Blurays are extremely robust, more so than CED or VHD, even though they are caddied.
The coating on Blurays I have owned so far is phenomenal, my HD-DVDs are mostly unplayable now, but my blurays all clean up to be completely pristine, even the ones the kids have strewn all over the floor.
Baby teeth and slobber have so far proved no problem for the BDs. I do remember my youngest sticking cake in the VHS slot of the player though. It didn't handle that very well...