Joshi AA, et al. - In this prospective, randomized clinical and biochemical study involving 20 patients with chronic periodontitis, researchers assessed the levels of platelet-derived growth factor-BB (PDGF-BB) in gingival crevicular fluid (GCF) during early healing period following the regenerative treatment of intrabony defects using beta tricalcium phosphate as a bone regeneration material with either platelet rich fibrin (PRF) membrane or collagen membrane (CM) treated with recombinant human PDGF-BB (rhPDGF-BB). For evaluation of PDGF-BB levels and alkaline phosphatase (ALP) levels, GCF samples were collected on days 3, 7, 14 and 30. The mean PDGF-BB levels at sites treated with PRF membrane or CM incorporated with rhPDGF-BB as a barrier membrane were not significantly different on days 3 and 7 following surgery. In samples collected on days 14 and 30, PDGF-BB levels reduced significantly with significant differences between both the groups. ALP levels increased significantly from day 3 to day 30 but no difference was found between two groups. Within the study limitations, PRF membrane, as well as CM incorporated with rhPDGF-BB initially showed comparable PDGF-BB GCF levels with PRF showing more sustained levels throughout the study period.