Retrospective analysis of implant overdenture treatment in the advanced prosthodontic clinic at the University of Illinois at Chicago

The aim of the present retrospective study was to evaluate the clinical outcomes of implant-supported overdenture treatment provided by prosthodontic specialty residents. Twenty-three patients with 25 implant-supported overdentures (IODs) participated in the study. Seventyfour implants were placed by periodontic, prosthodontics, or oral and maxillofacial surgery students. All prostheses were fabricated in the advanced prosthodontics clinic at University of Illinois at Chicago. The condition of the peri-implant soft tissue, implants, and prostheses were evaluated. Complications and any maintenance were documented. Patients completed an oral health impact profile-14 and semantic differential scale questionnaires. Statistical analyses were performed using SPSS statistical software. Twenty mandibular and 5 maxillary IODs were evaluated. Ninety-seven percent of the attachments were locators (Zest Anchors) and 3% ball attachments. None of the implants had lost osseointegration, but 14 implants (19%) had developed marginal bone loss in one-third of the implant length or more. Fourteen (19%) implants had developed dehiscence, which ranged from 1 to 4 mm. A variation in the width of the keratinized tissue, gingival, plaque, and calculus index was observed. There was a statistically significant relationship between the presence of plaque and the bleeding on probing on the buccal aspect of implants (P=.012). The incidence of dehiscence was significantly higher on the midfacial when the keratinized tissue was less than 2 mm (P <.0001). The majority of the complications were prosthetic in nature, such as broken denture teeth (74%) and worn or loose matrices (35%). Debris was observed in 19% of the locator abutments, and 36% of the overdentures were not stable in application of anterior force. Patients were compliant with oral hygiene protocols and their chewing ability was high (mean= 8.0). The overall experience was pleasant (mean=7.5); the treatment provided good esthetics (mean=8.3) and great satisfaction (mean=8.5). From an educational and clinical perspective, IOD therapy has been documented to be a predictable and successful treatment option. Patients should be informed of the required maintenance and the possible complications related to IOD therapy.