Combination injuries 2. The risk of pulp necrosis in permanent teeth with subluxation injuries and concomitant crown fractures

摘要

Background: The reported risk of pulp necrosis (PN) is generally low in teeth with subluxation injuries. A concomitant crown fracture may increase the risk of PN in such teeth. Aim: To analyse the influence of a concomitant trauma-related infraction, enamel-, enamel-dentin- or enamel-dentin-pulp fracture on the risk of PN in permanent teeth with subluxation injury. Material and Methods: The study included 404 permanent incisors with subluxation injury from 289 patients (188 male, 101 female). Of these teeth, 137 had also suffered a concomitant crown fracture. All the teeth were examined and treated according to a standardized protocol. Statistical Analysis: The risk of PN was analysed separately for teeth with immature and mature root development by the Kaplan-Meier method, the log-rank test and Cox regression analysis. The level of significance was set at 5%. Risk factors included in the analysis were gender, patient age, crown fracture type, mobility and response to an electric pulp test (EPT) at the initial examination. Results: Teeth with immature root development: The risk of PN was increased in teeth with a concomitant enamel fracture (log-rank test: P=0.002), enamel-dentin fracture (log-rank test: P<0.0001), enamel-dentin-pulp fracture (log-rank test: P<0.0001) and in teeth with no response to EPT at the initial examination [hazard ratio: 21 (95% confidence interval, CI: 2.5-172.5), P=0.005]. Teeth with mature root development: the risk of PN was increased in teeth with an enamel-dentin fracture [hazard ratio: 12.2 (95% CI: 5.0-29.8), P<0.0001], infraction [hazard ratio: 5.1 (95% CI: 1.2-21.4) P=0.04] and in teeth with no response to EPT at the initial examination [hazard ratio: 8 (95% CI: 3.3-19.5), P<0.0001]. Conclusion: A concomitant crown fracture and no response to EPT at the initial examination may be used to identify teeth at increased risk of PN following subluxation injury.