ABSTRACT
Currently, human magnetic resonance (MR) examinations are becoming highly specialized with a pre-defined and often relatively small target in the body. Conventionally, clinical MR equipment is designed to be universal that compromises its efficiency for small targets. Here, we present a concept for targeted clinical magnetic resonance imaging (MRI), which can be directly integrated into the existing clinical MR systems, and demonstrate its feasibility for breast imaging. The concept comprises spatial redistribution and passive focusing of the radiofrequency magnetic flux with the aid of an artificial resonator to maximize the efficiency of a conventional MR system for the area of interest. The approach offers the prospect of a targeted MRI and brings novel opportunities for high quality specialized MR examinations within any existing MR system.
Subject(s)
Breast Neoplasms/diagnostic imaging , Ceramics/radiation effects , Dielectric Spectroscopy/methods , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Adult , Ceramics/chemistry , Dielectric Spectroscopy/instrumentation , Electromagnetic Radiation , Equipment Design , Female , Healthy Volunteers , Humans , Magnetic Resonance Imaging/instrumentation , Phantoms, Imaging , Signal-To-Noise RatioABSTRACT
Antibiotic resistance genes (ARGs) have been detected in the atmosphere. Airborne ARGs transmission threatens human health. In the present study, we investigated the release and degradation of airborne ARGs from Escherichia coli bioaerosol through microwave (MW) irradiation. In this study, a new MW absorbing material (Fe3O4@SiC ceramic foam) that contributed to its stronger MW absorption is presented. When the MW input energy density was 7.4 × 103 kJ/m3, the concentration of airborne Escherichia coli decreased by 4.4 log. Different DNA forms were found in the air because MW irradiation ruptured cell membranes. The bound particles provide more protection for bound DNA in the degradation process than free DNA. After the self-degradation of the released airborne free ARGs, some of them would remain and continue to spread in the atmosphere. The released airborne free ARGs cannot be ignored. Total ARGs concentrations decrease rapidly with increased temperature. The inactivation rate constant of ARGs through MW irradiation is higher than that through the Fenton and UV, however, the energy efficiency per order of MW irradiation is lower. Therefore, MW irradiation with Fe3O4@SiC ceramic foam could efficiently degrade the distribution of ARGs in the atmosphere.
Subject(s)
Carbon Compounds, Inorganic/chemistry , Ceramics/chemistry , Drug Resistance, Bacterial/genetics , Escherichia coli/radiation effects , Ferrosoferric Oxide/chemistry , Genes, Bacterial/radiation effects , Silicon Compounds/chemistry , Aerosols/chemistry , Aerosols/radiation effects , Carbon Compounds, Inorganic/radiation effects , Ceramics/radiation effects , DNA, Bacterial/chemistry , DNA, Bacterial/radiation effects , Escherichia coli/chemistry , Escherichia coli/genetics , Ferrosoferric Oxide/radiation effects , Microwaves , Pyrolysis , Silicon Compounds/radiation effects , TemperatureABSTRACT
ABSTRACT Introduction Urological surgery is estimated to be the third most common cause of iatrogenic-retained foreign bodies 1. Presentation A 76-year old man was undergoing a transurethral resection of bladder tumor with a 26-Ch continuous flow resectoscope (Karl Storz, Germany). Before starting resection, a detachment of resectoscope sheath tip was noted. The ceramic tip was free-floating in the bladder lumen, and it would not fit within the sheath, making direct extraction using the loop impossible. An attempt was made to break it with a stone punch, but it was unsuccessful due to impossibility of closing it in the branches. Therefore, we decided to fragment the tip with holmium laser (RevoLix®, LISA Laser products, Germany), using an 800-micron, front-firing fiber. Laser device was settled at with 2.5 J energy and 5 Hz frequency. Ceramic appeared very hard, but it was difficult to carry on breaking with this setting because of tip retropulsion. Then, laser setting was switched to lower energy and higher frequency (1 J and 13 Hz). This setting guaranteed the same power of 13 W, but with minimal retropulsion. Results Tip was fragmented against the posterior bladder wall in seven pieces, which were retrieved trough the outer sheath. A total 5.62 kJ were used to fragment it. At the end, superficial lesions of the posterior bladder wall were highlighted. Surgical time was 55 minutes. Patient was discharged home next day without problems. Conclusions Holmium laser fragmentation is a safe and effective approach to remove foreign bodies from the bladder.
