• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.3
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• pp.103-110
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• 2014

Purpose: The current gold standard for clinical jawbone formation involves autogenous bone as a graft material. In addition, demineralized dentin can be an effective graft material. Although demineralized dentin readily induces heterotopic bone formation, conventional decalcification takes three to five days, so, immediate bone grafting after extraction is impossible. This study evaluated the effect of vacuum ultrasonic power on the demineralization and processing of autogenous tooth material and documented the clinical results of rapidly processed autogenous demineralized dentin (ADD) in an alveolar defects patient. Methods: The method involves the demineralization of extracted teeth with detached soft tissues and pulp in 0.6 N HCl for 90 minutes using a heat controlled vacuum-ultrasonic accelerator. The characteristics of processed teeth were evaluated by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Bone grafting using ADD was performed for narrow ridges augmentation in the mandibular area. Results: The new processing method was completed within two hours regardless of form (powder or block). EDS and SEM uniformly demineralized autotooth biomaterial. After six months, bone remodeling was observed in augmented sites and histological examination showed that ADD particles were well united with new bone. No unusual complications were encountered. Conclusion: This study demonstrates the possibility of preparing autogenous tooth graft materials within two hours, allowing immediate one-day grafting after extraction.

• Restorative Dentistry and Endodontics
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• v.49 no.2
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• pp.12.1-12.10
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• 2024

Objectives: This study evaluated the impact of different methods of irrigant agitation on smear layer removal in the apical third of curved mesial canals of 3 dimensionally (D) printed mandibular molars. Materials and Methods: Sixty 3D-printed mandibular second molars were used, presenting a 70° curvature and a Vertucci type II configuration in the mesial root. A round cavity was cut 2 mm from the apex using a trephine of 2 mm in diameter, 60 bovine dentin disks were made, and a smear layer was formed. The dentin disks had the adaptation checked in the apical third of the teeth with wax. The dentin disks were evaluated in environmental scanning electron microscope before and after the following irrigant agitation methods: G1(PIK Ultrasonic Tip), G2 (Passive Ultrasonic Irrigation with Irrisonic- PUI), G3 (Easy Clean), G4 (HBW Ultrasonic Tip), G5 (Ultramint X Ultrasonic tip), and G6 (conventional irrigation-CI) (n = 10). All groups were irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Results: All dentin disks were 100% covered by the smear layer before treatment, and all groups significantly reduced the percentage of the smear layer after treatment. After the irrigation protocols, the Ultra-X group showed the lowest coverage percentage, statistically differing from the conventional, PIK, and HBW groups (p < 0.05). There was no significant difference among Ultramint X, PUI-Irrisonic, and Easy Clean (p > 0.05). None of the agitation methods could remove the smear layer altogether. Conclusions: Ultramint X resulted in the most significant number of completely clean specimens.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.205-211
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• 2013

This paper studies on mechanical properties, fractures, and ultrasonic characteristics of Pure Titanium welds using ultrasonic attenuation. Ti specimen was made by using AR purge gas. When the titanium weld specimen is fractured, Tensile tests were conducted in order to observe the ultrasonic signal changes. A scanning electron microscope(SEM) was used to observe changes in failure surface and an ultrasonic normal probe with the central frequency of 4 MHz was used to obtain ultrasonic signals. As a result, the value of the mechanical properties in the weld zone was lower than that in the base zone and heat affected zone(HAZ) from Ti. Also the grain size in the weld zone was bigger than that in the weld zone and HAZ from Ti. Ultrasonic signals using a RMS method presents correlation between envelope area and the tensile strength. Consequently, the ultrasonic method could be potential tool for integrity evaluation of the Ti weld zone.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.9-15
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• 1999

Die-sinking electrical discharge machining(EDM) for conductive ceramic matrix composite(CMC) of Tic/$Al_2O_3$ was experienced with addition of ultrasonic emission, and the results were compared with ones obtained by the EDM only. From this experimental study, the values of material removal rate(MRR) and surface roughness($R_{max}$), scanning electron microscope(SEM) micrographs, and weibull probability distribution of bending strength for the specimens were obtained and compared. The trend of MRR was found to be increased slightly with the current and the duty factor for both EDM only and EDM with ultrasonic emission. The MRR values were found to be increased for EDM with ultrasonic emission. The SEM micrographs of EDMed surface by under various operating conditions showed less micro cracks in various places. Although smaller bending strength value was obtained by EDMed surface with ultrasonic emission by weibull probability distribution analysis of bending strength.

