- Participant has a permanent tooth with a necrotic pulp (as defined by lack of responsiveness to both electrical pulp tests and cold [EndoIce] tests). If the tooth was traumatized, then pulpal necrosis is defined as either: 1) no response to both electrical pulp test and cold [EndoIce] test by three months after trauma, or 2) presence of a periapical lesion, or 3) radiographic evidence of root resorption, or 4) discoloration of the crown.