Objective: Initial orthograde root canal therapy (RCT) is a common dental treatment. Persistent pain is a known outcome, but the impact of this outcome is unknown. Therefore, we compare the pain-related interference on daily life and additional care obtained between patients with and without pain. Method: 62 dentists within the National Dental PBRN (NationalDentalPBRN.org) enrolled consecutive patients requiring RCT. Data were collected 6 months following obturation by questionnaire. Persistent pain criteria included the report of tooth-related pain with an average intensity =1/10 on a numeric rating scale over a recall period of 1 month and =1 day of pain over that month. Additional questions about pain-related interference of daily activities and additional treatments received were asked. Result: 708 patients were enrolled over a 6-month period and follow-up data were collected from 651 (92%). Sixty-five (10%) patients met criteria for persistent pain. Over the preceding month, 4 (6.2%) patients reported days where pain inhibited daily activity, while none without pain reported such interference (p<0.0001). These 4 patients had an average of 4.75 days inhibited. During the 6-month post-obturation period, 12 (18%) persistent pain patients received additional RCT with a total of 30 appointments, while 21 (3.6%) patients without pain received additional RCT with a total of 36 visits (p<0.0001). Three (4.6%) patients with pain had teeth extracted, as opposed to 10 (1.7%) without pain (p=0.11). Eight (12%) patients with pain sought care with physicians, having 16 visits, and 2 (3.1%) with chiropractors, having 12 appointments. The relative proportion of pain-free patients seeking such care was statistically lower; 9 (1.5%; p<0.0001) saw physicians with 15 visits and 3 (0.5%; p=0.02) saw chiropractors. Conclusion: Six months following initial RCT, lost days of productivity and healthcare utilization were significantly greater in patients with pain compared to those without pain.