High quality scientific studies have shown that after resolution of readily detectable HPV (either due to treatment or as part of the natural course of the infection) there may be residual HPV DNA present in tissue when studied by special research tools.  In some instances, but not all, this residual DNA may become detectable again after being non-detectable.  As a generalization, the longer the interval since the initial infection became non-detectable, the less likely it will recur and be detectable in the future.  In your specific case, your treatment sought to remove the infected tissue and the fact that there has not been a detectable recurrence in the past 15 years makes it unlikely that it will recur in the future.  Your risk of developing cancer are very, very low and should it return, your regular PAP smears should detect it early, allowing management.

Sorry there are not precise percentages I can provide you but hope this reply will be helpful.  Your chances of recurrence are very, very low and you are doing the right thing in terms of ongoing management.  I see no reason for other testing than what you indicate you are already doing.  EWH

Regarding oral infection, it would assume all is OK unless you begin to experience persistent hoarseness, at which time I would ask your doctor to evaluate.  Otherwise regular dental exams and not smoking are the best practice for dealing with the VERY low risk of oral cancer.  The vast majority of people clear their oral HPV without therapy.  Limited data suggest that even with established infections the vaccine may help as well.

Give your plans for regular dental care and as a non-smoker I would really not worry.  

We provide up to three responses for each client's questions.  This is my 3rd response.  Thus this thread will be closed shortly.  Take care, please don't worry.  EWH

With this reply, I will now close the thread.  IT is unlikely that we will have further advice or suggestions beyond what we've already shared. EWH