Are tooth filling, dental veneers, or dental braces obstacles to perform wudu and ghusl?
It is permissible to have teeth filled or coated. Filling, coating, dental braces, implant, or fixed denture do not interfere with the validity of wudu and ghusl. However, the removable/unfixed dentures need to be removed while washing mouth ( mazmaza) in ghusl.
After having teeth filled and coated in order to protect the filling, the outer parts of filling and coating are considered as the outer part of the teeth. Therefore, when one washes his mouth, it is considered that he washes his teeth, too. For this reason, a person may have his teeth filled or coated and then perform ablution and ghusl to worship. It is possible to have the said treatments when one is not in the state of ablution or in the state of ceremonial impurity (janabah) or in menstruation period.
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS