Endodontic Resident Medical University of South Carolina Charleston, South Carolina, United States
The electronic pulp tester (EPT) has been used in pulpal diagnosis for more than half a century. The accuracy is questioned due to the high percentage of false negatives. Vitality Scanner (VS by Kerr, USA), the common model used in the US, is no longer in production. There is no current literature examining the accuracy of the new available models: the Digitest 3 Vitality Tester (DVT by Parkell, USA), and the C-Pulse Pulp Tester (PPT by COXO, China). To evaluate their accuracy it is important to first understand the basic physics of these units.
Objectives: Examine the voltage waveforms of each EPT unit across a 100k ohm resistor using an oscilloscope. Findings: The VS produced bursts of eight negative voltage pulses within 240 milliseconds (ms) every 500 ms, (-14 V peak amplitude) which increased incrementally in negative peak amplitude by small amounts over time (additional -0.7 V every second). The DVT produced bursts of eight oscillating voltage pulses within 125 ms every 250 ms, (8 V peak to peak amplitude) which increased incrementally in peak to peak amplitude by large amounts over time (additional +10 V every second). The PPT produced bursts of three positive voltage pulses within 8 ms every 600 ms, (+14 V peak amplitude) which increased incrementally in peak duration by small amounts over time (additional 20 microseconds every 1.6 seconds).
Conclusions: The amount of energy delivered by the different voltage waveforms and its rate of increase could affect the clinical accuracy of the three EPT units.
