Appropriate electrode placement site for electric pulp testing first molar teeth.

Twenty volunteers with first molars free of restorations and caries were recruited. One molar from each arch was selected, and rubber dam was applied. Seven sites on each crown were electric pulp tested 4 times with an Elements Diagnostic Unit, and lowest threshold responses were recorded. Data were analyzed with one-way analysis of variance and the Tukey test at the .01 level. The lowest response for both the maxillary and mandibular teeth was with the probe on the mesiobuccal cusp tip. Other sites showed an increase in level from the mesiobuccal cuspal surface, mesiobuccal gingival surface, and the center of the supporting cusps (palatal of maxillary molar, buccal of mandibular molar). No significant difference in responses was found between male and female subjects; however, male subjects responded at higher thresholds than female subjects on all test sites except the mesiobuccal cusp tip. The optimum site for pulp testing first molars is the mesiobuccal cusp tip.