• Title/Summary/Keyword: Roughness control

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SURFACE ROUGHNESS OF ESTHETIC RESTORATIVE MATERIALS BY POLISHING SYSTEMS (연마기구에 따른 심미 치아 수복재료의 표면 거칠기에 관한 비교 연구)

  • Park, Eun-Hae;Yang, Ku-Ho;Choi, Nam-Ki
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.520-529
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    • 2003
  • Proper finishing and polishing of tooth restorations enhance the esthetics and the longevity of the restored tooth. The aims of this study were to identify an appropriate polishing system for each esthetic restorative material(Z250, Heliomolar, Dyract AP, Fuji II LC), and to compare the efficiency of polishing systems(Enhance, Sof-Lex, Composite). The control group remains untouched. The results were as follows: 1. There was no significant difference of surface roughness among the materials, while a roughness value of Z250 was the lowest of all. 2. The smoothest surface was produced by Mylar sheet on all materials. The polishing procedures, however, increased a roughness value. 3. The smoothest surfaces were produced by Sof-Lex, and there was significant difference of surface roughness between Sof-Lex and Enhance systems. 4. The smoother surfaces on the control group showed many scratches after the polishing procedures in the SEM findings.

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Development of a Portable Measurement Instrument for Quality Control of Large-sized Die (대형 금형의 품질관리를 위한 이동식 측정기 개발)

  • Park, Jong-Nam
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.1844-1849
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    • 2014
  • Existing measurement methods using microscopes or surface roughness measurement instruments for surface control in manufacturing die are low in their efficiency when they are applied in industrial fields due to structural problems. Therefore, it is very important to develop a measurement and analysis system which can enhance efficiency in the measurement of different-sized manufacturing dies and provide quality control regardless of location. This study aimed at the development of a portable surface measurement system to satisfy this need. This measurement system was designed and manufactured in such a way as to divide it into three parts: the Base, the Body, and the Optical system. As a result of testing the system, the surface roughness was measured with an accuracy between 94.9 and 99.9%, and the deviation in the measurement value of a circle was within $2{\mu}m$.

A STUDY ON SURFACE ROUGHNESS OF COMPOSITE RESINS AFTER FINISHING AND POLISHING -an Atomic Force Microscope study (연마방법에 따른 복합레진의 활택도에 관한 연군 -Atomic Force Microscope를 이용한 연구)

  • Kim, Hyeong-Seob;Woo, Yi-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.4
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    • pp.719-741
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    • 1997
  • This study was undertaken to compare by Atomic Force Microscope the effects of various finishing and polishing instruments on surface roughness of filling and veneering composite resins. Seven composite resins were studied : Silux Plus (3M Dental Products, U.S.A.), Charisma (Heraeus Kulzer, Germany), Prisma THP (L.D.Caulk, Dentsply, U.S.A.), Photoclearfil (Kuraray, Japan), Cesead (Kuraray, Japan), Thermoresin LC (GC, Japan), Artglass (Heraeus Kulzer, Germany). Samples were placed and polymerized in holes (2mm thick and 8.5mm in diameter) machined in Teflon mold under glass plate, ensuring excess of material and moulded to shape with polyester matrix strip. Except control group (Polyester matrix strip), all experimental groups were finished and polishied under manufacturer's instructions. The finishing and polishing procedure were : carbide bur (E.T carbide set 4159, Komet, Germany), diamond bur (composite resin polishing bur set, GC, Japan), aluminum-oxide disc (Sof-Lex Pop-On, 3M Dental Products, U.S.A.), diamond-particle disc (Dia-Finish, Renfert Germany), white stone bur & rubber point( composite finishing kit, EDENTA, Swiss), respectively. Each specimens were evaluated for the surface roughness with Atomic Force Microscope (AutoProbe CP, Park Scientific Instruments, U.S.A.) under contact mode and constant height mode. The results as follows : 1. Except Thermoresin LC, all experimental composite resin groups showed more rougher than control group after finishing and polishing(p<0.1). 2. A surface as smooth as control group was obtained by $Al_{2}O_{3}$ disc all filling composite resin groups except Charisma and all veneering composite resin groups except Thermoresin LC(p<0.05). 3. In case of Thermoresin LC, there were no statistically significant differences before and after finishing and polishing(p>0.1). 4. Carbide bur, diamond bur showed rough surfaces in all composite resin groups, so these were inappropriate for the final polishing instruments.

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Factors Affecting Discrimination of Surface Property Using an Integrated Tactile Display;Roughness and Vibration

  • Jeong, Young-Ju;Yang, Gi-Hun;Kyung, Ki-Uk;Kwon, Dong-Soo;Kang, Sung-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.596-601
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    • 2004
  • In this paper, we describe a study on the influence of the frequency variation of normal vibration using an integrated tactile display. It is necessary to consider this study because we want to find a method of displaying finer texture and know that the perception of fine textures is heavily influenced by temporal variation. Our tactile display system used in this experiment can simulate the micro shapes and roughness of surface textures by individual drives of a 6x8 pin array. Two experiments are performed. The first is a psychophysical experiment on the definition and range decision of roughness, and through the experiment, we clear up the meaning of roughness. The second is the main experiment about the frequency variation of normal vibration. We find the correlation between the vibration frequency and the texture and the condition for better display and perception of fine surfaces. The experimental results yielded two pieces of information. One is that lateral movement affects texture discrimination, and another is that normal vibration can make the perceived texture feel finer than real texture. That is, the vibrating stimulus is more effective for displaying a fine surface than static pressure, and it makes possible to display finer texture, exceeding the physical limit of the device.

