الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Completely edentulous mandibular cast was prototyped using 3D printing technology. This was done via scanning an educational model and designing an STL file including all the details required; implants beds, mucosal space for mucosa simulation and vertical slots for strain gauges which were 1mm distal and labial to each implant. Mucosa simulation was planned to mimic the viscoelasticity of the fibrous mucoperiostium by prototyping a mucosa simulator over the scanned model after removing 2 mm space over the crest of the ridge and making interlocking grooves for stabilization of the removable mucosa Printing was ordered and mucosa simulation was done by an addition silicon rubber base utilizing the printed mucosa simulator. Two dummy implants were placed in their beds. Primary copings with 1-2 degrees taper were made by making wax patterns on Ti-based abutments and checking their taper by a dental surveyor. Then BioHPP was pressed utilizing the conventional lost wax technique. This study will be divided into 2 groups according to the type of telescopic over denture materials: group (1): BioHPP telescopic implant retained overdenture fabricated on BioHPP abutments. group (2): conventional acrylic resin with cobalt-chromium framework fabricated telescopic implant retained overdenture on BioHPP abutments. Strain gauges were supplied with fully encapsulated grid and attached wires. The wire used for strain gauges were insulated by a packing material. Before securing the mucosa simulator in its space and screwing the abutments. Strain gauges were installed at the distal and labial aspect of each implant. Mucosa was placed in its space, each abutment was screwed to its implant on the model then overdenture was fitted. The model was placed on the lower flat metal plate of the testing machine. A T-shaped load applicator was made to fit on the denture teeth bilaterally between the distal aspect of lower second premolar and mesial aspect of lower first molar. After fifteen minutes the same load was applied unilaterally on the right side to represent the working side between second premolar and first molar using I bar shaped load applicator. Micro-stains were recorded at each site of the strain gauges with enough time elapsed between each testing. A four channel strain meter was used to assess the strains induced by each applied load. The applied load started from zero up to 100N. The same steps were followed with each type of the overdentures after connecting it to the implants. All data were collected and tabulated, one- way ANOVA analysis at a significant level P < 0.05 was performed by Statistical Package for Social Science (SPSS) version 22. The results obtained from this study revealed no significant difference between the BioHPP telescopic overdenture and the conventional acrylic resin with cobalt chromium framework telescopic overdenture on the average stresses falling on the implants. And there is a significant difference between the BioHPP overdenture and the conventional acrylic resin with cobalt chromium framework telescopic overdenture on the average stresses falling on both implants and there is significant difference between the loaded and the non loaded side. The average stresses falling on the implants supporting the BioHPP overdenture was more than the average stresses falling on the implants supporting the conventional acrylic resin with cobalt chromium framework telescopic overdenture. The average stresses falling on the implant in the loaded side were more than the average stresses falling on the implant in the non loaded side. Stresses falling on the implant in the loaded side were more than the stresses falling on the implant in the non loading side supporting either over denture materials but in the BioHPP overdenture the difference between the stresses falling on the loaded and the unloaded side was less than the conventional acrylic resin with cobalt chromium framework telescopic overdenture.