Objective: To examine pulpal vitality in teeth suffering dental trauma during orthodontic therapy with fixed appliances.
Materials and methods: Pulpal condition was evaluated in 59 teeth that had suffered dental trauma during orthodontic treatment (TO-group), in 800 orthodontically treated teeth without previous dental trauma (O-group), and in 193 orthodontically untreated teeth with previous dental trauma (T-group). Pulpal vitality was examined clinically and with radiographs. Degree of pulp obliteration was rated as absent, partial, or total. All teeth in the TO-group showed a positive sensibility test prior to resumption of orthodontic therapy.
Results: Teeth in the TO-group revealed a significantly higher frequency of pulp necrosis than teeth in the O-group or teeth in the T-group (P < .001, respectively). In the TO-group, teeth with extrusive or lateral luxation (P = .031) and teeth with intrusive luxation (P = .015) injuries showed a significantly higher rate of pulp necrosis than teeth with fracture of enamel. In addition, teeth with total pulp obliteration showed a significantly higher frequency of pulp necrosis than teeth without pulp obliteration (P = .013).
Conclusion: Teeth with severe periodontal injury during orthodontic therapy and subsequent total pulp obliteration have an increased risk of pulp necrosis during additional orthodontic treatment stages.