_hm:- Yes you make a good point, nerve damage has to be a consideration, I think it will depend on the mechanism. If it is electromigration then I would expect there would be current localization and high current density at the point on the surface of the tooth where the new material (mineral/clacium) is being driven in and much lower along the return path. If the mechanism is more plating like (electro-chemical) then the current density over a large area of the tooth surface would expected to be lower. Until we get the facts we have to consider the possibility,(continuing my NV memory analogy) that they have created a lateral structure wiith some sort of coaxial electrode where only current across the surface of the tooth is involved. Here is a speculative figure.
_hm:- I understand the regulations in the USA and UK, Europe are different and will certainly have some impact on the timing once the procedure is fully developed and proven. To make any judgement of our own we need to know a few quantitative details with respect to: the voltage, the current, the pulse width, shape and repitition rate. How is the contact made to the active material solvent or electrolyte and how long the process takes. At some point we assume the pulses are carried by a metal to a hard or soft electrode (cloth soaked in electrolyte)either carrying the electrolyte or in contact with it and in contact with the tooth. What is the electrolyte?
At least there will some serious work for designers in the electronics industry to make an electric pulse generator and prove that it is safe and reliable enough to put into the patients mouth. That proof will be a serious part of the qualification step for whatever the country the device is used. I will attempt to find some answers to some of the questions in the next few days. I understand a formal work will be published in the near future.