Albilia JB DMD et al. found that intra-articular injections of liquid PRF appear to have significant analgesic effects lasting for 12 months in patients with localized painful internal derangement of the temporomandibular joint (TMJ), which is only one of many synovial joint diseases. In this preliminary investigation, patients suffering from Wilkes' stage IV (intermediate-late) and stage V (late) respond the best to this particular second-generation blood concentrate. 

The present study was conducted to examine the clinical advantages of liquid platelet-rich fibrin (PRF) in patients with temporomandibular joint (TMJ) pain and dysfunction.

All in all, 48 TMJs in 37 patients with painful internal derangement (ID) (Wilkes' I-V) were considered. At 2-week intervals, patients were injected with 1.5-2cc of PRF within the superior joint space. Pain and subjective dysfunction were noted via visual analog scale. ANOVA test was used for statistical analyses.

There was a significant reduction in pain at 8 weeks, and at 3, 6, and 12 months in 33 out of 48 TMJs (69%) Responders. There was no improvement in 15 of 48 TMJs (31%) non-responders. The most ideal Responders to liquid PRF injections were ID stages Wilkes' IV (78.5%) and V (100%), compared to Wilkes' I (0%), II (47%), and III (33%). There was a notable decrease in dysfunction. 

The preliminary findings support that liquid PRF portrays long-term analgesic effects in most patients with painful TMJ ID.