Abstract
Aimsof the study:The aim of this study is to evaluate the effect of a flowable composite and total etch adhesive on shear bond strength of repaired composite with a different types of tooth colored res-torations (microhybrid, nanohybrid, and ormocer). Materials and Methods Ninety Teflon mold (4 mm ×2mm), of Tetric® Ceram prepared then divided into two main groups 1st control ( without etch-ing ), 2 ed etched with 37 phosphoric acid. Both groups were divided into three subgroups according to a type of adhesiveapplied, 1st control, 2 ed the Excite® and in 3ed the tgflow appliedThe second split of Teflon mold (4mm×1mm)placed onto the prepared specimenEach subgroup (1st control, 2 ed the Excite® and in 3rd the tgflow) were farther divided into three subgroups which entrain filled as fallow: 1st split filled with a Tetric® Ceram, in 2 ed split filled with Tetric NCeram, and in 3 rd. split filled with Admira. Shear bond strength was measured by using Universal Testing Machine, and mode of failure examined by a stereomicroscope. Results: No significant difference in the surface treatment groups. For the adhesive, Tgflow showed superior shear value (3248 MPa) comparing to other adhe-sives while for the composite materials, The Tetric NCeram composite showed superior value of shear strength (2821MPa) comparing to other materialsConclusions: Phosphoric acid has no effect on shear value of repaired composite while Tgflow and Tetric NCeram give an improvement in its shear valueAll composites exhibited cohesive and adhesive type of failure.
