Prosthetic Complications of Implant-Fixed Complete Dental Prostheses

Objectives: The purpose of this study was to assess prosthetic complications and patient-reported outcomes for four types of implant-fixed complete dental prostheses (IFCDPs). Metal-acrylic (MA), retrievable crown (RC), monolithic zirconia (MZ), and zirconia prostheses with veneering porcelain (MZV) were included. Methods: Patients who received an IFCDP more than one year prior to recall were identified. Exclusion criteria were: (1) patients with an IFCDP opposing a complete denture, and (2) patients with a prosthesis in service >70 months. A total of 37 patients with 49 prostheses, including 21 MA, 14 RC, 7 MZ and 6 MZV were recalled. Prior complications were identified by chart review. Patients were clinically evaluated to determine undocumented prosthetic complications. Patient-reported outcomes were assessed via OHIP-49 and a scripted interview with open-ended questions regarding: General, Esthetics, Occlusion, Phonetics, Hygiene, and TMD. IRB approval was obtained (#2015-0554). Results: All designs had high complication rates (59% MA, 79% RC, 57% MZ, and 100% MZV). The most common complications were: (1) MA - posterior tooth wear (45% of prostheses), (2) RC - chipping and fracturing of the restorations (43%), (3) MZ - wear of opposing restorations (33%), and (4) MZV - chipping of opposing restorations (66%). Differences were analyzed using a two-sided Fischer exact test, revealing that more screw access plugs were lost with MZ and MZV than MA or RC (p=0.01). Average OHIP-49 scores among prosthetic designs ranged from 7 to 29, indicating a high oral health-related quality of life (OHQoL). ANOVA indicated that the differences between designs were not statistically significant (p=0.16). The standardized interview revealed trends among patients with IFCDPs that have not been previously reported. For example, most patients were “extremely happy” (73%), thought the prosthesis “looked great” (89%), and had no difficulty chewing (84%). Conclusions: All types of IFCDPs examined provided a solution that satisfied patients and resulted in high OHQoL. Complications were high and the type of complication varied with the material selected. However, even with complications, patients were generally extremely satisfied. Our results reinforce the importance of patient education regarding the nature and incidence of complications with different IFCDP designs prior to therapy.