I keep saying this over and over. If you look the the Walking Dead Wiki under zombies, it cites a letter response where Kirkman refuses to confirm the nature of the zombie. He only says that nothing is transmitted through the bite, it just becomes an infected wound in the way that any other wound would fester and kill you in a non-sterile environment. Since everyone dead turns into a zombie, you die and reanimate.
The interesting question here is - if you controlled the situation entirely, cleaned a zombie's mouth, disinfected the wound and cleaned everything perfectly, would the bite still kill you? Dale has avoided turning because of an amputation, so it's not a supernatural event. You have to die by physical means, it's not simply triggered by the bite. My theory is yes, a perfectly controlled disinfected bite would not turn someone. But until Kirkman gives an example of a shiny toothed zombie who bites someone in a newly refurbished hospital, we won't know.