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العنوان
Effect of Different Curing Distances on Some Physicomechanical Properties of Bulk-Fill Composite Resins /
المؤلف
Metwally, Lamia Nabil Mohamed.
هيئة الاعداد
باحث / لمياء نبيل محمد متولي
مشرف / مختار ناجي ابراهيم
مشرف / أميمة حسن غلاب
مشرف / محمد عمرو كامل
تاريخ النشر
2017.
عدد الصفحات
145 p. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
Dentistry (miscellaneous)
تاريخ الإجازة
1/1/2017
مكان الإجازة
جامعة عين شمس - كلية طب الأسنان - العلاج التحفظى
الفهرس
Only 14 pages are availabe for public view

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Abstract

This study was carried out to evaluate flexural strength, microhardness, water sorption and solubility both immediately and after 1 year storage time as well as cuspal deflection of three different bulk-fill composite resins used as a base.
For flexural strength testing a total of 240 specimens were divided into 3 groups according to the type of bulk-fill resin composite. Each group was divided into two subgroups according to the curing distance (2 and 4 mm from the surface), and further subdivided into two subgroups according to the storage time (24 hours and 1 year) in distilled water.
For microhardness testing a total of 60 specimens were divided into 3 groups according to the type of bulk-fill resin composite. Each group was divided into two subgroups according to the curing distance (2 and 4 mm from the surface), and further subdivided into two subgroups according to the storage time (24 hours and 1 year) in distilled water.
For water sorption and solubility testing a total of 60 specimens were divided into 3 groups according to the type of bulk-fill resin composite. Each group was divided into two subgroups according to the curing distance (2 and 4 mm from the surface), and further subdivided into two subgroups according to the storage time (24 hours and 1 year) in distilled water.
For cuspal deflection samples were divided into 3 groups according to the type of bulk-fill resin composite. Each group was divided into two subgroups according to according to the curing distance (2 and 4 mm from the bottom) and the mean total cuspal deflection between the two sides of the mold simulating the buccal and lingual cusps was measured and calculated.
After the testing the results showed that the type of resin composite material as well as the storage time have a statistically significant effect on mean flexural strength while the curing distance has no statistically significant effect.
The results also showed that the type of resin composite material have a statistically significant effect on mean microhardness while storage time and curing distance have no statistically significant effect. The type of resin composite material as well as the storage time and the curing distance have a statistically significant effect on mean water sorption.
The type of the resin composite material as well as storage time and curing distance have no statistically significant effect on mean solubility.
The type of resin composite materials have a statistically significant effect on mean cuspal deflection. While; the curing distance had no statistically significant effect .
Under the limitations of this study the following conclusions could be suggested:
1. The randomly oriented E glass fibers seem to have a valuable effect in the reinforcement of the resin matrix of fiber reinforced bulk-fill composite resin which was shown by the high values of flexural strength and microhardness compared to the other two materials although it may have a negative effect on cuspal deflection.
2. The microhardnes of different resin composite materials is highly dependent on the chemical formulation of the composite resin and the curing distance.
3. Water sorption is a time dependent variable in different tested bulk-fill composite resin materials.
4. Storage for one year may have a detrimental effect on both Flexural strength and microhardness values of bulk-fill resin composite.