Late-onset external root resorption following periodontal regenerative therapy using rhFGF-2 and DBBM: A case report.

BACKGROUND: Periodontal regenerative therapy using recombinant human fibroblast growth factor-2 (rhFGF-2) combined with deproteinized bovine bone mineral (DBBM) has demonstrated favorable and predictable clinical outcomes for intrabony defects. However, long-term outcomes and potential challenges following such combination therapies remain poorly documented. METHODS: A 40-year-old woman with generalized stage III grade C periodontitis underwent periodontal regenerative therapy using rhFGF-2 combined with DBBM for a one-wall defect at the mandibular left first molar (#19). RESULTS: Favorable periodontal healing was maintained for approximately 4 years. However, for tooth #19, the probing depth gradually increased at 5 years 2 months post-surgery, and the patient developed discomfort and pulpal symptoms by 6 years 2 months. Clinical examination revealed an agglomerate of DBBM particles and a palpable external root resorption lesion. The tooth was extracted due to irreversible pulpal involvement. CONCLUSION: This case illustrates that despite favorable early healing, periodontal regenerative therapy may lead to rare late-onset complications such as external root resorption. Long-term follow-up and careful consideration of biomaterial interactions are essential when employing combination regenerative approaches. KEY POINTS: Periodontal regenerative therapy using rhFGF-2 and DBBM achieved favorable clinical outcomes for 4 years before unexpected late-onset external root resorption developed. Long-term persistence and partial separation of DBBM particles, along with the response of macrophage- or osteoclast-lineage cells, are associated with a potential for delayed resorptive pathology on adjacent root surfaces. Clinicians should recognize the possibility of late complications and carefully consider biomaterial interactions when selecting regenerative strategies and informing patients.