I had to do a NIH R21 proposal on this topic. There are no substantial websites on the topic if you're delving into anything more than just a survey. Your best bet is to go on pubmed/medline and search for 'em. Look for review articles, and then go look on their bibliography and read the individual research articles. There is a textbook, very expensive though, called Laser-Tissue Interactions (I think). It is very hard to read if you're not an engineer, but it seems to be a gold standard on the topic.
be weary of overly optimistic efficacy reports, cause there is a lot of fluff/crap/commercially influenced data out there...
I am not enthusiastic and optimistic about the use of lasers in dentistry at this point.
lasers used in perio scaling is controversial at best, 2 caveats is that laser-ablation results in a dentine smear layer (with consequences thereof really unknown) and the fact that at the point of ablation tremendous shock waves are propagated throughout on the orders of 100 bars or so! which defeats the point of less-invasive scaling/cleaning.
currettage ablation has been deemed by the ADA as stupid and pointless.
and let's not forget the first FDA approved laser that supposedly was going to herald in an era of drill-less dentistry. It's very limited on the types of cavities it can be used on, and the developer/owner of the product, Collette Cuzeen, is serving jailtime for fraud in connection to the company that makes and markets the device!
I'm not saying that lasers have no place in dentistry, but simply that as of now, a lot of the optimism and hype is jsut that... hype.