الفهرس 
ZirconiaOnly 14 pages are availabe for public view
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Abstract
Abstract
Keywords: Marginal adaptation, fracture resistance, Bio HPP, zirconia
Objectives: The purpose of this in-vitro study is to evaluate the marginal
adaptation and fracture resistance of the Bio HPP three-Unit FPDs framework
and compare it with that of Y-TZP Zirconia.
Methods: Two groups of standardized three-unit FDPs framework with
flat occlusal surface (n=10/group) were fabricated. The first group (control)
was made of zirconia blank. The second group was made of Bio HPP blank
using (CAD/CAM) milling machine. The wall thickness of the framework was
0.7 mm and the connectors had an almost rectangular cross-section of 7.36
mm2 surface area, an occluso-gingival height of 3.2 mm, and a bucco-lingual
width of 2.3 mm. To evaluate the marginal adaptation, each specimen was
photographed before and after cementation using USB Digital microscope
with a built-in camera connected with an IBM compatible personal computer
using a fixed magnification of 50 X, a digital image analysis system was used
to measure and qualitatively evaluate the vertical gap width.
To evaluate the fracture resistance, all samples were individually
mounted on the universal materials testing machine, fracture test was done by
compressive static load applied occlousally at the center of the pontic with
upper movable compartment of a universal testing machine traveling at crosshead
speed of 1mm/min. The load required to fracture was recorded in
Newton.
Results: It was found that Zirconia group recorded statistically nonsignificant
higher marginal gap mean value (22.71±3.1μm) than Bio HPP
group (20.27±3.03μm) as indicated by three-way ANOVA followed by pairwise
Tukey’s post-hoc tests (P=0.0825>0.05)
It was noted that Bio HPP group recorded statistically significant
(p<0.05) higher fracture resistance mean value (1626.31±191.9 N) than
Zirconia group (1243.51±175.8 N) as indicated by student t-test (t= 3.1, p=
0.007<0.05)
Conclusions: Bio HPP FDPs framework showed non-significant better
marginal adaptation than Zirconia. Bio HPP framework showed significant
higher fracture resistance than Y-TZP Zirconia. It can be potentially used as
crown and bridge material even in posterior area.