scholarly journals Evaluation of Static Friction of Polycrystalline Ceramic Brackets after Conditioning with Different Powers of Er:YAG Laser

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Valiollah Arash ◽  
Saeed Javanmard ◽  
Zeinab Eftekhari ◽  
Manouchehr Rahmati-Kamel ◽  
Mohammad Bahadoram
Keyword(s):  
Laser Power ◽  
Er:Yag Laser ◽  
Testing Machine ◽  
Frictional Resistance ◽  
Static Friction ◽  
Study Groups ◽  
Control Group ◽  
Sem Images ◽  
Polycrystalline Ceramic ◽  
Ceramic Brackets

This research aimed to reduce the friction between the wire and brackets by Er:YAG laser. To measure the friction between the wires and brackets in 0° and 10° of wire angulations, 40 polycrystalline ceramic brackets (Hubit, South Korea) were divided into 8 study groups and irradiated by 100, 200, and 300 mj/s of Er:YAG laser power. Two groups of brackets were not irradiated. The friction between the wires and brackets was measured with universal testing machine (SANTAM) with a segment of .019 × .025 SS wire pulled out of the slot of bracket. ANOVA andt-test were used for analyzing the results. To evaluate the effect of the laser on surface morphology of the bracket, SEM evaluations were carried out. The mean frictional resistances between the brackets and wires with 0° of angulation by increasing the laser power decreased compared with control group, but, in 10° of angulation, the friction increased regardless of the laser power and was comparable to the friction of nonirradiated brackets. Furthermore, with each laser power, frictional resistance of brackets in 10° of angulation was significantly higher than 0° of angulation. These results were explained by SEM images too.

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.

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.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Sem Images ◽  
Group 4 ◽  
Modes Of Failure ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

scholarly journals Analysis of Shear Bond Strength and Morphology of Er:YAG Laser-Recycled Ceramic Orthodontic Brackets

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ruo-qiao Han ◽  
Kai Yang ◽  
Ling-fei Ji ◽  
Chen Ling
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Laser Scanning ◽  
Er:Yag Laser ◽  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Test Machine ◽  
Ceramic Brackets

Objective. The aim of this study was to compare the recycling of deboned ceramic brackets via an Er:YAG laser or via the traditional chairside processing methods of flaming and sandblasting; shear bond strength and morphological changes were evaluated in recycled brackets versus new brackets.Materials and Methods. 3M Clarity Self-Ligating Ceramic Brackets with a microcrystalline base were divided into groups subjected to flaming, sandblasting, or exposure to an Er:YAG laser. New ceramic brackets served as a control group. Shear bond strengths were determined with an Electroforce test machine and tested for statistical significance through analysis of variance. Morphological examinations of the recycled ceramic bracket bases were conducted with scanning electron microscopy and confocal laser scanning microscopy. Residue on the bracket base was analyzed with Raman spectroscopy.Results. Faded, dark adhesive was left on recycled bracket bases processed via flaming. Adhesive was thoroughly removed by both sandblasting and exposure to an Er:YAG laser. Compared with new brackets, shear bond strength was lower after sandblasting (p<0.05), but not after exposure to an Er:YAG laser. The Er:YAG laser caused no damage to the bracket.Conclusion. Er:YAG lasers effectively remove adhesive from the bases of ceramic brackets without damaging them; thus, this method may be preferred over other recycling methods.

scholarly journals Effect of Different Neutralizing Agents on Feldspathic Porcelain Etched by Hydrofluoric Acid

2019 ◽  
Vol 13 (01) ◽  
pp. 075-081 ◽  
Author(s):  
Tool Sriamporn ◽  
Ploypim Kraisintu ◽  
Lily Pachanin See ◽  
Somporn Swasdison ◽  
Awiruth Klaisiri ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Control Group ◽  
Sem Images ◽  
Carbonate Group ◽  
Aging Conditions ◽  
Feldspathic Porcelain ◽  
Group 5 ◽  
Group 2

