Mini dental crowns

I’m starting this thread because I wasn't quite sure where else to post this, but I am genuinely curious about something I stumbled upon

So, I was browsing the website for a dental clinic over in Chicago, and I noticed they offer these things called "onlays," which basically act like tiny caps for the top of a tooth when you've got worn enamel or maybe a tooth that’s been shortened from grinding or bruxism. The idea is that instead of having to shave down the entire tooth, they only work on the specific damaged area by creating a little ledge, which saves so much more natural tooth structure and lowers the risk of the tooth failing or the nerve getting irritated from all that drilling required for a standard crown. Honestly, doesn't that sound way better than just going for a full-blown traditional crown?

Does anyone here happen to know enough about this to explain it to a layman like me, and would you say it's actually a solid option to go for?

I went ahead and grabbed a few images from that clinic's site to show what I mean

http://imageshack.us/a/img198/8297/fs1.JPG

http://imageshack.us/a/img443/2640/pv4p.jpg

http://imageshack.us/a/img15/3299/0oup.jpg

http://imageshack.us/a/img706/5295/gdrb.jpg

Is there really not a single dentist wandering this forum who’s willing to weigh in on this? 😲 😕

Those back teeth look like partial crowns or maybe onlays/overlays—nothing out of the ordinary. As for the front ones, they might be minimally invasive, but you’re going to end up shattering them if there isn't an occlusal analysis performed and bruxism managed. Personally, I stick to traditional crowns; they've actually been proven to work.

I’ve actually never even heard of dental overlays before! 😲

It honestly sounds like a pretty solid way to handle my worn-down molars and those front teeth—specifically the canines, assuming they have enough structural integrity to hold some kind of ceramic. My main goal is to fix the uneven, chipped edges from all the wear and tear while also adding a little length back to my front teeth. I’d ideally love to just go with standard Emax or zirconia crowns, but the thought of grinding down perfectly healthy teeth just because of some chipping feels totally wrong. Plus, I imagine getting veneers would be a whole thing where I'd have to get them done all in one day, right?