الفهرس 
Resin-based Composites
Modifications of filler for reduced shrinkage/ stress:Only 14 pages are availabe for public view
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Abstract
This in-vitro study studied the marginal integrity of three types of Bulk
Fill Composite resins in Class II cavities.
Forty extracted human sound molars were selected. The teeth were
fixed with sticky wax to the base of plastic cylinder. The cylinder was filled
with self-curing acrylic resin so that only root was embedded within the selfcuring
acrylic resin. Simple Class II cavities with parallel walls were
prepared. The cavities were prepared using coarse diamond stone with water
spray and finished with fine- grained burs. The cervical margin was
established 1.5 mm above the cement - enamel junction. The overall
dimensions and depth of the cavities were standardized as follow: 4 mm
length occluso cervically and 4 mm width bucco lingually and 2 mm depth
axially. The teeth were randomly divided into four groups (n=10 each).
group 1: Tetric N bond Universal and Tetric Evo Ceram Bulk Fill
composite.
group 2: Single Bond Universal and Filtek Bulk Fill posterior composite.
group 3: Futura bond U and Admira Fusion X-Tra.
group 4: Tetric N bond Universal and Tetric Evo Ceram composite.
All samples were thermo cycled for 600 cycles from 5oc to 50oc.
Impressions of the teeth were made using a polyvinyl siloxane material (light
body). The impressions were then poured with epoxy resin. These replicas
were left 24 h for complete setting. Then, Gold sputtered and examined
under SEM with different magnifications (x50, x2000) magnification. The
marginal gap was measured for all the samples using Auto CAD software.