Comparison of Retentive Characteristics between Mechanical and Magnetic Overdenture Attachments

Objectives: The aims of this study were to 1) evaluate maximum retentive characteristics, i.e. retentive force and/or retentive energy of different overdenture attachments during vertical linear and rotational dislodgment slide and to 2) compare retentive characteristics between mechanical and magnetic types of attachments. Methods: The types of magnetic attachments tested were: Magnedisk 500, Magfit EX 600W, Root keeper (dome shaped), Hyperslim 4013, Hyperslim 4513. While mechanical attachments were; O-P anchor, Root Locator (pink), Era Overdenture (white and orange). Ten measurements of maximum retentive force and energy for each type of attachment were recorded by universal testing machine AGS-H with cross head speed 50 mm/m and software interface Trapezium. Statistical analysis was performed with SPSS for Windows ver.11. Results: The findings were: Magnetic attachments having adequate retentive force have low retentive energy (p<0.01) and retentive properties depend on dislodgment pattern. Conclusions: Understanding of retention dynamics aids in proper prescription of different attachments.