Tilted implants as an alternative to maxillary sinus grafting: a clinical, radiologic, and periotest study

Owing to mechanical and anatomic difficulties, implant treatment in the atrophic maxilla represents a challenge. The maxillary sinus floor augmentation procedure is still not universally accepted because of its complexity and its unpredictability.

In this study, a combination of tilted and axial implants was used in patients with severely resorbed posterior maxillae as an alternative to sinus grafting.

Twenty-five patients were rehabilitated with 29 fixed partial prostheses supported by 101 Brånemark System implants. Fifty-nine implants were installed in an axial and 42 in a tilted direction. The average follow-up period was 37 months (range: 21-87 mo post loading).

After 5 years, the implant cumulative success rate was 95.2% (survival: rate 100%) for the tilted implants and 91.3% (survival rate: 96.5%) for the axial implants, and the prosthesis survival rate was 100%. At the fifth year, the average marginal bone loss was 1.21 mm for the tilted implants and 0.92 mm for the axial ones. The mean Periotest values (PTV) at loading time were -2.62 and -3.57, and after 5 years the PTVs were -4.73 and -5.00 for the tilted and the axial implants, respectively. During the follow-up, all prostheses but two were mechanically stable, retightening of 18 abutment screws and of 5 gold screws in 14 prostheses was done, and fracture of two abutment screws and two occlusal surfaces was experienced.

Results indicate that the use of tilted implants is an effective and safe alternative to maxillary sinus floor augmentation procedures.