Lack of Keratinized GingivaNCT07440303
Star Matrix vs Autogenous Graft for Gingival Augmentation: Split-Mouth RCT
A study testing Starmatrix collagen membrane and Autogenous gingival graft in people with Lack of Keratinized Gingiva and Mucogingival Deformity - Insufficient Keratinized Tissue, run by Harvard Medical School (HMS and HSDM) at 1 site in United States.
Trial summary
This split-mouth randomized controlled clinical trial will test whether a ready-to-use collagen membrane (Star Matrix) can widen the protective band of gum tissue (keratinized gingiva) as effectively as the standard free gingival graft harvested from the palate. Read more about this study
- Who is it for?
- Ages 20 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Lack of Keratinized Gingiva, Mucogingival Deformity - Insufficient Keratinized Tissue
- What is being tested?
- Starmatrix collagen membrane and Autogenous gingival graft
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- 6 Nov 2025to 1 Oct 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults 20 - 80 years old who need gingival augmentation on both sides of the lower jaw.
- Able and willing to sign the consent form, follow study instructions and return for all visits
- Generally healthy (no significant illnesses or medicines that could interfere with healing).
- Demonstrates good daily oral hygiene (low plaque levels at baseline).
Who cannot join
- Does not meet any of the inclusion points or is unlikely to follow the schedule
- Previous gingival graft at the study site that failed
- Needs a root-coverage (recession-repair) procedure instead of simple width augmentation
- Active, untreated gum disease, cavities, infection, or chronic inflammation near the study teeth
- Used cigarettes, e-cigarettes, or other nicotine products within 3 weeks
- Insulin-dependent diabetes or hemoglobin A1c > 6.5 %
Show all 13Show fewer
- Cancer (other than minor skin cancers or in-situ cervical cancer) within the past 5 years
- Currently pregnant or breastfeeding
- Taking (or soon to begin) drugs that change bone turnover (e.g., bisphosphonates, steroids)
- Diseases that disturb bone metabolism (except common osteoporosis)
- Auto-immune disease or known allergy to porcine collagen or study materials
- Active infection at the planned graft site
- Current use of systemic blood thinners (anticoagulants or antiplatelet agents; e.g., warfarin, heparin/LMWH, DOACs such as apixaban/rivaroxaban/dabigatran/edoxaban, or P2Y12 inhibitors such as clopidogrel/prasugrel/ticagrelor)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Harvard Dental Center
Boston, Massachusetts, 02115
About this study
Official title: The Clinical Efficacy of Star Matrix Versus Autogenous Gingival Graft in Augmenting Keratinized Tissue Around Teeth- A Split-mouth Randomized Controlled Clinical Trial
This split-mouth randomized controlled clinical trial will test whether a ready-to-use collagen membrane (Star Matrix) can widen the protective band of gum tissue (keratinized gingiva) as effectively as the standard free gingival graft harvested from the palate.
Central question Can Star Matrix provide the same or better gain in keratinized tissue width-with less patient discomfort and chair-time-than an autogenous graft?
Read more
Primary objectives
Compare the 6-month increase in keratinized tissue width between Star Matrix and autogenous graft sites.
Assess patient-reported pain and morbidity associated with each treatment.
Secondary objectives
Measure operative time, early healing scores, esthetic outcomes, and (optional) histologic quality of the regenerated tissue.
Methods Twelve adults with ≤ 2 mm keratinized tissue on contralateral lower-jaw teeth will be enrolled. Each participant receives Star Matrix on one side and a conventional free gingival graft on the other. Follow-up visits at 2, 4, 8, 12 and 24 weeks include clinical measurements, standardized photographs, and a 7-day postoperative pain diary. An optional 2 mm punch biopsy at 6 months is analyzed microscopically.
Read the detailed description
Healthy gums include a "band" of firm, pink tissue (keratinized gingiva) that helps people brush comfortably and protects the area where the tooth meets the bone. Studies suggest that when this band is narrower than about 2 mm, plaque control becomes harder and the risk of recession rises; in one maintenance study, nearly one-fifth of such sites lost further tissue over time.
Since the 1960s the standard way to widen this band has been a free gingival graft-moving a strip of the patient's own palatal tissue to the thin area. The technique works, but it also creates a second surgical wound, offers only a limited amount of donor tissue, causes notable postoperative pain, and the graft can look or feel different from nearby gum.
Researchers have explored substitutes such as preserved sclera, freeze-dried skin, and acellular dermal matrix, yet none has matched the predictability of a patient-derived graft. For example, acellular dermal matrix shrank by about 71 percent and often healed as scar-like tissue with inflammatory reactions.
Star Matrix is a new cross-linked collagen membrane made from highly purified porcine type I collagen. It combines a smooth outer coating that shields the wound with a porous inner layer that welcomes cell ingrowth and is placed porous side down to encourage the patient's own cells to replace it over time. Because it is supplied sterile and ready-to-use, Star Matrix eliminates the donor-site injury and could shorten surgery. However, its effectiveness has never been directly compared with the current gold-standard graft in a controlled clinical trial-providing the rationale for the present study.
