The Variability of Electric Pulp Response Threshold in Premolars: A Clinical Study

IntroductionThis study was designed to determine the variability of the electric pulp response threshold in premolars and the relationship between the response threshold and age.MethodsNinety-seven volunteers were recruited, ranging from 20–72 years old. The volunteers were categorized into 6 age groups: group 1, 20–29 years; group 2, 30–39 years; group 3, 40–49 years; group 4, 50–59 years; group 5, 60-69 years; and group 6, 70–79 years. All intact premolars present in each dental arch were tested. Three sites (the tip of the buccal cusp, the center of the middle, and cervical third of the buccal surface) on each tooth crown were tested.ResultsIn total, 1965 measurements were done. A progressive increase of mean threshold value was observed from groups 1 to 6. The response threshold value showed significant differences among the 6 age groups. The effect of age was more intense in mandibular premolars. In first and second mandibular premolars the cusp tip required the lowest current to evoke a response. In maxillary premolars no significant differences among the sites were found. Also, the mean threshold value of the mandibular premolars was lower than that of the maxillary premolars in subjects of the same age, and the mean threshold value of the first premolars was lower than that of the second premolars. The buccal cusp tip of the first mandibular premolars responded more quickly than any other tested site.ConclusionsAge is related with higher response threshold values. The optimum site for testing the lower premolars is the buccal cusp tip.