Why aren't there anything dentists use to paint over/protect teeth yet?

Great idea, but unfortunately, it's a lot harder to do than it seems.  There is no paint currently on the market that is harder than enamel, once it dries.  And like most paint, if it is cracked or begins to peel, it would likely need to be scraped off completely, before being redone.  Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMD

Tried and failed.  So far.  We DO have dental sealants....  If you can invent it, you would be very rich, it just isn't that easy. Why don't we all have jet packs or hover boards like seen in Back to the Future?

Well, the STRONGEST BODY PART is the enamel of the tooth.  Stronger than bone, cartilage and muscle!However, almost everything wears out with time and usage, even teeth.Dentists have been utilizing dental sealants for decades, but that is only a polymer resin (type of plastic) and wears down even easier than tooth enamel.Fluoride makes teeth less likely to decay, and works well when applied by the dental hygienist after the teeth have been cleaned.  Systemic fluoride (pills you take, or in water you drink), has some shortcomings.  Many think it may be toxic, and certainly we have seen many people have permanently stained teeth from systemic fluoride (either white, brown or yellow spots or bands).You are right, something to strengthen teeth is still something we need, but nature has done a pretty good job.  Maybe the answer is just to take care of what you've got.  Good oral hygiene to prevent tooth decay and gum disease.  Watch your diet, avoid foods that help cavities form, and hard food that make break weak teeth.