Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Prosthodontics

The aim of this study was to evaluate the biomechanical response of the peri-implant bone to standard, short wide and double mini implants replacing missing molar supporting either hybrid ceramic crowns (Lava Ultimate restorative) or full metal crowns under 2 different loading conditions (axial and off axial loading ) using strain gauge analysis. 3 single molar implant designs: (1) single, 3.8 mm (regular) diameter implant, (2) single, 5.8 mm (wide) diameter implant, and (3) two 2.5 mm diameter (double) implants connected through a single-molar crown were embedded in epoxy resin by the aid of a surveyor to ensure their parallelism. Each implant supported full metal crowns made of Ni-Cr alloy and hybrid ceramic with standardized dimensions. Epoxy resin casts were prepared to receive 4 strain gauges around each implant design, on the buccal, lingual, mesial, and distal surfaces. Results were analyzed statistically. Results showed that implant design has statistically significant effect on peri implant microstrains; where the standard implant showed the highest mean microstrain values followed by double mini implants, while the short-wide implant showed the lowest mean microstrain values. Concerning the superstructure material, implants supporting lava ultimate crowns had statistically significant higher mean microstrain values than those supporting full metal crowns. Concerning the load direction, off-axial loading caused uneven distribution of load with statistically significant higher microstrain values on the site of off axial loading (distal surface) than the axial loading. Implant design, superstructure material and load direction significantly affect peri-implant microstrains.

Issued also as CD