scholarly journals Effects of Diode and Nd:YAG Laser Irradiation on Friction Forces Between Two Types of Ceramic Brackets and Rhodium-Coated Archwires

2021 ◽  
Vol 12 (1) ◽  
pp. e13-e13
Author(s):  
Hannaneh Ghadirian ◽  
Allahyar Geramy ◽  
Mohammad Ali Keshvad ◽  
Soolmaz Heidari ◽  
Nasim Chiniforush
Keyword(s):  
Laser Irradiation ◽  
Diode Laser ◽  
Nd:Yag Laser ◽  
Yttrium Aluminum Garnet ◽  
Testing Machine ◽  
Control Group ◽  
Friction Forces ◽  
X Ray ◽  
Custom Made ◽  
Ceramic Brackets

Introduction: Ceramic brackets have gained increasing popularity among dental clinicians and orthodontic patients but friction is a major concern when using them. This study sought to assess the effects of diode and Nd:YAG (neodymium-doped yttrium aluminum garnet) laser irradiation on friction forces between two types of ceramic brackets and rhodium-coated esthetic archwires. Methods: Thirty polycrystalline and 30 poly-sapphire brackets were divided into 6 groups (n=10) as follows: (I) control polycrystalline brackets (no laser irradiation), (II) polycrystalline brackets subjected to diode laser irradiation, (III) polycrystalline brackets subjected to Nd:YAG laser irradiation, (IV) control poly-sapphire brackets (no laser irradiation), (V) poly-sapphire brackets subjected to diode laser irradiation, and (VI) poly-sapphire brackets subjected to Nd:YAG laser irradiation. The bracket slots were laser-irradiated on a custom-made table. Sixty 5-cm pieces of rhodium-coated archwires were used for the friction test in a universal testing machine at a speed of 10 mm/min. Ten brackets from the six groups underwent scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). Results: The frictional resistance value of polycrystalline brackets was significantly higher than that of poly-sapphire brackets, irrespective of laser type (P<0.05). Irradiation of diode and Nd:YAG lasers, compared with the control group, had no significant effect on friction, irrespective of bracket type (P>0.05). Conclusion: It appears that diode and Nd:YAG laser irradiation cannot significantly decrease the friction. Future studies are warranted on different laser types with variable exposure.

scholarly journals Clinical Study of Pingyangmycin Combined with Nd:YAG Laser to Treat Venous Malformations in the Oral and Maxillofacial Region

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yongsheng Li
Keyword(s):  
Laser Irradiation ◽  
Nd:Yag Laser ◽  
Yttrium Aluminum Garnet ◽  
Control Group ◽  
Venous Malformations ◽  
Maxillofacial Region ◽  
Yttrium Aluminum ◽  
Oral And Maxillofacial Region ◽  
Experimental Group

Purpose: To explore the efficacy of pingyangmycin (PYM) combined with Neodymium yttrium aluminum garnet (Nd:YAG) laser to treat venous malformations in the oral and maxillofacial region. Methods: Eighty-six patients were randomly divided into two groups. Forty-two patients were allocated to the experimental group and were injected with PYM at the lesion site, followed by Nd:YAG laser irradiation two days later. Forty-four patients were allocated to the control group and received only Nd:YAG laser irradiation (15-30W of power). All patients came back for a follow-up examination one month later. Results: Twenty-eight patients in the experimental group (66.67%) and 16 patients in the control group (36.31%) had no lesions after one treatment. Additionally, 10 patients in the experimental group (23.81%) and nine patients in the control group (20.45%) showed significant improvement at one month post-treatment. Compared to the control group, the experimental group demonstrated superior outcomes and shorter treatment durations. The between-group difference was significant (p<0.05). Conclusion: PYM combined with Nd:YAG laser is an effective treatment of venous malformations in the oral and maxillofacial region, potentially shortening treatment durations.

scholarly journals Effect of Er:YAG and Er,Cr:YSGG Lasers on Ceramic Bracket Debonding from Composite Blocks

