Increasing pulse number during CO 2 laser irradiation of dental enamel extends acid dissolution time

2005 ◽  
Author(s):  
John D. B. Featherstone ◽  
Charles Q. Le ◽  
Daniel Fried
Keyword(s):  
Laser Irradiation ◽  
Dental Enamel ◽  
Pulse Number ◽  
Dissolution Time ◽  
Acid Dissolution

scholarly journals Chemical Changes Associated with Increased Acid Resistance of Er:YAG Laser Irradiated Enamel

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Jennifer Manuela Díaz-Monroy ◽  
Rosalía Contreras-Bulnes ◽  
Oscar Fernando Olea-Mejía ◽  
María Magdalena García-Fabila ◽  
Laura Emma Rodríguez-Vilchis ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Structural Changes ◽  
Er:Yag Laser ◽  
Laser Energy ◽  
Dental Enamel ◽  
Acid Resistance ◽  
Control Groups ◽  
Acid Dissolution ◽  
Chemical Changes ◽  
Group I

Background. An increase in the acid resistance of dental enamel, as well as morphological and structural changes produced by Er:YAG laser irradiation, has been reported.Purpose. To evaluate the chemical changes associated with acid resistance of enamel treated with Er:YAG laser.Methods. Forty-eight enamel samples were divided into 4 groups (n=12). Group I (control); Groups II, III, and IV were irradiated with Er:YAG at 100 mJ (12.7 J/cm2), 200 mJ (25.5 J/cm2), and 300 mJ (38.2 J/cm2), respectively.Results. There were significant differences in composition of irradiated groups (with the exception of chlorine) and in the amount of calcium released.Conclusions. Chemical changes associated with an increase in acid resistance of enamel treated with Er:YAG laser showed a clear postirradiation pattern characterized by a decrease in C at.% and an increase in O, P, and Ca at.% and no changes in Cl at.%. An increased Ca/P ratio after Er:YAG laser irradiation was associated with the use of higher laser energy densities. Chemical changes produced by acid dissolution showed a similar trend among experimental groups. Stable or increased Ca/P ratio after acid dissolution was observed in the irradiated groups, with reduction of Ca released into the acid solution.

Initial Dissolution Rate Studies on Dental Enamel after CO2 Laser Irradiation

1992 ◽  
Vol 71 (7) ◽  
pp. 1389-1398 ◽  
Author(s):  
J.L. Fox ◽  
D. Yu ◽  
M. Otsuka ◽  
W.I. Higuchi ◽  
J. Wong ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Laser Irradiation ◽  
Co2 Laser ◽  
Dental Enamel ◽  
Initial Dissolution Rate

Calcium solubility of dental enamel following Er, Cr:YSGG laser irradiation

2000 ◽  
Author(s):  
Christian Apel ◽  
Hans-Georg Graeber ◽  
Norbert Gutknecht
Keyword(s):  
Laser Irradiation ◽  
Dental Enamel ◽  
Calcium Solubility

scholarly journals Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation

2014 ◽  
Vol 15 (3) ◽  
pp. 283-287 ◽  
Author(s):  
Mateus Rodrigues Tonetto ◽  
Marcelo Ferrarezi de Andrade ◽  
Shelon Cristina Souza Pinto ◽  
Darlon Martins Lima ◽  
José Roberto Cury Saad ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Soft Tissues ◽  
Er:Yag Laser ◽  
Laser System ◽  
Dental Enamel ◽  
Target Tissue ◽  
Structural Effects ◽  
Ablation Process ◽  
Dental Tissues ◽  
Laser Systems

ABSTRACT Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations — namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. Clinical relevance Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems. How to cite this article Lima DM, Tonetto MR, de Mendonça AAM, Elossais AA, Saad JRC, de Andrade MF, Pinto SCS, Bandéca MC. Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation. J Contemp Dent Pract 2014;15(3):283-287.

