An observational study in Insufficient Keratinized Gingiva, sponsored by Biruni University. Not yet recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-01.
Sponsored by Biruni University · Observational
The purpose of this study is to evaluate the dimensional stability of free gingival grafts (FGG) and to investigate the relationship between graft shrinkage (GS) and the histological and biochemical characteristics of grafts reharvested from the same palatal donor site. The primary objective is to investigate the relationship between histological alterations in grafts reharvested from the same donor site and graft shrinkage at the recipient site.
This study is designed as a split-mouth study in which FGGs are applied to contralateral recipient sites within the same patient. Each participant will receive two grafts: an initial graft harvested from the palatal donor site and a second graft reharvested from the same donor site 63 days after the initial procedure.
Graft dimensional changes will be evaluated using three-dimensional digital measurements. Intraoral digital scans will be obtained at baseline, immediately after surgery, and at 1 and 3 months postoperatively. GS will be assessed through superimposition of digital models.
In addition, histological, histomorphometric, and immunohistochemical analyses will be performed on tissue samples obtained from the donor site to evaluate collagen characteristics and epithelial structure. Furthermore, protein expression levels of specific markers, including collagen type I, collagen type III, and alpha-smooth muscle actin (α-SMA), will be assessed. Early wound healing at the recipient site will be evaluated using the Landry healing index at postoperative days 7, 14, and 28. In addition, biological mediators, including transforming growth factor beta 1 (TGF-β1), vascular endothelial growth factor A (VEGF-A), and platelet-derived growth factor (PDGF), will be analyzed in wound exudate samples obtained from the recipient site to biochemically assess the early healing process.
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Systemically healthy, non-smoking individuals aged 18-65 years with insufficient keratinized gingiva (\<2 mm; Lang \& Löe, 1972) involving the bilateral mandibular canine and/or premolar regions will be included in the study.
Exclusion Criteria:
Recipient sites treated with free gingival grafts harvested from the palatal donor site during the initial surgical procedure.
Procedure: Free gingival graft
Recipient sites treated with free gingival grafts re-harvested from the same palatal donor site 63 days after the initial surgery.
Procedure: Re-harvested free gingival graft
Following adequate local anesthesia, a horizontal incision will be made at the level of the mucogingival junction to prepare the recipient bed. A split-thickness flap will be elevated without disturbing the periosteum. A free gingival graft will be harvested from the palatal donor site during the initial surgical procedure. The harvested graft will then be transferred to the recipient site, shaped to the desired dimensions, and stabilized with sutures.
Following adequate local anesthesia, a horizontal incision will be made at the level of the mucogingival junction to prepare the recipient bed. A split-thickness flap will be elevated without disturbing the periosteum. A free gingival graft will be reharvested from the same palatal donor site 63 days after the initial surgery. The harvested graft will then be transferred to the recipient site, shaped to the desired dimensions, and stabilized with sutures.
The three-dimensional changes of free gingival graft
An intraoral digital scanner will be used to assess the graft's dimensions alterations.
Time frame: Baseline
The three-dimensional changes of free gingival graft
An intraoral digital scanner will be used to assess the graft's dimensions alterations.
Time frame: Postoperative baseline (immediately after surgery)
The three-dimensional changes of free gingival graft.
An intraoral digital scanner will be used to assess the graft's dimensions alterations.
Time frame: 1st month
The three-dimensional changes of free gingival graft.
An intraoral digital scanner will be used to assess the graft's dimensions alterations.
Time frame: 3rd month
Histological alterations in free gingival grafts
Histomorphometric and immunohistochemical evaluation of epithelial thickness and Type I and Type III collagen ratios in free gingival graft samples obtained from the palatal donor site.
Time frame: Baseline (initial graft harvesting procedure)
Histological alterations in re-harvested free gingival grafts
Histomorphometric and immunohistochemical evaluation of epithelial thickness and Type I and Type III collagen ratios in free gingival graft samples reharvested from the same palatal donor site.
Time frame: 63 days after the initial surgery (re-harvesting procedure)
Keratinized mucosa width
The apical-coronal distance from the mucosal margin to the mucogingival junction (MGJ) Measurements will be made at three points on tooth (mesiobuccal, midbuccal, distobuccal) using a periodontal probe.
