Crown lengthening
![A palatal view of a maxillary premolar during a crown lengthening procedure.](/Images/godic/202501/07/Crownlen1344.jpg")
![Biologic width is the natural distance between the base of the gingival sulcus (G) and the height of the alveolar bone (I). The gingival sulcus (G) is a little crevice that lies between the enamel of the tooth crown and the sulcular epithelium. At the base of this crevice lies the junctional epithelium, which adheres via hemidesmosomes to the surface of the tooth, and from the base of the crevice to the height of the alveolar bone (C) is approximately 2 mm.](/Images/godic/202501/07/Periodontium.svg1344.png")
![These two X-ray films depict the teeth of the upper right quadrant. In the upper film, there is a tooth, #5, with a large, defective DO composite restoration. The lower film depicts the ideal bone level after a crown lengthening procedure has been completed, as well as the margin of the prosthetic crown in relation to the reduced height of bone. Note: this is a dramatization of the procedure. The lower film is a digital manipulation of the upper film, and not an actual film of the teeth after a crown lengthening procedure and crown cementation have been performed.](/Images/godic/202501/07/-5-CL-before_and_after1344.jpg")
Crown lengthening is a surgical procedure performed by a dentist to expose a greater amount of tooth structure for the purpose of subsequently restoring the tooth prosthetically. This is done by incising the gingival tissue around a tooth and, after temporarily displacing the soft tissue, predictably removing a given height of alveolar bone from the circumference of the tooth or teeth being operated on. While some general dentists perform this procedure, others frequently refer such cases to periodontists.