Microhardness and SEM after CO2 laser irradiation or fluoride treatment in human and bovine enamel

2010 ◽  
Vol 73 (11) ◽  
pp. 1030-1035 ◽  
Author(s):  
A.E. Souza-Gabriel ◽  
V. Colucci ◽  
C.P. Turssi ◽  
M.C. Serra ◽  
S.A.M. Corona
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Fluoride Treatment ◽  
Bovine Enamel

scholarly journals Influence of Ultrapulsed CO2 Laser, before Application of Different Types of Fluoride, on the Increase of Microhardness of Enamel In Vitro

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Marcia Regina Cabral Oliveira ◽  
Pedro Henrique Cabral Oliveira ◽  
Luiz Henrique Cabral Oliveira ◽  
Ravana Angelini Sfalcin ◽  
Renato Araujo Prates ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Tooth Enamel ◽  
The Other ◽  
Fluoride Varnish ◽  
Fluoride Treatment ◽  
Enamel Caries ◽  
Bovine Enamel ◽  
Caries Lesions

Objective. To evaluate the influence of ultrapulsed CO2 laser in combination with commercial fluoride products in order to verify the increase of microhardness of artificial enamel caries lesions. Materials and Methods. Bovine enamel specimens were prepared, and artificial enamel caries lesions were created. Teeth were randomly divided into 5 groups (n=10): treated with laser (L), laser + neutral fluoride gel 2% (LNF), laser + acidulated phosphate fluoride gel 1.23% (LAFG), laser + acidulated fluoride mousse 1.23% (LAFM), and laser + fluoride varnish 5% (LFV). Microhardness was evaluated at baseline, after caries induction, after CO2 laser irradiation + fluoride treatment in the 1st week, and after fluoride treatment at 3rd and 5th week. Results. There was a decrease in microhardness in all groups after artificial enamel caries lesion formation; no increase in microhardness was found in the first and third weeks in all groups (p > 0.05). In the fifth week, an increase in microhardness occurred in all groups (p < 0.05). Conclusion. Although CO2 laser irradiation in combination with different commercial fluoride products was capable of increasing microhardness on enamel caries lesions in bovine tooth enamel it is necessary to confirm these results by testing the isolated effect of fluoride on enamel surface microhardness. Also, although microhardness was higher in the fluoride varnish group than in the other groups in the fifth week it is not possible to discard the best effect of fluoride varnish treatment on absence of artifacts that may occur with the other fluoride treatments. Clinical Relevance. In order to prove that CO2 laser may contribute to an increase in microhardness when applied to enamel lesions in combination with different commercial fluoride products it is necessary to conduct additional studies. Also, higher microhardness of fluoride varnish group should be carefully considered.

Effect of CO2 laser irradiation on arc welding

1996 ◽  
Author(s):  
Nobuyuki Abe ◽  
Yasuo Agano ◽  
Masahiro Tsukamoto ◽  
Takeshi Makino ◽  
Masakazu Hayashi ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Arc Welding

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

Fast Ion and Neutron Emission in CO2 Laser Irradiation of Solid Deuterium Targets

1977 ◽  
pp. 657-675
Author(s):  
J. L. Bocher ◽  
J. P. Elie ◽  
J. Martineau ◽  
M. Rabeau ◽  
C. Patou
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Neutron Emission ◽  
Solid Deuterium ◽  
Fast Ion

Behavior of different PMMA qualities under CO2 laser irradiation

1993 ◽  
Author(s):  
Rene C. Joeckle ◽  
Bernard Gautier ◽  
Fabrice Lacroix ◽  
Stephane Clemens ◽  
Lam Thanh My
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser

scholarly journals Threshold of permanent cornea thermal damage due to incidental continuous wave CO2 laser irradiation

2010 ◽  
Vol 14 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Mayada Tahir
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Thermal Damage ◽  
Continuous Wave ◽  
Anterior Part ◽  
Outer Part ◽  
Human Cornea ◽  
Thermal Dose ◽  
Element Analysis ◽  
Reflex Blink

Cornea thermal damage due to incidental continuous wave CO2 laser irradiation is studied numerically based on bio-heat equation. The interaction of laser with tissue leads to a rapid temperature increased in target and the nearby tissue. As the temperature of the eye surface reaches 44?C, a sensation of pain will cause aversion response of the reflex blink and/or shifting away from the source of pain. The aim of the work is to predict numerically the threshold limit of incidental laser power that causes damage to the anterior part of the cornea, which can be healed within 2-5 days as long as damage is not exceeding the outer part of the eye (epithelium). A finite element analysis is used to predict temperature distribution through the cornea where the necroses region can be obtained using thermal dose equation. The thermal dose that required for damaging the cornea is predicted from previously published experimental data on rhesus monkeys and used later as a limit for shrinkage to human cornea. The result of this work is compared by international standard of safety and a good nearby result is obtained which verified the result of this work.