Subject(s)
Humans , Male , Aged , Urinary Bladder/surgery , Ceramics/radiation effects , Equipment Failure , Lasers, Solid-State/therapeutic use , Foreign Bodies/surgery , Radiation Dosage , Time Factors , Urinary Bladder Neoplasms/surgery , Treatment Outcome , Operative TimeABSTRACT
INTRODUCTION: Urological surgery is estimated to be the third most common cause of iatrogenic-retained foreign bodies (1). PRESENTATION: A 76-year old man was undergoing a transurethral resection of bladder tumor with a 26-Ch continuous flow resectoscope (Karl Storz, Germany). Before starting resection, a detachment of resectoscope sheath tip was noted. The ceramic tip was free-floating in the bladder lumen, and it would not fit within the sheath, making direct extraction using the loop impossible. An attempt was made to break it with a stone punch, but it was unsuccessful due to impossibility of closing it in the branches. Therefore, we decided to fragment the tip with holmium laser (RevoLix®, LISA Laser products, Germany), using an 800-micron, front-firing fiber. Laser device was settled at with 2.5 J energy and 5 Hz frequency. Ceramic appeared very hard, but it was difficult to carry on breaking with this setting because of tip retropulsion. Then, laser setting was switched to lower energy and higher frequency (1 J and 13 Hz). This setting guaranteed the same power of 13 W, but with minimal retropulsion. RESULTS: Tip was fragmented against the posterior bladder wall in seven pieces, which were retrieved trough the outer sheath. A total 5.62 kJ were used to fragment it. At the end, superficial lesions of the posterior bladder wall were highlighted. Surgical time was 55 minutes. Patient was discharged home next day without problems. CONCLUSIONS: Holmium laser fragmentation is a safe and effective approach to remove foreign bodies from the bladder.
Subject(s)
Ceramics/radiation effects , Equipment Failure , Foreign Bodies/surgery , Lasers, Solid-State/therapeutic use , Urinary Bladder/surgery , Aged , Humans , Male , Operative Time , Radiation Dosage , Time Factors , Treatment Outcome , Urinary Bladder Neoplasms/surgeryABSTRACT
The current effort demonstrates that lutetium oxyorthosilicate doped with 1-10% cerium (Lu2SiO5:Ce, LSO:Ce) radioluminescent particles can be coated with a single dye or multiple dyes and generate an effective energy transfer between the core and dye(s) when excited via X-rays. LSO:Ce particles were surface modified with an alkyne modified naphthalimide (6-piperidin-1-yl-2-prop-2-yn-1-yl-1 H-benzo[ de]isoquinoline-1,3-(2 H)-dione, AlNap) and alkyne modified rhodamine B ( N-(6-diethylamino)-9-{2-[(prop-2-yn-1-yloxy)carbonyl]phenyl}-3 H-xanthen-3-ylidene)- N-ethylethanaminium, AlRhod) derivatives to tune the X-ray excited optical luminescence from blue to green to red using Förster Resonance Energy Transfer (FRET). As X-rays penetrate tissue much more effectively than UV/visible light, the fluorophore modified phosphors may have applications as bioimaging agents. To that end, the phosphors were incubated with rat cortical neurons and imaged after 24 h. The LSO:Ce surface modified with AlNap was able to be successfully imaged in vitro with a low-output X-ray tube. To use the LSO:Ce fluorophore modified particles as imaging agents, they must not induce cytotoxicity. Neither LSO:Ce nor LSO:Ce modified with AlNap showed any cytotoxicity toward normal human dermal fibroblast cells or mouse cortical neurons, respectively.
Subject(s)
Ceramics/chemistry , Cerium/chemistry , Fluorescent Dyes/chemistry , Lutetium/chemistry , Silicates/chemistry , Animals , Ceramics/radiation effects , Ceramics/toxicity , Cerium/radiation effects , Cerium/toxicity , Fibroblasts/drug effects , Fluorescence , Fluorescence Resonance Energy Transfer , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/radiation effects , Fluorescent Dyes/toxicity , Humans , Lutetium/radiation effects , Lutetium/toxicity , Mice , Naphthalimides/chemical synthesis , Naphthalimides/chemistry , Naphthalimides/radiation effects , Naphthalimides/toxicity , Neurons/drug effects , Optical Imaging/methods , Rats , Rhodamines/chemical synthesis , Rhodamines/chemistry , Rhodamines/radiation effects , Rhodamines/toxicity , Silicates/radiation effects , Silicates/toxicity , X-RaysABSTRACT
PURPOSE: To evaluate the morphological properties, phase transformation, and microshear bond strength of composite cement to bioglass-coated zirconia surfaces treated with Nd:YAG laser. MATERIALS AND METHODS: Seventy-five zirconia disks were divided into five groups (n = 15). Group C received no surface treatment (control). Group S was subjected to sandblasting with 50-µm aluminum oxide particles. Group B samples were coated with bioglass 45S5. Groups BL9 and BL5 received bioglass coating and laser irradiation with 9 J/cm2 and 5 J/cm2 energy density. Morphological assessment was done using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Zirconia phase transformation was assessed by XRD. Microhear bond strength testing was performed using a modified microtensile tester. The data were analyzed using the Welch test and the Games-Howell test (p < 0.05). RESULTS: The sandblasted and bioglass-coated groups showed the highest bond strengths compared to other groups (p < 0.05). Group S showed the highest surface roughness and the highest frequency of cohesive failure. In all samples, the tetragonal phase decreased after surface treatment. Groups BL9 and BL5 showed some levels of tetragonal to cubic phase transformation. CONCLUSION: Bioglass coating of zirconia surfaces (using the slurry method) can increase its microshear bond strength comparable to that of sandblasting. Surface roughness of sandblasted zirconia was the highest among all methods. Irradiation of Nd:YAG laser on bioglass-coated zirconia surfaces is not effective and decreases its bond strength compared to sandblasting and bioglass coating. Increasing the Nd:YAG laser energy density cannot increase the surface roughness of bioglass-coated zirconia surfaces. Bioglass coating results in transformation of the tetragonal to the cubic phase.
