CHIEF COMPLAINT:
Patient has a complete denture and wants to have a “more fixed” denture.
DIAGNOSIS:
Female patient, 72 years-old, non-smoker. Patient had an edentulous mandible rehabilitated with a complete denture. To evaluate the possibility of placing dental implants, a CBCT scan was done. This exam revealed bone conditions (height and thickness) favorable to implants placement.
In the maxilla, patient presents two metal-ceramic 3-unit implant-supported bridges (16-14 ; 25-27). Tooth 13 had a root canal treatment and tooth 24 a class II OD restoration in composite. The periodontal status of the remaining teeth was satisfactory and patient presented a good oral hygiene.
TREATMENT PLAN:
After clinical and radiological exame, three treatment plan proposals were presented to the patient:
1. Full-arch metal-ceramic rehabilitation supported by 6 dental implants.
2. Full-arch metal-acrylic rehabilitation supported by 4 dental implants.
3. Overdenture retained by a bar (Ackermann) supported by 4 dental implants.
After discussing these proposals with the patient, the first proposal was excluded due to economical factors. Ease of oral hygiene was a key factor for the patient to chose the overdenture option.
TEAM PLAY ‘DENTIST – DENTAL TECHNICIAN’ NOTES:
Together with the patient, it was decided to proceed with the treatment plan for an overdenture retained by an Ackermann bar supported by 4 implants. The design of the overdenture included a castable metallic framework to reinforce the prosthesis.
Implants placement was studied considering the data obtained in the clinical exam and in the CBCT scan. After 8 weeks of osseo-integration an impression was done with an open-tray, and a double-mixture technique (putty-soft and light).
Then, occlusal wax-rims were done on a denture base, that included an implants transfer to allow the screw of the base to a dental implant.
These rims were modeled intra-orally in order to represent the correct OVD, inter-maxillary relations and support of the lips and cheek. With these inter-maxillary relations, working casts were assembled on the semi-adjustable articulator.
Then, teeth were mounted over the wax-rims and a try-in was done to evaluate function and aesthetics. A bite-registration was done with a silicone material in order to do a fine-tuning of the inter-maxillary relations and the working casts were reassembled in the semi-adjustable articulator.
With the approval of this try-in, a silicone index guided the manufacturing of the Ackermann bar according to the teeth position. The overdenture included a castable metallic framework to support and retain the bar clips.
The fit of the bar was evaluated in the mouth, clinically and with radiographs.
Finally, the overdenture was placed, making the final adjustments of the retentive elements.