الفهرس 
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Abstract
This study evaluated the shear bond strength of an
adhesive system to two types of zirconia (conventional ZI
zirconia and translucent TZI zirconia) after thermocycling.
Ten square shaped large samples from Incoris ZI blocks,
and another 10 from Incoris TZI blocks were sectioned with
larger dimensions (12 x 12 x 2 mm). Another 10 square shaped
small samples from each type of zirconia blocks were with
dimensions (6 x 6 x 2 mm), all of the samples sintered. The
surfaces of the large and small samples were air abraded in
sandblasting unit by 110 µm AL2O3 particles, then each small
sample was bonded to the large samples using two types of
cement (Single bond universal adhesive+ RelyX Ultimate
cement and Panavia F2.0 cement) and light cured for 20 sec.
Specimens were divided into 2 groups according to the type of
zirconia: 1) group C (Conventional zirconia) ; 2) group T
(Translucent zirconia). Each group was subdivided into 2
subgroups according to type of the cement: a) subgroup CP:
Cemented with Panavia F2.0 ; b) subgroup CR: Cemented with
RelyX Ultimate; c) subgroup TP: Cemented with Panavia F2.0;
d) subgroup TR: Cemented with RelyX Ultimate under 3kg load,
light cured for 20 sec per surface. All samples were
thermocycled and the shear bond strength was carried out using a
computerized universal testing machine at a crosshead speed 0.5
mm/min. Data were statistically analyzed. The cement/ zirconia
interface for each subgroup was examined under SEM. ResultsSummary and conclusion
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showed that no significant difference between shear bond
strength of all subgroups tested. Single bond universal adhesive
+ RelyX Ultimate cement yielded higher shear bond strength
(CR15.35MPa, TR18.06MPa) than Panavia F2.0 (CP14.15MPa,
TP15.91MPa) with two types of zirconia.