Regenerative endodontic procedures offer a biological treatment for immature permanent teeth after pulp necrosis, enabling root maturation and return of sensitivity. Platelet-rich fibrin (PRF) has been suggested as a biologically advantageous scaffold, although evidence comparing it with the traditional blood clot (BC) remains limited. The BC-treated tooth developed reinfection and required retreatment at 3 months, limiting direct comparison between the two scaffolds. Early outcomes favored PRF, with greater root maturation and apical closure within the first 12–28 months, while the BC-treated tooth showed partial closure and canal obliteration. However, the long-term outcomes differed markedly at the 80-month follow-up: PRF-treated tooth lost sensibility and developed an apical radiolucency, but the BC-treated tooth showed no apical pathology, and maintained an early positive sensibility response. Although direct conclusions cannot be drawn from this single case, the findings suggest that early radiographic signs of maturation may not necessarily predict long-term stability and underscore the importance of secondary infection and extended follow-up in regenerative endodontic treatment.