objectives: this study aimed to assess the effect of re-etching of desensitized dentin for five and 10 seconds on marginal microleakage of composite restorations. materials and methods: class v cavities (4x2x2mm) were prepared on the buccal surfaces of 64 third molars and randomly divided into four groups of 16. in the control group, single bond (sb) adhesive was applied after etching. in bb+sb...

We report the use of cavity ring-down spectroscopy (CRDS) as a diagnostic tool to study sputter erosion of the VHITAL (Very High Isp Thruster with Anode Layer) thruster. The lifetime of the VHITAL thruster is largely governed by sputter erosion of guard-rings and other critical components. The CRDS technique will be used to measure sputtered molybdenum in the plume of the thruster for various t...

Aspartic acid racemization has been found to be an accurate measure of age at death for recent forensic material. This paper examines the practicality of using acid etching of the tooth surface to extract amino acids from the enamel for racemization analysis. By serial etching of the tooth and contamination of the teeth with bovine serum albumin prior to etching, the ability of etching to remov...

o bjectives: bond strength of composite resin to enamel and dentin of primary teeth is lower than that to permanent teeth; therefore, it may compromise the ad- hesive bonding. new methods, such as laser application have been recently intro- duced for tooth preparation. the purpose of this study was to evaluate the effect of tooth preparation with bur and er:yag laser on shear bond strength of c...

The single conical nanochannel investigated here was produced in polymer films using the ion track-etching technique. [S1] Before the chemical etching process, the samples of PET were exposed to the UV light for 1 h from each side. To produce a conical nanochannel, etching was performed only from one side, the other side of the cell contains a solution that is able to neutralize the etchant as ...

In this treatment method laser radiation, which is guided from a co-axially expanding liquid jet-stream, locally initiates on a metal surface a thermochemical etching reaction, which leads to selective material removal. Time-resolved measurements of the electrical potential were correlated with the specific processing parameters to identify conditions for stable and enhanced chemical etching re...

In recent years, the establishment of an ultimate machining method for realizing further ultra precision, ultra smoothness, and ultra micronization is becoming increasingly essential in the manufacture of various microdevices, which are functional structures. This need demand is particularly strong in the areas of object electronics, mechatronics, biology, and medicine. The accuracy sought rang...

Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enablin...

micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. the purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1) acid etching, 2) fissure enameloplasty and acid etching, and 3) air abrasion and a...