scholarly journals Energy output reduction and surface alteration of quartz tips following Er:YAG laser contact irradiation on soft and hard tissues in vitro

2016 ◽  
Vol 35 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Taichen LIN ◽  
Rie KAWAMURA ◽  
Akira AOKI ◽  
Shizuko ICHINOSE ◽  
Koji MIZUTANI ◽  
...  
Keyword(s):  
Er:Yag Laser ◽  
Energy Output ◽  
Hard Tissues ◽  
Surface Alteration

Energy output reduction and surface alteration of quartz and sapphire tips following Er:YAG laser contact irradiation for tooth enamel ablation

2009 ◽  
Vol 41 (8) ◽  
pp. 595-604 ◽  
Author(s):  
Toru Eguro ◽  
Akira Aoki ◽  
Toru Maeda ◽  
Aristeo Atsushi Takasaki ◽  
Mitsuru Hasegawa ◽  
...  
Keyword(s):  
Er:Yag Laser ◽  
Tooth Enamel ◽  
Energy Output ◽  
Surface Alteration

The Influence of Er:YAG Laser on the Dissolution Rate and Morphology of the Root Cement A scanning electron microscopic study

2018 ◽  
Vol 69 (6) ◽  
pp. 1574-1577
Author(s):  
Monica Monea ◽  
Daniela Esian ◽  
Reka Soos ◽  
Adrian Tohati ◽  
Alexandru Sitaru ◽  
...  
Keyword(s):  
Er:Yag Laser ◽  
Electron Microscopic ◽  
Morphological Alterations ◽  
Dental Tissues ◽  
Dental Hard Tissues ◽  
Hard Tissues ◽  
Root Planning ◽  
Scaling And Root Planning ◽  
Scanning Electron

Lasers can interact with dental tissues inducing changes in tooth characteristics, regarding the surface morphology and elemental composition. The alterations were observed in Calcium, Phosphorus, Sodium, Oxygen and Carbon elements, which influence the resistance and chemical properties of dental hard tissues. The thermal energy used by laser reduces water content of the tissues and as a consequence, the level of oxygen composition decreases after irradiation. Numerous studies had demonstrated its ability to ablate hard-tissues, without any detrimental thermal effects such as cracking or melting for the adjacent tissues. The aim of this article is to present the in vitro effects of Er:YAG laser in comparison with sonic, ultrasonic and manual instruments on the root cement during scaling and root planning, evaluated by scanning electron microscope. The study was conducted on extracted teeth, divided in four groups according to the method used for scaling and root planning. The specimens were analyzed by scanning electron microscopy and the morphological alterations of the cement were evaluated based on a scoring system. Data were statistically analyzed using Mann-Whitney test and the level of significance was set at p[0.05.We noted unfavorable results on the root cement after using Er:YAG laser as craters and cracks induced by heat. There was a greater amount of roughness on the root surface after Er:YAG was used for scaling and root planning compared to manual, sonic and ultrasonic methods. Despite favorable results obtained after the use of Er:YAG laser during periodontal treatment, further clinical studies are necessary in order to determine in which moment of the therapy these methods are most suitable.

scholarly journals In VitroEffects of Two Topical Varnish Materials and Er:YAG Laser Irradiation on Enamel Demineralization around Orthodontic Brackets

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Feyza Ulkur ◽  
Elif Sungurtekin Ekçi ◽  
Didem Nalbantgil ◽  
Nuket Sandalli
Keyword(s):  
Laser Irradiation ◽  
Er:Yag Laser ◽  
Orthodontic Brackets ◽  
Energy Output ◽  
Surface Microhardness ◽  
Sem Images ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Group 1

The aim of thisin vitrowas to evaluate the effects of tricalcium phosphate (TCP) and amorphous calcium phosphate (ACP) containing varnish materials and Er:YAG laser irradiation on enamel demineralization around orthodontic brackets. Forty extracted human premolar teeth were randomly divided into four treatment groups (i.e., 10 in each group): (1) 5% NaF-ACP varnish, (2) 5% NaF-TCP varnish, (3) Er:YAG laser, and (4) control (no treatment). Er:YAG laser was operated at a wavelength of 2.94 μm and the energy output was 80 mJ per pulse; a pulse duration of 200 μsec and and a frequency of 2 Hz were used with water cooling. All samples were then put into pH cycles. Surface microhardness values and representative SEM images were assessed. Surface microhardness values were evaluated using Kruskal-Wallis and Mann-WhitneyUtests. The results revealed that demineralization was significantly lower in the TCP and ACP varnish groups, whereas mean surface microhardness values of the TCP varnish were found higher than the ACP(P<0.05). TCP and ACP varnish materials were found effective for reducing enamel demineralization around orthodontic brackets. Use of Er:YAG laser irradiation as described in this study for inhibition of demineralization was found not satisfactory.

scholarly journals In Vitro Adhesion of Streptococcus sanguinis to Dentine Root Surface After Treatment with Er:Yag Laser, Ultrasonic System, or Manual Curette

