If you have filling, your body can't be completely normal. No matter what that filling is made of, there is one thing for sure, the most deadliest of bacteria can live under it, in an oxygen free environment where the blood can't get to it and it breeds 24/7 for the rest of your life and seaps down the throat with food, water, and air for ever doing such minor damage and waiting for the day your Immune System can no longer fight it and then it can establish your body as its host.
If the fillings are metal, then you have tripple the problems.
A tooth with a filling can never recover, if it has a root canal is is forever dead, like a stump in the woods rottening, so is your dead tooth and you know what lives on dead things!
The numbing fluids used in all operations I have read is one of the reasons why healing can not completely take place and then when you apply a metal or a plastic, that tooth is never the same.
A natural tooth has a decay normally from bad blood so full of acids that the pressures within will pop a hole out the tooth and yellow puss will push up around the tooth. Brushing does very little for tooth decay, unless it is so full of toxic metals such as flourides that it harms your Immune System enough that your body is no longer able to expell the toxins via the tooth/gums!!! The wax in the ears is the same process.
IF you fast the blood clean, tooth decay and ear wax, etc. will cease to be a problem. But like all surgeries, a dentist damaged tooth in my opinion has no way to regrow enamle.