2019 ◽  
Author(s):  
Amir Hossein Mirhashemi ◽  
Seyed Mohammad Hashem Hossaini ◽  
Ardavan Etemadi ◽  
Mohammad Javad Kharazifard ◽  
Abolghasem Bahador ◽  
...  
Keyword(s):  
Bond Strength ◽  
Yttrium Aluminum Garnet ◽  
Er:Yag Laser ◽  
Testing Machine ◽  
Control Group ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Ceramic Brackets ◽  
The Difference ◽  
Ceramic Bracket

Objectives: This study aimed to assess the effect of erbium-doped yttrium aluminum garnet (Er:YAG) and erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) lasers on the shear bond strength (SBS) of ceramic brackets debonding from the surface of composite blocks. Materials and Methods: Thirty-six composite blocks were fabricated using Filtek Z250 light-cure composite. Block surfaces were etched with 37% phosphoric acid for 30 seconds and then rinsed with water for 20 seconds and dried. Maxillary right central incisor ceramic orthodontic brackets were bonded to the surfaces of composite blocks using Transbond XT adhesive and were cured for 40 seconds. Twelve samples were irradiated with Er:YAG laser, while 12 samples were irradiated with Er,Cr:YSGG laser, and the brackets were then debonded using a universal testing machine. Twelve samples served as controls (debonding using the universal testing machine without using a laser). The adhesive remnant index (ARI) score and bracket or composite cracks were evaluated under a stereomicroscope. One-way analysis of variance (ANOVA) was used for the comparison of the three groups. Kruskal-Wallis test was used to compare the ARI scores. Results: The mean SBS was 17.01±5.22 MPa with Er:YAG laser, 18.03±6.46 MPa with Er,Cr:YSGG laser, and 16.61±6.73 MPa in the control group; the difference of the three groups was not significant (P=0.835). The difference in the ARI scores and enamel and composite cracks was not significant either (P>0.05). Conclusion: This study did not show any reduction in the bond strength of ceramic bracket to composite blocks after Er:YAG and Er,Cr:YSGG laser irradiation.

Antibacterial Efficacy of Diode and Er:YAG Laser Irradiation in Experimentally Contaminated Primary Molar Root Canals

2009 ◽  
Vol 34 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Senem Selvi Kuvvetli ◽  
Nuket Sandalli ◽  
Nursen Topcuoglu ◽  
Guven Kulekci
Keyword(s):  
Laser Irradiation ◽  
Diode Laser ◽  
Er:Yag Laser ◽  
Positive Control ◽  
Control Group ◽  
Antibacterial Efficacy ◽  
Primary Molar ◽  
Root Canals ◽  
Number Of Bacteria

Objective: In vitro comparison of the antibacterial efficacy of Diode and Er:YAG laser irradiation with that of NaOCl irrigation in contaminated primary molar root canals. Study Design: 96 root canals prepared from 32 extracted primary molar teeth were mechanically enlarged and the teeth were randomly divided into 4 subgroups. The roots were inoculated with an overnight culture of Enterococcus faecalis in tryptic soy broth for 24 hours. The root canals irradiated with diode and Er:YAG laser and irrigated with NaOCl(5.25%) were experimental groups and untreated canals served as positive control group. Bacterial growth was analysed by counting viable E.faecalis on tryptic soy agar plates. Results: The number of bacteria was significantly reduced in experimental groups in comparison with the control group. Diode laser was determined to be more effective in reducing the number of bacteria when compared to Er:YAG laser. NaOCl irrigation was found significantly most effective. Conclusions: Diode laser irradiation and 5.25 % NaOCl application provided a significant antibacterial effect in vitro, in contaminated primary molar root canals.

scholarly journals 3D Biomimetic Porous Titanium (Ti6Al4V ELI) Scaffolds for Large Bone Critical Defect Reconstruction: An Experimental Study in Sheep

