In this paper, the dynamic behavior of laser induced optical breakdown in impure water was studied by using a pump- probe technique. The plasma was induced by a 1064 nm Nd:YAG laser pulse (with pulse duration ~10 ns) in distilled water with two types of impurities: (I) a solution (highly diluted salt water as a conductor) and (II) a colloidal (TiO2 in colloidal nanoparticle form as a dielectric...

this study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets.fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: groups 1 (control) and 2: the brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. t...

the aim of this project is to fabricated an aluminium-copper bimetal through the fusion method and examine its performance. an aluminium-copper-aluminium bimetal was built by the laser cladding method. the laser power as well as the annealing time effects on its interfacial properties of the bonding’s formed through the laser cladding were investigated. to fabricate the multilayer bimetal, the ...

introduction: the aim of this study was to evaluate the effect of various concentrations of naocl on shear bond strength of composite resin to dentin of primary teeth, prepared with laser and bur. methods: in this in vitro study, 48 primary molars were sectioned at mesiodistal direction and were randomly divided into 6 groups; g1: bur, g2: bur + naocl 2.5%, g3: bur + naocl 5.25%, g4: laser, g5:...

conclusions caffeic acid treatment reduced bacterial growth and resulted in a decreased number of colony formation. the simultaneous effect of caffeic acid and laser at three time courses showed a synergic effect in reducing colony formation compared to the control and caffeic acid, and laser alone. objectives the aim of this study was to investigate the effect of caffeic acid and low-power las...

background recently, the clinical use of low power lasers has increased, and it is said that wound healing is accelerated by their irradiation. the aim of this study was evaluation of the effect of platelet-rich plasma on proliferation and differentiation of human dental pulp stem cells with or without ga-al-as laser. methods: in this experimental study, human lower third molar dental pulp cell...

ftr-raman spectra of human dental enamel, both laser-irradiated and untreated, are reported. spectra are compared with hydroxyapatite. it is evident that unlike the co2 laser, the nd/yag laser does not induce any chemical change in dental enamel.

a quantum theory of a two and three-level laser with injected atomic coherence is developed by using a density operator method, to the best of our knowledge, for the first time. the initial atomic coherence plays an essential role. at steady state, the equation of motion for the density operator yields to exhibit laser without inversion and a phase locking but no threshold for the laser field. ...