Our study will test a new, ready-to-use collagen membrane called Star Matrix as an alternative for the conventional surgery that takes a strip of a patient's own tissue from the roof of the mouth (an autogenous gingival graft) to augment thin or missing gum. We will enroll twelve adult patients who need gum thickening on both sides of their lower jaw; each person will receive Star Matrix on one side and their own tissue on the opposite side, so every patient acts as their own control. Our goals are:
- Primary aim - gingival augmentation
- Find out whether Star Matrix can widen the firm, protective gum (keratinized gum tissue) around teeth by at least the same amount as the patient-derived tissue six months after surgery.
- Comfort aim - early healing experience
- Compare how much pain patients feel during the first week after each procedure, using a simple daily pain scale (0 = no pain, 10 = worst possible pain).
- Appearance aim - color and texture match
- Judge how well the new gum created by each method blends in with nearby gum (color and surface feel) six months after surgery, using standardized photographs and a validated rating sheet.
- Efficiency aim - surgery time
- Record and compare the time the periodontist needs to complete each type of procedure, to see if Star Matrix shortens time in the chair for patients and clinicians.
- Exploratory aim - tissue quality (optional) o In volunteers who give permission, collect a very small gum sample (2x2 mm2) at six months to look under the microscope and describe how Star Matrix has been replaced by the patient's own tissue.
These aims will show whether Star Matrix can provide equal or better gum growth with less pain and surgical time, potentially giving patients a single-site, more comfortable alternative to current care.
- Being tested
- Starmatrix collagen membrane, Autogenous gingival graft
- Keywords
- mucogingival deformity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Starmatrix collagen membraneDevice
Our study will test a new, ready-to-use collagen membrane called Star Matrix as an alternative for the conventional surgery that takes a strip of a patient's own tissue from the roof of the mouth (an autogenous gingival graft) to augment thin or missing gum.
Autogenous gingival graftOther
gingival insufficiency will be treated with autogenous gingival graft
| Study group | Role | What they receive |
|---|---|---|
| Autogenous gingival graft/ free gingival graft (FGG) | Active comparator | the area will receive conventional gingival augmentation procedure with use of autogenous gingival graft/ free gingival graft (FGG) Receives: Other: Autogenous gingival graft |
| Starmatrix collagen membrane | Experimental | the area will receive conventional gingival augmentation procedure with use of Starmatrix collagen membrane Receives: Device: Starmatrix collagen membrane |
What is being measured
The primary outcome is the main question the study is designed to answer.
increase in keratinized-tissue width
pre- and post-operative width of keratinized gingiva in the treated area will be measured and compared
Measured: 6 months
Secondary outcomes (2)
pain level
p't will be given a scale of 0-10 for pain experienced during the first week after procedure
Measured: 7 days
color matching
standardized photographs will be used to evaluate gingival color
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Feb 2026
- Study start6 Nov 2025
- Primary completion1 May 2026 (estimated)
- Study completion1 Oct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Lack of Keratinized GingivaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- randomized split-mouth study
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Harvard Medical School (HMS and HSDM)
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Kim, Harvard Medical School (HMS and HSDM)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07440303
- Sponsor's protocol ID
- IRB25-0932
- Status last verified
- Feb 2026
- First submitted
- 23 Feb 2026
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Clinical Efficacy of Star Matrix Versus Autogenous Gingival Graft in Augmenting Keratinized Tissue Around Teeth- A Split-mouth Randomized Controlled Clinical Trial
- ClinicalTrials.gov ID
- NCT07440303
- Acronym / sponsor ID
- IRB25-0932
- Keywords
- mucogingival deformity
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- Harvard Medical School (HMS and HSDM)University, hospital or other
- Study start
- 6 Nov 2025 (actual)
- Primary completion
- 1 May 2026 (estimated)
- Study completion
- 1 Oct 2026 (estimated)
- First posted
- 27 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This split-mouth randomized controlled clinical trial will test whether a ready-to-use collagen membrane (Star Matrix) can widen the protective band of gum tissue (keratinized gingiva) as effectively as the standard free gingival graft harvested from the palate.
Central question Can Star Matrix provide the same or better gain in keratinized tissue width-with less patient discomfort and chair-time-than an autogenous graft?
Primary objectives
Compare the 6-month increase in keratinized tissue width between Star Matrix and autogenous graft sites.
Assess patient-reported pain and morbidity associated with each treatment.
Secondary objectives
Measure operative time, early healing scores, esthetic outcomes, and (optional) histologic quality of the regenerated tissue.
Methods Twelve adults with ≤ 2 mm keratinized tissue on contralateral lower-jaw teeth will be enrolled. Each participant receives Star Matrix on one side and a conventional free gingival graft on the other. Follow-up visits at 2, 4, 8, 12 and 24 weeks include clinical measurements, standardized photographs, and a 7-day postoperative pain diary. An optional 2 mm punch biopsy at 6 months is analyzed microscopically.