Subject(s)
Ceramics/radiation effects , Dental Bonding , Dental Materials/radiation effects , Lasers, Solid-State , Zirconium/radiation effects , Aluminum Oxide/chemistry , Dental Materials/chemistry , Materials Testing , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Phase Transition , Shear Strength , Surface Properties , Tensile Strength , Tooth Abrasion , Zirconium/chemistryABSTRACT
OBJECTIVE: The present study aimed to evaluate the analgesic and anti-inflammatory effects of far infrared-emitting ceramics (cFIRs) in a model of persistent inflammatory hyperalgesia and to elucidate the possible mechanisms of these effects. METHODS: Mice were injected with complete Freund's adjuvant (CFA) and treated with cFIRs via placement on a pad impregnated with cFIRs on the bottom of the housing unit for different periods of time. Mice underwent mechanical hyperalgesia and edema assessments, and tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and IL-10 levels were measured. Twenty-four hours after CFA injection and 30â¯min before cFIR treatment, mice were pretreated with a nonselective adenosinergic antagonist, caffeine, the selective adenosine receptor A1 antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), the selective cannabinoid receptor type 1 antagonist, AM281, the selective cannabinoid receptor type 2 antagonist, AM630, or the nonselective opioid receptor antagonist, naloxone, and mechanical hyperalgesia was assessed. RESULTS: cFIRs statistically (Pâ¯<â¯0.05) decreased CFA-induced mechanical hyperalgesia ((82.86⯱â¯5.21)% in control group vs (56.67⯱â¯9.54)% in cFIR group) and edema ((1699.0⯱â¯77.8) µm in control group vs (988.7⯱â¯107.6)⯵m in cFIR group). cFIRs statistically (Pâ¯<â¯0.05) reduced TNF-α ((0.478⯱â¯0.072)â¯pg/mg of protein in control group vs (0.273⯱â¯0.055)â¯pg/mg of protein in cFIR group) and IL-1ß ((95.81⯱â¯3.95)â¯pg/mg of protein in control group vs (80.61⯱â¯4.71)â¯pg/mg of protein in cFIR group) levels and statistically (Pâ¯<â¯0.05) increased IL-10 ((18.32⯱â¯0.78)â¯pg/mg of protein in control group vs (25.89⯱â¯1.23)â¯pg/mg of protein in cFIR group) levels in post-CFA-injected paws. Peripheral pre-administration of inhibitory neuroreceptor antagonists (caffeine, DPCPX, AM281, AM630 and naloxone) prevented the analgesic effects of cFIRs (Pâ¯<â¯0.05). CONCLUSION: These data provide additional support for the use of cFIRs in the treatment of painful inflammatory conditions and contribute to our understanding of the neurobiological mechanisms of the therapeutic effects of cFIRs.