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1389 ◽  
Author(s):  
Alberto Maria Crovace ◽  
Luca Lacitignola ◽  
Donato Monopoli Forleo ◽  
Francesco Staffieri ◽  
Edda Francioso ◽  
...  
Keyword(s):  
Bone Defects ◽  
Porous Titanium ◽  
Control Group ◽  
Large Animal ◽  
Sintered Titanium ◽  
Porous Hydroxyapatite ◽  
X Ray ◽  
Custom Made ◽  
Critical Defect ◽  
Large Bone

The main goal in the treatment of large bone defects is to guarantee a rapid loading of the affected limb. In this paper, the authors proposed a new reconstructive technique that proved to be suitable to reach this purpose through the use of a custom-made biomimetic porous titanium scaffold. An in vivo study was undertaken where a complete critical defect was experimentally created in the diaphysis of the right tibia of twelve sheep and replaced with a five-centimeter porous scaffold of electron beam melting (EBM)-sintered titanium alloy (EBM group n = 6) or a porous hydroxyapatite scaffold (CONTROL group, n = 6). After surgery, the sheep were allowed to move freely in the barns. The outcome was monitored for up to 12 months by periodical X-ray and clinical examination. All animals in the CONTROL group were euthanized for humane reasons within the first month after surgery due to the onset of plate bending due to mechanical overload. Nine months after surgery, X-ray imaging showed the complete integration of the titanium implant in the tibia diaphysis and remodeling of the periosteal callus, with a well-defined cortical bone. At 12 months, sheep were euthanized, and the tibia were harvested and subjected to histological analysis. This showed bone tissue formations with bone trabeculae bridging titanium trabeculae, evidencing an optimal tissue-metal interaction. Our results show that EBM-sintered titanium devices, if used to repair critical bone defects in a large animal model, can guarantee immediate body weight-bearing, a rapid functional recovery, and a good osseointegration. The porous hydroxyapatite scaffolds proved to be not suitable in this model of large bone defect due to their known poor mechanical properties.

Effect of Nd:YAG Laser Irradiation Pretreatment on the Long-Term Bond Strength of Etch-and-Rinse Adhesive to Dentin

2017 ◽  
Vol 42 (1) ◽  
pp. 62-72 ◽  
Author(s):  
J Gan ◽  
S Liu ◽  
L Zhou ◽  
Y Wang ◽  
J Guo ◽  
...  
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Nd:Yag Laser ◽  
Knoop Hardness ◽  
Control Group ◽  
In Vitro Test ◽  
Dentin Surface ◽  
Etch And Rinse ◽  
Significant Difference

SUMMARY Purpose: To investigate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation pretreatment on the long-term bond strength of an etch-and-rinse adhesive to dentin. Methods: Fifty molars were sectioned parallel to the occlusal plane and randomly divided into two groups (n=25 per group): control group (no treatment) and laser group (dentin surfaces were treated with Nd:YAG laser at a setting of 100 mJ/10 Hz). Afterward, resin was bonded to the dentin surface using a two-step etch-and-rinse adhesive (Adper SingleBond 2), and then 150 beams of each group were produced. Each group was divided into three subgroups (n=50 each group): 24 hours of water storage, thermocycling, and NaOCl storage. The microtensile bond strength (MTBS), failure modes, nanoleakage expression, and Masson's trichrome staining were evaluated. An additional 20 molars were sectioned to obtain 2-mm-thick flat dentin slices. These slices were randomly divided into control and laser-treated groups as mentioned previously. Then slices of each group were examined by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and the Knoop hardness test. Results: The results of ATR-FTIR and Masson's trichrome verified that laser irradiation partly removed collagen fibers from the dentin surface; however, no significant difference was found in the Knoop hardness (p&gt;0.05). The XRD result showed similar crystalline structure regardless of laser pretreatment. There is no significant difference in short-term MTBS between control and laser-treated groups (p&gt;0.05); however, long-term MTBS differed between the groups (p&gt;0.05). Furthermore, the laser-treated group showed less silver deposition than the control group after aging (p&lt;0.05). Conclusion: Pretreatment by Nd:YAG laser irradiation appeared to have a positive effect on the adhesive-dentin bonding in vitro test, and the bonding effectiveness could be preserved after aging.

