Esthetic Crown Repair
Jon Richards DDS MS
This is an interesting case for several resons:
- The diagnosis was made much easier and definitive with the CBCT scan.
- A “middle mesial” canal was located and treated
- An esthetic porcelain-bonded crown repair was placed that virtually erased any external evidence of endodontic treatment through the new crown.
The patient was visiting from out of town and is ironically the spouse of a retired dentist. Her complaint was recent onset of pain and sensitivity to hot. The crown was placed approximately 6 months ago, and now the tooth has spontaneous pain and sensitivity to hot. Her husband recommended she see an endodontist, and I was fortunate to be trusted with her care.
Clinical exam resulted in discovering tooth #30 was nonresponsive to cold, but normal to percussion and palpation. The adjacent teeth responded normally to diagnositc testing. A CBCT was taken which revealed a periapical finding associated with the M root apex.
Conservative access is made much more possible by use of magnification with the dental operating microscope, wihch helps decrease the chance of crown/porcelain fracture. Every effort should be made to preserve dentin, even if under a crown. Careful troughing dicovered 3 mesial canals (also a huge benefit of effective use of the microscope in all phases of treatment), and 2 distal canals.
After 3 weeks of Ca(OH)2 therapy, the patient returned for completion without any symptoms. 5 canals were obturated with warm gutta percha and sealer. While still isolated under the rubber dam, the crown was repaired in our usual manner:
- scrubbing the pulp chamber to remove any remnants of sealer or debris. A celan chamber is critical for maximized bond strength
- phosphoric acid dentin etch for 30 seconds
- hydrofluoric acid porcelain etch for one minute
- phosphoric acid porcelain etch to clear debris and prepare the bonding surface
- silane over the poreclain for one minute
- dual-cure two-bottle bonding agent
- dual-cure composite resin core
- layer of light cured opaque resin
- hybrid-filled composite occlusal veneered layer for improved wear and comsetic properties
- finishing/polishing/occlusion check
The importance of a proper restorative approach cannot be overemphasized. If porcelain bonding procedures are not utilized, the polymerization shrinkage may create invisible avenues of leakage at the endodontic access margins. Restoring at the time of completion, while isolated under rubber dam and after the confirmation of resolution of symptoms, will contribute to long-term success and a much better value to our patients.
The pre-treatment and post-treatment photos of the crown show a very good esthetic result.