Use of L-PRF membranes for peri-implant soft tissue thickness augmentation: a randomized clinical trial with a three-year follow-up

After the popularization of osseointegrated implants, factors related to tissue aesthetics have gained prominence within Implantology. The search for substitutes for connective tissue grafts grew and the use of leucocyte and platelet rich fibrin (L-PRF) membranes, due to their biological potential, began to gain attention. The objective of this prospective longitudinal study with 3 years of follow-up was to evaluate whether there was an increase in the thickness of the buccal mucosa in single implants in the anterior area of the maxilla with the use of three L-PRF membranes over the ridge at the time of implant installation. A sample of 27 patients, among the individuals who participated of the study and returned for a three-year follow-up, was divided into a test group (n=15), which received three L-PRF membranes inserted over the ridge, and a control group (n=12), who only received the dental implant. The thickness of the vestibular mucosa (EMV), buccal ridge defect (DVR), and height of keratinized tissue (ATQ) were evaluated, in addition to professional (PES/WES) and patientcentered (VAS) aesthetic evaluation. The results showed that the use of L-PRF membranes was not able to increase EMV in the test group after three years post- surgery. The DVR measure showed a significant reduction in the test group after three months of follow-up and was maintained at three years. And the ATQ measure showed a statistically significant reduction after three years. There was no significant difference between the groups in the 3-year postoperative follow- up regarding clinical measurements or aesthetic analyses.