Abstract Objective The aim of this study was to evaluate the effect of neutralizing agents on the shear bond strength of hydrofluoric (HF)–etched porcelain in nonaging and aging conditions. Subjects and Methods One hundred and twenty feldspathic porcelain specimens were prepared and divided into six groups to undergo different surface conditioning methods—group 1: control; group 2: HF; group 3: HF + calcium hydroxide; group 4: HF + calcium carbonate; group 5: HF + calcium gluconate; and group 6: HF + ultrasonic. All samples were immersed in 37°C distilled water for 24 h. Half of the samples were thermocycled in water for 5,000 cycles. The shear bond strength test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were statistically analyzed by two-way ANOVA and Tukey's multiple comparison test at a 95% confidence level. The surface micromorphology and surface elements were analyzed using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. Results The shear bond strengths of groups 2–6 were significantly higher than the control group in both aging and nonaging conditions (p < 0.05). There were no significant differences among all of the HF-etched porcelain groups (p > 0.05). SEM images of groups 2–6 illustrated similar patterns of irregularity on the specimen surfaces. Elemental analysis of EDX demonstrated identical elements on surfaces of specimens of groups 2–6. Conclusion Within the limitations of this study, shear bond strength values between HF-etched porcelain, HF-etching followed by application of neutralizing agents, and HF-etching followed by ultrasonic cleaning were not significantly different in both nonaging and aging conditions.

scholarly journals Effects of Er:YAG laser pre-treatment on dentin structure and bonding strength of primary teeth: An in vitro study

2020 ◽  
Author(s):  
Jun hui WANG ◽  
Kuan YANG ◽  
Bai ze ZHANG ◽  
Zhi fei ZHOU ◽  
Zi rui WANG ◽  
...  
Keyword(s):  
Shear Strength ◽  
Surface Treatment ◽  
Bonding Strength ◽  
Primary Teeth ◽  
Er:Yag Laser ◽  
Testing Machine ◽  
Acid Etching ◽  
Control Group ◽  
Interface Failure ◽  
Pre Treatment

Abstract Background: To investigate the effects of Er:YAG laser pre-treatment on the dentin structure and shear bond strength of primary teeth.Methods: Dentin specimens were prepared using freshly extracted intact primary molars and divided randomly into four groups based on the surface treatment applied. The control and etchant groups received no treatment and conventional acid etching treatment, respectively, while the energy and frequency groups received laser surface treatment with variable energy (50-300 mJ) and frequency (5-30 Hz) parameters. The morphology was observed using scanning electron microscopy. The surface-treated dentin slices were bonded to resin tablets, followed by thermocycle treatment. The shear strength was determined using a universal testing machine and de-bonded surfaces were observed using a stereomicroscope.Results: SEM observation showed that the surface morphology of the dentin slices changed after etching as well as after Er:YAG laser pre-treatment with different energy and frequency values. The dentin tubules opened within a specific energy (50-200 mJ) and frequency (5-20 Hz) range. Beyond this range, the intertubular dentin showed cracks and structural disintegration. Shear strength tests showed no significant changes after acid etching. The shear strength increased significantly (P<0.05) after Er:YAG laser pre-treatment compared with that of the control group. The shear strength increased within the same energy (50-200 mJ) and frequency (5-20 Hz) range as the tubule opening, but not significantly (P>0.05). The most common mode of interface failure was adhesive (interface) failure, followed by mixed and resin cohesive failure.Conclusions: Pre-treatment using Er:YAG laser opens the dentinal tubules without the formation of a smear layer and improves the bonding strength between the primary teeth dentin and the resin composites.

scholarly journals Comparison of cleaning methods on debris, surface roughness and static friction of retrieved stainless steel archwires

