Author(s):
1. Nataša Knežević, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
2. Aleksandra Đeri, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
3. Ognjenka Janković, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
4. Irena Kuzmanović, Radman, Republic of Srpska, Bosnia and Herzegovina
5. Renata Josipović, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina
6. Vladan Mirjanić, Medicinski fakultet Banja Luka , Republic of Srpska, Bosnia and Herzegovina

Abstract:
Introduction Micro-morphological and organic-inorganic changes of dental structure as well as the effect of hydrogen peroxide on polymerisation of composite materials cause lower adhesion, i.e. poor bond quality between composite material and bleached tooth. Objective The aim of this study was to determinate the effect of different concentrations of carbamide (16%, 20% and 30%) and 35% hydrogen peroxide on bond strength of the composite materials and bleached endodontic treated teeth. Methods The current study included 40 extracted human endodontically treated human teeth. Internal bleaching was done using the “Walking bleach technique” method. The teeth were bleached with 16%, 20%, 30% carbamide or 35% hidrogen peroxide. After internal teeth bleaching a class V cavity was prepared and restored with Tetric EvoCeram nanocomposite material. Microleakage was determined using dye method (silver nitrate) and measured on the incisal and gingival walls using stereoloupes. Results The smallest dye penetration on the oclusal wall was found of teeth bleached with 20% carbamide peroxide (5,45 µm), and the largest dye penetration was on teeth bleached with 30% carbamide peroxide (7,25 µm). The smallest dye penetration on the gingival wall was found of teeth bleached with 16% carbamide peroxide (12,25 µm) and the largest dye penetration was on teeth bleached with 30% carbamide peroxide (20,00 µm). The difference was statistically significant (p <0.05). Conclusion Microleakage was detected in all teeth restored with composite and bleached with the internal bleaching technique with 16%, 20%, 30% carbamide or 35% hydrogen peroxide.

Thematic field:
SYMPOSIUM B - Biomaterials and nanomedicine

Date of abstract submission:
20.07.2018.

Conference:
Contemporary Materials 2018 - Savremeni Materijali