objective: etching of enamel and dentin is an important step in restoration of teeth with composite resin ensuring the retention of restoration and decreasing microleakage. this in vitro study sought to compare the effects of kimiya and etch-rite acid etchants on the microleakage of composite restorations.   methods: this experimental study was conducted on 30 sound human molar teeth. class v c...

Samples of 53 materials that are used or potentially can be used or in the fabrication of microelectromechanical systems and integrated circuits were prepared: single-crystal silicon with two doping levels, polycrystalline silicon with two doping levels, polycrystalline germanium, polycrystalline SiGe, graphite, fused quartz, Pyrex 7740, nine other preparations of silicon dioxide, four preparat...

Chemical etching of silicon assisted by various types carbon materials is drawing much attention for the fabrication micro/nanostructures. We developed a method chemical that utilizes graphene oxide (GO) sheets to promote reaction in hydrofluoric acid–nitric acid (HF–HNO3) etchant. By using an optimized composition HF–HNO3 etchant, rate under GO was 100 times faster than our HF–H2O2 system used...

The purpose of this study was to investigate the effect of phosphoric acid etching on the bond strength between enamel and three luting materials employing self-etching primer (PanaviaF2.0, Linkmax, and Multibond). A luting material without self-etching primer (Super-Bond) was used as a control. Two etching agents (K-etchant and Red Activator) were prepared. The surfaces of bovine enamel were g...

In this study, a 35% phosphoric acid gel (3M Scotchbond etchant), a nonrinse etchant (NRC), and two EDTA-containing conditioners (RC-Prep and File-Eze) were tested in vitro for blocking nerve conductance evoked in the rat sciatic nerve after local application. The phosphoric acid gel and NRC completely and irreversibly inhibited conductance. On the other hand, RC-Prep reduced the compound actio...

Light-assisted etching is a processing method that enables selective by light illumination onto semiconductors in an etchant. In this study, we propose the cylindrical surface forming technique light-assisting using leaking from glass fibers. When propagating fiber was placed contact with semiconductor wafer, wafer vicinity of area exposed. addition, immersing contacted etchant, only exposed ex...

The acid-etch technique is used extensively in dentistry. Variations in rinse time are found throughout the dental literature. Even though controversies concerning the appropriate rinse time exist, all investigators agree that copious water lavage is important. This study compared different rinse times using both liquid and gel etchants labeled with 32Phosphorus. Each etchant type was evaluated...

The aim of this study was to evaluate the effect of acid etching time and technique on bond strength of a two-step etch-and-rinse adhesive system to dentin and enamel. Thirty human third molars were mesio-distally sectioned, parallel to the long axis of each tooth, in two halves. Buccal/lingual surfaces were abraded to obtain both flat exposed enamel and dentine. The etchant was applied with an...

This study investigated the effects of surface treatments on the bond strength of a resin composite to a commercially pure titanium. The bonding surfaces of all titanium specimens were ground with 1,000-grit silicon carbide paper and then subjected to one or more of these surface treatments: sandblasting with alumina (sand), etching with 45wt% H2SO4 and 15wt% HCl (SH-etchant) at 70°C for 10 min...

A new mathematical model based on the total concentration approach is proposed for modeling wet chemical etching process. The proposed mathematical model is a fixed domain formulation of the etching problem. The governing equation based on the total concentration includes the interface condition too. The total concentration of etchant includes the reacted and the unreacted concentration of etch...