I am in my late 50s. i recently had surgery, and subsequently took several antibiotics for a staph infection. my teeth grayed significantly. im sure its the dentin. i have tried bleaching, to no avail. my teeth are clean and polished. help?

In adults, EXTRINSIC or SUPERFICIAL DISCOLORATION of the teeth has been reported with both tetracycline and beta-lactam antibiotics. This doesn't involve the tooth dentin but due to formation of deposits on the tooth surface. This side effect is rare and mostly reversible. The discoloration can usually be removed by careful brushing or professional cleaning. You should visit a dentist.

The enamel is the outer layer of your teeth, the dentin is underneath. Try laser bleaching, it is more penetrating. Most bleaching techniques are effective if done right.