Upper and lower dentures on Rhein83 components
In this clinical case are illustrated in a very schematic way some stages of the realization of an upper and lower overdenture on eight implants, four on the upper and four on the lower jaw (Fig. 1). This solution will provide greater stability to the prosthesis during the phonation and the chewing functions, allowing the patient to relate in their social sphere with safety and confidence.
This technique uses the spherical attachments that allow the clinician to reduce the final costs of the article compared to a solution with a bar.
The presence of the retention given by the implants do not exclude that the prosthesis must have the same requirements of a traditional one, namely it must have an appropriate extension of the edges, a correct vertical dimension, a centric relationship repetable and a correct assembly of the teeth (Figs. 3-5). The prosthesis thus conceived will not have only an implant support but will also have a mucous support.
If the prosthesis doesn’t meet the above-mentioned requirements, it may occur a failure of the device and the implants loss.
We illustrate only the steps related to the finalization of the work.
After the esthetic and functional tests and the approval of clinical and patient, the prosthesis will be completed.
In the presence of reduced vertical dimensions and a high number of implants it is preferred the use of a superstructure of cobalt chromium that will prevent any breakage in correspondence of the metal housings containing the retentive caps (Figs. 6, 6a).
Before the construction of the structures the silicone keys of the teeth assembly are made that will allow you later, to reposition the teeth and to check the available spaces. The structures will be opacified to prevent the metal shine through the resin (Figs. 7, 7a).
Once polymerized the prosthesis (in this case in a traditional muffle with the coloring of the prosthetic flanges), finished and polished, the completed devices is then send the in the studio for the final delivery (Figs. 8-10).
The clinician before fixing the retentive caps (Figs. 2, 2a, 2b) will check the insertion paths of the prosthesis eliminating residual areas of compressions with a special pasta and the centric contacts.
The fixing of the retentive caps with liquid resin will be facilitated by the use of protective disks that prevent the resin from invading the undercuts of the attachments allowing an easy removal of the prosthesis once cured (Fig. 11).
After the curing, the excess of resin will be finished with a bur (Fig. 12).
Before the final delivery, the patient will be instructed to store and clean properly the prosthesis and implants. The prosthesis in situ, with the clear satisfaction of the patient (Figs. 13-18). Thanks to Mr. Vincenzo Liberati for the construction of the superstructure (Lab.DentaLine).