The objective of this study was to assess, over a period of 5 years, implant prosthesis and patient-reported outcomes of complete dentures retained by four implant-supported attachments in the edentulous maxilla facing either natural teeth or fixed rehabilitation in the lower jaw.
Maxillary implant overdentures (IOD) aim to improve the retention and the stability of complete dentures in patients with persistent complaints or insufficient residual tissue support.
Implant overdentures are widely described as dentures on bars supported by four to five implants, and the literature reports implant survival rates higher than 95% when implants are splinted.
However, IOD supported by individual attachments are increasingly proposed to restore the maxilla of elderly patients because of limited anatomical contra-indications, cost-effectiveness and ease to clean.
In the literature, different protocols with various types of attachments and implant number are described to restore the edentulous maxilla.
In a recent systematic review, implant survival rates varied from 95% to 100% when maxillary IOD are supported by at least four unsplinted implants attachments and implant survivals decreased from 73.5% to 100% with less than four implants.
However, these data mainly considered short-term data and prospective longor medium-term studies are rather limited.
Ma and co-workers reported in a 10-year prospective study on three unsplinted implant attachments an implant survival rate that yielded 86.3%.
Moreover, two retrospective studies evaluating the clinical outcomes of IOD supported by four unsplinted implants, reported respectively implant survival rates 98.7% and 95.2% at 5 years.
Prospective studies with a longer follow-up are therefore needed to evaluate the implant survival rate of such removable implant rehabilitations.
Additionally, the literature on maxillary overdentures mainly focuses on implant results while the prosthodontic outcomes and complications remain poorly investigated.
