interferon itself does not destroy the teeth. the constant dry and warm mouth can certainly cause some cavaties. More than likely, the HCV over many years is the true culprit of the teeth issue...i had bad teeth and bones all my life. i did treatment and only lost one tooth, but, it had a big hole in it to begin with.
since treatment (post 4 years now) i have not had one cavaty. i have even lost a filling and had the hcv been active, i'd of lost the tooth a long time ago. i've been letting it ride for three years and still no further decay. i am purposely doing this to prove all of what HCV can do to a body and what it can't after treatment.
HCV resides in every tissue in your body, chances are, like a said before, your husband probably had issues before treatment...and yes, the treatment can certainly aggrivate the hcv to the point of not being able to handle the treatment. It exaborates the sides of the actual virus. JMO, but I can certainly be safe in saying, many others who have done treatment can attest to this issue.
how is your husband doing?