الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 132 |  |  |
| | | from | 132 | | |
Abstract
Summary
This simulation study was conducted to evaluate and compare the effect of two treatment modalities on stresses induced on implants and the supporting structure, screw retained overdenture and telescopic retained overdenture were the two proposed treatment modalities both fabricated from Bio HPP.
A 3D printed models was constructed to simulate completely edentulous maxilla, six implants osteotomies were designed axially with 00 in the FDI positions 15, 13, 11, 21, 23, and 25.
Two experimental maxillary prostheses supported by dental implants were constructed for this study on the 3D printed model. According to the difference between the two treatment modalities the experimental prosthesis was classified into:
The first design was full arch screw retained fixed detachable overdenture. The framework was milled of BioHPP using CAD CAM technology in thimble cut back design and the teeth part was milled of zirconia using CAD CAM technology as well.
The second design was full arch telescopic overdenture with primary copings directly attached to the implants` abutments and the housing of the primary copings embedded in the fitting surface of the prosthesis. The framework was milled of BioHPP using CAD CAM technology in thimble cut back design and the teeth part was milled of zirconia using CAD CAM technology as well.
Two strain gauges were installed on the distal aspect of the terminal implants of the model to record the strain induced by the loads applied on both overdentures.
A special loading device was used to apply standardized static vertical unilateral, bilateral and oblique loads on the two models, Micro strains were recorded at each site of the strain gauge with enough time elapsed between each loading to allow complete rebound of the resilient structures.
Data was collected, tabulated and statistically analyzed using Independent t-test to compare the two designs.
This study revealed No statistically significant differences between the screw retained fixed detachable design and the telescopic retained design regarding stresses transmitted to the implants. It was found that Telescopic retained design transmitted more stress to the implants than the screw retained fixed detachable prosthesis in bilateral and unilateral vertical and oblique loading but with NO statistically significant differences.
This statistical finding may be attributed to the fact that the two attachment designs used are classified as rigid attachments that transmit all stress to the implants and the implant supporting structure, and the fact that the two superstructure designs where fabricated using the same material having the same mechanical properties.