The Magic of Crown Lengthening Surgery
Crown Lengthening Surgery allows you to deliver an extended variety of restorative options and allows your patients to keep their teeth for longer. It can help transform unrestorable teeth to restorable.
The following blog takes you through a step by step journey of how we were able to save Beryl's tooth using crown lengthening surgical techniques...
Subgingival Cavity... Cervical Root Resorption
Our patient presented with a concealed subgingival lesion. It was completely submerged below the gingival margin that it could have easily been missed if the area wasn't explored with a probe. Plaque accumulation at the crown margin did however give us a clue that something may be going on!
It was decided to remove the bridge pontics and the patient was advised to improve their oral hygiene. Soon after, the gingival inflammation settled a little and the lesion started to become more visible. On probing the underlying dentine was hard indicative of a cervical resorption lesion. The only possible option to save the tooth was to undertake a crown lengthening procedure to expose the lesion. We could then make an assessment of the prognosis and restorability of the tooth.
Raising a flap...
After raising a flap we were able to directly visualise the lesion. It was indeed non-carious. We can see that the bone crest to lesion distance was 1.5mm which is too short to enable a healthy biologic width. Biologic Width is the distance from the tip of the bone crest to the base of the pocket/sulcus. It comprises connective gingival tissue and a junctional epithelium. It is estimated to be somewhere between 2-2.5mm.
Restoring the Biologic Width
Osteoplasty was done to increase the distance between the bone crest and lesion margin to 3.5mm. This is more than enough to allow for 2.5mm of biologic width, 0.5mm for sulcus depth and 0.5mm of tooth tissue between the lesion margin and the gingival margin.
Since the amount of keratinised tissue around this tooth was already decreased care was taken to prevent any soft tissue loss. Instead a releasing incision was done to allow apical re-positioning of the flap.
After healing was complete (6 weeks) we were able to remove the crown and fill the cervical lesion as a part of a new core. New crown margins were defined for a PFM crown. It is important to allow 6 weeks for adequate soft tissue healing before starting restorative procedures. This includes any procedure which may require the use of a rubber dam or impressions. If the tooth is in an esthetic location it is prudent to wait for 6 months to allow adequate maturation of the tissues before placement of the final restoration.
A milled PFM crown was made to incorporate a mesial rest seat and palatal guide plane to allow the construction of a co/cr denture.
This is a perfect example of how crown lengthening surgery can help you as a dentist to deliver results which are otherwise not possible. We were able to transform this patient's upper molar to a functioning denture abutment which initially was deemed to be unrestorable.
For full pictures and steps taken during this case visit our cases gallery.