Abstract
Aim The purpose of this in vitro investigation was to assess the impact of mechanical loading on various denture materials on supporting structures.
materials and methods: Two completely edentulous epoxy casts, four implant-retained overdentures were used in this study and divided into two groups; group (I): epoxy cast with two titanium implants and group; (II) two zirconia implants, each group is retaining a conventional acrylic overdenture and a flexible acrylic overdenture in place. The implants were positioned in the epoxy resin casts at the canine region with the aid of a surgical guide. To simulate the soft tissues, soft liner material was used at the distal extension area. Measuring the peri-implant strains during unilateral and bilateral loading was carried out using two linear strain gauges bonded at the buccal and lingual aspects of each cast at each implant.
Results: The flexible acrylic overdenture with titanium implants showed the highest strain values during bilateral loading, while the conventional acrylic overdenture with zirconia implants showed the lowest strain values. The conventional acrylic overdenture with zirconia implants showed the lowest strain values during unilateral loading, while the flexible overdenture with titanium implants demonstrated the highest strain values in the loading side.
Conclusion: It was discovered that, relative to the other materials, flexible overdentures held in place by titanium implants transmitted more occlusal stresses at the marginal bone area, within the confines of this in vitro investigation.