EBME Forums Forums Maintenance Technical Assistance Testing tooth pulp tester

Dear Sir/Madam,

Hope this thread finds you well and in good health,

I have two different pulp testers for checking, which are Parkell: Digitest II and D626D. I found an academic paper on page two fig.2(attached). Describing how he tested three different pulp testers at 2Megahom resistor load, gradually increasing the voltage/current till 250V.
Then, I connected a 2megaohm resistor between the pulp tester(EPT) tip and the wire from the machine and measured the signal across the resistor with a scope(x10 probe). The two EPT are operated at there maximum output and taken two screenshots of the scope attached(Digitest II, and D626D). As I deduce(If I am not wrong) the output signals of the EPTs are similar but differ a little bit the amplitude.

Kindly, I need an advice or opinion if the outputs of the machines acceptable?

Thank you in advance for your advice,

Yes; it's encouraging that the outputs are so similar.

If I remember rightly, the pulp tester is basically a big nerve stimulator (a bit like TENS) ... that's "big" in terms of pulse amplitude (voltage).

There should be a patient response push-button; so you shouild check that out as well.

If I were you I would sketch (or photo) outputs at various settings to be able to compare when you check "next time" (PM, or whatever).

Have you been able to check that the user has been happy with performance? ... "tingling" sensation by the patient?

I was wondering why Wang et al chose a 2 Meg load ... I would like to see what results would be with (our old friend) 1 K. But then I found this in a Users Manual for another tester (so it's yet another case of Ohm's Law):-


Extract from the Digitest Users Manual:-

Max AC Component Amplitude:- 500 V peak-to-peak

Peak Output Current Maximum:- 250 uA

Pulse Durations (Packet Width):-

High (3 bars): 60.5 ms
Medium (2 bars): 100 ms
Low (1 bar): 124 ms

Dear Geoff Hannis,

Million thanks for your kind help, your advice was really help full,

I truly appreciate,

Saviour Muscat