Background
pericoronitis, tooth
RECURRENCE, PERICORONITIS, ERUPTION
The mandibular third molar is a newly erupted tooth at young age, and located distally to the second molar. It is often impacted due to insufficient space or improper eruption direction. Frequent recurrence of the third molar pericoronitis might cause severe bone resorption in the distal area of second molar [Concentrate growth factors (CGF) has become one of the new methods for alveolar bone defect reconstruction because of its strong ability of bone regeneration. CGF is a new biomaterial discovered after platelet-rich plasma (PRP) and platelet rich fibrin (PRF), which contains a variety of high concentration growth factors and fibrin [Based on comprehensive consideration, we innovatively proposed a new bone repair protocol: combining autogenous bone, Bio-Oss, CGF gel and CGF membrane which provided a new strategy for the clinical protection of the second molar. So far there was no long-term follow-up report of this new bone repair protocol. Therefore, detailed investigations on the efficacy were urgently needed before further clinical promotion.