Immediately Loaded Zygomatic Implants versus Conventional Dental Implants in Augmented Atrophic Maxillae: 1-year Post-loading Results from a Multicentre Randomised Controlled Trial

Objectives: To compare clinical outcomes of immediately loaded cross-arch maxillary prostheses supported by zygomatic implants vs conventional implants placed in augmented bone.

Methods: In total 71 edentulous patients with severely atrophic maxillae were randomised according to a parallel group design to receive zygomatic implants to be loaded immediately vs grafting with a xenograft followed after 6 months of graft consolidation by placement of conventional dental implants submerged for 4 months. Provisional prostheses were provided and replaced by definitive ones 4 months after loading. Outcome measures were: prosthesis, implant and augmentation failures, complications, quality of life (OHIP-14), patients’ number of days with total or partial impaired activity, time to function and number of dental visits.

Results: Six prostheses failed in the augmentation group vs one prosthesis in the zygomatic group (P = 0.045). Patients lost 35 implants in the augmentation group vs four zygomatic implants (P = 0.037). A total of 14 augmented patients were affected by 22 complications vs 28 zygomatic patients (40 complications) (P = 0.005). The number of days of partial infirmity were on average 14.24 for the augmented group and 12.17 for the zygomatic group (P = 0.048). Mean number of days needed to have a functional prosthesis was 444.32 for augmented patients and 1.34 for zygomatic ones (P < 0.001). The average number of dental visits was 19.72 for augmented patients and 15.12 for zygomatic patients (P = 0.055).

Conclusion: Preliminary 1-year post-loading data suggest that immediately loaded zygomatic implants were associated with statistically significantly fewer prosthetic failures, implant failures and time needed to functional loading when compared to augmentation procedures. Even if more complications were reported for zygomatic implants, they seem to be a better rehabilitation modality for severely atrophic maxillae. Long-term data are however needed to confirm these preliminary results.