Prevalence of persistent pain 3 to 5 years post primary root canal therapy and its impact on oral health-related quality of life: PEARL Network findings.

Introduction: The frequency of persistent pain 3-5 years after primary root canal therapy and its impact on the patient's perceived oral health-related quality of life was determined in a practice-based research network.

Methods: All patients presenting to participating network practices who received primary root canal therapy and restoration for a permanent tooth 3-5 years previously were invited to enroll. Persistent pain was defined as pain occurring spontaneously or elicited by percussion, palpation, or biting. The patient also completed an oral health-related quality of life questionnaire (Oral Health Impact Profile-14).

Results: Sixty-four network practices enrolled 1323 patients; 13 were ineligible, 12 did not receive a final restoration, and 41 were extracted, leaving 1257 for analysis. The average time to follow-up was 3.9 ± 0.6 years. Five percent (63/1257) of the patients reported persistent pain, whereas 24 of 63 (38%) exhibited periapical pathosis and/or root fracture (odontogenic pain). No obvious odontogenic cause for persistent pain was found for 39 of 63 (62%). Teeth treated by specialists had a greater frequency of persistent pain than teeth treated by generalists (9.3% vs 3.0%, respectively; P < .0001). Sex, age, tooth type, type of dentist, and arch were not found to be associated with nonodontogenic persistent pain; however, ethnicity and a preoperative diagnosis of pulpitis without periapical pathosis were. Patients reporting pain with percussion tended to experience pain with other stimuli that negatively impacted quality of life including oral function and psychological discomfort and disability.

Conclusions: These results suggest that a small percentage (3.1%) of patients experience persistent pain not attributable to odontogenic causes 3-5 years after primary root canal therapy that may adversely impact their quality of life.