitivity, higher risk of root decay, and aesthetic concerns. A commonly used surgical treatment is the coronally advanced flap combined with a connective tissue graft (CAF + SCTG), which aims to cover the exposed root and improve gum health.

Hyaluronic acid (HA) is a naturally occurring substance in the body that plays an important role in wound healing. It may help improve tissue repair, reduce inflammation, and enhance healing after surgery.

This study aims to evaluate whether the use of hyaluronic acid (hyaDENT BG®) in addition to standard surgical treatment improves clinical outcomes in patients with gingival recession. Participants will be randomly assigned to receive either standard treatment alone or standard treatment with hyaluronic acid.

The main outcome is the proportion of sites with complete root coverage after 12 months. Additional outcomes include healing, gum tissue improvement, patient-reported pain and discomfort, and aesthetic results.

The study also includes a laboratory component to investigate how hyaluronic acid affects cells involved in gum healing.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Gingival recession (GR) is a common mucogingival condition characterized by apical displacement of the gingival margin beyond the cemento-enamel junction, leading to root exposure, dentin hypersensitivity, increased risk of root caries, and aesthetic impairment. The coronally advanced flap combined with a subepithelial connective tissue graft (CAF + SCTG) is considered the gold standard for the treatment of single gingival recession defects, providing predictable root coverage and long-term stability. However, postoperative morbidity, donor-site discomfort, and incomplete root coverage may still occur.

Hyaluronic acid (HA) is a key component of the extracellular matrix with biological properties that promote wound healing, including stimulation of angiogenesis, cell migration, proliferation, and modulation of inflammatory responses. Cross-linked HA formulations exhibit prolonged bioactivity and may enhance soft tissue healing and regeneration in periodontal surgery.

This study is a prospective, randomized, controlled, post-market clinical follow-up (PMCF) trial designed to evaluate the clinical effectiveness and safety of adjunctive cross-linked hyaluronic acid (hyaDENT BG®) in combination with CAF + SCTG for the treatment of single RT1 and RT2 gingival recession defects. A total of 34 patients will be enrolled and randomly allocated in a 1:1 ratio to either the test group (CAF + SCTG with adjunctive HA) or the control group (CAF + SCTG alone). Randomization will be stratified by recession type (RT1 vs RT2), and outcome assessors will be blinded to treatment allocation.

The primary endpoint is complete root coverage (CRC) at 12 months, defined as recession depth equal to 0 mm relative to the cemento-enamel junction. Secondary endpoints include mean root coverage, recession reduction, clinical attachment level gain, probing depth reduction, keratinized tissue gain, early wound healing (Early Wound Healing Score), patient-reported outcomes (pain, discomfort, and oral health-related quality of life), and aesthetic outcomes assessed using the Root Coverage Esthetic Score (RES).

Clinical assessments will be performed at baseline and at predefined follow-up visits up to 12 months post-surgery using standardized protocols and calibrated examiners. Patient-reported outcomes will be collected using validated instruments, including visual analog scales (VAS) and the OHIP-14 questionnaire.

In parallel, an in vitro component will be conducted using primary human gingival fibroblasts isolated from connective tissue grafts obtained during surgery. These cells will be used to evaluate the effects of HA on cell viability, proliferation, migration, gene expression related to wound healing and inflammation, and activation of intracellular signaling pathways.

This combined clinical and translational approach aims to provide comprehensive evidence on both the clinical performance and biological mechanisms of action of hyaluronic acid in periodontal plastic surgery.

Study Type

Interventional

Enrollment (Estimated)

34

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

Study Locations

  • Portugal
    • Porto District
      • Porto, Porto District, Portugal, 4350-110
        • CEPI - Clinical Center for Periodontology and Implantology
        • Contact:

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
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • - Age ≥ 18 years, in good general health (ASA I or II)
  • Presence of a single gingival recession defect classified as RT1 or RT2
  • Recession depth ≥ 2 mm with identifiable cemento-enamel junction (CEJ)
  • Presence of at least 1 mm of keratinized tissue at the defect site
  • No active periodontal disease (probing depth ≤ 4 mm and no bleeding on probing at the selected tooth)
  • Full-Mouth Plaque Score (FMPS ≤ 20%) and Full-Mouth Bleeding Score (FMBS ≤ 20%)
  • Vital tooth without caries, cervical lesions, or defective restorations
  • Good oral hygiene and motivation to maintain plaque control
  • Ability and willingness to comply with study procedures
  • Signed informed consent

Exclusion Criteria:

