الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
This in -vitro study was performed to evaluate the effect of finishing tools and time of finishing on the surface roughness of one type of bulk fill resin composite. A total of 70 bulk fill resin composite specimens prepared from specially constructed split Teflon molds of 8 mm diameter and 2 mm thickness were used for this study .The specimens were divided into four main groups(n=14) according to finishing procedures: (I) finishing diamond bur + silicone impregnated rubber polishers ( jiffy polishers). (II) finishing diamond bur +(aluminum oxide discs) stem polishing discs.(III) finishing carbide bur+ silicone impregnated rubber polishers( jiffy polishers).(V) finishing carbide bur +aluminum oxide discs (stem polishing discs) . Each group was further divided into two subgroups(n=7) according to finishing time (immediate and delayed (after 24 hours). In addition, fourteen specimens which did not receive further treatment after curing against a Mylar matrix strip(control group), surface roughness was measured immediately after curing for seven specimens of control and other seven specimens after 24 hours.
After application of different finishing procedures , profilometer (TR 220 surface Roughness Tester, Time Group, Pittsburgh, PA, USA) was used for evaluation of surface roughness.
The surface roughness results showed finishing procedures, finishing time and interaction between finishing techniques and finishing time had a statistically significant effect on surface roughness of bulk fill resin composite at (P=0001, P=0.035, and P=0.038 respectively) .
In addition, the control group where no finishing was performed showed the lowest mean surface roughness value and there was significant difference between control group and different finishing and polishing techniques in both immediate and delayed finishing .
In immediate finishing the results showed that diamond bur +jiffy polishers group showed the highest mean surface roughness value and there was significant difference with other finishing and polishing techniques and there was no significant difference between diamond burs+ stem discs, carbide bur + jiffy polishers and carbide bur +stem discs.
In delayed finishing, there was significant difference between diamond bur+ jiffy polishers group and carbide bur +stem discs group, with the highest mean surface roughness value for the diamond + jiffy polishers group there was no significant difference between diamond bur +jiffy polishers and diamond burs+ stem discs and carbide bur +jiffy polishers .Also, there was no significant difference between diamond burs+ stem discs group, carbide bur + jiffy polisher group and carbide + bur stem discs in delayed finishing.
Also the results showed that for the control group, carbide bur + jiffy polishers and carbide bur +stem discs group there was no significant difference between immediate and delayed finishing and there was significant difference between immediate and delayed finishing for diamond bur + jiffy polishers group and diamond bur+ stem discs group at where delayed finishing showed lower surface roughness values