IADR Abstract Archives
The Effect of Metal Framework Design on Maxillary Implant Overdenture : Strain analysis
Objectives: The aim of this study was to investigate the ideal denture design on maxillary implant overdenture (IOD) regarding palatal coverage areas and metal framework types
Methods: An edentulous maxilla model and complete dentures were fabricated with polymethyl methacrylate(PMMA) resin. Four implants (3.75x10mm, Nobel Biocare) were embedded at bilateral canine, and first molar areas connected with Locator (Zest Anchors) attachments. Four biaxial strain gauges (strain gauge; KFG-020120-C1, Kyowa) were attached to the midline palatal, midline buccal, the top of the attachment, and left tuberosity on each denture to measure the bending strains on these areas. The experiment included two parts. First, from the area between incisive papilla to fovea palatine, the areas of palatal coverage on IOD were fabricated and divided into 100%, 75%, 50% and 25%. Part two was to investigate the effect of different metal framework design on the denture strain of IOD under the condition of 25 % palatal coverage. Control group was IOD with fully PMMA resin (25% palatal coverage). Testing groups were Co-Cr alloy metal framework embedded including U-shaped palatal plate only, palatal plate with and without covering the top of attachments. A vertical static load of 100N was applied to the denture on one biting plate cross bilateral posterior occlusion rims for 20 times in each condition. Comparisons of the bending strains were made by an analysis of variance (P<0.05).
Results: As the decrease of the IOD palatal coverage area from 100%,75%, 50% to 25%, the values of strain increased under loading. Furthermore, the values of strain increased significantly and dramatically in 25 % palatal coverage area comparing to the other groups. Additionally, under the 25 % palatal coverage of IOD, metal framework embedded decreased the strain on denture in all test groups, compare to the control group. Moreover, the most effective metal framework design was the one which covered the top of attachment.
Conclusions: Within the limitation of the study, the denture strain increased while the extension of IOD palatal coverage decreased. Moreover, in the decrease of palatal coverage, the metal-framework design with the covering over the top of the attachments decreased the strain on denture under loading.
Methods: An edentulous maxilla model and complete dentures were fabricated with polymethyl methacrylate(PMMA) resin. Four implants (3.75x10mm, Nobel Biocare) were embedded at bilateral canine, and first molar areas connected with Locator (Zest Anchors) attachments. Four biaxial strain gauges (strain gauge; KFG-020120-C1, Kyowa) were attached to the midline palatal, midline buccal, the top of the attachment, and left tuberosity on each denture to measure the bending strains on these areas. The experiment included two parts. First, from the area between incisive papilla to fovea palatine, the areas of palatal coverage on IOD were fabricated and divided into 100%, 75%, 50% and 25%. Part two was to investigate the effect of different metal framework design on the denture strain of IOD under the condition of 25 % palatal coverage. Control group was IOD with fully PMMA resin (25% palatal coverage). Testing groups were Co-Cr alloy metal framework embedded including U-shaped palatal plate only, palatal plate with and without covering the top of attachments. A vertical static load of 100N was applied to the denture on one biting plate cross bilateral posterior occlusion rims for 20 times in each condition. Comparisons of the bending strains were made by an analysis of variance (P<0.05).
Results: As the decrease of the IOD palatal coverage area from 100%,75%, 50% to 25%, the values of strain increased under loading. Furthermore, the values of strain increased significantly and dramatically in 25 % palatal coverage area comparing to the other groups. Additionally, under the 25 % palatal coverage of IOD, metal framework embedded decreased the strain on denture in all test groups, compare to the control group. Moreover, the most effective metal framework design was the one which covered the top of attachment.
Conclusions: Within the limitation of the study, the denture strain increased while the extension of IOD palatal coverage decreased. Moreover, in the decrease of palatal coverage, the metal-framework design with the covering over the top of the attachments decreased the strain on denture under loading.