Immediate occlusal loading of full-arch rehabilitations: screw-retained versus cement-retained prosthesis. An 8-year clinical evaluation.

PURPOSE

The aim of this study was to evaluate the survival and success of screw-retained versus cement-retained implant restorations in immediately loaded implants at 8-year follow-up.

MATERIALS AND METHODS

Patients who were scheduled for full-arch ceramic prosthetic restorations were divided into two groups by randomization: in one group, prosthetic frameworks were screwed onto implants (screw-retained group, SRG), and in the second group, the frameworks were cemented on abutments (cement-retained group, CRG). Dental implants were placed both in postextraction and in healed sites. A temporary full-arch prosthesis was placed immediately after implant placement. Intraoral digital radiographic examinations (evaluating marginal bone levels) were made at baseline, 6 months, and each year after implant placement.

RESULTS

In 28 patients, 24 full arches and 192 implants were placed in the maxilla and 10 full arches and 80 implants in the mandible (17 rehabilitations in each group). After an 8-year follow-up period, a survival rate of 99.27% was reported for all implants. Within the first year after implant placement, bone loss was recorded as follows: the CRG showed mean bone levels of -1.23 ± 0.45 mm, while the SRG showed mean bone levels of -1.01 ± 0.33 mm. After a 3-year follow-up, a slight increase was found (0.30 ± 0.25 mm in CRG and 0.45 ± 0.29 mm in SRG). After that point, marginal bone levels remained stable over time, up to the 8-year follow-up. No statistically significant differences were found between groups (P > .05).

CONCLUSION

Definitive cement- and screw-retained ceramic restorations are highly predictable, biocompatible, and esthetically pleasing, and the two groups presented no statistically significant differences in bone loss.