Analysis of Soft Tissue Healing Over Socket Orifice Sealed with Platelet-Rich Fibrin Membrane

Socket sealing is a technique for alveolar ridge preservation following tooth extraction. Leukocyte and platelet-rich fibrin (L-PRF), an autologous platelet-derived material rich in growth factors, is used to support healing. However, its benefits for soft tissue healing compared with collagen sponge or spontaneous healing remain unclear. This study evaluated soft tissue healing outcomes, wound margin distance, inflammation, postoperative pain, and wound closure area, among sockets treated with L-PRF membrane, collagen sponge, or spontaneous healing.

A randomized controlled clinical trial was conducted on 45 extraction sites at the Faculty of Dentistry, Mahidol University, Bangkok, Thailand. Sockets were randomly assigned to L-PRF sealing, collagen sponge sealing, or spontaneous healing. Primary outcomes included wound margin distance reduction percentage, soft tissue healing index, and postoperative pain. The secondary outcome was wound closure area reduction percentage between the L-PRF and collagen sponge groups. Measurements were recorded postoperatively and on days 7, 14, and 21. Pain scores were recorded daily for 1 week. Age, sex, tooth position, and arch were evaluated as covariates.

One-way ANOVA with least significant difference post-hoc test was used for primary outcomes, and an independent t-test was used for secondary outcomes (p < 0.05).

Forty-five teeth were enrolled. Three teeth from the collagen sponge group were excluded due to infection and loss to follow-up; three additional teeth were recruited using the original allocation and randomization protocol. On day 7, L-PRF showed a significantly superior soft tissue healing index than collagen sponge (p = 0.002, 95% CI: [0.28, 1.18]) and spontaneous healing (p = 0.002, 95% CI: [0.28, 1.18]). On day 5, L-PRF reduced pain more than collagen sponge (p = 0.036, 95% CI: [0.04, 1.03]) and spontaneous healing (p = 0.026, 95% CI: [0.07, 1.06]). No significant differences in wound closure distance reduction percentage or wound area reduction percentage were observed among the groups.

L-PRF improved soft tissue healing and reduced postoperative pain within the first week, but showed no added benefit in wound closure compared with collagen sponge or spontaneous healing. L-PRF may support short-term symptom relief but not enhanced post-extraction soft tissue regeneration at the clinical relevance level.