Subject(s)
Ceramics/chemistry , Cytokines/immunology , Freund's Adjuvant/adverse effects , Hyperalgesia/immunology , Hyperalgesia/therapy , Sensory Receptor Cells/immunology , Animals , Ceramics/radiation effects , Cytokines/genetics , Disease Models, Animal , Humans , Hyperalgesia/chemically induced , Infrared Rays , Interleukin-10/genetics , Interleukin-10/immunology , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Male , Mice , Pain Management , Peripheral Nerves/immunology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
OBJECTIVES: To evaluate the effects of airborne-particle abrasion (APA) and Er,Cr:YSGG laser irradiation on 4-point-flexural strength, phase transformation and morphologic changes of zirconia ceramics treated at pre-sintered or post-sintered stage. METHODS: Three hundred and forty-two bar shaped zirconia specimens were milled with different sizes according to the flexural strength test (nâ¯=â¯10), X-ray diffraction (XRD) (nâ¯=â¯4) and field emission scanning electron microscope (FE-SEM) (nâ¯=â¯4) analyses. For each test protocol, specimens were divided into 4 main groups whether the surface treatments applied before or after sintering and whether the specimens received heat treatment or not as pre-sintered, post-sintered no-heat and post-sintered heat-treated groups, and a group was served as control. Main groups were further divided into 6 equal subgroups according to surface treatment method applied (2â¯W-, 3â¯W-, 4â¯W-, 5â¯W-, 6â¯W-laser irradiations and APA). Surface treatments were applied to pre-sintered groups before sintering and to post-sintered groups after sintering. Post-sintered heat-treated groups were subjected to veneer ceramic firing simulation after surface treatments. Flexural strength and flexural modulus values were statistically analysed and monoclinic phase content was calculated. Weibull analysis was used to evaluate strength reliability and fractographic analysis was conducted. RESULTS: Highest flexural strength values were detected at post-sintered no-heat APA and 4W-laser groups (Pâ¯<â¯0.05). Pre-sintered groups showed statistically lower flexural strength values. Heat treatment decreased the strength of the specimens. Monoclinic phase content was only detected at post-sintered no-heat groups and the highest amount was detected at APA group. Rougher surfaces and deeper irregularities were detected at FE-SEM images pre-sintered groups. CONCLUSIONS: Application of surface treatments at pre-sintered stage may be detrimental for zirconia ceramics in terms of flexural strength. CLINICAL SIGNIFICANCE: Treating the surface of zirconia ceramic before sintering process is not recommended due to significant decrease in flexural strength values. 2â¯W-4â¯W Er,Cr:YSGG laser irradiations can be regarded as alternative surface treatment methods when zirconia restoration would be subjected to veneer ceramic firing procedures.
Subject(s)
Air Abrasion, Dental/methods , Flexural Strength/radiation effects , Lasers, Solid-State , Shear Strength , Zirconium/chemistry , Zirconium/radiation effects , Carbon Compounds, Inorganic , Ceramics/radiation effects , Dental Materials , Hot Temperature , Materials Testing , Microscopy, Electron, Scanning , Phase Transition , Silicon Compounds , Surface Properties/radiation effects , Tensile Strength , X-Ray DiffractionABSTRACT
OBJECTIVE: The aim of this study was to measure the effect of irradiation with a novel 445-nm diode laser on the shear bond strength (SBS) of ceramic brackets before debonding. MATERIALS AND METHODS: Thirty ceramic brackets (In-Ovation® C, GAC) were bonded in standard manner to the planed and polished buccal enamel surfaces of 30 caries-free human third molars. Each tooth was randomly allocated to the laser or control group, with 15 samples per group. The brackets in the laser group were irradiated with the diode laser (SIROLaser Blue®; Sirona) on three sides of the bracket bases for 5 sec each (lateral-coronal-lateral, a total of 15 sec) immediately before debonding. SBS values were measured for the laser group and control group. To assess the adhesive remnant index (ARI) and the degree of enamel fractures, micrographs of the enamel surface were taken with 10-fold magnification after debonding. RESULTS: The SBS values were significantly lower statistically in the laser group in comparison with the control group (p < 0.05). The ARI scores were also significantly lower statistically in the laser group in comparison with the control group (p < 0.05). No bracket fractures or enamel fractures occurred in either group after debonding. CONCLUSIONS: Irradiation of ceramic brackets with the novel diode laser before debonding significantly reduces the SBS values. This is of clinical importance, as it means that the risk of damage to the teeth, bracket fractures, and the overall treatment time can be reduced.
