Toby: That’s certainly a scary-looking collection of tools.
Ester: Yes, some of them do look quite menacing, don’t they?
Toby: Is that titanium? The drill handle?
Ester: Um… yes.
Toby: I’m an engineer, that’s why I, am…
Ester: Oh, I see. Yes, titanium’s great. It’s expensive, obviously, but very light. That’s the advantage. Ideally, you want it to be lightweight, to give better control.
Toby: Nn…
Ester: These are the most impressive things, though, the burs on the end. The latest ones can rotate at over half a million revs per minute.
Toby: Nn.
Ester: They are coated with tungsten carbide, which I think is one of the hardest materials in existence, isn’t it? Along with diamond. That’s also used.
Toby: Nn.
Ester: The requirement is abrasion resistance, of course. Obviously, they need to be very durable. And you don’t want them snapping either. The last thing, you want is brittle material. Apparently, that was the trouble they had in the past, making the bur tough enough so it didn’t break. I think part of the problem was heat, as well. Drilling into a tooth at high speed, you obviously get a lot of heat build-up. You need a good degree of thermal stability.
Toby: Nn.
Ester: See what I mean? You can actually smell burning. And that’s after a few seconds. Imagine the heat build-up after several minutes.