The effectiveness of 2-implant overdentures- a pragmatic international multicenter study

Objective: Several randomized controlled trials (RCTs) have demonstrated the significantly greater efficacy of mandibular dentures retained by two implants (IODs) over conventional dentures (CDs) with respect to patient-based outcomes. However, the positive results obtained in efficacy studies may be due to their having been carried out under ‘ideal' study circumstances. From a pragmatic perspective, patients play an integral part in treatment choice and often pay the entire cost of therapy, factors which may influence their overall satisfaction and quality of life. The purpose of this observational study was to determine patient satisfaction and oral health-related quality of life (OHRQoL) with either CDs or IODs in a ‘real-world' setting.

Methods: Two hundred and three edentulous patients (age range, 41-93 years) were recruited and examined at eight centers in North America, South America and Europe. At baseline and at six months following denture delivery, they rated denture satisfaction on 100mm visual analogue scale questionnaires and OHRQoL using the Oral Health Impact Profile (OHIP-20). In this study, both patient and clinician decided on the preferred treatment, and the cost of that therapy was borne either by the patient or through governmental health coverage. This project was supported by a grant from the ITI Foundation for the Promotion of Oral Implantology, Switzerland.

Results: Although both groups reported improvements, the IOD group reported significantly higher ratings of overall satisfaction, comfort, stability, and ability to speak and chew. Although OHIP-20 effect sizes were higher in the IOD group, no significant between group differences in post treatment ratings were seen.

Conclusions: The results of this study support previous findings from RCTs carried out under tightly controlled conditions. They suggest that patients who choose IODs have significantly greater improvements in satisfaction and a greater impact on OHRQoL, despite their relatively higher cost, than patients who receive new CDs.