Crown lengthening is a procedure to increase the length of a tooth. There are many situations in which a tooth may become too short, including tooth wear, acid erosion, decay and repeated fillings over many years. When a tooth becomes too short, it becomes difficult for new fillings or crowns to be retentive. By trimming away some of the gum around the tooth, its length can be increased to improve the restorative prognosis. Crown lengthening may also be done to improve the appearance of upper front teeth if it they become too short.
The following is an example of crown lengthening of a tooth in which decay has extended the cavity under the gum. In this situation, it is difficult for the dentist to place a filling that fits well. The second image shows how crown lengthening can expose the margin of the decay which will then allow a filling to be placed with precision.
The next case illustrates crown lengthening to approve the appearance of front teeth. As can be seen from the first image, the 2 upper central incisors are short and very square in outline. The second image shows the same case 5 years after treatment. Crown lengthening has increased the length of the 2 teeth by relocating the gum line to a higher position. The 4 upper front teeth were subsequently restored with porcelain veneers, which has resulted in a significant improvement in the appearance of the teeth.