PURPOSE: To evaluate the clinical, radiographic, and patient-reported outcomes of posterior screw-retained implant-supported zirconia and metal-ceramic fixed partial dentures (FPDs) using non-engaging abutments that were restored up to 5 years. MATERIALS AND METHODS: One hundred implants (Straumann Bone Level or Bredent Copasky) supporting 50 screw-retained FPDs in 34 patients were evaluated clinically and radiographically up to 5 years after definitive loading. Each patient went through an interview, clinical examination, and radiographic examination. Radiographic measurements of marginal bone loss (MBL) were obtained based on periapical radiographs taken on the day of interview and clinical examination. Incidences of biological complications were recorded, including bleeding on probing (BoP) and pus discharge (suppuration). Prosthetic complications included screw loosening, screw fracture, ceramic chipping, prosthetic fracture, loss of screw access hole material, and prosthetic debonding. Patient-reported outcomes were measured using Oral Health Impact Profile-14 (OHIP-14). Data were analyzed using t-tests, chi-square tests, and ANOVA, with significance level set at p < 0.05. RESULTS: Fifty-four percent of FPDs remained free of complications during the follow-up period. There were no reported implant failures, resulting in a 100% implant survival rate. The prosthesis survival rate was 92%, with only four FPDs requiring replacement. Mean MBL was 1.48 mm for mesial and 1.27 mm for distal implants, with no statistically significant difference. BoP was observed in 30% of mesial implants and 36% of the distal implants supporting the FPDs, whereas no suppuration was detected. Mechanical complications affected 40% of FPDs; screw loosening was the most common complication, with an incidence of 38% in 15 FPDs and a total of 19 occurrences. Technical complications were observed in 36%. Smokers demonstrated markedly greater BoP and bone loss compared to nonsmokers. Complications reduced patient-reported satisfaction scores measured by OHIP, in comparison to those without complications. CONCLUSIONS: Screw-retained FPDs with non-engaging abutments placed in the posterior segments demonstrated high survival rates. Smoking was associated with higher risk of biological complications. Mechanical complications were common in all restorations, with ceramo-metal exhibiting more complications. Screw loosening was the most reported mechanical complication. Occurrence of complications reduced overall patient satisfaction.
Rababah et al. (Mon,) studied this question.