الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Summary and Conclusions
Our study aimed to measure and compares the fracture toughness
value of different adhesives-dentin interfaces by laboratory testing and by
finite element analysis before and after 6 months of storage in distilled
water.
In this study the fracture toughness of adhesive-dentin interfaces
was determined using a chevron-notched beam (CNB) test. The prepared
chevron notch caused the fracture to propagate along the adhesive
interface when subjected to 4-point bending test setup using a universal
testing machine after 24 hours.
Specimen storage for 6 months in distilled water was done to test
the durability and predict the longevity of resin dentin bond.
Finite element analysis has been used to measure the fracture
toughness value by analyzed the von Mises and maximum principal
stresses of the adhesive layer at the adhesive-dentin interface induced by
the fracture loads obtained from the experimental work and to compare
the fracture toughness results with the finite element analysis results.
The results of the fracture toughness value test different adhesive
systems showed that the multi-step adhesives bonded more effectively
than simplified one-step adhesives, Self-adhesive resin cement showed the
lowest fracture toughness values after 24 hours and 6 month due to the
relative shallow interaction with the underlying dentin.
Summary and Conclusion
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After 6 month aging the results of the fracture toughness value of
all adhesive approaches showed significantly lower values than 24 hours
groups due to resin hydrolysis, plasticization and subsequent degradation
of dentin-resin interface by water.