It is the treatment applied for the partial absence of teeth or in cases where healthy tooth tissue is not adequate for performing a filling. It is disadvantageous for people who are allergic to metal. It poses an aesthetical problem in the course of time among people whose gums are liable to recede. It is suggested for economic reasons, very short teeth and long-standing absence of teeth.
The opaque applied on the metal in order to cover its colour at the production stage decreases the light permeability coefficient of the porcelain and creates a stained appearance under white light.