Acid dissolution of synthetic aluminous goethite before and after transformation to hematite by heating

Clay Minerals ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 55-65 ◽  
Author(s):  
H. D. Ruan ◽  
R. J. Gilkes
Keyword(s):  
Surface Area ◽  
Heating Temperature ◽  
Dissolution Kinetics ◽  
Frequency Factor ◽  
Dissolution Time ◽  
Unit Surface Area ◽  
Acid Dissolution ◽  
Al Substitution ◽  
Before And After ◽  
Kinetics Of

AbstractMeasurements of the kinetics of acid dissolution of synthetic aluminous goethites and corresponding hematites produced by heating of parent Al-goethites at various temperatures were carried out in 1 M HC1 at 30, 40 and 50°C. Dissolution-time curves show sigmoidal shapes for the goethites (110°C), whereas deceleratory shapes were obtained for most of the partly and fully dehydroxylated samples. The dissolution rate for all materials decreased with increasing Al substitution and increased with increasing dissolution temperature, specific surface area and heating temperature. On a unit surface area basis, hematite dissolved ∼ 2–8 times faster than goethite. Dissolution kinetics of most heated goethite samples (200–260°C) were quite well described (R2 > 0.96) by the modified first-order Kabai equation. The activation energy and frequency factor for dissolution increased with increasing Al substitution.

Sub ablative Er: YAG laser irradiation on surface roughness of eroded dental enamel

2015 ◽  
Vol 78 (11) ◽  
pp. 989-993 ◽  
Author(s):  
Fabiana Almeida Curylofo-Zotti ◽  
Taísa Penazzo Lepri ◽  
Vivian Colucci ◽  
Cecília Pedroso Turssi ◽  
Silmara Aparecida Milori Corona
Keyword(s):  
Surface Roughness ◽  
Laser Irradiation ◽  
Dental Enamel ◽  
Yag Laser

Effects of 960-nm Diode Laser Irradiation on Calcium Solubility of Dental Enamel: Anin VitroStudy

2006 ◽  
Vol 24 (6) ◽  
pp. 689-693 ◽  
Author(s):  
Ilka T. Kato ◽  
Eduardo K. Kohara ◽  
Jorge E.S. Sarkis ◽  
Niklaus U. Wetter
Keyword(s):  
Laser Irradiation ◽  
Diode Laser ◽  
Dental Enamel ◽  
Calcium Solubility

scholarly journals Synergistic effect of fluoride and laser irradiation for the inhibition of the demineralization of dental enamel

2017 ◽  
Author(s):  
Raymond Lee ◽  
Kenneth H. Chan ◽  
Jamison Jew ◽  
Jacob C. Simon ◽  
Daniel Fried
Keyword(s):  
Synergistic Effect ◽  
Laser Irradiation ◽  
Dental Enamel

scholarly journals Overcoming Multidrug Resistance by On-Demand Intracellular Release of Doxorubicin and Verapamil

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jianwei Jiang ◽  
Shaojuan Liu ◽  
Chunlei Wang ◽  
Hongyan Zhang
Keyword(s):  
Multidrug Resistance ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
Chemotherapeutic Agents ◽  
Pulse Number ◽  
Phospholipid Bilayer ◽  
Multidrug Resistance Proteins ◽  
High Concentration ◽  
On Demand

Multidrug resistance (MDR) is one of the major obstacles to the successful application of cancer chemotherapy. Herein, we developed light-responsive doxorubicin-and-verapamil-coencapsulated gold liposomes to overcome MDR. Upon ns-pulsed laser irradiation, the highly confined thermal effect increased the permeability of the phospholipid bilayer, triggering the release of doxorubicin and verapamil, leading to high concentrations in cells. Free verapamil efficiently inhibited the membrane multidrug resistance proteins (MRPs), while the high concentration of doxorubicin saturated MRPs, thus overcoming MDR. We showed that nanosecond- (ns-) pulsed laser- (532 nm, 6 ns) induced doxorubicin release from gold liposomes depended on laser fluence and pulse number. More than 58% of the doxorubicin was released with a 10-pulse irradiation (100 mJ/cm2). Furthermore, ns laser pulses also liberated doxorubicin from endocytosed gold liposomes into the cytosol in MDA-MB-231-R cancer cells. The cytotoxicity of doxorubicin coencapsulated with verapamil was significantly enhanced upon laser irradiation. This study suggested that light-triggered on-demand release of chemotherapeutic agents and MRP inhibitors could be used advantageously to overcome multidrug resistance.

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