According to The Guardian scientists from the UK have developed a tool to repair cavities without filling or injections.
The new treatment, called Electrically Accelerated and Enhanced Remineralisation (EAER), accelerates the natural movement of calcium and phosphate minerals into the damaged tooth.
A two-step process first prepares the damaged area of enamel, then uses a tiny electric current to push minerals into the repair site.
I found this claim very interesting. I went to the manufacturer's website to learn more about how this works and saw this:
Our invention accelerates the mineral uptake but also drives the mineral right to the deepest part of the subsurface lesion and rebuilds substantially all of the damage. For this reason we called it Electrically Assisted Enhanced Remineralization (EAER). This uses a tiny electrical current of a few micro Amps (a millionth of an Amp) that is too small to cause any physical sensation in the patient, to help accelerate mineral ions deep into the tooth enamel and providing a complete rebuild of the caries affected tissue rather than just a remineralization limited to just the enamel surface.
Based on my limited research it seems like this tech uses ultrasound-driven iontophoresis to transport minerals into the tooth to reverse tooth decay.
Is there any evidence that such an intervention might reverse tooth decay? The only other use of iontophoresis I found was to treat hyperhidrosis so there's limited information about this idea.