Effect of injectable platelet-rich fibrin on orthodontically induced root resorption during tooth movement: a biomarker-based randomized controlled trial

Objectives: Orthodontically induced root resorption (OIRR) is a common adverse effect of orthodontic treatment, and early detection remains challenging. This randomized controlled trial aimed to evaluate the biological effect of injectable platelet-rich fibrin (i-PRF) on OIRR using dentin sialophosphoprotein (DSPP) levels in gingival crevicular fluid (GCF) as a biomarker during orthodontic tooth movement. Materials and methods: Thirty patients requiring bilateral maxillary first premolar extraction were randomly allocated to an i-PRF group (n = 15) or a control group (n = 15). In the intervention group, i-PRF was administered submucosally before incisor alignment. GCF samples were collected from maxillary central and lateral incisors at baseline (T0) and monthly for six months (T1–T6). DSPP concentrations were quantified using an enzyme-linked immunosorbent assay. Longitudinal changes in DSPP levels were analyzed using linear mixed-effects models to account for repeated measurements. Results: DSPP levels showed a significant time-dependent increase in both groups for central and lateral incisors (p < 0.001). However, the pattern of DSPP release differed significantly between groups. From the fourth month onward, DSPP levels were significantly lower in the i-PRF group compared with controls (p < 0.05). Lateral incisors consistently exhibited higher DSPP concentrations than central incisors. Conclusions: Administration of i-PRF before incisor alignment was associated with lower DSPP expression during orthodontic tooth movement, suggesting a possible biological effect of i-PRF on OIRR. Clinical relevance: The study provides preliminary biological evidence that i-PRF may influence processes associated with OIRR. If confirmed by future studies, i-PRF could serve as a minimally invasive adjunct to help reduce the risk of root resorption during orthodontic treatment. Trial registration no: CTRI/2023/08/056931 (Clinical Trial Registry of India) © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2026.