  • Uncontrolled systemic diseases (e.g., uncontrolled diabetes, severe cardiovascular disease, immunodeficiency)
  • Pregnant or breastfeeding women
  • Autoimmune diseases or immunosuppressive therapy
  • Known hypersensitivity to hyaluronic acid
  • Heavy smokers (>10 cigarettes/day) or recent tobacco use
  • Active periodontal disease at the study site
  • Caries, root fractures, endodontic lesions, or defective restorations at the study tooth
  • Previous mucogingival surgery at the study site
  • Recent use of antibiotics, corticosteroids, or anti-inflammatory drugs
  • Coagulation disorders or anticoagulant therapy contraindicating surgery
  • Hormonal disorders affecting wound healing
  • Acute oral infections
  • Any condition that may interfere with study participation or follow-up

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: CAF + SCTG + Hyaluronic Acid
Participants undergo coronally advanced flap (CAF) surgery combined with a subepithelial connective tissue graft (SCTG) with adjunctive application of cross-linked hyaluronic acid (hyaDENT BG®). The graft is immersed in hyaluronic acid prior to placement, and the gel is applied to the recipient site before flap closure.
Procedure: Coronally Advanced Flap with Connective Tissue Graft
Standard periodontal plastic surgery procedure for root coverage involving coronally advanced flap (CAF) combined with a subepithelial connective tissue graft (SCTG). The technique aims to cover exposed root surfaces and improve soft tissue thickness and stability.
Other Names:
  • CAF + SCTG
Device: Cross-linked Hyaluronic Acid Gel
Application of cross-linked hyaluronic acid gel (hyaDENT BG®) as an adjunct to periodontal surgery. The gel is applied to the recipient site and used to immerse the connective tissue graft prior to placement, aiming to enhance soft tissue healing, promote cell proliferation and angiogenesis, and improve clinical outcomes.
Other Names:
  • hyaDENT BG®
Active Comparator: CAF + SCTG
Participants undergo coronally advanced flap (CAF) surgery combined with a subepithelial connective tissue graft (SCTG) without adjunctive hyaluronic acid. The graft is handled under standard conditions and hydrated with sterile saline prior to placement.
Procedure: Coronally Advanced Flap with Connective Tissue Graft
Standard periodontal plastic surgery procedure for root coverage involving coronally advanced flap (CAF) combined with a subepithelial connective tissue graft (SCTG). The technique aims to cover exposed root surfaces and improve soft tissue thickness and stability.
Other Names:
  • CAF + SCTG

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Complete Root Coverage (CRC)
Time Frame: 12 months
Proportion of treated sites achieving complete root coverage, defined as recession depth equal to 0 mm relative to the cemento-enamel junction, assessed using a calibrated periodontal probe by a blinded examiner.
12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Mean Root Coverage (MRC)
Time Frame: 12 months
Percentage of root coverage achieved relative to baseline recession depth at the treated site.
12 months
Recession Reduction (RecRed)
Time Frame: 12 months
Change in gingival recession depth (mm) from baseline to follow-up, measured using a calibrated periodontal probe.
12 months
Clinical Attachment Level (CAL) Gain
Time Frame: 12 months
Change in clinical attachment level (mm) from baseline to 12 months, measured using a periodontal probe.
12 months
Probing Depth (PD) Reduction
Time Frame: 12 months
Reduction in probing depth (mm) from baseline to 12 months, measured using a periodontal probe.
12 months
Keratinized Tissue Width (KT) Gain
Time Frame: 12 months
Increase in the width of keratinized gingiva (mm) from baseline to follow-up.
12 months
Early Wound Healing Score (EHS)
Time Frame: 3 days, 14 days, and 6 weeks
Assessment of early soft tissue healing using the Early Wound Healing Score at predefined postoperative time points.
3 days, 14 days, and 6 weeks
Postoperative Pain and Discomfort (VAS)
Time Frame: 3 days, 14 days, and 6 weeks
Patient-reported pain and discomfort assessed using a visual analog scale (VAS).
3 days, 14 days, and 6 weeks
Oral Health-Related Quality of Life (OHIP-14)
Time Frame: 3 days, 14 days, and 6 weeks
Patient-reported oral health-related quality of life measured using the OHIP-14 questionnaire.
3 days, 14 days, and 6 weeks
Root Coverage Esthetic Score (RES)
Time Frame: 12 months
Esthetic outcome assessed using the Root Coverage Esthetic Score based on standardized clinical photographs.
12 months
Surgical and Postoperative Complications
Time Frame: up to 12 months
Incidence of intraoperative and postoperative complications, including flap dehiscence, infection, or graft necrosis.
up to 12 months

Collaborators and Investigators

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

Sponsor

Universidade do Porto

Collaborators

Regedent AG, Zürich

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)

May 1, 2026

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

April 7, 2026

First Submitted That Met QC Criteria

April 7, 2026

First Posted (Actual)

April 14, 2026

Study Record Updates

Last Update Posted (Actual)

April 20, 2026

Last Update Submitted That Met QC Criteria

April 14, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 24/2023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

No final decision has been made regarding individual participant data sharing. Data sharing will be considered in accordance with applicable regulations and institutional policies.

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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