Pain associated with root canal treatment.

Aim: To determine the pain experienced by patients during root canal treatment and to correlate with age and gender, pulpal diagnosis, previous periapical status, dental characteristics and length of treatment.
Methodology: One hundred and seventy-six patients (68 men and 108 women), with ages ranged from 6 to 83 years, were randomly recruited. Patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain experienced during root canal treatment.
Results: The mean pain level during root canal treatment was 1.2 +/- 0.8 in a VAS between 0 and 10. Fifty-four per cent of patients did not experience pain. There were no significant differences in relation to gender or age groups. Mandibular teeth had a significantly (P < 0.05) higher percentage incidence of pain in comparison with maxillary teeth. Pain was absent in 63% of anterior teeth compared with 44% in posterior ones (P < 0.01). Interventions shorter than 45 min resulted in a significantly higher percentage of pain absence (P < 0.05). Root canal treatment was significantly (P < 0.05) more painful in teeth with irreversible pulpitis and acute apical periodontitis compared to the group with necrotic pulps and chronic apical periodontitis (P = 0.049).
Conclusions: Root canal treatment in teeth with irreversible pulpitis and acute apical periodontitis was more painful. Age, tooth type and length of the treatment were factors associated with increased risk for pain experienced during the procedure. Knowledge of pain levels endured by patients will allow dentists to decide when to use supplemental local anaesthesia.