الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Dental implant have become a significant aspect of tooth replacement in prosthodontic treatment. Despite of high success rates, complications and failures still occur .
Despite the high success rates reported by a vast number of Clinical studies, early or late implant failures are still unavoidable. Late implant failures are observed after prosthesis delivery and are mainly related to biomechanical complications. There is a consensus that, the location and magnitude of occlusal forces affect the quality and quantity of induced strains and stresses in all components of the bone-implant prosthesis complex.
The aim of this research was to study the effect of three CAD/CAM crown materials ( Cerasmart , BioHPP and PMMA ) with two load directions ( vertical and 45o ) on strain transmitted around immediately loaded implants .
The materials tested in this study represent the different possibilities encountered in the dental market aiming to provide information about the appropriate material which produces the least functional load on immediately loaded implant to fulfil the demands of the patients.
Three implants were embedded in epoxy resin blocks A,B,C. Scanning of implant abutments was done using CAD/CAM machine . Milling of 30 crowns (n=30) using CERASMART CAD/CAM, BioHPP CAD/CAM and
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Summary
CAD temp blocks as follows:
group (I) : CERASMART crowns (n=10).
group (II) : BioHPP crowns (n=10)
group (III): PMMA crowns (n=10 ).
Each crown of each group was cemented on abutment of its block using temporary cement .
Loading on each crown was done with two load directions (vertical and lateral (45o) loading) and strain on each implant was measured using strain gauge.
Two strain gauges were fixed mesially and distally to the upper part of each implant and load of 100 N was applied on each crown vertically and at 45o using special device to put the crowns at angulation of 45 degrees, load was oriented to touch the central fossa in both cases.
The output readings were analysed using computer software.
The results of strain showed that implants supporting BioHPP crowns showed statistically significantly higher mean microstrain values than those supporting CERASMART & PMMA crowns and there was no statistical significant differences between CERASMART & PMMA in specimens exposed to vertical and 45o loads.