Despite the name, crown lengthening does not touch a dental crown and does not make a tooth longer. It moves the gum, and often a little of the bone beneath it, further down the tooth so that more of the tooth you already have is exposed. Dentists recommend it for two quite separate reasons: to give a damaged tooth enough height above the gum to be repaired, or to change how much gum shows across the front of a smile.
A tooth needs something to hold on to
Most people meet crown lengthening when a back tooth breaks or decays down to, or just below, the gum. A filling or crown can only seal and grip onto sound tooth. If the edge of the damage sits under the gum, the dentist cannot keep the area dry while bonding, cannot see the margin clearly, and the finished restoration would sit in a spot that is very hard to keep clean.
A crown also lasts better when it can wrap around a band of healthy tooth above the core, which dentists call the ferrule. A literature review by Juloski and colleagues in the Journal of Endodontics (2012) concluded that a ferrule of about 1.5 to 2 mm improves the fracture resistance of root-filled teeth, and that a partial ferrule is better than none.
There is a second limit. The gum and bone are joined to the root by a strip of soft tissue attachment just above the bone. If a filling or crown edge is pushed down into that zone, the gum around it tends to stay inflamed and can recede unpredictably. Crown lengthening lowers the bone and gum together so the new restoration edge can sit on sound tooth without invading that attachment.
When it works, this can be the step that lets a badly broken tooth be kept rather than removed. Our article on a tooth broken off at the gum line explains how dentists weigh that decision, and the choice can also overlap with the questions covered in root canal versus extraction.
When the concern is how much gum shows
Some people have front teeth that look short or square because gum covers more of the enamel than usual. The teeth themselves may be a normal length. In those cases a measured amount of gum, and sometimes bone, can be removed and reshaped so the gum line sits higher and runs more evenly from tooth to tooth.
Not every gummy smile has this cause. Extra gum showing can also come from an upper lip that lifts a long way, from the way the upper jaw has grown, or from teeth that have over-erupted. Each of those calls for a different approach, and removing gum will not fix a lip or jaw problem. That is why a gummy smile assessment looks at the lip at rest and in a full smile, the length of the teeth, and X-rays of the bone. Our guide to gummy smile treatment covers the full range of causes and options.
Cosmetic crown lengthening is often one stage in a larger plan with veneers, bonding or crowns, as part of a smile makeover. If only a small amount of gum needs to come away and the bone is far enough below, gum contouring of the soft tissue alone may be enough.
On the day
The area is numbed with local anaesthetic, so the procedure itself should not be painful. For a single tooth, the gum is opened on either side, the bone edge is trimmed and smoothed by a small, planned amount, and the gum is laid back at its new level and held with fine stitches. Cosmetic cases follow the same principle across several front teeth, with careful measuring so the result is symmetrical. Appointment length depends on how many teeth are involved.
The procedure may be done by a general dentist with the relevant training or by a registered periodontist, a specialist in gums. Complex or multi-tooth cosmetic cases are often referred.
The first weeks afterwards
Expect tenderness and some swelling for a few days. Many people manage with over-the-counter pain relief, taken as directed, and return to work the next day. The gum will look raw and uneven at first.
Brush the rest of the mouth normally and clean the surgical area exactly as you are shown, which often means a very soft brush or a prescribed mouthrinse for a period. Soft food on the other side for several days, no smoking, and avoiding prodding the area with your tongue or fingers all help healing. Stitches, if they are not the dissolving kind, are removed at a review visit.
Why the final crown or veneer waits
The gum keeps changing position for months after surgery. In a 12-month study of 84 teeth in 30 patients (Pontoriero and Carnevale, Journal of Periodontology, 2001), the gum margin crept back up the tooth during healing, and this regrowth was greater in people with thick gum tissue. A temporary crown is usually worn in the meantime.
For that reason dentists wait for the gum to settle before making the final restoration. The wait tends to be shorter for a back tooth, where a millimetre of change is less visible, and longer for front teeth, where the gum line is part of how the smile looks. Your dentist will set the timing for your case.
When it may not be the answer
Removing bone around one tooth also removes some support, and it can expose part of the root and change the gum around the neighbouring teeth. If a fracture runs very deep, the root is short, or the tooth sits close to a sinus or nerve, lengthening may leave the tooth with too little support to be worth saving. Moving the tooth up with orthodontic extrusion is an alternative in some cases, and the same 2012 review suggested it should be considered ahead of surgery when almost no tooth is left above the gum. Sometimes replacing the tooth is the more reliable option. These trade-offs are why the decision is made with X-rays rather than from how the tooth looks.
Cost depends on the reason and the number of teeth
Fees vary with how many teeth are treated, whether bone needs reshaping, and who performs the surgery. The crown, veneers or filling that follow are charged separately. As a guide to the second stage, a typical Australian market range for a crown is about $1,500 to $2,500 per tooth (not a Lumi fee). Once the plan is clear, you will usually receive a written treatment plan, often by email, and you can see our current offers for consultation details.
Questions we are often asked
Is crown lengthening the same as gum contouring?
Not quite. Gum contouring reshapes soft tissue only. Crown lengthening usually also recontours the bone, which is needed when the gum cannot be moved without crowding that attachment zone above the bone.
Will the gum grow back?
Some creeping back of the gum during healing is normal, particularly with thick gums, which is why the final restoration is timed after the tissue settles. Good cleaning and regular reviews help keep the result stable.
Can a single broken tooth be treated?
Yes. Functional crown lengthening on one tooth is common, provided enough root and bone support remains afterwards.
Will my teeth feel sensitive afterwards?
Exposed root surfaces can be sensitive to cold for a while. This often eases with time and a sensitive toothpaste, and the final restoration usually covers much of the exposed area.
If you have been told a tooth needs more height before it can be crowned, or you would like your gum line assessed, we can examine the area, take X-rays and explain the options and the likely sequence of treatment. Contact Lumi Dental at Melrose Park to arrange a visit, or read our comparison of crowns and veneers and our guide to inlays, onlays, crowns and fillings.
This article is general information and not a substitute for an individual dental assessment.