• Corrosion Science and Technology
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• v.12 no.4
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• pp.185-190
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• 2013

In the present study, $Ni-TiO_2$ composite coatings were electrodeposited in a sulfamate bath containing $TiO_2$ particles. The influence of the ultrasonic treatment on the co-deposition of $TiO_2$ particles in the coating and the hardness of the electrodeposited $Ni-TiO_2$ composite has been investigated. Three different ultrasonic treatments (pretreatment before the electrodeposition (pre-UT), pretreatment + applied during the electrodeposition (UT), and the electrodeposition without the ultrasonic treatment (w/o UT)) were performed. The $Ni-TiO_2$ composite coatings are characterized using scanning electron microscopy (SEM), image analyzer, and hardness tester. Comparison of results indicates that the volume fraction is more important factor than the agglomerated particle size in terms of the strength improvement, and the strength of the electrodeposited $Ni-TiO_2$ composite coatings is enhanced with pre-UT condition.

• Textile Coloration and Finishing
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• v.32 no.4
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• pp.274-280
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• 2020

This study compared the mechanical properties of bamboo fiber composites and kenaf fiber composites through physical treatment (ultrasonic treatment). Kenaf, a composite of PP reinforced with bamboo fiber, was made using injection molding technology. PP was used as a binder and the ultrasonic treatment time of bamboo and kenaf was increased by 30 minutes to compare and study various mechanical properties of bamboo and kenaf composites through physical treatment. Interfacial properties such as internal cracks and internal structure of the wave cross section were confirmed using a scanning electron microscope (SEM). As a result of the ultrasonic treatment, most of the characteristics were fragile as the ultrasonic treatment time was increased, and it was confirmed that the natural characteristics of the twisted fibers had a great influence on the characteristics of the composite material.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.795-799
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• 2013

This paper describes a novel hybrid surface polishing process combining non-traditional electrochemical polishing (ECP) with external artificial ultrasonic vibration. The purpose of this study is to develop an easier method for improving stainless steel surfaces. To this end, vibration electrochemical polishing (VECP), a novel ultrasonic manufacturing process, for enhancing electrochemical reaction and surface quality compared with that achieved using conventional ECP is suggested. In addition, for finding the optimized experimental conditions, the two methods are compared under various current densities. Localized roughness of the work material is measured with atomic force microscopy (AFM) and scanning electron microscopy (SEM) for obtaining detailed surface information.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.11
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• pp.9-16
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• 1995

In this paper, an ultrasonic phased array transducer with spherical liquid lens, which utilizes both electronic focusing by linear phased array and variable geometric focusing by spherical lens. is investigated. This system reduces the elevational beamwidth which is disadvantage of the 1-dimensional linear phased array, and adds real-time dynamic focusing capability by controlling the volume of liquid in the lens. A prototype of this transducer is constructed and tested. The experimental results are compared with those of computer simulations. The range of applications are in the hyperthermia applicators or ultrasonic image system with narrow beam and rapid scanning characterisitcs.

• Journal of Sensor Science and Technology
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• v.14 no.5
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• pp.362-367
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• 2005

ZnO films were deposited on MgO substrates (ZnO/MgO) by ultrasonic spray pyrolysis. Substrate temperature varied from $250^{\circ}C$ to $350^{\circ}C$. The crystallographic properties and surface morphologies of the ZnO/MgO films were studied by X-ray diffraction and scanning electron microscopy. The properties of photoluminescence (PL) for the films were investigated by dependence of PL spectra on the substrate temperature and the annealing temperature. The ZnO/MgO films prepared at $350^{\circ}C$ showed the strongest Ultraviolet light emission peak at 18 K and 300 K among the films in this study. The annealing process increases the visible light emission, which is due to the increased oxygen vacancies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.58-63
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• 2006

In this Paper, ZnO films mixed with iron oxide were prepared by an ultrasonic spray pyrolysis method. The chemical composition and structural properties as a function of the Fe atomic ratio in the deposition solution were studied. Zinc acetate and ferrous chloride were used as precursors of Zn and Fe, respectively. Fe atomic ratio to Zn varied from 0.15 to 10.0. Substrate temperature was fixed at $250^{\circ}C$. The crystallographic properties and surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Electron probe X-ray microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS) were carried out to analyse the chemical composition and state of Zn and Fe atoms.