Flexible bond. I imagine optics want resilience, but also a bit of rigidity. The stuff used in LambdaPro laser heads is very rigid. Too much, maybe. RS, as ever, haven't got any. RS are great but too often when I search for stuff they haven't got it, and that happens over the course of years for stuff other people have recognised a need for.
The dentist who told me about it said it wasn't fussy. I suspect many of them work on a wide range of short wavelengths, and as shortwave light gives the clue that high energy is needed, perhaps that's the problem, getting enough of it in. Assuming it has to absorb it to work efficiently, that means it has to penetrate something that is already trying to block it. Andy, how strong were your laser pointers?