I think it all makes a lot of sense. But is it safe?
[wakes up, so still a little zombie]
This looks neat. Likely to have much better accuracy than a human dentist, and can use hyperspectral vision (due to lack of constraints of human vision) to see the reflective and fluorescent spectral characteristics of damaged/intact enamel and dentin.
There are devices out there that can image teeth and assess their state. A human has to look at a display and then follow the image. A robot can go directly via the image, with way higher accuracy.
Then there are the possibilities for soft tissue surgery/biopsy. Illuminate tissues with 400 nm light, watch in the green band, and you can see anomalies that would be otherwise virtually invisible.
You can also see fluorescence of some porphyrine-class compounds associated with certain bacteria.
The robot does not have to be just a CNC mill. It can also deposit materials into the formed cavity - possibly even live cells in a matrix to regenerate the dentin. Another possibility could be removal of the very outer layer of enamel and replacing it with a synthetic resin or ceramics, possibly with superhydrophobic/superoleophobic coating - voila, no more biofilms.
Just some thoughts…
Now I’m imagining scrambled eggs constantly bouncing out of my mouth when I try to eat them. Or ice cream.
Just the teeth, not everything. 
Imagine never having anything stuck to your teeth again. 
By the look of it, it’s controlled by the dentist remotely. So more like a small scale Da Vinci “surgical robot”. So as safe (or not) as one of those. They aren’t that common but are approved for human use.
Neat delta motion control system for the drill head though. 
WTF, Dr. Mengele would love this!
Dr. Mengele?
I reckon dentistry was probably too tame for Josef the Sadistic Nazi Bastard. Lets not do him the courtesy of using a professional title he didn’t deserve.
Righteous my main man or woman!
Its perfectly safe.
It is a cute, completely prototype-free animation. The basic idea seems sound, even if the size of the device seems un-realistic. However, recently other types of treatments for decay have seemed promising, ones obviate the need for the precision mapping envisioned here in favor of laser or abrasion that affects the soft decay rather than the hardened enamel.
Nothing is perfectly safe, but I’d say this has a pretty good chance of being way safer than a dentist doing it manually.
Which cannot be used to everything; e.g. when you need to grind down the whole tooth to put a crown on top of it.
I for one welcome our surgical robot overlords.
True, but the theoretical micro CNC mill touted in this animation isn’t being sold as prep for a crown, either. it is too small and doesn’t have sufficient freedom of movement.
The bigger one later in the animation does. Also, think about it as Mk.1, or a prototype, or a development stage device. I see a big potential here.
By the look of it, it’s controlled by Lara Croft remotely. If you are not in the Illuminati, it is probably safe.
