Effectiveness of three treatment modalities for the edentulous mandible. A five-year randomized clinical trial.
Currently, 3 treatment options are available for patients with denture complaints and an edentulous mandible with a height of at least 15 mm: meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), and construction of an implant-retained mandibular overdenture (IRO). The aim of this study was to evaluate patient satisfaction and subjective chewing ability of edentulous patients treated with one of these treatment modalities. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 mm) were randomly assigned to receive 1 of these 3 groups. Denture satisfaction and chewing ability were assessed using questionnaires focusing on denture-related complaints and problems chewing different types of food were assessed before treatment, and 1- and 5-years after treatment. At the 1-year evaluation, significantly better scores were observed in the 2 surgical groups (IRO, PPS) than in the CD group. At 5-year evaluation the "complaints of the lower denture" showed a significantly better score in the IRO group when compared to the PPS and CD groups. No significant differences were observed between the PPS and CD group. From this study it is concluded that both in the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are therefore a satisfactory treatment modality for edentulous patients with problems with their lower denture, even in cases of not severely resorbed mandibles.
There is weak evidence from the results of one randomised controlled trial including 60 subjects that patients are generally less satisfied with preprosthetic surgery and a conventional denture than with an implant retained denture. There is a need for more well designed trials comparing the success and cost-effectiveness of preprosthetic surgery and implant supported dentures. Such trials should be reported according to the CONSORT guidelines (www.consort-statement.org/). However, since preprosthetic surgery is considered to be an obsolete treatment nowadays, almost completely replaced by dental implants, it may be that new RCTs on this topic will not be designed.