Detailed description
Healthy gums include a "band" of firm, pink tissue (keratinized gingiva) that helps people brush comfortably and protects the area where the tooth meets the bone. Studies suggest that when this band is narrower than about 2 mm, plaque control becomes harder and the risk of recession rises; in one maintenance study, nearly one-fifth of such sites lost further tissue over time.
Since the 1960s the standard way to widen this band has been a free gingival graft-moving a strip of the patient's own palatal tissue to the thin area. The technique works, but it also creates a second surgical wound, offers only a limited amount of donor tissue, causes notable postoperative pain, and the graft can look or feel different from nearby gum.
Researchers have explored substitutes such as preserved sclera, freeze-dried skin, and acellular dermal matrix, yet none has matched the predictability of a patient-derived graft. For example, acellular dermal matrix shrank by about 71 percent and often healed as scar-like tissue with inflammatory reactions.
Star Matrix is a new cross-linked collagen membrane made from highly purified porcine type I collagen. It combines a smooth outer coating that shields the wound with a porous inner layer that welcomes cell ingrowth and is placed porous side down to encourage the patient's own cells to replace it over time. Because it is supplied sterile and ready-to-use, Star Matrix eliminates the donor-site injury and could shorten surgery. However, its effectiveness has never been directly compared with the current gold-standard graft in a controlled clinical trial-providing the rationale for the present study.
Our study will test a new, ready-to-use collagen membrane called Star Matrix as an alternative for the conventional surgery that takes a strip of a patient's own tissue from the roof of the mouth (an autogenous gingival graft) to augment thin or missing gum. We will enroll twelve adult patients who need gum thickening on both sides of their lower jaw; each person will receive Star Matrix on one side and their own tissue on the opposite side, so every patient acts as their own control. Our goals are:
- Primary aim - gingival augmentation
- Find out whether Star Matrix can widen the firm, protective gum (keratinized gum tissue) around teeth by at least the same amount as the patient-derived tissue six months after surgery.
- Comfort aim - early healing experience
- Compare how much pain patients feel during the first week after each procedure, using a simple daily pain scale (0 = no pain, 10 = worst possible pain).
- Appearance aim - color and texture match
- Judge how well the new gum created by each method blends in with nearby gum (color and surface feel) six months after surgery, using standardized photographs and a validated rating sheet.
- Efficiency aim - surgery time
- Record and compare the time the periodontist needs to complete each type of procedure, to see if Star Matrix shortens time in the chair for patients and clinicians.
- Exploratory aim - tissue quality (optional) o In volunteers who give permission, collect a very small gum sample (2x2 mm2) at six months to look under the microscope and describe how Star Matrix has been replaced by the patient's own tissue.
These aims will show whether Star Matrix can provide equal or better gum growth with less pain and surgical time, potentially giving patients a single-site, more comfortable alternative to current care.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- randomized split-mouth study
| Arm | Type | Receives |
|---|---|---|
| Autogenous gingival graft/ free gingival graft (FGG) | Active comparator | Other: Autogenous gingival graftthe area will receive conventional gingival augmentation procedure with use of autogenous gingival graft/ free gingival graft (FGG) |
| Starmatrix collagen membrane | Experimental | Device: Starmatrix collagen membranethe area will receive conventional gingival augmentation procedure with use of Starmatrix collagen membrane |
Who may qualify
- Ages
- 20 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults 20 - 80 years old who need gingival augmentation on both sides of the lower jaw.
- Able and willing to sign the consent form, follow study instructions and return for all visits
- Generally healthy (no significant illnesses or medicines that could interfere with healing).
- Demonstrates good daily oral hygiene (low plaque levels at baseline).
Key exclusion criteria (13 listed)
- Does not meet any of the inclusion points or is unlikely to follow the schedule
- Previous gingival graft at the study site that failed
- Needs a root-coverage (recession-repair) procedure instead of simple width augmentation
- Active, untreated gum disease, cavities, infection, or chronic inflammation near the study teeth
- Used cigarettes, e-cigarettes, or other nicotine products within 3 weeks
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Starmatrix collagen membraneOur study will test a new, ready-to-use collagen membrane called Star Matrix as an alternative for the conventional surgery that takes a strip of a patient's own tissue from the roof of the mouth (an autogenous gingival graft) to augment thin or missing gum. | Device | Starmatrix collagen membrane |
| Autogenous gingival graftgingival insufficiency will be treated with autogenous gingival graft | Other | Autogenous gingival graft/ free gingival graft (FGG) |
Primary outcome
increase in keratinized-tissue width
Time frame: 6 months
pre- and post-operative width of keratinized gingiva in the treated area will be measured and compared
2 secondary outcomes
pain level
Time frame: 7 days
color matching
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Starmatrix collagen membrane and Autogenous gingival graft in people with Lack of Keratinized Gingiva and Mucogingival Deformity - Insufficient Keratinized Tissue, run by Harvard Medical School (HMS and HSDM) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact David Kim, DDS, DMSc ((617) 432-1434, dkim@hsdm.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
increase in keratinized-tissue width (time frame: 6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Feb 2026.