IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-9-5-25040 Original Research Paper Bond strength of self adhering composite as post endodontic restoration after non vital bleaching- an ex-vivo study Aishwarya Sinha Dr. Dr. Vineeta Nikhil Dr. May 2020 9 5 01 02 ABSTRACT

Objectives: To evaluate the bond strength of self adhering composite as a post endodontic restoration after non vital bleaching. Material and Methods: 80 freshly extracted intact human permanent mandibular first molars were embedded in acrylic resin with their occlusal surfaces facing upwards, which were then ground axially till 2mm below the DEJ. The mounted samples were then randomly divided into two groups: Group 1(unbleached), further subdivided into SUB(Self adhering composite), SSUB(Self etch+ Self adhering composite), NUB(Self etch+ Nanohybrid composite), and Group 2(bleached), in which samples were first subjected to non vital bleaching and subdivided into two subgroups; Subgroup A consisting of: SAB1(Bleaching+Self adhering composite), SAB2 (Bleaching+Self etch+Self adhering composite), SAB3 (Bleaching+Antioxidant+Self adhering composite), SAB4 (Bleaching+Antioxidant+Self etch+Self adhering composite); and Subgroup B, which included NHB (Bleaching+Antioxidant+Self etch+Nanohybrid composite).Thereafter, composite cylinders were fabricated on the surface of all the samples using teflon molds according to the type of composite for each group. The samples were then incubated for 24hours and then subjected to shear bond strength testing. The results obtained were subjected to statistical analysis by One Way ANOVA F–Test and Unpaired “t” test were used. Result: The mean bond strength values obtained were: Unbleached: NUB> SSUB> SUB Bleached: NHB> SAB4> SAB2> SAB3> SAB1 Conclusions: Self adhering composites exhibited significantly higher bond strength when used with self etch approach. If immediate bonding after non vital bleaching is necessary, antioxidant treatment should be done