Comparative evaluation of application of platelet rich fibrin (PRF) membrane and platelet rich fibrin matrix (PRFM) gel on healing after gingival depigmentation - A clinical and histological study

AIM OF THE STUDY

The aim of this study is to evaluate and compare the clinical and histological effects of platelet rich fibrin (PRF) membrane and platelet rich fibrin matrix (PRFM) gel application on healing after gingival depigmentation.

I. STUDY DESIGN:

This is the double blind nonrandomized interventional study.

II.STUDY SETTING:

A total of 42 sites from 14 patients of Outpatient Department, Department of Periodontics, at Dr HSRSM Dental College and Hospital will be included in the study with prior informed and written consent.

III. STUDY POPULATION:

The study will be performed on systemically healthy volunteer subjects screened for inclusion and exclusion criteria from the Outpatient Department, Department of Periodontics, at Dr HSRSM Dental College and Hospital, after obtaining an informed and written consent through signed document in English and local language to participate in the study.

Test Group:

Group A: Right maxillary quadrant will receive the PRF membrane application after gingival depigmentation. Group B: Left maxillary quadrant will receive the PRFM gel application after gingival depigmentation.

Control Group:

Group C: The mandibular anterior sextant will receive only the periodontal dressing (co-pack) placement after gingival depigmentation.

IV. METHOD OF SELECTION OF STUDY SUBJECTS:

A written consent in English and regional local language with a detailed case history will be recorded from all 14 patients.

i. INCLUSION CRITERIA:

♦   Systemically and periodontally healthy male and female with an age range of 18–30 years.

♦   Patients with esthetic concern due to gingival hyperpigmentation.

♦   Patients with good oral hygiene, with the plaque index score of <1 and gingival index score <1, more than 2mm of attached gingiva.

♦   Diffuse continuous physiological pigmentation of the gingiva involving the facial aspect of teeth classified under Dummet Oral Pigmentation Index (DOPI), minimum score 2 (Moderate clinical pigmentation).

ii. EXCLUSION CRITERIA:

♦   Patients suffering from any known systemic diseases.

♦   Individuals with a habit of smoking/tobacco chewing.

♦   Alcoholic patients.

♦   Pregnant and lactating mothers.

♦   Patients suffering from neurological deficiency.

iii. SUBJECT WITHDRAWL CRITERIA

♦   Any subject meeting exclusion criteria during the study.

♦   Any subject willing to exit the study voluntarily.

♦   Any subject with adverse effects if any.

♦   If the subject cannot adhere to study timelines and appointments.

♦   Any subject developing any systemic disease during the study.

Any subject withdrawing from the study shall be followed up indicated treatment as per their condition and shall be treated for any adverse effect if any.

**iv.**SAMPLE SIZE:

The total sample size for this study will be 42; with 14 samples in each study group.

V. METHOD OF MEASUREMENT

1. Dummet Oral Pigmentation Index (DOPI) (Dummet and Gupta, 1964)

2. Plaque index (PI) (Sillness and Loe, 1964)

3. Gingival Index (GI) (Loe and Sillness, 1963)

4. Visual analogue scale (VAS) for pain

5. Healing index (HI) (Landry et al, 1988)

6. Epithelialization Test

7. Histological Analysis

TREATMENT DETAILS:

Informed and written consent will be obtained from all patients and a detailed case history will be recorded. Periodontal status will be assessed using Plaque Index (Sillness & Loe, 1964), Gingival Index (Loe & Sillness, 1963). Physiological melanin pigmentation will be assessed using Dummet Oral Pigmentation Index (Dummet and Gupta, 1964).

The depigmentation procedure will be carried out by abrasion technique with the use of a precision soft tissue trimming ceramic bur under high-speed rpm without using water coolant spray. Due to friction, the heat which is produced by the bur causes immediate tissue coagulation and reduces bleeding, hence the use of coolant is avoided.  After the removal of the entire pigmented epithelium, saline will be used for irrigation.

Individuals will be divided into 3 groups based on the application of platelet concentrates following depigmentation procedure. 10 ml of blood samples will be withdrawn from antecubital vein from the individual.

Preparation of PRF membrane

5ml of blood transferred to glass vacutainer will be centrifuged at 2800 rpm for 12 min. The gel obtained following the centrifugation contains three layers. The top layer being platelet poor plasma and bottom layer consists of concentrated red blood cells. The middle layer harboured fibrin network gel will be compressed in between sterile gauze pieces, and the supernatant should be discarded to obtain PRF membrane.

The right maxillary quadrant will receive the PRF membrane. Membrane will be stabilized with 5-0 absorbable suture followed by periodontal dressing placement.

Preparation of PRFM gel

5ml of blood will be transferred to Meresis PRFM kit (Meresis, laboratory, Bangalore, India) and will be centrifuged at rpm of 3000 for 10 min. The supernatant obtained at the top of gel will be removed to achieve the PRFM gel.

Left maxillary quadrant will receive the PRFM gel uniformly spread over depigmented epithelium followed by periodontal dressing placement.

Whereas the mandibular anterior sextant will receive only the periodontal dressing placement after depigmentation. The individuals are asked to refrain from brushing for 3 days following the procedure and will be instructed to rinse their mouth with 0.2% chlorhexidine digluconate mouthwash.

The clinical and histological parameters will be evaluated following the surgical procedure on 5th day, such as visual analog scale (VAS) and healing index (HI). All clinical parameters will be measured by an examiner other than surgeon.

For epithelialization test, patient will be asked to rinse the mouth twice with water for 20 seconds to remove debris. Then 1% acetic acid will be applied for 20 seconds to remove ropey saliva, followed by 1% TB application for 20 seconds with cotton swab and stain uptake will be visualized. After the procedure 2 rinses with 1% acetic acid will be performed to reduce the extent of mechanically retained stain and the mouth will be rinsed with water.

Histological analysis will be carried out on 5th day through punch biopsy. Infiltrative anesthesia will be given in the buccal fold. The incision will be performed positioning the punch perpendicular and performing simultaneous rotational movements under gentle pressure to the depigmented gingival epithelium, from the lateral incisor region in maxillary arch and mandibular arch. Collected specimen will be transfer into 10% formalin fixative immediately after removal from the patient and will be send to laboratory. Patient is asked for consumption of analgesics if and when required after punch biopsy procedure. The patient will be recalled after 3 months for re-evaluation.