scholarly journals Effect of Nd:YAG laser in the bond strength of fiberglass posts

2015 ◽  
Vol 18 (4) ◽  
pp. 19
Author(s):  
Rayssa Ferreira Zanatta ◽  
Beatriz Maria da Fonseca ◽  
Stella Renata Steves ◽  
Carlos Rocha Gomes Torres ◽  
Sergio Eduardo Paiva Gonçalves
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Nd:Yag Laser ◽  
Root Canal ◽  
Testing Machine ◽  
Adhesive System ◽  
Bonding Performance ◽  
Fiber Posts ◽  
Bond Strengths ◽  
Push Out

<p>The aim of the present study was to compare the effects of Nd:YAG laser application in root canals on bond strengths of fiber posts. Thirty single-rooted bovines were randomly divided into three groups (n=10); root canal instrumentation was performed, and pretreatment was conducted as follows: C group: conventional treatment (without laser irradiation); ALC group: Nd:YAG laser was applied after adhesive; and LAC group: Nd:YAG laser was applied before adhesive. The fiber posts Rebilda 15 DC (Voco) were cemented with an adhesive system and resin cement, in accordance with the manufacturer’s instructions. Six slices with 1.0mm height was obtained for of each root and bond strength was measured by push-out test using a universal testing machine (0.5 mm/min). Data were analyzed using Kruskal-Wallis and Dunn’s tests (p &lt;0.05). Push-out bond strengths to root canal dentin were affected by the type of treatment and root third. The use of Nd:YAG laser after the application of adhesive system had a higher bonding performance compared with the use of laser before the application. Also, cervical and medium third presented higher bond strength values than the apical third. It must be conclude that the laser irradiation over the non-cured adhesive system is more efficient for increase in bond strength than the irradiation after the application of the adhesive. However, the use of 60mJ of laser energy is not sufficient to improve the bonding performance.</p>

scholarly journals Effects of the laser irradiation on graphene oxide foils in vacuum and air -=SUP=-*-=/SUP=-

2019 ◽  
Vol 61 (7) ◽  
pp. 1385
Author(s):  
L. Torrisi ◽  
M. Cutroneo ◽  
L. Silipigni ◽  
M. Fazio ◽  
A. Torrisi
Keyword(s):  
Graphene Oxide ◽  
Carbon Content ◽  
Laser Irradiation ◽  
Alpha Particle ◽  
Nd:Yag Laser ◽  
Rutherford Backscattering Spectrometry ◽  
Photoemission Spectroscopy ◽  
X Ray ◽  
Photon Irradiation ◽  
Chemical Effects

AbstractA Nd:YAG laser operating at 1064 nm was used to irradiate, at different intensities, graphene oxide foils placed in vacuum and in air. The laser irradiated GO foils were analysed successively by using different techniques such as 2.0 MeV alpha particle Rutherford backscattering spectrometry, X-ray photoemission spectroscopy and SEM-EDX. In particular, in vacuum irradiated graphene oxide samples the oxygen reduction has been observed with increment of the carbon content. In air irradiated GO samples an increase in oxygen has instead been highlighted. Furthermore thermal and chemical effects are induced by the photon irradiation. Results will be presented and discussed.

scholarly journals The Effect of Laser Irradiation on Reparative Osteogenesis

2018 ◽  
Vol 1 (2) ◽  
pp. 10-19
Author(s):  
Yu. М. Iryanov ◽  
N. A. Kiryanov
Keyword(s):  
Laser Radiation ◽  
Radiation Exposure ◽  
Bone Regeneration ◽  
Laser Irradiation ◽  
Light And Electron Microscopy ◽  
Infrared Laser ◽  
Control Group ◽  
X Ray ◽  
Low Intensity ◽  
The Impact

