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Start Over Journal lasers in medical science
4 results

1. Effect of lights with various wavelengths on bleaching by 30% hydrogen peroxide

Author

Masayuki Otsuki, Junji Tagami, Thwe Zin Ei, Minh N Luong, Yasushi Shimada, and Yasunori Sumi

Subjects
Paper, Materials science, Light, Color, Dermatology, Photochemistry, medicine.disease_cause, 030207 dermatology & venereal diseases, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Image Processing, Computer-Assisted, Tooth Bleaching, medicine, Potential source, Irradiation, Tooth Bleaching Agents, Hydrogen peroxide, Colorimeter, Light irradiation, Hydrogen Peroxide, 030206 dentistry, Wavelength, chemistry, Color changes, Surgery, Ultraviolet
Abstract

The objective of this study was to evaluate the bleaching effect of light sources with various wavelengths using 30% hydrogen peroxide (HP) in vitro. The hematoporphyrin-stained paper was bleached with HP and irradiated for 10 min using LED light sources with 265, 310, 365, 405, or 450 nm respectively. In control group, HP was applied for 10 min without light irradiation. The bleaching procedure was repeated two times. The L*a*b* values of the samples before bleaching and after each bleaching step were measured using a colorimeter. Color changes of specimens were then calculated and statistically analyzed. There was an interaction between light sources and time of irradiation in the color change (p 0.05). Time and light sources significantly affected ΔE and ΔL (p 0.05). The light source of 256 nm showed the highest bleaching effect over time followed by that of 310 nm, which were statistically different from other groups (p 0.001). The 365 nm, 450 nm groups, and control group showed low bleaching effect visually with no significant differences in ΔE and ΔL (p 0.05). It was concluded that the wavelengths of the light sources affected the bleaching by HP. The 310-nm light can be a potential source for bleaching.

Published
2018

2. In vitro and in vivo studies of osteoblast cell response to a titanium-6 aluminium-4 vanadium surface modified by neodymium:yttrium–aluminium–garnet laser and silicon carbide paper

Author

Mohammad E. Khosroshahi, Mahboobeh Mahmoodi, and H. Saeedinasab

Subjects
Male, Paper, Materials science, Surface Properties, Carbon Compounds, Inorganic, chemistry.chemical_element, Lasers, Solid-State, Dermatology, In Vitro Techniques, Cell Line, Mice, chemistry.chemical_compound, Osseointegration, Yttrium aluminium garnet, Aluminium, Materials Testing, Alloys, Cell Adhesion, Surface roughness, Animals, Surface Tension, Composite material, Titanium, Osteoblasts, Goats, Silicon Compounds, Metallurgy, Titanium alloy, Prostheses and Implants, Hardness, Corrosion, chemistry, Nd:YAG laser, Vickers hardness test, Microscopy, Electron, Scanning, Surgery, Adsorption
Abstract

The effects of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser and silicon carbide (SiC) paper on the surface micro-topography of titanium-6 aluminium-4 vanadium (Ti6Al4V) alloy were examined in relation to the response of bone cells. The study was performed in three distinct stages: (1) after surface treatment of samples by laser and SiC paper, the surface hardness, surface roughness, corrosion resistance and surface tension were evaluated; (2) the growth of mouse connective tissue fibroblast cells (L-929) on untreated and treated samples was assessed in vitro; (3) the response of goat osteoblast cells to untreated and treated implanted samples was assessed in vivo. The surface roughness varied between 7 +/- 0.02 for laser-treated samples (LTSs) at 140 J cm(-2) and 21.8 +/- 0.05 for mechanically treated samples (MTSs). The surface hardness was found to vary from 377 Vickers hardness number (VHN) for MTSs to 850 VHN for LTSs. A corrosion potential of -0.21V was achieved for the LTSs compared with -0.51V for the MTSs. The LTSs exhibited a more hydrophilic behaviour (i.e. wettability) than did the MTSs. No cytotoxicity effect, unlike for the MTSs, was observed for the LTSs. The results of in vivo tests indicated longitudinal growth of osteoblast cells along the grooves on the samples formed by the SiC paper, and multidirectional spreading of the cells on the LTSs.

