ABSTRACT: Sufficient crown height is necessary for the placement of crown .Inorder to place a crown it is necessary to lengthen the height of the crown by gingivectomy. Appropriate amount of crown structure is necessary for crown placement because retention is obtained by the crown structure which is remaining so that the crown placed remains undisturbed.The concept of crown lengthening was first introduced by D.W. Cohen (1962)2 and is presently a procedure that often employs some combination of tissue reduction or removal, osseous surgery, and / or orthodontics for tooth exposure. The amount of tooth structure exposed above the osseous crest (about 4mm) must be enough to provide for a stable dentogingival complex and biologic width to permit proper tooth preparation and account for an adequate marginal placement, thus ensuring a good marginal seal with retention for both provisional and final restorations.