Tooth does not posses the regenerative ability, found in most other tissues there-fore once enamel, dentin is lost as a result of caries, trauma or wear, this will require crown to re-establish form and function, which will require tooth preparation, so careful attention should be given to all these procedures, such a way that the further procedures are made comfortable, the principles of tooth preparation can be divided into three categories Biologic considerations which affect the health of oral tissues,mechanical considerations which affect the intergrity and durability of the restoration esthetic consideration which affects the appearence of the patient, metal ceramic crown is indicated in teeth that require complete coverage where significant esthetic demands are palced on the dentist, metal ceramic crown are more durable and better marginal fit than the metal free ceramic crowns, the metal ceramic crown combines the largedegree of strength of cast metal with esthetics of all ceramic crowns compared to all ceramic restoration the metal ceramic crown may have inferior esthetics but can be used in higher stress situations or teeth which does not provide support for all ceramic crowns