Hello,
It is a valid question.
It would depend on 3 factors
1)What material was used for filling. There are filling materials used to help in remineralization of the affected part.
2) How good a seal was achieved there is no leakage, so no nutrients reach the bacteria.
3) How well oral hygiene is maintained?
Next Steps
You can get answers for the first 2 questions from your dentist.
The third would be in our hands, proper brushing, flossing, regular follow ups will help
Health Tips
Use proper brushing techniques, flossing and regular follow ups and xray with the dentist.