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Investigations on the effects of mouthrinses on the colour stability and surface roughness of different dental bioceramics

  • Soygun, Koray;Varol, Osman;Ozer, Ali;Bolayir, Giray
    • The Journal of Advanced Prosthodontics
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    • v.9 no.3
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    • pp.200-207
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    • 2017
  • PURPOSE. In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS. One hundred and twenty ceramic samples, with dimensions of $2{\times}12{\times}14mm$, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS. There was a positive correlation between the ${\Delta}E$ and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ${\Delta}E$ and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.

Effects of Repeated Instrumentation for Periodontal Therapy on the Marginal Portion of Artificial Crown (치주처치를 위한 기구들의 반복조작이 인공치관 변연부에 미치는 영향)

  • Kim, Jae-Ho;Yun, Gi-Yon;Choi, Kwang-Soo;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.30 no.2
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    • pp.443-455
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    • 2000
  • The aim of periodontal therapy is a removal of a bacterial plaque butthe instrumentation for plaque control has two nature : removal of a bacterial plaque and increase of surface roughness. Complication of instrumentation is enable to damage to the root surface and artificial crown. Therefore this study was conducted to evaluate the effects of repeated instrumentation on the marginal portion of artificial crown. Fifteen proximal surfaces of ten extracted periodontally diseased maxillary first molars were used. The finish line was placed on the root surface, and then the crown was casted and cemented in usual manner. Three kinds of instruments: hand curet, ultrasonic scaler, and ultrasonic curet were used. After instrumentation, final polishing was done with rubber cup and pumice. And surface changes were evaluated by stereomicroscope and scannig probe microscope. Roughness was increased after instrumentation in all groups, and was decreased after polishing except ultrasonic scaler group. Roughness in the ultrasonic scaler group was lower than others, and roughness after polishing in the hand curet group was lower than others. These results indicate that polishing procedure is recommended, because periodontalinstruments increase the surface roughness and induce the irreversible damage to the marginal portion.

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The effect of Er:YAG laser irradiation on the surface microstructure and roughness of $TiO_2$ implant (Er:YAG 레이저 조사가 산화 티타늄 블라스팅 임플란트 표면 미세 구조 및 거칠기에 미치는 영향)

  • An, Jang-Hyuk;Kwon, Young-Hyuk;Park, Joon-Bong;Herr, Yeek;Chung, Jong-Hyuk
    • Journal of Periodontal and Implant Science
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    • v.38 no.1
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    • pp.67-74
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    • 2008
  • Purpose: The aim of this study was to evaluate the effect of Er:YAG laser on microstructure and roughness of $TiO_2$ blasting implant surface. Materials and Methods: Ten $TiO_2$ blasting implant were used in this experiment. One implant was control group, and nine $TiO_2$ blasting implant surfaces were irradiated with Er:YAG laser under 100 mJ/pulse, 140 mJ/pulse, and 180 mJ/pulse condition for 1 min, 1.5 min, and 2 min respectively. Optical interferometer and scanning electron microscopy was utilized to measure roughness and microstructure of specimens. Results: The surface roughness was decreased after Er:YAG laser irradiation in all groups, but there was no significant difference. 100 mJ/pulse and 140 mJ/pulse group did not alter the $TiO_2$ blasting implant surface in SEM study while 180 mJ/pulse group altered the $TiO_2$ blasting implant surface. Implant surfaces showed melting, microfracture and smooth surface in 180 mJ/pulse group. Conclusion: Detoxification of implant surface using Er:YAG laser must be irradiated with proper energy output and irradiation time to prevent implant surface alteration.

Surface analysis of metal clips of ceramic self-ligating brackets

  • Kim, Kyung Sook;Han, Se Jik;Lee, Tae-Hee;Park, Tae-Joon;Choi, Samjin;Kang, Yoon-Goo;Park, Ki-Ho
    • The korean journal of orthodontics
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    • v.49 no.1
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    • pp.12-20
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    • 2019
  • Objective: The aim of this study was to analyze the surface composition, roughness, and relative friction of metal clips from various ceramic self-ligating brackets. Methods: Six kinds of brackets were examined. The control group (mC) consisted of interactive metal self-ligating brackets while the experimental group (CC, EC, MA, QK, and WA) consisted of interactive ceramic self-ligating brackets. Atomic force microscopy-lateral force microscopy and scanning electron microscopy-energy-dispersive X-ray spectroscopy were used to analyze the surface of each bracket clip. Results: All the clips in the experimental groups were coated with rhodium except for the QK clip. The results showed that the QK clip had the lowest average roughness on the outer surface, followed by the MA, EC, WA, and CC clips. However, the CC clip had the lowest average roughness on the inner surface, followed by the QK, WA, MA, and EC clips. The QK clip also had the lowest relative friction on the outer surface, followed by the MA, EC, CC, and WA clips. Likewise, the CC clip had the lowest relative friction on the inner surface, followed by the QK, WA, MA, and EC clips. Conclusions: The surface roughness and relative friction of the rhodium-coated clips were generally higher than those of the uncoated clips.