Introduction: The use of non-medicinal facilities for correcting processes in various pathological conditions is one of the most urgent problems of modern medicine. Purpose of the Work: To study the effect of low-intensity infrared laser radiation on reparative bone formation and angiogenesis in bone regeneration which is formed in treatment of fractures under conditions of transosseous osteosynthesis. Material and Methods: A tibia fracture was modeled experimentally in rats in the control and experimental groups. Reposition and fixation of fragments were performed. The fracture zone in the experimental group animals was exposed to the impact of pulsed infrared laser irradiation of low intensity. Animals from the control group underwent the impact simulation. The operated bones were investigated using the methods of X-ray, light and electron microscopy, X-ray electron probe microanalysis. Results: It was established that laser radiation exposure sessions activated fibrillogenesis and angiogenesis, accelerated compacting of newly formed bone tissue and increased its maturity while primary fracture healing occurred. Prolonged capillary dilatation and endothelium-dependent vasodilation, intensive capillarogenesis were noted after sessions of laser therapy in bone regeneration. Endothelial outgrowth was formed in the lumen of the vessels forming capillary buds that propagate along the “mother” vessels (endovascular capillarogenesis). Conclusion: The data obtained revealed a possible mechanism of laser radiation exposure at the level of a whole organism and proved the effectiveness of its application in clinical practice at the early stages of patient rehabilitation under conditions of transosseous osteosynthesis.

scholarly journals Low-Level Laser Therapy with a 635 nm Diode Laser Affects Orthodontic Mini-Implants Stability: A Randomized Clinical Split-Mouth Trial

2019 ◽  
Vol 9 (1) ◽  
pp. 112 ◽  
Author(s):  
Rafał Flieger ◽  
Tomasz Gedrange ◽  
Kinga Grzech-Leśniak ◽  
Marzena Dominiak ◽  
Jacek Matys
Keyword(s):  
Total Energy ◽  
Laser Irradiation ◽  
Diode Laser ◽  
Control Group ◽  
Laser Application ◽  
Pain Level ◽  
Mini Implants ◽  
Attached Gingiva ◽  
Significant Difference ◽  
Secondary Stability

Background: The study aimed to clinically estimate an influence of a 635 nm diode laser on the stability of orthodontic mini-implants, to assess mini-implants loss, and to evaluate a pain level after the treatment. Materials and Methods: The randomized clinical split-mouth trial included 20 subjects (13 women and 7 men; age: 32.5 ± 6.1 years), 40 implants (RMO, West Colfax Ave., Denver, CO, USA) with a diameter 1.4 mm and length of 10 mm. Mini-implants were placed in the area of the attached gingiva between the second premolar and first molar teeth, 2 mm below the mucogingival junction of both sides of the maxilla. Each implant on the right side (G1, n = 20) of the maxilla was irradiated with a diode laser, and the implants on the opposite side (left, G2, n = 20) were a control group (without laser irradiation). The 635-nm laser parameters; dose: 10 J per point (20 J/cm2), time: 100 s per point, two points (irradiation on a buccal, and a palatal side of the alveolus/implant), the total energy per session 20 J. Laser application protocol: immediately and 3, 6, 9, 12, 15, and 30 days after surgery. The total energy after all therapeutic sessions was 140 J. The implants’ stability was measured employing a Periotest device (Periotest Test Value—PTV) immediately and 3, 6, 9, 12, 15, 30, and 60 days after the insertion of the mini-implants. Results: We found significantly higher secondary stability, lower mean PTV (6.18 ± 5.30) and (1.51 ± 2.25), for self-drilling mini-implants (G1, test group) in contrast to the control, G2 group (9.17 ± 8.25) and (5.00 ± 3.24), after 30 (p = 0.0003) and 60 days (p = 0.0000). Moreover, the analysis of the mini-implants stability after 635-nm diode laser application revealed significant higher stability in comparison with none irradiated implants (G2 group) after 3 days. (p = 0.0000) There was no significant difference in pain level measured on the NRS-11 scale on both sides of the maxilla. (p = 0.3665) An important finding was that all inserted mini-implants survived during a two-month observation period. Conclusions: 635-nm diode laser at laser irradiation increases the secondary stability of orthodontic mini-implants.

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