Method: Two non-concurrent groups of consecutively treated completely edentulous patients each with two interforaminal endosseous implants (either machined Branemark type implants, Nobel Biocare, Canada, or SLA Solid Screw, Straumann Canada) were managed using either magnetic attachments (17 patients, MAGFIT, Aichi Steel Corporation, Japan) or ball abutment attachments (42 patients, spherical stud - retentive anchor and gold matrix, Straumann Canada) to retain existing dentures. Sixteen magnet patients had prior experience with ball or bar implant overdentures.
Result: During the first year, mean satisfaction of the 17 magnet patients (using a standardized 100 point visual analogue scale) increased from 66 to 93, whereas the mean satisfaction of 41 available ball patients increased from 48 to 90. By the third year, the 14 available magnet patients reported a mean satisfaction of 86, whereas 21 available ball patients reported a mean score of 84. No corrosion or failure of magnetic retention was observed during the period, nor did any magnet patients experience a fracture of their denture base, whereas 14 ball patients required at least one matrix tightening and 4 experienced at least one denture base fracture. A small number of patients in both groups also required tightening of the implant abutment component or reacrylization of the magnet or matrix component loosened from the denture base. No implants failed in either group during loading.
Conclusion: High levels of patient satisfaction were found with both magnet and ball retained overdentures, and no unusual difficulties were encountered in maintaining either group.