A COMPARISON BETWEEN TWO DIFFERENT TYPES OF ATTACHMENTS IN IMPLANT RETAINED MANDIBULAR OVERDENTURES (A STRESS ANALYSIS STUDY)

Background: The target of this in vitro study was to evaluate the distribution of stresses using strain gauges around two mandibular implants installed in the inter-foraminal region retaining an overdenture with two different types of attachments; ball attachment and magnet attachment.
Materials and Methods: In this Invitro study, a mandibular conventional denture model was constructed using heat cured acrylic resin. In the canine region, two box shaped preparations with a 1mm thickness buccally, lingually, mesialy and distaly were done into which two dummy implants were mounted and bonded to the model using self-cure acrylic resin. Over each surface, strain gauges of length 5mm, resistance of 120.4±0.4 Ω and a gauge factor of 2.09 ± 1 %, were anchored. Unilateral and bilateral vertical static load of 100N using a universal testing machine was applied onto both types of overdentures; one retained by the ball and one by the magnet and 10 readings were recorded for each attachment.
Results: When comparing the micro strain mean values of both groups while applying strain both bilaterally and unilaterally, the study has shown that there was a statistically significant difference in the mean values of micro strain between the Ball and Magnet attachment in the non-loading side where (p<0.001). The highest mean value of micro strain was found in Ball attachment while the least mean value of micro strain was found in the Magnet in both events. Results also revealed that there was a statistically significant difference in mean values of micro strain between the Loaded side and the Unloaded side where (p<0.001) where The highest mean value of micro strain was found in the Loaded side while the least mean value of micro strain was found in Unloaded side in both groups.
Conclusion: Within the limitations of this study, it can be concluded that ball attachments induce higher micro-strain on the bone implant interface than the magnet attachment