Healing a tooth is likely to take a number of years.
The teeth depend on the kidney energy which is slow moving.
Depending on your age and sex, there are kidney maturity cycles upon which you could rely to resolve the issue, occurring every 8 years for men and 7 years for women, starting at birth.
This is why menstruation typically occurs around 14 years old in women (obviously this is approximate) and puberty reaches full height at 16 for men (again, approximately).
Subsequent cycles up to around the early to late 30's are growth cycles and following on from that cycles of decay (typically and depending on constitution, lifestyle and diet).
If you are close to one of these cycles, hit the tooth hard with magic to heal the cavity and if you are some way from it, then you may need to apply a more patient approach.
For a strong reference point to the end of the most powerful kidney cycle in both sexes (the 4th in women and the 3rd in men), this coincides with the first saturn return.