scholarly journals Microleakage of "Bulk-Fill" Composite Resin for Class II Restorations Pretreated With CO2 Laser in Deciduous Molars: An In Vitro Study

2019 ◽  
Vol 10 (4) ◽  
pp. 304-309
Author(s):  
Larissa Costa Santos ◽  
Ravana Angelini Sfalcin ◽  
Eugenio José Garcia ◽  
Fátima Antônia Aparecida Zanin ◽  
Aldo Brugnera Junior ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Laser Irradiation ◽  
Co2 Laser ◽  
Class Ii ◽  
Composite Resins ◽  
Acid Etching ◽  
Dentin Hypersensitivity ◽  
Significant Difference ◽  
Acid Gel

Introduction: Microleakage has been reported to cause dentin hypersensitivity because of the passage of bacteria and their products through the restoration-tooth interface and is one of the main reasons for replacement of restorations. CO2 laser can be used for treatment of dentin hypersensitivity. Thus, this study aimed to evaluate in vitro the microleakage in composite restorations following surface pretreatment with acid etching and CO2 laser. Methods: Twelve human caries-free primary molars were selected. Class II cavities were prepared on occlusal mesial and occlusal distal surfaces. Specimens were randomly divided into four groups (n=6): Group 1 (G1) – 37% phosphoric acid gel etching + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 2 (G2) – 37% phosphoric acid gel etching + SDR Bulk-Fill Flow (Dentsply); Group 3 (G3) – CO2 laser irradiation + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 4 (G4) – CO2 laser irradiation + SDR Bulk-Fill Flow (Dentsply). Surfaces were restored with bonding agent (Natural Bond DE, DFL). Specimens were cut longitudinally and immersed in 0.5% methylene blue solution for 4 hours. Microleakage scores were assessed under a magnifying glass at x3,5 and qualitatively analyzed by scanning electron microscope (SEM). Data were analyzed using nonparametric Wilcoxon test (P < 0.05). Results: Scores prevailed between 0 and 2, however, no statistically significant difference was found among the groups (P= 0.05). Conclusion: It could be concluded that all composite resins bulk fill did not show significant difference among them regarding microleakage using either CO2 laser or 37% phosphoric acid etching.

scholarly journals The Bactericidal Effect of CO2 Laser on Pseudomonas aeruginosa Isolated from Wound and Burn Infections, In-Vitro

2015 ◽  
Vol 12 (3) ◽  
pp. 485-495
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Laser Irradiation ◽  
Virulence Factors ◽  
Co2 Laser ◽  
Exposure Time ◽  
Antibiotic Susceptibility ◽  
Bactericidal Effect ◽  
Bacteriological Diagnosis ◽  
The Mean ◽  
Power Densities

A total of 60 cotton swabs are collected from patients suffering from burn wound and surgical site infections admitted to Baghdad Teaching Hospital and Burn Specialist Hospital in Baghdad city during 9/2013 to 11/2013. All cotton swabs are cultured initially on blood agar and MacConkey agar and subjected for standard bacteriological procedures for bacteriological diagnosis. Twenty samples out of sixty are identified as Pseudomonas aeruginosa by conventional methods. The results of antibiotic susceptibility test illustrate that the antibiotics resistance rate of Pseudomonas aeruginosa isolates is as follows:100% (2020) for ceftriaxone, cefepime and carbencillin, 70% (14/20) for amikacin, 65%(13/20) for tobramycin, ceftazidim and gentamycin, 55% (11/20) for ciprofloxacin and norfloxacin, 50% (10/20) for piperacillin and impeneme, 30% (6/20) for aztreonam. All Pseudomonas aeruginosa isolates are investigated for detection of some virulence factors (haemolysin, protease, lipase enzymes, and extracellular pigments) and biofilm formation. The results of virulence factors reveal that all the isolates are haemolysin, protease, lipase enzymes and extracellular pigments producer, while 95% of the isolates are biofilm producer. Six isolates are selected to irradiation by using CO2 laser according to the results of antibiotic susceptibility and virulence factors at power densities (2000, 2500, and 3000) W/cm2 with exposure time (60 and 90) second. The results of CO2 laser irradiation illustrate that CO2 laser irradiation lead to a reduction in the mean value of the viable number CFU/ml of Pseudomonas aeruginosa isolates with the increase of the power density and exposure time. The results of the statistical analysis by using analysis of variance (ANOVA) one way and least significant differences-LSD show that there are statistical significant differences in the mean of the viable number CFU/ml between different power densities and different exposure times. After irradiation, antibiotic susceptibility and virulence factors tests of the irradiated strains are performed. The current study concludes that CO2 laser has bactericidal effect on P. aeruginosa isolates without any effect on its antibiotics susceptibility and virulence factors.

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