Introduction: The use of implant-supported overdentures is a common approach for treating edentulous mandibles. Retention and stability are provided through attachments; bar attachments being probably the most retentive due to greater mechanical stability and better wear resistance. Micro and macro movement between the retentive surfaces of an attachment during mastication, insertion and removal will lead to wear and decrease of the retentive capacity. Using CAD/CAM technology should produce more precise frameworks with better retention.
Objectives: was to compare the retention of different Cobalt Chromium bar attachments fabricated by CAD/CAM technology and conventional methods.
Materials and methods: Two bar attachments of different method of fabrication were studied. The bars were divided into two different groups according to whether the bar was fabricated using the conventional method or CAD/CAM technology. The retention provided by each bar was tested using Universal testing machine. The difference in retention was compared between the groups.
Results:Data was collected, tabulated and statistically analyzed using the appropriate test. Group 1 needed 32.91N dislodging force. Group 2 needed 62.8N to separate the clip from the bar
Conclusions: CAD/CAM fabricated bars showed a significantly higher retentive force in comparison to conventional bars.