2018 ◽  
Vol 32 (3) ◽  
pp. 131
Author(s):  
Fabiano Dalla Lana Mattiello ◽  
Paulo Ricardo Baccarin Matje ◽  
Kim Beom Kim ◽  
Eduardo Gonçalves Mota ◽  
Eustáquio Afonso Araújo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Statistical Difference ◽  
Testing Machine ◽  
Static Friction ◽  
Steel Wool ◽  
Sem Images ◽  
Cleaning Method ◽  
Cleaning Methods ◽  
Reduced Surface

OBJECTIVE: To evaluate the amount of debris, surface roughness and static friction in retrieved stainless steel (SS) archwires after four weeks of intraoral exposure and afterwards compare the effects of different cleaning methods.METHODS: The sample gathered seventeen as-received and eighty-five retrieved SS archwire segments, which were allocated in cleaning method groups (N=17): retrieved (RT); sodiumbicarbonate jet (SB-jet); ultrasonic cleaner (U-sonic); alcohol soaked gauze (A-gauze); and steel wool sponge (S-wool). Debris (SEM images), surface roughness (rugosimeter) and static friction(universal testing machine) were compared between as-received and retrieved SS wires and between cleaning method groups.RESULTS: Debris and surface roughness were statistically higher in RT wires than in as-received (p<0.001), whereas static friction showed no statistical difference (p>0.05). Debris were significantly lower in groups A-gauze and S-wool than in groups RT, SB-jet and U-sonic (p<0.001). Surface roughness was statistically lower in group S-wool compared to other groups (p<0.001). Static friction showed no statistical difference between cleaning methods (p>0.05).CONCLUSION: Retrieved SS archwires showed higher debris and surface roughness than asreceived, after four-weeks intraorally. A-gauze and S-wool were effective cleaning methods to control debris, but only S-wool has reduced surface roughness.

scholarly journals Role of enamel deminerlization and remineralization on microtensile bond strength of resin composite

2016 ◽  
Vol 10 (03) ◽  
pp. 376-380 ◽  
Author(s):  
Abbas Rizvi ◽  
Muhammad S. Zafar ◽  
Yasser Al-Wasifi ◽  
Wamiq Fareed ◽  
Zohaib Khurshid
Keyword(s):  
Bond Strength ◽  
Tooth Enamel ◽  
Resin Composite ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Polarized Light ◽  
Study Groups ◽  
Control Group ◽  
Microtensile Bond Strength ◽  
Time Intervals

ABSTRACT Objective: This study is aimed to establish the microtensile bond strength of enamel following exposure to an aerated drink at various time intervals with/without application of remineralization agent. In addition, degree of remineralization and demineralization of tooth enamel has been assessed using polarized light microscopy. Materials and Methods: Seventy extracted human incisors split into two halves were immersed in aerated beverage (cola drink) for 5 min and stored in saliva until the time of microtensile bond testing. Prepared specimens were divided randomly into two study groups; remineralizing group (n = 70): specimens were treated for remineralization using casein phosphopeptides and amorphous calcium phosphate (CPP-ACP) remineralization agent (Recaldent™; GC Europe) and control group (n = 70): no remineralization treatment; specimens were kept in artificial saliva. All specimens were tested for microtensile bond strength at regular intervals (1 h, 1 days, 2 days, 1 week, and 2 weeks) using a universal testing machine. The results statistically analyzed (P = 0.05) using two-way ANOVA test. Results: Results showed statistically significant increase in bond strength in CPP-ACP tested group (P < 0.05) at all-time intervals. The bond strength of remineralizing group samples at 2 days (~13.64 megapascals [MPa]) is comparable to that of control group after 1 week (~12.44 MPa). Conclusions: CPP-ACP treatment of teeth exposed to an aerated drink provided significant increase in bond strength at a shorter interval compared to teeth exposed to saliva alone.

