EXAMINATION OF THE DENTAL PULP VITALITY FOLLOWING ORTHODONTIC TOOTH MOVEMENT

Aim: to investigate the effect of orthodontic tooth movement involving the six maxillary anterior teeth on the pulp response to both thermal and electric stimuli during active orthodontic treatment and retention. material and method: twenty-seven subjects who required fixed orthodontic appliances were used as a study group with 27 non-orthodontic subjects recruited as a control group. cold and electrical stimuli were applied to the maxillary incisors and canines immediately before and after the placement of fixed appliances and at regular intervals for both groups during active treatment and 4 months into retention. the numbers of negative responses for each tooth at each time interval were recorded for both groups. analysis of the data were performed by using mann whitney-u and chi-square tests (p<0.05). results: in the control group, all teeth tested positively to the ept and thermal pulp tests at all time intervals. in the orthodontic group, two teeth failed to respond to ept and only one tooth to thermal testing at baseline (t0). after that, the number of negative responses to both tests increased gradually at each time interval reac- hing a peak after 3 months of active treatment (t3) and then declined gradually towards the end of obser- vation period (t6). at baseline, response thresholds to electric testing were typically higher for orthodontic subjects, particularly for the maxillary lateral incisor tooth. for the control group, the response threshold over the study period was relatively constant. for the orthodontic group, application of force immediately increased the response threshold to ept (t1), which peaked after 2 months (t3) and then gradually redu- ced. at the end of the active treatment, response thresholds remained elevated, but they returned to pre-treatment values towards the end of the retention phase. conclusion: dental practitioners should interpret responses to electrical pulp testing cautiously in orthodontic patients.