Hello Sir ! Since you have not mentioned any presence of Pain or Sensitivity ( From drinking cold water or Hot tea). I am not able to determine the seriousness of your condition.
Next Steps
1. You probably just need to refill the tooth with new material.
2. The Dentist you consult must take an Xray to determine the Vitality of your tooth ( How alive is the tooth)
3. Also make sure to ask for Composite Material as this is best available material and will not Break easily.
Health Tips
Warning : If you have a Nonvegetarian Diet or when eating Hard foods like Badam, please dont chew food on the side of the Restoration (Filling) for the first week after Treatment.
Always get a routine check up at a dentist every 6 months after your Filling ( This is Must).