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العنوان
The Effect of Flowable Bulk Fill Vs Multi Increment Composite on Microleakge and Polymerization Shrinkage Strain in Pulpotomized Primary Molars /
المؤلف
Zayed,Dina Salah Eldin Ahmed.
هيئة الاعداد
باحث / Dina Salah Eldin Ahmed Zayed
مشرف / Noha Samir Kabil
مشرف / Amira Saad Badran
تاريخ النشر
2017
عدد الصفحات
124p.:
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
طب الأسنان
تاريخ الإجازة
1/1/2017
مكان الإجازة
جامعة عين شمس - كلية طب الأسنان - أسنان الأطفال
الفهرس
Only 14 pages are availabe for public view

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from 124

Abstract

Success of restoration of pulpotomized molars is highly associated with the biological seal provided by the final restoration that prevent bacterial infiltration of the remaining vital pulp tissue.
Stainless steel crowns have been the golden standard to restore pulpotomized primary molars with high success rate. However, recently parents show increasing demands to provide esthetic restorations for their children causing resin based composites more popular for the restoration of primary molars.
This study was designed to assess and compare the microleakage of different restorative materials: Stainless steel crowns, multi Increment restorative composite resin, and bulk fill flowable restorative composite resin, used in restoration of pulpotomized primary molars using two different adhesive systems. Also to compare between the polymerization shrinkage strain of the two composite resins used.
In the microleakage test the extracted primary second molars were cleaned with rubber cup and pumice and scaled by ultra-sonic scaler to remove any debris on their surfaces and stored in distilled water at room temperature within one month after extraction until use. All the specimens were randomly divided into 3 groups according to the material used as follows: group 1: include specimens that were restored by 3M ESPE stainless steel crowns
group 2: include specimens that were restored by SDR flowable bulk fill composite.
group 3: include specimens that were restored by Ceram.X one multi incremental composite.
Each of groups 2 and 3 were subdivided into 2 subgroups:
Subgroup a (self etch adhesive): In which the composite material was applied after pretreating the surface with self etch adhesive
Subgroup b (total etch adhesive): In which the composite material was applied after pretreating the surface with phosphoric acid etching and single bond universal adhesive.
Standardized class-II proximo-occlusal cavity was prepared involving two surfaces,the buccolingual width of occlusal preparation was 2.5mm, while the depth of occlusal preparation was 6mm, measured from pulpal floor to cuspal tip). The buccolingual width of proximal box was ( 4mm) and the gingival seat was located 2mm coronal to CEJ . The length of proximal buccal and lingual walls was 4mm measured from gingival seat to cuspal tip.
ZOE paste was placed on the pulp chamber floor and filled the entire cavity in the group one, while in the remaining groups filled the pulp chamber floor, but it was not extended to the outer margin of the cavity, then a layer of glass ionomer cement was applied over it and the occlusal depth of the cavity calibrated by reamer with a stopper to be the same depth from cusp tips to the cement base for all teeth about 4 mm.Standard SSC preparations were made on teeth of group one. The crowns was cemented by using glass ionomer cement.
group two and three teeth were restored by bulk fill and multi increment composite respectively, using two different adhesive systems: self etch adhesive and etch and rinse adhesive. All restoration procedures were done according to the manufacturer recommendations.
The teeth of the three groups were thermocycled between 5°C and 55 °C water baths for 500 thermal cycles, then were sectioned and the dye penetration along the cavity wall (including both axial and gingival margins) was assessed with a measuring Stereomicroscope.
Polymerization shrinkage strain was evaluated using strain gage method. A custom made split Teflon mold was designed with central hole of 4 mm diameter, 4 mm thickness and external holding ring. The flowable bulk fill composite and the universal nano ceramic conventional composite both were placed in 4mm bulk thickness for standardization.
Data was tabulated and statistically analyzed. The results showed that none of the three groups were free from dye penetration, and showed no significant difference between all groups. It was found that the highest dye penetration scores mean value recorded with group 1(Teeth restored with stainless steel crowns) followed by subgroup2b (Teeth restored with SDR flowable bulk fill composite with self etch adhesive) then subgroup 3a (Teeth restored by Ceram.X-one multi incremental composite with total etch adhesive) and subgroup 3b (Teeth restored by Ceram.X one multi incremental composite with self etch adhesive) respectively while the lowest dye penetration scores mean value recorded with subgroup2a(Teeth restored with SDR flowable bulk fill composite with total etch adhesive).
Polymerization shrinkage test results showed that the multi incremental group (The universal nano ceramic CeramX-one composite) recorded higher polymerization shrinkage mean value than Bulk fill group (SDR), while the difference between the two groups was statistically non-significant.