原创 No-drill tooth repair: NVM in the dentist chair

Teeth may soon be repaired without the drill, so dreaded by some, as a new technique has been developed at King’s College London.

It is called electrically accelerated and enhanced re-mineralization (EAER), and the inventors claim that it accelerates the natural movement of calcium and phosphate minerals into the damaged tooth. The technique employs a two-step process. First, the damaged area of enamel in the tooth is prepared, and then tiny electric current pulses are used to move the minerals needed for repair into the repair site. It is currently in development, and its developers suggest it could be available for general use in about three years.

To those of us with an interest in non-volatile (NV) memory, the process strikes a chord. The movement of material by electro-migration is a bane to developers of some types of emerging non-volatile memory, and the very driving force for others.

The building of links, usually conducting, by electro-migration-driven movement, by electro-chemical means (e.g., plating), by electro-crystallization, or by electric field, in a manner that can be reversed, are now all part of the emerging NV memory mix. Those same effects can also appear as reliability problems by shortening the life of some types of memory device as well as other solid-state devices.

The similarity between this new emerging dentistry and NV memory technology is illustrated in the two cross sections shown in the figure below. On the right-side is a cross section of a generic NV memory with the active material between two electrodes (green). The conducting link required to write the memory to one of its logic states grows from one electrode towards the other.

On the left side of the figure is the cross-section of a tooth undergoing repair with the electric pulses. The repaired tooth material is growing into the active material. The active material (shown in pink in the tooth cross-section) is what must be applied as part of the preparation process described as the first step. This will also need to have a sort of electrode in contact with it in order to apply the electric pulses. Unlike most non-volatile memory, the material deposited as the repair does not have to be conducting. But the pink preparation material will need to be (unless the process of moving the material is electric field driven, in which case it could be dielectric and more insulating). In the figure, we have assumed that a ground link to complete the circuit is through the body and gum.

Clearly, the dentists and their patients do not require the growth to be reversed, so perhaps in an electronics industry analogy, this process should be more accurately classified as one-time programmable memory (PROM). In any case, it is certainly an interesting development.

A new company named Reminova, based in Perth, Scotland, has been set up to commercialize the research and is in the process of seeking private investment to develop the EAER technology. It is the first company to emerge from the King's College London Dental Innovation and Translation Centre, which was set up to take novel technologies and turn them into new products and practices.

Ron Neale is an independent electrical/electronic manufacturing professional.