Subject(s)
Dental Debonding/methods , Lasers, Semiconductor/therapeutic use , Low-Level Light Therapy/methods , Orthodontic Brackets , Shear Strength , Ceramics/chemistry , Ceramics/radiation effects , Dental Stress Analysis , Humans , In Vitro Techniques , Molar/radiation effects , Random Allocation , Reference ValuesABSTRACT
OBJECTIVE: To evaluate the surface of glazed lithium disilicate dental ceramics after irradiation under different irradiation settings of Nd:YAG and Er:YAG lasers using a scanning electron microscope (SEM). MATERIALS AND METHODS: Three glazed-press lithium disilicate ceramic discs were treated with HF, Er:YAG, and Nd:YAG, respectively. The laser-setting variables tested were laser mode, repetition rate (Hz), power (W), time of exposure (seconds), and laser energy (mJ). Sixteen different variable settings were tested for each laser type, and all the samples were analyzed by SEM at 500× and 1000× magnification. RESULTS: Surface analysis of the HF-treated sample showed a typical surface texture with a homogenously rough pattern and exposed ceramic crystals. Er:YAG showed no effect on the surface under any irradiation setting. The surface of Nd:YAG-irradiated samples showed cracking, melting, and resolidifying of the ceramic glaze. These changes became more pronounced as the power increased. At the highest power setting (2.25 W), craters on the surface with large areas of melted or resolidified glaze surrounded by globules were visible. However, there was little to no exposure of ceramic crystals or visible regular surface roughening. CONCLUSIONS: Neither Er:YAG nor Nd:YAG dental lasers exhibited adequate surface modification for bonding of orthodontic brackets on glazed lithium disilicate ceramics compared with the control treated with 9.5% HF.
Subject(s)
Ceramics/radiation effects , Dental Porcelain/radiation effects , Lasers, Solid-State , Microscopy, Electron, Scanning , Acid Etching, Dental , Dental Bonding/methods , Hydrofluoric Acid , Materials Testing , Surface PropertiesABSTRACT
OBJECTIVE:: The aim of this study was to assess in vitro the influence of the CO2 laser and of the type of ceramic bracket on the shear bond strength (SBS) to enamel. METHODS:: A total of 60 enamel test surfaces were obtained from bovine incisors and randomly assigned to two groups, according to the ceramic bracket used: Allure (A); Transcend (T). Each group was divided into 2 subgroups (n = 15): L, laser (10W, 3s); C, no laser, or control. Twenty-four hours after the bonding protocol using Transbond XT, SBS was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. After debonding, the Adhesive Remnant Index (ARI) was evaluated at 10 x magnification and compared among the groups. Data were analyzed by one-way ANOVA, Tukey's, Mann-Whitney's and Kruskal-Wallis tests (α = 0.05). RESULTS:: Mean SBS in MPa were: AL = 0.88 ± 0.84; AC = 12.22 ± 3.45; TL = 12.10 ± 5.11; TC = 17.71 ± 6.16. ARI analysis showed that 73% of the specimens presented the entire adhesive remaining on the tooth surfaces (score 3). TC group presented significantly higher SBS than the other groups. The lased specimens showed significantly lower bond strength than the non-lased groups for both tested brackets. CONCLUSION:: CO2 laser irradiation decreased SBS values of the polycrystalline ceramic brackets, mainly Allure.
Subject(s)
Ceramics/radiation effects , Dental Bonding , Dental Cements/radiation effects , Lasers, Gas/adverse effects , Orthodontic Brackets , Shear Strength/radiation effects , Acid Etching, Dental , Animals , Cattle , Dental Enamel , Dental Stress Analysis , Incisor , Materials Testing , Resin Cements/radiation effects , Stress, MechanicalABSTRACT
ABSTRACT OBJECTIVE: The aim of this study was to assess in vitro the influence of the CO2 laser and of the type of ceramic bracket on the shear bond strength (SBS) to enamel. METHODS: A total of 60 enamel test surfaces were obtained from bovine incisors and randomly assigned to two groups, according to the ceramic bracket used: Allure (A); Transcend (T). Each group was divided into 2 subgroups (n = 15): L, laser (10W, 3s); C, no laser, or control. Twenty-four hours after the bonding protocol using Transbond XT, SBS was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. After debonding, the Adhesive Remnant Index (ARI) was evaluated at 10 x magnification and compared among the groups. Data were analyzed by one-way ANOVA, Tukey’s, Mann-Whitney’s and Kruskal-Wallis tests (α = 0.05). RESULTS: Mean SBS in MPa were: AL = 0.88 ± 0.84; AC = 12.22 ± 3.45; TL = 12.10 ± 5.11; TC = 17.71 ± 6.16. ARI analysis showed that 73% of the specimens presented the entire adhesive remaining on the tooth surfaces (score 3). TC group presented significantly higher SBS than the other groups. The lased specimens showed significantly lower bond strength than the non-lased groups for both tested brackets. CONCLUSION: CO2 laser irradiation decreased SBS values of the polycrystalline ceramic brackets, mainly Allure.
