Analysis of inflammatory complications around implant‑supported removable dentures in the long‑term follow‑up period: a retrospective study

Abstract

Removable dentures on implants are inferior in a number of qualities to crowns and bridge dentures on implants due to greater mobility in the mouth, the presence of a plastic base. Meanwhile, in frequent cases, due to the lack of bone tissue in the lateral parts of the jaws, health problems, and subjective reasons, removable dentures on implants remain the only possibility for satisfactory prosthetics. Removable (covering) prostheses on implants are used in the case of complete absence of teeth and are supported by two, four, or six intraosseous implants, which are usually connected by a metal beam; the covering prosthesis is attached to the beam using semi-lable (with an elastic matrix) or rigid locks.

Aim:

Analyze the frequency of detection and types of inflammatory complications in the periimplant tissues under removable covering prostheses.

Materials and methods:

 The analysis of the condition of implants and the removable prostheses themselves in patients with complete absence of teeth, which over a ten-year period were made 56 removable prostheses on implants. By design, the prostheses were divided into prostheses with a beam on four implants with semi-labile or rigid locks, as well as prostheses with a beam and semi-labile locks on two implants. Balks made of chromium-cobalt alloy in most cases were cast. The base was made of polymethyl methacrylate, and Bredent locks were used. Patients did not visit the clinic on a regular basis to correct the base, locks, or dentition.

Results:

The average lifespan of the overdentures on the implants, regardless of their design, did not exceed five years. After five years, 24.7% of the implants were still in place. The remaining implants had bone tissue resorption: 14.6% – by 1/2 of the implant length and 9.6% – by 1/3. All functioning prostheses had four implants in the support: with semi-labile locks – 17.9% of the implants under the prostheses with a beam and semi-labile locks and 46.7% of the implants under the prostheses with a beam and rigid locks. Removable prostheses on a beam on two implants were no longer available after 5 years due to the removal of the supporting implants.

Conclusion:

The study demonstrates the advantages of overdentures on four implants and with a rigid attachment to the beam that connects the implants in the orthopedic treatment of complete tooth loss. Semi-mobile attachment provides a lower efficiency of prosthetics on implants in terms of the timing of functioning and the detectability of inflammatory complications. The longevity of the functioning of overdentures on two implants does not exceed five years. The service life of implant-supported full dentures can be extended through systematic dispensary adjustments of the denture base, locking attachments, and implant and denture hygiene.