The diagnostic value of coronal dark-gray discoloration in primary teeth following traumatic injuries

The diagnostic value of dark-gray discoloration of the crown of primary incisors following traumatic injury as a predictor of pulp vitality is controversial. This retrospective study attempted to examine the condition of the pulp of primary incisors with dark-gray discoloration following traumatic injuries. Forty-eight gray caries-free, traumatized primary incisors were examined clinically and radiographically prior to treatment. All teeth included in the study were free of any clinical and/or radiographic signs of pulp necrosis. Crown discoloration was the only clinical or radiographic sign of pulp involvement. Pulpectomy was performed in five teeth within the first month after trauma, in 16 teeth during the second month, 11 teeth between 2 and 6 months, seven teeth between 6 and 12 months, and three teeth after more than a year. In six teeth the time of injury was unknown. Endodontic treatment was initiated without local anesthetic under rubber dam, access to the pulp chamber with high speed, and debridement with a barbed broach. Assessment of the pulp condition was made upon opening the pulp chamber, as follows: Vital-pulp bled when exposed; partial necrosis-bleeding disclosed at the apical area during debridement; total necrosis-no bleeding was observed. Pulp necrosis was found in 37 teeth (77.1%), 10 teeth (20.8%) presented partial necrosis, and only one tooth (2.1%) had a vital pulp. Dark-gray discoloration of primary incisors could be interpreted as an early sign of pulp degeneration that would deteriorate into necrosis. Moreover, discolored primary incisors can be necrotic even without presenting tenderness to percussion, increased mobility, and periapical osteitis.