OBJECTIVES This in-vitro study aimed to compare the push-out bond strength of composite to prepared and unprepared intracanal dentin using a 5th generation bonding agent in primary anterior teeth after etching for seven and 15 seconds. MATERIALS AND METHODS Sixty primary anterior teeth were randomly divided into four groups. In groups one and two, intracanal dentin remained intact while in gr...

The purpose of this study was to evaluate the bond strength of metallic orthodontic brackets to feldspathic ceramic with different etching times, bonding materials and with or without silane application. Cylinders of feldspathic ceramic were etched with 10% hydrofluoric acid for 20 or 60 s. For each etching time, half of the cylinders received two layers of silane. Metallic brackets were bonded...

Purpose: To evaluate microleakage of pit and fissure sealant after using four different pit and fissure preparation techniques 1) Pumice prophylaxis and acid etching 2) Fissure enameloplasty and acid etching 3) Self etching adhesive system 4) Air abrasion and acid etching. Methods: Eighty exfoliated primary molars with no clinical evidence of caries were randomly divided into 4 groups of 20 eac...

Desorption/ionization on porous silicon mass spectrometry (DIOS-MS) is a novel method for generating and analyzing gas-phase ions that employs direct laser vaporization. The structure and physicochemical properties of the porous silicon surfaces are crucial to DIOS-MS performance and are controlled by the selection of silicon and the electrochemical etching conditions. Porous silicon generation...

A tribochemistry-induced selective etching approach is proposed for the first time to produce silicon nanostructures without lattice damage. With a ~1 nm thick SiOx film as etching mask grown on Si(100) surface (Si(100)/SiOx) by wet-oxidation technique, nano-trenches can be produced through the removal of local SiOx mask by a SiO2 tip in humid air and the post-etching of the exposed Si in potas...

CO2 laser-induced pyrolysis of silane (photothermal aerosol synthesis) was used to produce Si nanoparticles. Particles with an average diameter as small as 5 nm were prepared directly from silane in the gas phase. Etching these particles with mixtures of hydrofluoric acid (HF) and nitric acid (HNO3) is shown to be an effective method to reduce the size of the particles produced by silane pyroly...

background: based on contradictory findings concerning the use of lasers for enamel etching, the purpose of this study was to investigate the shear bond strength of teeth prepared for bonding with er-yag laser etching and compare them with phosphoric acid etching. materials and methods: in this in vitro study forty – eight premolars, extracted for orthodontic purposes were randomly divided in t...

Spectroscopic ellipsometric monitoring of electron cyclotron resonance plasma etching of GaAs and AlGaAs" (1995). Faculty Publications from the Department of Electrical and Computer Engineering. 73. In situ real time spectroscopic ellipsometry measurements were made during electron cyclotron resonance plasma etching of radio frequency biased GaAs and AlGaAs samples. Gas mixtures used were CH 4 ...

In this experimental work, by using the method of plasma-chemical etching, we have dealt with the causes of the creation of a distorted layer on the surface of silicon wafers during mechanical machining processes, in addition, the elucidation of connections between the structure of this layer and characteristic parameters of the mechanical strength of these wafers have been studied. Experimenta...

Contradictory evidence exists as to the acid necessary for producing optimum enamel etching on buccal tooth surfaces. The aims of this study were to (1) compare the etching abilities of four different acids; (2) identify the acid concentrations required for optimum etching; and (3) determine the concentration stability of phosphoric acid solutions. Crowns of caries-free molar teeth were pumiced...