Fig. 4

Proposed protocol for the management of avulsed teeth of various conditions. A, B) Non cell-based PDL regeneration. Avulsed tooth was kept wet in a storage medium. For condition in B, the regeneration of PDL relies mainly on the remaining PDL cells in the tooth socket. Addition of PRF is necessary to increase chances of better outcomes. C–E Cell-based PDL regeneration. Once the avulsed tooth is dried or stayed extra oral time more than 7 days, all cells on the root become non-viable or mostly non-viable. PDL cells in the tooth socket also have reduced or disappeared. Thus, cell-based PDL regeneration is necessary. For condition in E, recreating the tooth socket with implant drills is needed because bone has begun to regenerate. Clinical images, courtesy of Dr. Mitsuhiro Tsukiboshi