RESUMO OBJETIVO: o objetivo deste estudo foi avaliar in vitro a influência do laser de CO2 sobre a resistência ao cisalhamento da colagem (RCC) no esmalte dentário, usando diferentes tipos de braquetes cerâmicos. MÉTODOS: no total, 60 superfícies de esmalte de incisivos bovinos foram obtidas e aleatoriamente divididas em dois grupos, de acordo com o braquete cerâmico utilizado: Allure (A) e Transcend (T). Cada grupo foi dividido em dois subgrupos (n = 15): L, laser (10W, 3s); C, sem laser, ou controle. Vinte e quatro horas após a colagem dos braquetes com o sistema Transbond XT, foi realizado o teste de resistência ao cisalhamento, com velocidade de 0,5 mm/min, em máquina universal de ensaios mecânicos. Após a descolagem, o Índice de Remanescente de Adesivo (IRA) foi avaliado com aumento de 10X e comparado entre os grupos. Os dados foram analisados pelo ANOVA one-way, testes de Tukey’s, Mann-Whitney’s e Kruskal-Wallis (α = 0,05). RESULTADOS: as médias da RCC em MPa foram: AL = 0,88 ± 0,84; AC = 12,22 ± 3,45; TL = 12,10 ± 5,11; TC = 17,71 ± 6,16. A análise do IRA mostrou que 73% dos corpos de prova apresentaram todo o compósito remanescente aderido à superfície do esmalte (escore 3). O grupo TC apresentou valor significativamente maior de RCC do que os outros grupos. Os corpos de prova dos grupos com laser obtiveram valores adesivos significativamente menores do que os corpos de prova dos grupos sem laser, com ambos os tipos de braquetes. CONCLUSÃO: a irradiação com laser de CO2 diminuiu os valores de RCC dos braquetes policristalinos testados, principalmente do Allure.
Subject(s)
Animals , Ceramics/radiation effects , Dental Bonding , Orthodontic Brackets , Dental Cements/radiation effects , Shear Strength/radiation effects , Lasers, Gas/adverse effects , Stress, Mechanical , Acid Etching, Dental , Materials Testing , Cattle , Resin Cements/radiation effects , Dental Enamel , Dental Stress Analysis , IncisorABSTRACT
The purpose of this study is to determine the CO2 laser irradiation in comparison with sandblasting (Sb), hydrofluoric acid (Hf) and silane coupling agent (Si) on shear bond strength (SBS), roughness (Rg) and wettability (Wt) of resin cement to CAD/CAM ceramics. Sixty (CAD/CAM) ceramic discs were prepared and distributed into six different groups: group A, control lithium disilicate (Li); group B, control zirconia (Zr); group C, Li: CO2/HF/Si; group D, Li: HF/Si; group E, Zr: CO2/Sb/Si; group F, Zr: Sb/Si. Result showed significant difference between irradiated and non-irradiated in terms of shear bond strength for zirconia ceramics (p value = 0.014). Moreover, partial surface wettability for irradiated and non-irradiated ceramics. Irradiated surface demonstrated more rough surface in lithium disilicate than zirconia ceramics. CO2 irradiation could increase shear bond strength, surface roughness and wettability for both CAD/CAM ceramics.
Subject(s)
Ceramics/radiation effects , Computer-Aided Design , Lasers, Gas , Materials Testing , Microscopy, Atomic Force , Shear Strength , Dental Porcelain/radiation effects , Hydrofluoric Acid/chemistry , Resin Cements/chemistry , Resin Cements/radiation effects , Stress, Mechanical , Wettability , Zirconium/radiation effectsABSTRACT
Lasers have the potential for reducing the required debonding force and can prevent the mechanical damage given to the enamel surface as a result of conventional debonding procedure. However, excessive thermal effects limit the use of lasers for debonding purposes. The aim of this study was to investigate the optimal parameters of 1940-nm Tm:fiber laser for debonding ceramic brackets. Pulling force and intrapulpal temperature measurements were done during laser irradiation simultaneously. A laser beam was delivered in two different modes: scanning the fiber tip on the bracket surface with a Z shape movement or direct application of the fiber tip at one point in the center of the bracket. Results showed that debonding force could be decreased significantly compared to the control samples, in which brackets were debonded by only mechanical force. Intrapulpal temperature was kept equal or under the 5.5°C threshold value of probable thermal damage to pulp. Scanning was found to have no extra contribution to the process. It was concluded that using 1940-nm Tm:fiber laser would facilitate the debonding of ceramic brackets and can be proposed as a promising debonding tool with all the advantageous aspects of fiber lasers.
