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.
OBJECTIVE
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.


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.
Gioacchino
G
Cannizzaro
Ignazio
I
Loi
Paolo
P
Viola
Vittorio
V
Ferri
Michele
M
Leone
Anna
A
Trullenque-Eriksson
Marco
M
Esposito
D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging; D000539:Alveolar Process / Q000000981:diagnostic imaging; D015519:Bone Density / Q000502:physiology; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003779:Denture Design; D003824:Denture, Complete; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading / Q000379:methods*; D007575:Jaw, Edentulous / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D016300:Radiography, Bitewing; D013524:Surgical Flaps / Q000601:surgery; D014025:Titanium / Q000737:chemistry; D016896:Treatment Outcome
D015921:Dental Implants; D003764:Dental Materials; D014025:Titanium