Crown Lengthening

When restoring a tooth with a crown, we strive to have at least a 2mm ferrule for proper retention. A ferrule can be thought of as the surface which the crown engages the tooth. Sometimes when there is little tooth structure left, a crown lengthening procedure can be done to gain the necessary tooth structure needed for the tooth preparation. The procedure can be broken down into five steps: (1)Achieving proper anesthesia, (2) opening an full thickness envelope flap, (3) debridement/gingivectomy, (4)osseous reduction and (5) suturing.

Primarily, the patient is administered lidocaine with epinephrine, or a suitable anesthetic and adequate time is given for the anesthesia to be achieved. We then make an incision on the buccal and lingual aspects of the tooth being lengthened. The incision however spans from the mid-buccal aspect of the tooth mesial and distal to the target. For example, If we are lengthening #4, the primary incision is made from the mid-buccal of #3 , along the gingival margin to the mid-buccal of #5. It's important to be sure that the incision is made straight through the periosteum for the creation of a clean flap. An identical incision is also made on the lingual aspect and the gingival full thickness flaps are freed from the bone using a periosteum, or curette. This step can be quite time consuming, as we want to be sure to clear all interproximal tissue before initiating the osseous reduction. Next, an end cutting bur is used in the reduction of the alveolar bone surrounding the tooth. The end cutting bur allows us to remove bone, with less risk of damaging tooth structure. Once the reduction is complete, two 4.0 silk sutures are placed, introducing each from the buccal aspect of the interproximal areas.

Post operative instructions are similar to those given in the case of an extracted tooth. The patient is advised that they will be sore in that area, and may ooze some blood, which may look like more than it is actually due to the blood mixing with saliva. They should brush the area, only very gently  and avoiding flossing the area for a couple of days. Ibuprofen is recommended to control pain, every 4-6 hours as needed.