Subject(s)
Ceramics/radiation effects , Dental Debonding/methods , Dental Debonding/standards , Dental Enamel/radiation effects , Lasers , Orthodontic Brackets , Dental Debonding/instrumentation , HumansABSTRACT
OBJECTIVE: The purpose of this work was to evaluate the effects of several surface treatment methods on the shear bond strengths of metal brackets bonded to a silica-based ceramic with a light-cured adhesive. MATERIALS AND METHODS: Silica-based ceramic (IPS Classic(®)) with glazed surfaces was cut into discs that were used as substrates. A total of 80 specimens were randomly divided into four groups according to the method used: 9.6 % hydrofluoric acid (group 1), 9.6 % hydrofluoric acid (HF) + silane coupling agent (group 2), sandblasting (aluminum trioxide, 50 µm) + silane (group 3), and tribochemical silica coating (CoJet™ sand, 30 µm) + silane (group 4). Brackets were bonded to the treated specimens with a light-cure adhesive (Transbond XT, 3 M Unitek). Shear bond strength was tested after bracket bonding, and the Adhesive Remnant Index (ARI) scores were quantified after debonding. RESULTS: Group 4 showed the highest bond strength (12.3 ± 1.0 MPa), which was not significantly different from that of group 3 (11.6 ± 1.2 MPa, P > 0.05); however, the bond strength of group 4 was substantially higher than that of group 2 (9.4 ± 1.1 MPa, P < 0.05). The shear bond strength of group 1 (3.1 ± 0.6 MPa, P< 0.05) was significantly lower than that of the other groups. CONCLUSION: Shear bond strengths exceeded the optimal range of ideal bond strength for clinical practice, except for the isolated HF group. HF acid etching followed by silane was the best suited method for bonding on IPS Classic(®). Failure modes in the sandblasting and silica-coating groups revealed signs of damaged ceramic surfaces.
Subject(s)
Ceramics/chemistry , Dental Etching/methods , Light-Curing of Dental Adhesives/methods , Metals/chemistry , Orthodontic Brackets , Resin Cements/chemistry , Adhesiveness/radiation effects , Ceramics/radiation effects , Dental Materials/chemistry , Dental Stress Analysis , Light , Metals/radiation effects , Radiation Dosage , Resin Cements/radiation effects , Shear Strength/radiation effects , Silicon Dioxide/chemistry , Silicon Dioxide/radiation effects , Stress, Mechanical , Surface Properties , Tensile Strength/radiation effectsABSTRACT
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.
Subject(s)
Ceramics/chemistry , Orthodontic Brackets , Bicuspid/physiology , Ceramics/radiation effects , Dental Cements , Humans , Lasers, Solid-State , Materials Testing , Shear Strength , Spectrum Analysis, RamanABSTRACT
PURPOSE: To assess the light irradiance (LI) delivered by two light-curing units and to measure the degree of conversion (DC) of three composite cements and one flowable composite when cured through zirconia or ceramic-veneered zirconia plates with different thicknesses. MATERIALS AND METHODS: Three dual-curing composite cements (Clearfil Esthetic Cement, Panavia F2.0, G-CEM LinkAce) and one light-curing flowable composite (G-aenial Universal Flo) were investigated. Nine different kinds of zirconia plates were prepared from three zirconia grades (YSZ: Aadva and KATANA; Ce-TZP/Al2O3: NANOZR) in three different thicknesses (0.5- and 1.5-mm-thick zirconia, and 0.5-mm-thick zirconia veneered with a 1.0-mm-thick veneering ceramic). Portions of the mixed composite cements and the flowable composite were placed on a light spectrometer to measure LI while being light cured through the zirconia plates for 40 s using two light-curing units (n = 5). After light curing, micro-Raman spectra of the composite films were acquired to determine DC at 5 and 10 min, 1 and 24 h, and at 1 week. RESULTS: The zirconia grade and the thickness of the zirconia/veneered zirconia plates significantly decreased LI. Increased LI did not increase DC. Only the Ce-TZP/Al2O3 (NANOZR) zirconia was too opaque to allow sufficient light transmission and resulted in significantly lower DC. CONCLUSION: Although zirconia-based restorations attenuate the LI of light-curing units, the composite cements and the flowable composite could be light cured through the YSZ zirconia. LI is too low through Ce-TZP/Al2O3 zirconia, necessitating the use of self-/dual-curing composite cements.
