One way of treating tooth wear is by placing a crown to cover and protect the teeth and replace the lost tooth structure. However, for a crown to have a predictable long-term lifespan, then you need a minimum amount of tooth structure all the way around the tooth for the crown to sit on. This is called a “ferrule”. In cases of tooth wear, then this may not be the case, and therefore crown lengthening is needed prior to the tooth preparation for the crown.
Functional Crown Lengthening
This is a treatment that involves surgically removing excess gum tissue so that a crown restoration may fully cover the tooth being restored. By exposing more of the tooth structure, the area increases for proper fitting of the crown restoration. Depending on treatment needs, part of the bone around the tooth may need removing for more tooth surface coverage. In large cases of multiple teeth impressions and planning appointments are needed.
Suitability of Crown Lengthening
Crown lengthening is also appropriate in cases where decay extends under the gum line or in on root surface and where insufficient tooth exists due tooth wear or fracture. Scenarios where crown lengthening may not be considered a suitable treatment include poor oral hygiene, uncontrolled gum disease or in cases of excessive damage which is not salvageable.
Preparation for Crown Lengthening
The clinician or periodontist examines the patient’s oral health for suitability of crown lengthening treatment. Measurements are taken of the patient’s mouth, with an x-ray to check the length of the root, root infection and to assess the presence or extent of any decay. If the tooth is suitable for crown lengthening and patient understands the procedure, then they can book the next appointment.
In some cases, especially if it is for many teeth, or front teeth, then impressions of the mouth are taken prior to surgery. These oral impressions and images are used to create a wax crown example, which mimic the result of a tooth with crown restoration. Patients then can see what their teeth will look like after crown lengthening. If patients are happy to proceed then the appointment can be booked, or if there are any issues with the desired look then this can be altered prior to the next appointment.
The Procedure
Ensure you eat beforehand as you will be given local anaesthetic to numb the area and won’t be able to eat for several hours afterwards. The excess gums are removed around the desired tooth/teeth. Bone will then be removed to the desired measurements. Stitches are then placed to position the gums where they need to be. When you go home, you will need to be careful to not brush the area, using mouthwash as an alternative, and you may need to take painkillers for a few days. People can experience some sensitivity to cold but this is usually short lived to 1 or 2 weeks, rubbing sensitive toothpaste on the tooth at night can help with this. Usually you would attend a follow up appointment to ensure that the gums have healed well, and that you can then proceed to see the dentist for the crown preparation appointment.
Alternatives to crown lengthening
Orthodontic treatment causing forced tooth eruption – this can take several months, but is a non-surgical treatment option for those people who don’t want to undergo a surgical procedure but this also has its limitations.