From blood to biology: evaluating platelet-rich plasma as a scaffold in regenerative endodontics — a systematic review

Background: To compare autologous platelet concentrates (platelet-rich plasma [PRP] and platelet-rich fibrin [PRF]) with conventional induced blood clot (BC) and other scaffold approaches in regenerative endodontic therapy (RET) for necrotic immature permanent teeth. Data: Randomized controlled trials (RCTs) reporting clinical outcomes and/or radiographic measures of continued root development (e.g., root length, dentinal wall thickness, apical closure, periapical healing) after RET. Sources: A systematic search of PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar was conducted for studies published from February 2015 to February 2025. Reference lists of included studies were hand-searched. The review followed PRISMA 2020 reporting guidance. Study selection: Eligible studies were human RCTs evaluating PRP and/or PRF as a scaffold for RET in necrotic immature permanent teeth, with a comparator scaffold (BC or another platelet-derived scaffold). Two reviewers independently screened and selected studies. Six RCTs met the inclusion criteria. Conclusions: Across six small-to-moderate sized RCTs, platelet concentrates achieved high clinical survival and infection control comparable to BC. Radiographic outcomes (root length and wall thickening, apical closure, and periapical healing) were inconsistently reported and variably favored PRP/PRF or showed no between-group differences. Substantial methodological and clinical heterogeneity (protocols, imaging modalities, outcome definitions, and follow-up) limited quantitative synthesis. Standardized RET protocols and a core outcome set, with validated radiographic measurements (including CBCT where feasible), are needed to determine whether platelet concentrates provide clinically meaningful advantages over BC.