What is a tooth filling?
To treat a cavity your dentist will remove the decayed portion of the tooth and then 'fill' the area on the tooth where the decayed material once lived. Fillings are also used to repair cracked or broken teeth and teeth that have been worn down from misuse (such as from nail-biting or tooth grinding).
Do fillings make teeth weaker?
Composite fillings fill the cavity and bond directly to the patients teeth. Because of this, the tooth and filling work together. This means that composite fillings do not make your teeth weaker, but they may make your teeth stronger.