Subject(s)
Composite Resins/radiation effects , Dental Materials/radiation effects , Light , Resin Cements/radiation effects , Zirconium/chemistry , Aluminum Oxide/chemistry , Ceramics/chemistry , Ceramics/radiation effects , Cerium/chemistry , Composite Resins/chemistry , Curing Lights, Dental/classification , Dental Materials/chemistry , Dental Veneers , Humans , Light-Curing of Dental Adhesives/instrumentation , Materials Testing , Methacrylates/chemistry , Microspectrophotometry , Polyethylene Glycols/chemistry , Polymerization , Polymethacrylic Acids/chemistry , Polyurethanes/chemistry , Radiation Dosage , Resin Cements/chemistry , Scattering, Radiation , Spectrum Analysis, Raman , Surface Properties , Yttrium/chemistryABSTRACT
PURPOSE: The authors evaluate the capability of a beryllium oxide (BeO) ceramic fiber-coupled luminescence dosimeter, named radioluminescence/optically stimulated luminescence (RL/OSL) BeO FOD, for dosimetric verification of high dose rate (HDR) treatments. The RL/OSL BeO FOD is capable of RL and OSL measurements. METHODS: The RL/OSL BeO FOD is able to be inserted in 6F proguide needles, used in interstitial HDR treatments. Using a custom built Perspex phantom, 6F proguide needles could be submerged in a water tank at 1 cm separations from each other. A second background fiber was required to correct for the stem effect. The stem effect, dose linearity, reproducibility, depth-dose curves, and angular and temperature dependency of the RL/OSL BeO FOD were characterised using an Ir-192 source. The RL/OSL BeO FOD was also applied to the commissioning of a 10 mm horizontal Leipzig applicator. RESULTS: Both the RL and OSL were found to be reproducible and their percentage depth-dose curves to be in good agreement with those predicted via TG-43. A combined uncertainty of 7.9% and 10.1% (k=1) was estimated for the RL and OSL, respectively. For the 10 mm horizontal Leipzig applicator, measured percentage depth doses were within 5% agreement of the published reference calculations. The output at the 3 mm prescription depth for a 1 Gy delivery was verified to be 0.99±0.08 Gy and 1.01±0.10 Gy by the RL and OSL, respectively. CONCLUSIONS: The use of the second background fiber under the current setup means that the two fibers cannot fit into a single 6F needle. Hence, use of the RL is currently not adequate for the purpose of in vivo brachytherapy dosimetry. While not real-time, the OSL is shown to be adequate for in vivo brachytherapy dosimetry.
Subject(s)
Beryllium/radiation effects , Brachytherapy/instrumentation , Ceramics/radiation effects , Dose Fractionation, Radiation , Fiber Optic Technology/instrumentation , Thermoluminescent Dosimetry/instrumentation , Beryllium/chemistry , Ceramics/chemistry , Computer Systems , Equipment Design , Equipment Failure Analysis , Luminescent Measurements/instrumentation , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Atmospheric plasma or ultraviolet (UV) treatment alters the surface characteristics of tetragonal zirconia polycrystal (TZP), increasing its hydrophilicity by reducing the contact angle against water to zero. This suggests that such treatment would increase the wettability of bonding resin. The purpose of this study was to determine how increasing the hydrophilicity of TZP through plasma irradiation, UV treatment, or application of ceramic primer affected initial bonding with resin composites. Here, the effect of each pre-treatment on the hydrophilicity of TZP surfaces was determined by evaluating change in shear bond strength. Plasma irradiation, UV, or ceramic primer pre-treatment showed no significant effect on bonding strength between TZP surfaces and resin composites. In addition, alumina blasting yielded no significant increase in bond strength. Plasma irradiation, UV treatment, or ceramic primer pre-treatment did not lead to significant increase in bond strength between TZP and resin composites.
Subject(s)
Ceramics/chemistry , Resin Cements/chemistry , Zirconium/chemistry , Ceramics/radiation effects , Dental Bonding , Electromagnetic Radiation , Hydrophobic and Hydrophilic Interactions , Resin Cements/radiation effects , Surface Properties , Ultraviolet Rays , Zirconium/radiation effectsABSTRACT
OBJECTIVES: The aim of the study was to determine the effect of CO2 laser on surface roughness of In-Ceram-Alumina-ceramic. MATERIALS AND METHODS: Four aluminum-oxide ceramic disc specimens were prepared of In-Ceram Alumina. Discs received CO2 laser irradiation with different engraving speeds (100, 400, 600 and 800 mm/min) as a surface treatment. The roughness of the surfaces was measured on digital elevation models reconstructed from stereoscopic images acquired by scanning-electron-microscope. Surface roughness data were analyzed with One-Way-Analysis-of-Variance at a significance level of p<0.05. RESULTS: There was no significant difference between the roughness values (p=0.82). Due to higher laser durations, partial melting signs were observed on the surfaces. Tearing, smearing and swelling occurred on melted surfaces. Swelling accompanying melting increased the surface roughness, while laser power was fixed and different laser engraving speeds were applied. CONCLUSION: Although different laser irradiation speeds did not affect the roughness of ceramic surfaces, swelling was observed which led to changes on surfaces.