Ahmed A El Zohairy

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OBJECTIVES To investigate the Microtensile bond strength (microTBS) and failure mode of resin cements bonded to composite and ceramic CAD/CAM blocks following various surface treatments. METHODS Paradigm composite blocks and Cerec Vitablocs received three surface treatments following the control treatment of surface grinding with 600 SiC grit. (1)(More)
OBJECTIVE Recent studies have shown that adhesives containing acidic monomers combined with composites can adversely effect the polymerization reaction producing low bond strengths. This phenomenon may also occur in making composite build-ups, jeopardizing one of the key factors for a successful core build-up restoration. The aim of this study was to(More)
PURPOSE This study compared the microshear bond strengths to ground enamel of three one-step self-etching adhesive systems, a self-etching primer system and an etch-and-rinse adhesive system. MATERIALS AND METHODS Three self-etching adhesives, Futurabond DC (Voco), Clearfil S Tri Bond (Kuraray) and Hybrid bond (Sun-Medical), a self-etching primer,(More)
OBJECTIVE The aim of the study was to evaluate the efficacy of the microtensile bond test (microTBS) and the microshear bond test (microSBS) in ranking four dental adhesives according to bond strength to enamel and identify the modes of failure involved. MATERIALS AND METHODS Forty-four caries-free human molars were randomly assigned to one of two bond(More)
OBJECTIVE The purpose of this study was to compare proximal contact tightness (PCT) of MOD resin composite restorations placed with different matricing protocols. METHODS Forty-five ivorine lower right first molars with standardized MOD cavities were equally divided into three groups according to the restoration protocol. Group 1: Sectional matrix(More)
OBJECTIVES This study was carried out to examine the effect of application of four different disinfecting agents on the micro-shear bond strength (μ-SBS) of an etch-and-rinse and self-etch adhesive systems. MATERIALS AND METHODS One hundred flat dentin surfaces of human molars were produced by wet grinding the buccal surfaces. Specimens were randomly(More)
OBJECTIVE The objective of the current study was to compare in-vitro the proximal contact tightness (PCT) of Class II resin composite restorations (RCR) placed with different established and new placement techniques. METHODS 105 ivorine lower left first molars with standardized MO cavities were randomly divided into seven groups (n = 15) as follows:(More)
OBJECTIVES To investigate the role of different acid surface-treatments and hydrophilic and hydrophobic bonding agents on resin ceramic bond durability. METHODS Two resin cements, Tetric Flow and Nexus 2, were applied to CAD/CAM Cerec Vitablocs with six bonding strategies: (1) HF-etching and silanization, (2) HF-etching, silanization and application of a(More)
PURPOSE To evaluate the influence of thermal and mechanical load cycling on the microtensile dentin bond strength of two self-etching and one total-etch adhesives. METHODS The adhesive materials were: a two-step self-etch adhesive (Clearfil SE Bond), a one-step self-etch adhesive (Hybrid Bond), and a total-etch one-step adhesive (Admira Bond). Sixty(More)
The higher microtensile bond strength values found for specimens with a smaller cross-sectional area are often explained by the lower occurrence of internal defects and surface flaws. We hypothesized that this aberrant behavior is mainly caused by the lateral way of attachment of the specimens to the testing device, which makes the strength dependent on the(More)