Capacitance effect of rubber gloves on electric pulp testers

Abstract

Electric pulp testers (EPTs) are widely used to assess tooth pulp vitality. With many unipolar EPTs the electrical circuit is completed through the operator. Since dentists now routinely wear rubber gloves, these might be expected to provide electrical insulation, and therefore to break the circuit. The objective of this investigation was to define the electrical effect of wearing rubber gloves. Two battery-powered unipolar EPTs were examined using a digital storage oscilloscope with an input impedance of 1 M omega. The probe tip was connected directly to the positive input lead of the oscilloscope. Three conditions were tested: (i) with the conductive handle connected directly to the negative input lead; (ii) with the ungloved operator holding the negative input lead in one hand and the conductive handle of the EPT in the other; and (iii) holding the conductive handle in a gloved hand. While the two EPTs produced different patterns of voltage spike, for each there was no difference between conditions (i) and (ii). However, when the conductive handle was held in a gloved hand (condition iii), there was a reduction in peak negative voltage and a change in wave form with positive overshoot. The alteration in wave form could be reproduced by substitution of the operator's gloved hand with a capacitance of 47 pF. These results support the hypothesis that a rubber glove acts partly as a capacitor in series with the electric pulp tester, and will alter the performance of EPTs unless the glove is bypassed electrically.

Review of pulp sensibility tests. Part ΙΙ: electric pulp tests and test cavities

“…Another method is for the cuff of the dentist’s gloves to be rolled down to allow contact of the dentist’s wrist with the EPT handle and with the patient’s face. However, this may potentially compromise protection of the dentist and the patient (Treasure 1989).…”

Electric pulp testing: a review

“…Another study found that the use of gloves while performing pulp tests did not alter the readings (Anderson & Pantera 1988). Latex gloves act as a capacitance, altering the electrical output from the EPT (Treasure 1989). Current advice is that gloves can be worn, providing the patient completes the circuit by holding the metal handle of the EPT probe, or a lip clip is used (Kolbinson & Teplitsky 1988, Cailleteau & Ludington 1989, Guerra et al.…”

The assessment of pulpal vitality

“…In a recent study by Booth and Kidd (1988), the use of rubber gloves prevented the functioning of one type of pulp tester, but gave a higher reading with another. Treasure (1989) has shown that the glove acts as a capacitance. The current flow can be altered by turning a dial on the handle of the tester or, in the case of more recent electronic models, the voluge is autotnatically increased with a digital readout to indicate the stimulus.…”