Nanoparticles as void fillers in glass ionomer cement for enhanced physicomechanical properties

2020 ◽  
Vol 10 (11) ◽  
pp. 1960-1964
Author(s):  
Mansour K. A. Assery ◽  
Abdulrahman Alshubat ◽  
AlWaleed Abushanan ◽  
Nawaf Labban ◽  
Mohamed Hashem
Keyword(s):  
Vickers Microhardness ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Study Groups ◽  
Control Group ◽  
Glass Ionomer ◽  
Universal Testing ◽  
Microhardness Testing ◽  
Diametral Tensile Strength ◽  
Ionomer Cement

The study evaluated the addition of silver (Ag) and titanium dioxide (TiO2) nanoparticles to conventional glass ionomer cement (GIC), considering compressive strength (CS), diametral tensile strength (DTS), flexural strength (FS), and hardness. Ag and TiO2 nanoparticles were blended into the powder of a commercially available GIC restorative material at 5% (w/w). Unblended powder was used as a control. One hundred twenty samples were prepared from two study groups and one control group (n = 10). CS, DTS, and FS were evaluated using a universal testing machine, while hardness was measured by Vickers microhardness testing. The data obtained were analyzed using One-way analysis of variance and the Tukey?s test (p < 0.05). GIC containing Ag and TiO2 nanoparticles significantly improved the CS, DTS, and hardness compared to the control group (p < 0.05). However, the FS was not much affected by the addition of either of the nanoparticles (p >0.05). TiO2 blended GIC demonstrated significantly higher CS (154.20+2.38) and DTS (13.2±0.5 MPa) compared to control 117.2±1.2 MPa and 7.2 ±0.8 MPa, respectively. While Blend of GIC+Ag nanoparticles showed the highest FS (29.0±0.7 MPa). Additionally, the blend of GIC+TiO2 exhibited the highest hardness (90.4±1.1 VHN). Ag and TiO2 blended GICs might guarantee their use in occlusal or higher stress-bearing areas.

scholarly journals Effect of Metalloproteinase Inhibitors on the Microtensile Bond Strength of Composite Resin to Er:YAG Laser-Irradiated Dentin

2016 ◽  
Vol 27 (4) ◽  
pp. 442-445 ◽  
Author(s):  
Beatriz Carlos Correa ◽  
Rodrigo Galo ◽  
Camila Scatena ◽  
Maria Cristina Borsatto ◽  
Aloísio Oro Spazzin ◽  
...  
Keyword(s):  
Bond Strength ◽  
Composite Resin ◽  
Er:Yag Laser ◽  
Testing Machine ◽  
Adhesive System ◽  
Fracture Pattern ◽  
Chemical Degradation ◽  
Control Group ◽  
Microtensile Bond Strength ◽  
Cross Sectional

Abstract This study evaluated the effect of matrix metalloproteinase (MMP) inhibitors - 2% (CHX) and sodium fluoride (NaF) (5000 ppm) - on microtensile bond strength (μTBS) of composite resin to Er:YAG laser-irradiated dentin after chemical degradation of the bond interface. The occlusal surface of forty sound human molars was removed exposing the dentin surface (n=10), which was polished, irradiated with Er:YAG laser, acid etched and dried. Twenty specimens were rewetted with 2% CHX (control group) and 20 were rewetted with NaF (5000 ppm). The adhesive system was applied and a 4-mm-high plateau of light-cured composite resin was built up. Resin-dentin sticks were obtained with a rectangular cross-sectional area (0.8-1 mm2) and were either stored in water at 37 ?#61616;C for 24 h or submitted to chemical degradation. For chemical degradation, they were immersed in 10% NaOCl aqueous solution for 5 h and rinsed in water for 1 h. The sticks were submitted to microtensile test in a mechanical testing machine at 0.5 mm/min until failure. Fracture pattern was analyzed using SEM. μTBS values were calculated in MPa and submitted to analysis of variance ANOVA (α=0.05). The variance analysis showed that the 'MMP inhibitor' and 'degradation' factors (p=0.214 and p=0.093, respectively) and interaction between the factors were not statistically significant (p=0.143). Mixed failure predominated in all groups. In conclusion, the 2% CHX and NaF 5000 ppm presented similar μTBS of composite resin to laser-irradiated dentin before and after chemical degradation

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