With crown lengthening, both for aesthetic and retentive purposes, one of the most frequently asked questions is, "can it be done with a gingivectomy?" The answer to this question depends on two factors: the position of the bone and the amount of attached gingiva.
Everyone would like to do crown lengthening with a gingivectomy. It is much easier and quicker. It doesn't matter if the gingivectomy is to be done with a knife or a laser. The criteria are still the same.
Factor #1, Is it necessary to remove bone? By definition, if you have to remove bone to increase the crown length, then a gingivectomy will Not work. It will be necessary to open a flap. Chisels and burs won't work through the gingiva. The new lasers that remove bone may be an exception, but one has to be careful. Frequently, the teeth that require aesthetic crown lengthening are in individuals where the teeth suffered from altered active eruption, and there is a thick ledge of bone on the facial. Using a laser through the sulcus will create a crater next to the tooth in this thick ledge of bone which will not give the best aesthetic result now and may create a periodontal problem later.
Factor #2, Is there enough attached gingiva? We always want to leave keratinized, attached gingiva on the facial of the tooth. How much is open to some debate but you probably want to leave at least a millimeter. So if the proposed increased crown length requires removal of all of the facial attached gingiva, then a gingivectomy won't work. Again, it will be necessary to elevate a flap and move it apically.
So gingivectomy only works when there is lots of attached gingiva, and it is not necessary to remove bone. This is true whether the crown lengthening is for aesthetics, only on the facial, or it is for retention and involves going completely around the tooth.
So how do we measure attached gingiva and how do we determine the position of the crest of bone? We’ll talk about this in the next posting.