Keywords
Dental implants, grafting material, ITI implants, osteotome, posterior maxilla, sinus lift, sinus osteotome
Abstract
Objective: The aim of the present pilot study was to evaluate: (1) the predictability of an osteotome sinus floor elevation procedure with ITI-SLA implants without placing a bone grafting material, and (2) the possibility to gain bone height without filling the created space with a bone grafting material.
Material and methods: Seventeen patients received 25 implants protruding in the sinus. Most implants (21/25) were 10 mm long, eight were inserted in type 2 bone, 12 in type 3 and five in type 4 bone. At implant placement, the mean residual bone height (RBH) under the maxillary sinus was 5.4 ± 2.3 mm; it was 5.7 ± 2.6 mm on the mesial side and 5.1 ± 1.9 mm on the distal side. Nineteen implants had less than 6 mm of bone on at least one side and six implants had less than 6 mm on both sides. A healing period of 3–4 months was allowed before abutment tightening at 35 Ncm. The percentage of stable implants at abutment tightening and at the 1-year control was calculated. The endo-sinus bone gain and the crestal bone loss (CBL) at the mesial and distal sides were measured.
Results: Abutments were tightened after 3.1 ± 0.4 months. All implants but one (96%) resisted the applied 35 Ncm torque. At the 1-year control, all implants were clinically stable and supported the definitive prosthesis. All showed endo-sinus bone gain; the mean gain was 2.5 ± 1.2 mm. The mean CBL was 1.2 ± 0.7 mm. Endo-sinus bone gain and RBH showed a strong negative correlation (r ¼ — 0.78 on the mesial side and — 0.80 on the distal side). A good correlation (r ¼ 0.73) was found between implant penetration in the sinus and endo-sinus bone gain.
Conclusion: Elevation of the sinus membrane alone without addition of bone grafting material can lead to bone formation beyond the original limits of the sinus floor. Despite a limited RBH at implant placement, a healing period of 3 months was sufficient to resist a torque of 35 N cm and to lead to a predictable implant function at the 1-year control.