# Autologous Platelet Concentrates and Photobiomodulation as Biologically Active Modifiers of Hard and Soft Tissue Healing: A Randomised Controlled Trial

## TL;DR

This study tested how platelet concentrates and light therapy affect healing after tooth extraction, finding that combining them may improve tissue regeneration.

## Contribution

The study is the first to compare multiple platelet concentrate types and their combination with photobiomodulation in a randomized trial for tissue healing.

## Key findings

- Photobiomodulation significantly reduced postoperative pain compared to the control group.
- CGF combined with photobiomodulation showed higher bone regeneration in the mid socket region.
- Not all outcomes showed significant differences between groups, suggesting variability in treatment effects.

## Abstract

Background/Objectives: This study evaluated autologous platelet concentrates (APCs), including advanced platelet-rich fibrin (A-PRF+) and concentrated growth factors (CGFs), as biologically active matrices, and photobiomodulation (PBM) as a biophysical stimulus affecting soft and hard tissue regeneration following mandibular third molar extraction. Methods: A six-arm parallel randomised controlled trial was conducted including 135 patients. A total of 122 participants completed follow-up and were analysed: control (n = 22), photobiomodulation (n = 20), A-PRF+ (n = 19), CGF (n = 20), A-PRF+ plus photobiomodulation (n = 22), and CGF plus photobiomodulation (n = 19). The primary endpoint was postoperative pain intensity assessed on postoperative day 3 using an 11-point visual analogue scale (VAS). Secondary outcomes included swelling, trismus, wound healing assessed by the early healing index, and bone regeneration assessed by CBCT-based fractal dimension analysis at 4 months. Results: On postoperative day 3, mean VAS pain was 2.95 ± 2.65 in the control group and 1.00 ± 1.65 in the photobiomodulation group, corresponding to a mean difference of 1.95 VAS points. The overall between-group difference for day 3 pain was statistically significant. In swelling outcomes, no statistically significant between-group differences were observed at days 1, 3, or 7 across facial measurement lines. In CBCT fractal analysis, a significant group effect was detected for the mid socket region, with higher fractal dimension at 4 months in the CGF plus photobiomodulation group compared with the control. Conclusions: Both APCs and PBM positively influenced postoperative healing. Their combined application, particularly CGF with PBM, showed the most consistent regenerative effects, although not all outcomes differed significantly between groups. These minimally invasive strategies may support soft and hard tissue regeneration.