الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The modern take a look at attempted to evaluate in-vitro between the retention forces and stress analysis of 3 solitary ball attachments versus layout of milled bar implant supported mandibular overdenture. An acrylic resin model become made out of a commercially available mold and 3 equal implants have been inserted on the dog location bilaterally and left significant incisor location. 3 equator abutments were connected to implants and 3 scan bodies screwed over equator abutments scanning the placement of the implants was made using extra oral scanner. A CAD CAM milled titanium bar was constructed. Creation of skeleton metallic frameworks digitally , more oral scanner was used for Scanning then A CAD software become used for designing framework one for solitary and the opposite for two designs of milled bar , the two framework were revealed via the use of 3-D laser metal printing gadget to Co-Cr framework using laser additive procedure . Two acrylic overdenture changed into built. Simulation of the mucosa overlaying the residual ridge by using amendment of the epoxy resin solid to create a area of two mm for a mould cavity for simulation of smooth tissue which turned into packed with self-cured silicon soft liner. Nylon caps and their metal housing have been located over the ball attachments for both corporations of solitary implants and milled bar with supra attachments and selecting- up method turned into executed. Retention forces became measured for each group by making use of tensile pressure the use of widespread trying out gadget. The vertical arm of the system was hooked to the metallic plate of the overdenture. Care was taken to ensure that the hook suits passively into the plate and overdenture became properly gripped firmly within the lower fixed compartment of computer-managed testing system. Slow tensile load became then implemented, and most retentive force turned into recorded and measured. Based totally on the assumption that a affected person eliminates his/her prosthesis three instances each day, repeated cycles of removal and insertion became made to simulate the real medical scenario. Retention turned into evaluated at (T0) and after 30 cycle(T1) ,ninety cycles(T2), 270 cycles(T3) , 540 cycles(T4), 810 cycles(T5) , 1080 cycles(T6) ,1620 cycles (T7),2160 cycles(T8), 3240 cycles(T9), 4320(T10), 5400 cycles (T11) which constitute 5 years of overdenture use.
Pressure became recorded and measured with the aid of the usage of stress gauges that have been bonded on eight of the prepared surfaces around implants middle implant and right one to monitor the effect of the vertical load carried out on solitary balls and designs of milled bar, the implant in left canine aren’t prepared due to the fact the proper and left implant were contralateral to each other so we used one of them. Information have been accrued and statistically in comparison.
Evaluating the three companies at the equal time period cycle we determined that, solitary ball attachments confirmed the highest retention force at T0 time period cycle by using one hundred fifty five.89 N in evaluating to Bar with out and with attachments corporations which showed 111.Four N and 142.Five N respectively. While at T1 term cycle solitary attachments showed the lowest retention force in examine to different organizations via 88.01 N, ninety six.24 N and 127.25 N respectively. At T4 term cycle continued to make a dramatic lower in comparing to others agencies by way of 35.Forty six N , 61.77 N and 70.38 N respectively. At T11 time period cycle the result showed 14.Thirteen N, 18.74 N and 22.96 N for the solitary, bar with out attachments and bar with attachment.