Aim: To compare the shear bond strength (SBS) of a solvent free self-etch adhesive with solvent containing adhesives. Methods: Forty-five human teeth were sectioned longitudinally to expose superficial dentin and substrates polished with 600-grit SiC paper. The adhesive area was isolated with a cylindrical Teflon mold 3x4 mm. Fifteen specimens were prepared for each material. Were evaluated a s...

OBJECTIVE This study evaluated marginal integrity of bonded posterior resin composite fillings to enamel and dentine with and without 4mm flowable base, before and after thermo-mechanical loading (TML). METHODS 80 MOD cavities with one proximal box beneath the CEJ were prepared in extracted human third molars. Direct resin composite restorations (SDR with CeramX mono, Tetric EvoCeram, Filtek ...

The interaction of H atoms with the curved concentric graphene walls of a multiwall carbon nanotube and the stacked planar graphene sheets of graphite was investigated using a combination of high resolution transmission electron microscopy HRTEM in conjunction with electron energy-loss and Raman spectroscopies. Continuous cylindrical graphene walls of a nanotube are etched and amorphized by the...

We study the effects of plasma etching on the evolution of surface roughness of GaN and AlN. The etch-induced roughness is investigated using atomic force microscopy by systematically varying plasma power, chamber pressure, and Cl2 /Ar mixture gas composition. GaN etches three to four times more rapidly than AlN for identical plasma conditions. For both GaN and AlN, we find that the surface rou...

The etching of silicon in remote microwave discharges fed with NF3 /O2 has been investigated. In situ ellipsometry and x-ray photoelectron spectroscopy ~XPS! were used to monitor surface effects, while mass spectrometry was used to monitor the gas phase dynamics. Varying the microwave power from 600 to 1400 W has little effect, due to the near complete dissociation of the NF3, even at lower pow...

OBJECTIVE Bioactive glass air abrasion is a conservative technique to remove initial decalcified tissue and caries. This study examined the shear bond strength of composite resin to sound and decalcified enamel air-abraded by bioactive glass (BAG) or alumina using etch-and-rinse and self-etch adhesives. MATERIALS AND METHODS Forty-eight permanent molars were root-amputated and sectioned mesio...

This study determined the effect of cleansing solutions on microtensile bond strengths of self-etch adhesives to saliva-contaminated dentin. Seventy five human molars were ground flat to expose mid-depth dentin, and randomly assigned to 5 groups (n=15): no contamination, saliva contamination without cleansing, saliva and cleansing with water, saliva and cleansing with 2% chlorhexidine, and sali...

The etching of silicon nitride (Si3N4) and silicon dioxide (SiO2) in the afterglow of NF3 and NF3 /O2 microwave discharges has been characterized. The etch rates of both materials increase approximately linearly with the flow of NF3 due to the increased availability of F atoms. The etch rate of Si3N4 is enhanced significantly upon O2 injection into the NF3 discharge for O2 /NF3 ratios of 0.3 an...

AIM This study evaluated and compared the role of newer dental adhesives to bond composite resin to the resin modified glass ionomer (RMGIC) liner. MATERIALS AND METHODS Thirty-six specimens were prepared on acrylic blocks, with wells prepared in it by drilling holes, to retain the RMGIC. The specimens were randomly divided into three groups of 12 specimens each. In group I, a thin layer of a...

Mutation of the tobacco etch virus (TEV) protease nucleophile from cysteine to serine causes an approximately ∼104 -fold loss in activity. Ten rounds of directed evolution of the mutant, TEVSer , overcame the detrimental effects of nucleophile exchange to recover near-wild-type activity in the mutant TEVSer X. Rather than respecialising TEV to the new nucleophile, all the enzymes along the evol...