Electrical resistance correlation with tactile examination on occlusal surfaces.

Electrical resistance of the tooth was measured through the dental pulp by a relatively simple method. The primary resistance is in the enamel, and the total resistance drops severalfold as dental caries develop. This resistance has been measured on the occlusal surfaces of 122 teeth of children. The differences between explorer categories showed statistically different resistance values (P greater than 0.9995, excluding the offscale sound-tooth category). After 3 to 4 months, 9 of the 32 teeth of the incipient caries category became obviously carious, while none of the caries-free teeth became carious.