2009 ◽  
Vol 27 (5) ◽  
pp. 735-741 ◽  
Author(s):  
Claudia Ota-Tsuzuki ◽  
Fernanda L. Martins ◽  
Ana Paula O. Giorgetti ◽  
Patrícia M. de Freitas ◽  
Poliana M. Duarte
Keyword(s):  
Er:Yag Laser ◽  
Root Surface ◽  
Laser Ultrasonic ◽  
Streptococcus Sanguinis ◽  
In Vitro Adhesion

scholarly journals Er:YAG laser-induced damage to a dental composite in simulated clinical scenarios for inadvertent irradiation: an in vitro study

2021 ◽  
Author(s):  
Katharina Kuhn ◽  
Carmen U. Schmid ◽  
Ralph G. Luthardt ◽  
Heike Rudolph ◽  
Rolf Diebolder
Keyword(s):  
Laser Irradiation ◽  
Laser Fluence ◽  
Ablation Threshold ◽  
Er:Yag Laser ◽  
In Vitro Study ◽  
Vitro Study ◽  
Crater Diameter ◽  
Clinical Scenarios ◽  
Laser Induced Damage

AbstractInadvertent Er:YAG laser irradiation occurs in dentistry and may harm restorative materials in teeth. The aim of this in vitro study was to quantify Er:YAG laser-induced damage to a nanohybrid composite in simulated clinical scenarios for inadvertent direct and indirect (reflection) laser irradiation. The simulation was performed by varying the output energy (OE;direct˃indirect) reaching the specimen and the operating distance (OD;direct˂indirect). Composite specimens were irradiated by an Er:YAG laser. The ablation threshold was determined and clinically relevant parameters were applied (n = 6 for each OE/OD combination) for direct (OE: 570 mJ/OD: 10 mm, OE: 190 mJ/OD: 10 mm) and indirect irradiation (OE: 466 mJ/OD: 15 mm, OE: 57 mJ/OD: 15 mm, OE: 155 mJ/OD: 15 mm, OE: 19 mJ/OD: 15 mm). The extent of damage in the form of craters was evaluated using a laser scanning microscope (LSM) and a conventional light microscope (LM). The ablation threshold was determined to be 2.6 J/cm2. The crater diameter showed the highest value (LM: 1075 ± 18 µm/LSM: 1082 ± 17 µm) for indirect irradiation (reflectant:dental mirror) (OE: 466 mJ/OD: 15 mm). The crater depth showed the highest and comparable value for direct (OE: 570 mJ/OD: 10 mm; LSM: 89 ± 2 µm) and indirect irradiation (OE: 466 mJ/OD: 15 mm; LSM: 90 ± 4 µm). For each OD, the crater diameter, depth, and volume increased with higher laser fluence. However, the OD—and thus the laser spot diameter—also had an enlarging effect. Thus, indirect irradiation (reflectant:dental mirror) with only 47% of the laser fluence of direct irradiation led to a larger diameter and a comparable depth. The three-dimensional extent of the crater was large enough to cause roughening, which may lead to plaque accumulation and encourage caries, gingivitis, and periodontitis under clinical conditions. Clinicians should be aware that reflected irradiation can still create such craters.

Bactericidal Effect of the Er:YAG Laser on Dental Implant Surfaces: An In Vitro Study

2002 ◽  
Vol 73 (11) ◽  
pp. 1292-1298 ◽  
Author(s):  
Matthias Kreisler ◽  
Wolfgang Kohnen ◽  
Claudio Marinello ◽  
Hermann Götz ◽  
Heinz Duschner ◽  
...  
Keyword(s):  
Dental Implant ◽  
Er:Yag Laser ◽  
In Vitro Study ◽  
Bactericidal Effect ◽  
Vitro Study

The Relations Between Yolk and White in the Hen'S Egg

1931 ◽  
Vol 8 (3) ◽  
pp. 319-329
Author(s):  
JOSEPH NEEDHAM ◽  
MARJORY STEPHENSON ◽  
DOROTHY MOYLE NEEDHAM
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Lactic Acid ◽  
Carbon Dioxide Production ◽  
Energy Output ◽  
Vitelline Membrane ◽  
Aerobic Respiration ◽  
Anaerobic Conditions ◽  
Hen’S Egg

1. The vitelline membrane of the infertile hen's egg exhibits no dehydrase activity. 2. The vitelline membrane has no measurable aerobic respiration in vitro, nor has the yolk of the infertile egg. This confirms the view that the carbon dioxide production of the intact egg is not the result of any true respiration. 3. When incubated anaerobically in vitro, bacteriologically sterile yolk produces consistently small amounts of lactic acid. 4. This glycolysis is not the result of any catalytic activity of the vitelline membrane, but takes place throughout the substance of the yolk. 5. Under similar conditions, bacteriologically sterile yolk produces small amounts of a substance or substances estimatable as ethyl alcohol. 6. If the yolk suspension is bacterially contaminated, however, lactic acid and alcohol are produced in amounts closely similar to those found by earlier workers on this subject. 7. The heat of glycolysis, under anaerobic conditions, calculated from the amounts of lactic acid experimentally found to be formed, is of the same order as (a) the calculated requirement of the vitelline membrane (Straub), and (b) the observed heat production (Langworthy and Barott). Thus even if the vitelline membrane is capable of using energy to do osmotic work, the yolk is only capable of supplying it by means of its glycolytic mechanism if the whole energy output of the whole yolk can be made available for doing work at the membrane.

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