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Updated: Dec 19, 2025

Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition:
Alice Bouhy1, Eric Rompen2, Marc Lamy1
1Department of Removable Prosthodontics, University of Liège, Liège, Belgium.
Objectives:
The aim of this prospective study was to evaluate the implant, prosthesis, and patient-reported outcomes of maxillary removable prostheses retained by 4 implant-supported study abutments after a follow-up period of 1 year in patients with natural teeth or a fixed rehabilitation in the mandible.
Materials And Methods:
A total of 30 patients were included, and all received 4 implants in the upper maxilla. After 12 weeks, the prostheses were connected to the implant with unsplinted attachments. The implant and prosthodontics outcomes were assessed over a follow-up period of 1 year. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and an adaptation of the McGill Denture Satisfaction Instrument using a visual analogue scale (VAS).
Results:
A single patient dropped out. At the post-operative 12-week follow-up, 79.3% (95% CI: 64.6%-94.1%) of the patients displayed peri-implant mucosa hyperplasia and 69.0% (95% CI: 52.1%-85.8%) showed pain. After 1 year, 16 implants failed in 10 patients, leading to an implant survival rate of 86.2% (95% CI: 79.0%-92.5%), and the mean peri-implant bone loss was 1.01 ± 0.77 mm (95% CI: 0.85-1.16 mm). The prosthesis survival rate was 96.6% (95% CI: 82.2%-99.9%). The OHIP-20 and VAS scores both improved significantly from baseline to 1 year (p < .001).
Conclusion:
The implant survival rate was lower compared to the literature for the upper maxilla. Despite the encountered problems, PROMs showed significant improvement with the implant overdenture retained by 4 unsplinted implants compared to conventional dentures.

