Bone Height Changes between Anterior Adjacent Implants - A Retrospective Study

Objective: The purpose of this study was to evaluate changes in bone height between anterior maxillary adjacent immediate and non-immediate implants over time. Methods: The study was conducted on 49 patients' files. Intervals between anterior maxillary adjacent immediate and non-immediate implants were evaluated. All implants were restored with definitive fixed restorations. The measurements were performed using panoramic radiographs. Distance and bone height between adjacent implants was measured in the aesthetic zone (between first premolars). Bone height was measured midway between implants, first at or a few days subsequent to implant placement and than after a follow-up period of rehabilitation with a definitive fixed restoration. Results: There were 35 patients with maxillary adjacent immediate and 14 with non-immediate implants. The mean follow-up time was 55 months (range 8 - 146). The average bone loss between implants was 1.05 mm (SD 0.9 mm), the mean distance being 2.9 mm (SD 0.96 mm) (range 1 - 5.5 mm). For the immediate implants there was a negative correlation between distance and vertical bone loss (p=0.054). Conclusions: There is a rather low vertical bone loss between anterior maxillary implants with no regard to implant timing. For immediate implants, the larger the distance between implants, the lower the vertical bone loss. A further study with a larger cohort is warranted.