Crown otherwise known as "a cap" is a dental restoration which covers the entire tooth.
It may be required in case of :
1) Root canal treated teeth.
2) Broken down old or very large fillings.
3) Fractured, chipped or sensitive teeth.
4) Discoloured unesthetic teeth.
5) Large old silver fillings
Bridge is used to replace one or several teeth. A bridge is placed in case of missing tooth/teeth with teeth on either sides of the open space as support. Bridge is fixed and cannot be removed by the patient.