Condition category
Oral Health
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Gingival recession, also known as receding gums, is the exposure of the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth. Treatment involves surgical procedures promoting root recovery. A widely accepted technique is the connective tissue graft (CTG) procedure. The tissue graft is often taken from the palate (roof of the mouth), frequently between the canine and first upper molar. There are often difficulties with wound healing, causing longer and more uncomfortable post-surgical experiences for the patients. Recently, leukocyte-platelet-rich fibrin (L-PRF) has been used to promote tissue regeneration. Consequently, patients experience less pain and better quality of life. Therefore, the aim of this study is to confirm these expected better characteristics on the palatal wound of CTG harvest procedures.

Who can participate?
Patients aged 18 to 45 years of age undergoing CTG harvest procedures

What does the study involve?
Participants undergo a CTG harvest procedure and are randomly allocated to either A-PRF application on the palatal wound or a standard surgical absorbable sponge. Pain is assessed using for the following 30 days after surgery.

What are the possible benefits and risks of participating?
The benefits of participating are the treatment of gingival recession using a standard or an innovative technique, both extremely safe. The only risk is during blood collection, although it is always performed by a trained and experienced nurse., patients may experience nausea and faint.

Where is the study run from?
Egas Moniz Dental Clinic (Portugal)

When is the study starting and how long is it expected to run for?
September 2019 to September 2020

Who is funding the study?
Egas Moniz University (Portugal)

Who is the main contact?
Dr João Botelho

Trial website

Contact information



Primary contact

Dr João Botelho


Contact details

Campus Universitário
Quinta da Granja Monte de Caparica
2829 - 511 Caparica
+351 (0)212946840

Additional identifiers

EudraCT number

Nil known number

Nil known

Protocol/serial number


Study information

Scientific title

Clinical assessment of A-PRF application on the healing process of palatal wound after connective tissue graft harvest: a randomized clinical trial



Study hypothesis

A-PRF provides improves the healing process of palatal wounds and better post-surgical pain experience

Ethics approval

Egas Moniz Ethics Committee (Campus Universitário, Quinta da Granja, Monte de Caparica, 2829 - 511 Caparica, Portugal; Tel: +351 (0)212 946 767, Rectory Room; Email:, Process number 819/2020

Study design

Single-centre triple-blinded randomized clinical trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Palatal wound after connective tissue graft harvest


Patients were randomly assigned in a 1:1 ratio to the PRF group or control group. A random allocation sequence was performed by using a randomization program (http://www. Although the surgeon and the clinical examiner are blinded to the allocation, to avoid differences in the evaluation of parameters. Since all patients underwent single-incision technique, the clinical appearance was not misleading for the clinician who evaluated the parameters.

All interventions are performed under strict sterile conditions and local anesthesia (articaine 72 mg + epinephrine 0.009 mg / 1.8 mL). A free gingival graft with about 1.5 mm thickness was removed from the palatal area from first premolar to first molar. All surgeries were supervised by the same periodontist (RA). The treatment at the test site was performed as follows:
1. Preparation of A-PRF: It was performed a standard venipuncture (median basilica vein, median cubital vein, median cephalic vein). Ten mL of blood was drawn into a tube without anticoagulant. A-PRF is prepared by centrifuged according to the manufacturer instructions at 1,500 rpm for 8 minutes. After centrifugation, A-PRF clot from was removed from the tube and separated from the red element phase at the base with pliers. Then, A-PRF was delicately squeezed between a sterile metal plate and a metal box (gravity, no loading)
2. Palatal wound, as a result of free gingival graft harvesting, was occupied by two A-PRF clot membrane after careful positioning, and criss-cross sutures were done to hold it in position

For the control group, the surgical wound as a result of the graft collecting was filled with lyophilized hydrolyzed collagen sponge (TechnewTM, Rio de Janeiro, Brazil)

Intervention type



Drug names

Primary outcome measure

Pain assessed using the Visual Analogue Scale at baseline and for the following 30 days after surgery

Secondary outcome measures

1. Edema visually measured at 7, 14 and 30 days after surgery
2. Analgesic consumption measured using a personal diary at baseline and for the following 30 days after surgery
3. Healing process measured using early healing index at 7, 14 and 30 days after surgery.
4. Connective tissue graft volume and PRF volumes measured using a periodontal probe during surgery

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients ranging from 18 to 45 years of age
2. Need connective tissue for tunnel operation or coronally flap operation
3. Non-smoking
4. Good oral hygiene
5. No gag reflex
6. No periodontal surgery before at operation site

Participant type


Age group




Target number of participants

52 (26 per group: 26 with A-PRF and 26 with standard absorbable sponge)

Participant exclusion criteria

1. Systemic disorders (immunologic diseases, uncontrolled diabetes mellitus, ongoing chemotherapy or radiotherapy)
2. Pregnancy/lactation/menstruation
3. Chronic use of anti-inflammatory or analgesic
4. Inability or unwillingness to provide informed consent

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Egas Moniz Dental Clinic
Campus Universitário, Quinta da Granja Monte de Caparica
2829 - 511

Sponsor information


Egas Moniz - Cooperativa de Ensino Superior

Sponsor details

Campus Universitário
Quinta da Granja Monte de Caparica
2829 - 511 Caparica
+351 (0)212946840

Sponsor type




Funder type


Funder name

Egas Moniz University

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Both study protocol and statistical plan will not be available because they are written in Portuguese. The researchers plan to publish the results in peer-review journals.

IPD sharing statement
All data will be anonymised, with codification preventing identification of the participants. All patients will provide consent. Data will be freely available, with access request needed before shared. Database will be uploaded after trial completion in Zenodo, including age, sex, VAS scores for each day, analgesic consumption, graft and PRF volumes.

Intention to publish date


Participant level data

Stored in repository

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

31/01/2020: Trial's existence confirmed by Egas Moniz Ethics Committee.