Front teeth that have fillings can often appear to be different shades especially if they were filled at different times and have discoloured depending on what we eat and drink. Veneers will be able to mask this and are very colour stable especially if they are made of porcelain.
Heavily filled teeth may also need to be strengthened so your dentist may recommend porcelain crowns which will not only be a better shade but also be more durable.
Teeth whitening will not brighten existing crowns and fillings. Your dentist will be able to advise the most suitable solution to your problem.
