Comparing the quality of anaesthesia in normal and inflamed teeth by pulp testing.

Failure to achieve complete anaesthesia of teeth with acutely inflamed pulps is a well-known clinical symptom. In this study, we compared the quality of anaesthesia in intact and inflamed mandibular teeth by using an electric pulp tester. Thirty patients with inflamed lower teeth, which had spontaneous or night pain, were selected; two healthy teeth in the same quadrant were used as control teeth. Electric pulp testing and thermal tests were made on each inflamed and control tooth. Teeth were then anaesthetised by inferior alveolar nerve block and electric pulp tests were repeated on inflamed and control teeth. Significant differences were found between electrical stimulation of inflamed and intact pulp (p approximately 0). There was no significant difference between the responses of inflamed teeth to electric pulp testing before and after anaesthesia (p = 0.327), which showed that the teeth could become resistant to anaesthesia due to the inflammation.