Immediate loading of two (fixed on 2) versus three (fixed on 3) implants placed flapless supporting cross arch fixed prostheses: One year results from a randomised controlled trial.
PURPOSE To evaluate the outcome of two (fixed on 2 FO2) versus three (fixed on 3 FO3) implants placed flapless in fully edentulous jaws and immediately restored with metal resin screw retained crossarch prostheses. MATERIALS AND METHODS Forty edentulous or to be rendered edentulous patients (20 in the maxilla and 20 in the mandible) were randomised to the FO2 group (20 patients: 10 in the maxilla and 10 in the mandible) and to the FO3 group (20 patients: 10 in the maxilla and 10 in the mandible) according to a parallel group design. To be immediately loaded, implants had to be inserted with a minimum torque of 60 Ncm. Outcome measures were prosthesis and implant failures, complications and periimplant marginal bone level changes evaluated up to 1 year post loading. RESULTS Flaps were raised in four patients and two prostheses were loaded early at 8 weeks in the FO2 group. One year after loading no dropout or implant failure occurred, however one FO2 maxillary prosthesis had to be remade because of repeated screw loosening (risk difference 0.05; 95% CI: 0.05 to 0.15; Fisher's exact test P 1.000) Three FO2 patients were affected by complications versus five FO3 patients (risk difference 0.1; 95% CI: 0.35 to 0.15; Fisher's exact test; P 0.695) There were no statistically significant differences for prosthetic failures and complications between groups. There were no statistically significant differences for marginal peri implant bone levels between the two groups (estimate of the difference 0.031 mm; 95% Cl: 0.22 to 0.28; P (ancova) 0.803) with both groups losing marginal bone in a statistically significant way (0.27 mm for FO2 patients and 0.24 mm for FO3 patients) CONCLUSIONS These preliminary results suggest that immediately loaded cross arch prostheses can be supported by only two or three dental implants at least up to 1 year post loading. Longer follow ups are needed to properly evaluate both these therapeutic options.
European journal of oral implantology