Effects of injectable platelet-rich fibrin and Hank’s balanced salt solution as rejuvenating media for the periodontal ligament cells of avulsed teeth

BACKGROUND: The problem of avulsed teeth often being brought to the clinic in a dry state remains unresolved in the literature. Before an avulsed tooth is replanted, the periodontal ligament (PDL) cells require an appropriate storage medium to preserve their viability and biological properties. Hank's balanced salt solution (HBSS) is the reference medium recommended for this purpose in the literature. OBJECTIVES: The aim of the present study was to compare the effects of the reference solution - HBSS - and injectable platelet-rich fibrin (I-PRF) on the differentiation of PDL fibroblasts by examining the differentiation markers associated with osteoblastic, osteoclastic, fibroblastic, and cementoblastic lineages. MATERIAL AND METHODS: Twenty freshly extracted third molar teeth were used for cell isolation. After being left to dry for 30 min, the teeth were immersed for 30 min at room temperature in HBSS (n = 7) or I-PRF (n = 7). For the positive control group (n = 3), cells were isolated immediately after extraction, whereas for the negative control group (n = 3), cells were isolated after 30 min of dry time. Viable cells were counted, and immunofluorescence staining was performed to assess cell differentiation, using antibodies against Runt-related transcription factor 2 (RUNX2), receptor activator of nuclear factor kappa-B ligand (RANKL), collagen type I (COL1), and cementum attachment protein (CAP). Integrated density (IntDen) was measured using the ImageJ software. RESULTS: There were no statistically significant differences between the HBSS and I-PRF groups in the expression of RUNX2, RANKL or CAP. The I-PRF group showed significantly higher expression of COL1 (p < 0.01). CONCLUSIONS: Injectable PRF may contribute to the regeneration of PDL cells when used as a rejuvenating medium before replantation following an extraoral dry period.