Pulp and Periodontal Regeneration of an Avulsed Permanent Mature Incisor Using Platelet-rich Plasma after Delayed Replantation: A 12-month Clinical Case Study

Numerous publications have reported revascularization of necrotic immature permanent teeth, but the regenerative potential of pulp in mature teeth has rarely been considered. Platelet-rich plasma (PRP) meets many requirements of a scaffold for regenerative endodontics. To the best of our knowledge, no clinical study has evaluated PRP for endodontic regeneration in a mature avulsed tooth. The present case evaluated PRP for pulpal regeneration in an avulsed mature incisor (>8 hours extraoral dry time) of an 11-year-old boy after delayed replantation. The canal was disinfected after extraoral access cavity preparation and pulp extirpation. The root apex was enlarged, and the tooth was placed in doxycycline solution for 20 minutes. After tooth replantation and splinting, PRP was injected up to the level of the cementoenamel junction and sealed with glass ionomer cement. The 6-month follow-up revealed evidence of internal and external root resorption with periapical radiolucency and an apparent periodontal ligament space. Access was reopened; slurry of 2 antibiotics (minocycline and metronidazole) was inserted into the canal and sealed. Nine- and 12-month radiographs revealed resolution of periapical radiolucency with no further progression of internal resorption. The tooth showed a positive response to thermal and electric pulp tests. The findings observed in this case warrant further research under controlled conditions to evaluate endodontic and periodontal regeneration in a tooth that would otherwise be expected to have an unfavorable prognosis.