CHIEF COMPLAINT:
Repeated fractures of an extensive reconstruction in composite resin of tooth 11.
DIAGNOSIS:
Male patient, 45 years old, smoker, with oesophageal reflux and poor oral hygiene. Teeth 11 and 21 presented an endodontic treatment and tooth 21 was rehabilitated with a Richmond type crown done 12 years ago. Tooth 11 presented an extensive restoration in composite resin in the buccal surface bonded exclusively to dentin. The palatal surface presented acid erosion and an extensive reconstruction in the endodontic access. The clinical crown was 4,5mm height and the root had 11mm.
TREATMENT PLAN:
An endodontic crown was proposed to the patient due to the reduced dimension of the clinical crown and the (almost) full absence of enamel. Two goals to be achieved:
• Try to get some mechanical retention in the interior of the endodontic access cavity. • Do not prepare the root canal to prevent its weakness.
The endocrown should be constructed with a zirconia framework with an ‘intra-root’ and crown components, being this last one veneered with ceramics.
TEAM PLAY ‘DENTIST – DENTAL TECHNICIAN’ NOTES: After a correct gingiva retraction, a dental impression was done with a double-mixture technique. A plastic tutor was used to reinforce and stabilize the silicone inside the crown. Then, the model was created and scanned in a CAD-CAM system. The intra-coronal part was easily scanned because the walls were divergent through the occlusal surface and its extension was reduced. The design of the endocrown followed some considerations:
• Zirconia framework corresponds to almost all crown morphology, excluding the buccal surface that was subsequently veneered with ceramics. • The intra-crown component didn’t extend more apically than the finishing line.
With this design, we tried to conciliate the resistance offered by a zirconia framework that corresponded almost to the full crown, with the most personalized aesthetic appearance provided by the veneering ceramic.
DENTAL LABORATORY: Dentalmaia, Castelo da Maia, Portugal