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.
TREATMENT NOTES
Implants placement was done. Guided by the treatment plan, the implantologist took special care on placing the implants: parallel to each other; well distributed all over the mandible; with their necks at the same height.
After 8 weeks of osseo-integration an impression was done with an open-tray, and a double-mixture technique (putty-soft and light). Then, the occlusal wax-rims were done on the working casts, with a denture base that had an implant transfer that allowed the screw of this base. In this way, denture base was “fixed” to a dental implant easing the intermaxillary registration.
The occlusal vertical dimension was determined with these occlusal wax-rims and the intermaxillary registration done with a bite-registration material (silicone) . The parallelism of the occlusal plan in relation to the bi-pupilary line was registered by incorporating a horizontal plastic stick (eg. microbrush) into an anterior extension of the bite-registation material.
Wax (teeth) try-in was done maintaining the screw to the implant, easing functional and aesthetic evaluation. With the approval of this try-in, a silicone index guided the manufacturing of the Ackermann bar. Its fit was evaluated in the mouth, clinically and with radiographs.
Finally, the overdenture was placed, making the final adjustments of the retentive elements.
Oral hygiene instructions were given to the patient, with special focus on the denture and the Ackermann bar.