Comparative evaluation of cobalt–chromium chain versus polyether ether ketone chain for reinforcing mandibular overdenture assisted by single implant using CAD/CAM and conventional techniques

Abstract Aim: The aim of this in-vitro study was to comparatively evaluate cobalt–chromium chains versus polyether ether ketone chains for reinforcing single implant-assisted mandibular overdentures using CAD/CAM and conventional techniques. Materials and methods: Four identical mandibular epoxy resin models, each covered by a 2 mm silicone resilient layer simulating the mucosa, were used. A single implant was inserted in the midline region of each model, and four identical mandibular overdentures were fabricated on the edentulous models. The four models were divided into four groups. A strain gauge was used to measure the strain around the implant upon the application of vertical and oblique loads. Results: The highest strain was recorded in group A, while the lowest was observed in group D. There were significant differences between groups A and B and groups C and D under both vertical and oblique loading. A significant difference was also observed between groups A and C, except at the buccal and lingual surfaces under oblique loading. On the other hand, there was no significant difference between groups B and D, except at the buccal, lingual, and distal surfaces under oblique loading. Analysis of variance testing revealed a significant difference among the four groups. Conclusion: Overdentures reinforced with cobalt–chromium produced more strain on the implant than those reinforced with polyether ether ketone. Significant differences were found between groups A and B and groups C and D under vertical and oblique loads.