Thin Gingival Phenotype
Conditions
Keywords
gingival phenotype, injectable platelet-rich fibrin, hyaluronic acid, split-mouth trial, periodontology
Brief summary
Thin gingival phenotype may increase susceptibility to soft-tissue complications in the presence of local anatomical or mechanical risk factors. Minimally invasive injectable approaches such as injectable platelet-rich fibrin (i-PRF) and hyaluronic acid (HA) have been proposed to increase gingival thickness. This randomized split-mouth clinical trial compared repeated i-PRF and non-cross-linked HA injections in adults with a thin mandibular anterior gingival phenotype. Each participant received i-PRF on one mandibular anterior hemi-arch and HA on the contralateral hemi-arch. The primary objective was to compare changes in gingival thickness and keratinized tissue width between the two interventions. Periodontal clinical parameters and injection-related morbidity were assessed as secondary outcomes.
Detailed description
Eleven systemically healthy adults with bilateral thin gingival phenotype in the mandibular anterior region were enrolled. A computer-generated random sequence assigned the left or right mandibular anterior hemi-arch to i-PRF; the contralateral side received non-cross-linked sodium hyaluronate. Allocation was concealed using sealed opaque envelopes. Participants were masked to side allocation; the clinical operator who prepared and administered the interventions and performed outcome measurements was aware of allocation. Both interventions were delivered during the same treatment sessions in a within-participant split-mouth design, with three injection sessions at 7-day intervals (Day 0, Day 7, and Day 14). Gingival thickness and keratinized tissue width were assessed at baseline, 30 days after the third injection, and 2 months after the first follow-up.
Interventions
BIOLOGICALInjectable Platelet Rich Fibrin
At each session, 10 mL of venous blood was collected into an anticoagulant-free tube and immediately centrifuged using a DUO Quattro centrifuge (Process for PRF, Nice, France) at 700 rpm (approximately 60 x g at the maximum rotor radius). Centrifugation was performed for 5 minutes in female participants and 6 minutes in male participants, according to the protocol used in the study. The upper orange liquid fraction was collected. Using 1-mL insulin syringes with integrated 30-gauge needles, i-PRF was slowly injected at two points per treated tooth: approximately 3 mm apical to the free gingival margin and apical to the mucogingival junction. Injection continued until visible tissue blanching; no predetermined fixed volume was administered per injection point or tooth. Three sessions were performed on Day 0, Day 7, and Day 14.
DRUGHyaluronic Acid
Non-cross-linked sodium hyaluronate (ADANT, 10 mg/mL; 2.5-mL prefilled syringe) was used. Using 1-mL insulin syringes with integrated 30-gauge needles, hyaluronic acid was slowly injected at two points per treated tooth: approximately 3 mm apical to the free gingival margin and apical to the mucogingival junction. Injection continued until visible tissue blanching; no predetermined fixed volume was administered per injection point or tooth. Three sessions were performed on Day 0, Day 7, and Day 14.
Sponsors
University of Yaounde 1
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Participants were unaware of which biomaterial was allocated to each mandibular hemi-arch. The clinical operator was aware of allocation.
Intervention model description
Randomized split-mouth (within-participant) parallel design. Each participant received both interventions concurrently at different intra-oral sites: i-PRF on one mandibular anterior hemi-arch and HA on the contralateral hemi-arch. The intervention side was determined by randomization; there was no time-based treatment sequence or washout period.
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
No
Inclusion criteria
* Systemically healthy adults aged 18 to 40 years * Non-smokers * Good oral hygiene with plaque index below 15% * Bilateral thin gingival phenotype in the mandibular anterior region * Thin gingival phenotype confirmed by visibility of a periodontal probe through the gingival tissue * Presence of the six mandibular anterior teeth required for split-mouth evaluation * Willingness to participate and provision of written informed consent
Exclusion criteria
* Periodontal probing depth greater than 3 mm in the study region * Severe bleeding on probing or active periodontal inflammation * Previous mucogingival or periodontal surgery in the mandibular anterior region * Ongoing orthodontic treatment * Pregnancy or breastfeeding * Coagulation or platelet disorders * Use of medications known to affect gingival morphology or periodontal tissues * Tooth mobility in the study region * Missing or supernumerary teeth in the mandibular anterior study region
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Gingival Thickness (GT) | Baseline; 30 days after the third injection; 2 months after the first follow-up | Gingival thickness measured in millimeters by standardized transgingival probing and digital caliper. |
| Keratinized Tissue Width (KTW) | Baseline; 30 days after the third injection; 2 months after the first follow-up | Keratinized tissue width measured in millimeters from the free gingival margin to the mucogingival junction. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Gingival Inflammation | Baseline; 30 days after the third injection; 2 months after the first follow-up | Gingival inflammation assessed using a 0 to 3 ordinal gingival index. |
| Bleeding on Probing | Baseline; 30 days after the third injection; 2 months after the first follow-up | Bleeding on probing assessed using the study 0 to 5 ordinal bleeding severity scale. |
| Probing Depth Category | Baseline; 30 days after the third injection; 2 months after the first follow-up | Probing depth recorded as an ordinal category: less than 3 mm, 3 to 5 mm, or greater than 5 mm. |
| Injection-Related Pain | Day 0; Day 7; Day 14 | Pain assessed on a four-grade verbal scale: absent, mild, moderate, or severe. |
| Injection-Related Edema | Day 0; Day 7; Day 14 | Edema assessed on a four-grade verbal scale: absent, mild, moderate, or severe. |
| Postoperative Bleeding | Day 0; Day 7; Day 14 | Postoperative bleeding assessed on a four-grade verbal scale: absent, mild, moderate, or severe. |
Countries
Cameroon
Contacts
PRINCIPAL_INVESTIGATORJules Julien Ndjoh
Department of Implantology-Periodontology-Prosthodontics, Faculty of Medicine and Biomedical Sciences, University of Yaounde I
Outcome results
None listed