Marginal bone loss in association with different vertical implant positions

VICSE ePOSTER CLINICAL RESEARCH – PERI-IMPLANT BIOLOGY

Background: The implant has become one of the most preferred treatments for partially edentulous patients. However, marginal bone loss around implants was common following implant placement. Several studies investigated the relationship between the vertical position of the implant and marginal bone loss, but there are only a limited number of studies in the current literature with human subjects who were followed up for longer than 1 year

Aim/Hypothesis: The purpose of this study was to retrospectively evaluate the relationship between the vertical position of the implant-abutment interface and marginal bone loss over 3 years using radiological analysis.

Materials and Methods: In total, 286 implant surfaces of 143 implants from 61 patients were analyzed. Panoramic radiographic images were taken immediately after implant installation and at 6, 12, and 36 months after loading. The implants were classified into 3 groups based on the vertical position of the implant-abutment interface: group A (above bone level), group B (at bone level), and group C (below bone level). The radiographs were analyzed by a single examiner after the magnification and contrast were increased using Adobe Photoshop CS5.

Results: Changes in marginal bone levels of 0.99 ± 1.45, 1.13 ± 0.91, and 1.76 ± 0.78 mm were observed at 36 months after loading in groups A, B, and C, respectively, and bone loss was significantly greater in group C than in groups A and B. There was no significant difference in bone loss between the internal- and external-connection implants at the same vertical position. The amount of bone loss was greater in the subcrestal group than in the other 2 groups for both internal- and external-connection implants. .

Conclusions and Clinical Implications: The vertical position of the implant-abutment interface may affect marginal bone level change. Marginal bone loss was significantly greater in cases where the implant-abutment interface was positioned below the marginal bone. Further long-term study is required to validate our results.

Keywords: Alveolar bone loss, Bone-implant interface, Dental implants