Immediate fixed rehabilitation supported by axial and tilted implants of edentulous jaws: a prospective longitudinal study in HIV-positive patients

Aim The purpose of this study is to evaluate the success of implant prosthetic rehabilitation "All on four" in HIV positive patients. Materials and Methods HIV-positive patients under a strict medical control with edentulous mandible and/or maxilla, were enrolled for the present study. The "all on four" protocol was applied with immediate fixed rehabilitations. Marginal bone loss, implant and prosthetic failure, biological and mechanical complications, serological levels (CD4 cell count, CD4/CD8 ratio and HIV-RNA) were recorded at 6, 12 and 24-month follow-up. Results A total of 108 implant were placed in 21 patients, and 27 rehabilitations were delivered. Five implants were lost (survival rate = 95.37%). At the 24-months radiographic evaluation, perimplant crestal bone loss averaged 0.98 ± 0.21 mm for upright maxillary implants (n = 30 implants) and 0.87 ± 0.18 mm for tilted maxillary implants (n = 30 implants). In the mandible, a mean peri-implant crestal bone loss of 0.88 ± 0.32 mm for upright implants (n = 24) and 0.91 ± 0.30 mm for tilted implants (n = 24) was found. No statistically significant difference in the marginal bone loss between tilted and axially placed implants, and between jaws at 6, 12 and 24-month follow-up evaluation (P>0.05). Moreover, not statistically significant linear correlations were found between serological levels and marginal bone loss. Conclusions Within its limitations, the present study reported that the "all on four" protocol can be a suitable treatment option in immunocompromised but immunologically stable HIV positive patients.