Time frame: Baseline (prior to therapy)
Keratinized mucosa width
The apical-coronal distance from the mucosal margin to the mucogingival junction (MGJ) Measurements will be made at three points on tooth (mesiobuccal, midbuccal, distobuccal) using a periodontal probe.
Time frame: 1st month
Keratinized mucosa width
The apical-coronal distance from the mucosal margin to the mucogingival junction (MGJ) Measurements will be made at three points on tooth (mesiobuccal, midbuccal, distobuccal) using a periodontal probe.
Time frame: 3rd month
Gingival Recession Width
The widest horizontal distance between the mesial and distal gingival margins of the recession defect at the level of the cementoenamel junction (CEJ) will be measured using a periodontal probe held horizontally.
Time frame: Baseline (prior to therapy)
Gingival Recession Width
The widest horizontal distance between the mesial and distal gingival margins of the recession defect at the level of the cementoenamel junction (CEJ) will be measured using a periodontal probe held horizontally.
Time frame: 1st month
Gingival Recession Width
The widest horizontal distance between the mesial and distal gingival margins of the recession defect at the level of the cementoenamel junction (CEJ) will be measured using a periodontal probe held horizontally.
Time frame: 3rd month
Gingival Thickness
Following local anesthesia, measurements will be performed at the distobuccal, midbuccal, and mesiobuccal aspects of the teeth in the recipient area by inserting a #20 spreader with a silicone stopper perpendicular to the gingival surface, 2 mm apical to the gingival margin. After hard tissue contact is achieved, the distance between the tip of the spreader and the silicone stopper will be measured using a digital caliper. The mean value of the measurements will be recorded.
Time frame: Baseline
Gingival Thickness
Following local anesthesia, measurements will be performed at the distobuccal, midbuccal, and mesiobuccal aspects of the teeth in the recipient area by inserting a #20 spreader with a silicone stopper perpendicular to the gingival surface, 2 mm apical to the gingival margin. After hard tissue contact is achieved, the distance between the tip of the spreader and the silicone stopper will be measured using a digital caliper. The mean value of the measurements will be recorded.
Time frame: 3rd month
Landry Healing Index
Healing at the recipient site will be evaluated according to tissue color, presence of bleeding and granulation tissue, suppuration, and epithelialization. Healing will be scored on a scale ranging from 1 to 5.
Time frame: 7th day
Landry Healing Index
Healing at the recipient site will be evaluated according to tissue color, presence of bleeding and granulation tissue, suppuration, and epithelialization. Healing will be scored on a scale ranging from 1 to 5.
Time frame: 14th day
Landry Healing Index
Healing at the recipient site will be evaluated according to tissue color, presence of bleeding and granulation tissue, suppuration, and epithelialization. Healing will be scored on a scale ranging from 1 to 5.
Time frame: 28th day
Growth factor levels in wound fluid
Wound fluid samples will be collected from the mesiocoronal, distocoronal, mesioapical, and distoapical margins of the surgical recipient site using paper strips (Periopaper®, Oraflow, Plainview, NY, USA). The strips will be gently placed at the relevant sites for 30 seconds while avoiding mechanical trauma. VEGF-A, PDGF, and TGF-β1 levels will be evaluated.
Time frame: 3rd day
Growth factor levels in wound fluid
Wound fluid samples will be collected from the mesiocoronal, distocoronal, mesioapical, and distoapical margins of the surgical recipient site using paper strips (Periopaper®, Oraflow, Plainview, NY, USA). The strips will be gently placed at the relevant sites for 30 seconds while avoiding mechanical trauma. VEGF-A, PDGF, and TGF-β1 levels will be evaluated.
Time frame: 7th day
Protein expression levels in free gingival grafts,
Biochemical evaluation of type I collagen, type III collagen, and α-SMA protein expression levels in free gingival graft samples obtained from the donor site.
Time frame: Baseline (initial graft harvesting procedure)
Protein expression levels in free gingival grafts
Biochemical evaluation of type I collagen, type III collagen, and α-SMA protein expression levels in free gingival graft samples obtained from the same donor site.
Time frame: 63 days after the initial surgery (re-harvesting procedure)
Patient reported outcomes
After the surgical procedure, patients will be asked to complete a form consisting of 3 items: (1) assessment of the intensity of postoperative pain/discomfort (by Visual Analog Scale), (2) duration of pain (in days) and (3) number of analgesic tablets taken.
Time frame: 10th day
This study is not yet recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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