Radiographic Bone Changes Surrounding Implants of Different Attachment Systems

This study was conducted to compare the effect of GPS attachment, OT Equator attachment and Ball and Socket attachment on crestal bone around implants in implant retained mandibular overdenture cases. Materials and Methods: Following two stage surgical protocol eighteen completely edentulous patients received two implants placed bilaterally in the canine region (36 implants) to retain mandibular overdentures. Inclusion Criteria: Patients were all healthy men, non-smokers, Following Misch rules of bone classification patients with bone density ranging from 850-1250 HU (D2) and bone height and width more than 10 mm and 5 mm respectively. Four months following the surgery patients were randomly divided into three equal groups; the first group received OT Equator attachment (Group OT), the second group received GPS attachment (Group GPS) and the third Group received Ball and Socket attachment (Group BS). Patients were then placed on zero, three, six and twelve months follow-up periods using cone beam computed tomography. Measurements were taken on crestal bone height surrounding the implants till its apex and then the results were statistically analyzed. Results: All three groups showed statistically significant bone changes. The GPS attachment showed the least bone changes around the implants, followed by equator attachment, whereas ball and socket showed more bone changes than the other two attachment types, with the highest signifcant increase (p<0.001) in bone change found in group BS. Group BS showed a statistically significant difference from Groups OT and GPS at 3 months, at 6 months and at 12 months, while Group OT showed a significant difference from Group GPS at 6 and 12 months. Conclusion: GPS attachment is least destructive to bone surrounding the implants, followed by the equator attachment, while ball and socket attachment showed the greatest bone changes surrounding the implant.