Published
2008

3. Effect of lights with various wavelengths on bleaching by 30% hydrogen peroxide.

Author

Luong MN, Otsuki M, Shimada Y, Ei TZ, Sumi Y, and Tagami J

Subjects
Color, Image Processing, Computer-Assisted, Paper, Hydrogen Peroxide pharmacology, Light, Tooth Bleaching, Tooth Bleaching Agents pharmacology
Abstract

The objective of this study was to evaluate the bleaching effect of light sources with various wavelengths using 30% hydrogen peroxide (HP) in vitro. The hematoporphyrin-stained paper was bleached with HP and irradiated for 10 min using LED light sources with 265, 310, 365, 405, or 450 nm respectively. In control group, HP was applied for 10 min without light irradiation. The bleaching procedure was repeated two times. The L*a*b* values of the samples before bleaching and after each bleaching step were measured using a colorimeter. Color changes of specimens were then calculated and statistically analyzed. There was an interaction between light sources and time of irradiation in the color change (p < 0.05). Time and light sources significantly affected ΔE and ΔL (p < 0.05). The light source of 256 nm showed the highest bleaching effect over time followed by that of 310 nm, which were statistically different from other groups (p < 0.001). The 365 nm, 450 nm groups, and control group showed low bleaching effect visually with no significant differences in ΔE and ΔL (p > 0.05). It was concluded that the wavelengths of the light sources affected the bleaching by HP. The 310-nm light can be a potential source for bleaching.

Published
2019
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4. In vitro and in vivo studies of osteoblast cell response to a titanium-6 aluminium-4 vanadium surface modified by neodymium:yttrium-aluminium-garnet laser and silicon carbide paper.

Author

Khosroshahi ME, Mahmoodi M, and Saeedinasab H

Subjects
Adsorption, Alloys, Animals, Carbon Compounds, Inorganic, Cell Adhesion physiology, Cell Line, Corrosion, Goats, In Vitro Techniques, Male, Materials Testing, Mice, Microscopy, Electron, Scanning, Osseointegration physiology, Osteoblasts ultrastructure, Paper, Silicon Compounds, Surface Properties, Surface Tension, Lasers, Solid-State, Osteoblasts physiology, Prostheses and Implants ultrastructure, Titanium
Abstract

The effects of neodymium:yttrium-aluminium-garnet (Nd:YAG) laser and silicon carbide (SiC) paper on the surface micro-topography of titanium-6 aluminium-4 vanadium (Ti6Al4V) alloy were examined in relation to the response of bone cells. The study was performed in three distinct stages: (1) after surface treatment of samples by laser and SiC paper, the surface hardness, surface roughness, corrosion resistance and surface tension were evaluated; (2) the growth of mouse connective tissue fibroblast cells (L-929) on untreated and treated samples was assessed in vitro; (3) the response of goat osteoblast cells to untreated and treated implanted samples was assessed in vivo. The surface roughness varied between 7 +/- 0.02 for laser-treated samples (LTSs) at 140 J cm(-2) and 21.8 +/- 0.05 for mechanically treated samples (MTSs). The surface hardness was found to vary from 377 Vickers hardness number (VHN) for MTSs to 850 VHN for LTSs. A corrosion potential of -0.21V was achieved for the LTSs compared with -0.51V for the MTSs. The LTSs exhibited a more hydrophilic behaviour (i.e. wettability) than did the MTSs. No cytotoxicity effect, unlike for the MTSs, was observed for the LTSs. The results of in vivo tests indicated longitudinal growth of osteoblast cells along the grooves on the samples formed by the SiC paper, and multidirectional spreading of the cells on the LTSs.

Published
2009
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