Comparison of pain associated with mechanical and chemomechanical removal of caries

Previous studies have indicated that a chemomechanical caries removal system (CRS) has been effective in minimizing the use of conventional mechanical instruments and that it may reduce the need for local anesthesia. In the present study, a comparison of the pain experienced both during treatment with a chemomechanical technique and during conventional caries removal (control) was made for each of 47 patients who initially were not given a local anesthetic. One of two dentists was randomly selected to examine and treat patients with a matched pair of carious teeth, and each pair of teeth was treated in a randomized order with the CRS or control procedure. Responses to the McGill Pain Questionnaire (MPQ) revealed a significantly higher level of pain (p < 0.025) associated with the conventional treatment compared with the chemomechanical procedure. A significantly greater number of patients (p < 0.05) requested local anesthetic for the tooth subjected to the control procedure than for the tooth subjected to the CRS procedure. However, 72.3% of the patients did not request local anesthesia for either treatment, although pain was experienced by these patients in 46.8% of the control teeth and 27.7% of the teeth which received the CRS treatment. Of the 20 pain descriptor categories listed on the MPQ, the sensory categories accounted for the greatest mean number of pain descriptors selected for both the CRS (4.4) and control procedures (8.0), compared with the mean number of descriptors selected from the affective pain categories for the CRS (0.8) and control procedures (1.0). The results suggest that sensory pain factors are more important than affective pain factors in controlling the overall discomfort of patients and the need for local anesthetic during caries removal and subsequent restorative procedures.