• Title/Summary/Keyword: 광중합기

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MICROLEAKAGE IN RESIN COMPOSITE POLYMERIZED WITH VARIOUS LIGHT CURING UNITS (수종의 광중합기에 의한 복합레진 중합시 미세누출에 관한 연구)

  • Park, Sung-Jin;Kim, Dae-Eup;Lee, Kwang-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.32 no.4
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    • pp.604-610
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    • 2005
  • This study was to evaluate the effects of several light curing units on the microleakage of composite resin restorations in primary teeth. The types of curing units were traditional low intensity halogen light(Optilux 360), plasma arc light(Filpo) low heat plasma arc light(Aurys) and high intensity LED(Freelight 2). After preparing cavities on sound primary teeth, cavities were filled with composite resin(Z100) using the same resin bond agent(Scotchbond Multi-Purpose) and were cured with each curing light system. After storing each specimen in sterile water for 24 hours, thermal circulation was done 1,000 times followed by pigmentation using 2% methylene blue solution. Each specimen was sliced and the degree of pigmentation was graded. When microleakage is graded, the average of Aurys was 0.95 which was the lowest and Freelight 2(1.05), Filpo(1.25), Optilux 360(1.30) followed. But values were not shown statistically significant difference (P>0.05). The results suggest that the newly developed curing units which has advantage in children by decreasing discomfort and procedure time can increase the microleakage of the composite resin.

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Characteristic of LED light curing unit and classification by generation for clinicians (임상가가 알아두면 유용한 LED 광중합기의 특성과 세대별 분류)

  • Shim, Young-Bo;Choi, An-Na;Park, Jeong-Kil
    • Journal of Dental Rehabilitation and Applied Science
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    • v.33 no.4
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    • pp.245-251
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    • 2017
  • Since light curing composite resin was introduced in the 1960s, light curing process has been considered as an essential process. Herein, various light sources became available for the process. Quartz-tungsten-halogen (QTH) light curing units (LCUs) dominated the market until the 1990s, before the LED LCUs started replacing them in the 2000s. The LED, developed approximately 50 years ago, came into use in the dentistry field from the late 1990s, and the LED LCUs, with the 2000s. Since then, the LED LCUs have gone through many advancements to its current fourth generation. In accordance to such advancements of the LED light curing unit, the majority of light curing unit used today are LED LCUs. As much as its usage has increased, it is necessary that dental clinicians understand the characteristics of the device. The objective of this review report is to provide the history of the scientific development and describe the characteristics of the LED LCUs.

Comparison of the shear bond strength of brackets in regards to the light curing source (광중합기의 광원에 따른 브라켓 전단결합강도 비교)

  • Cha, Jung-Yul;Lee, Kee-Joon;Park, Sun-Hyung;Kim, Tae-Weon;Yu, Hyung-Seog
    • The korean journal of orthodontics
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    • v.36 no.3 s.116
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    • pp.198-206
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    • 2006
  • With the introduction of the xenon plasma arc curing light and the LED curing light as orthodontic curing lights, the polymerizing time of orthodontic composites has clearly decreased. In contrast to various research cases regarding the polymerization time and bond strength of the xenon plasma arc curing light, not enough research exists on the LED curing light, including the appropriate polymerization time. The objective of this research was to compare the bond strength of the plasma curing light and the LED curing light in regards to the polymerization time. The polymerization time needed to achieve an appropriate adhesion strength of the bracket has also been studied. After applying orthodontic brackets using composite resin onto 120 human premolars, the plasma arc curing light and the LED curing light were used for polymerization for 4, 6, and 8 seconds accordingly. This research proved that the LED curing light provided appropriate bond strength for mounting orthodontic brackets even with short seconds of polymerization. The expensive cost and large size of the device limits the use of the plasma arc curing light, whereas the low cost and easy handling of the LED curing light may lead to greater use in orthodontics.

Shear bond strength of dentin bonding agents cured with a plasma arc curing light (전단접착강도와 관련된 Plasma Arc Curing Light의 중합효율평가)

  • Kwon, Young-Chul;Kim, Sun-Young;Chung, Sae-Joon;Han, Young-Chul;Lee, In-Bog;Son, Ho-Hyun;Um, Chung-Moon;Cho, Byeong-Hoon
    • Proceedings of the KACD Conference
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    • 2008.05a
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    • pp.213-223
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    • 2008
  • The objective of this study was to compare dentin shear bond strength (DSBS) of dentin bonding agents (DBAs) cured with a plasma arc (PAC) light curing unit (LCU) and those cured with a light emitting diode (LED) LCU. Optical properties were also analyzed for Elipar freelight 2 (3M ESPE); LED LCU, Apollo 95E (DMT Systems); PAC LCU and VIP Junior (Bisco); Halogen LCU. The DBAs used for DSBS test were Scotchbond Multipurpose (3M ESPE), Singlebond 2 (3M ESPE) and Clearfil SE Bond (Kuraray). After DSBS testing, fractured specimens were analyzed for failure modes with SEM. The total irradiance and irradiance between 450 nm and 490 nm of the LCUs were different. LED LCU showed narrow spectral distribution around its peak at 462 nm whereas PAC and Halogen LCU showed a broad spectrum. There were no significant differences in mean shear bond strength among different LCUs (P > 0.05) but were significant differences among different DBAs (P < 0.001).

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Shear bond strength of dentin bonding agents cured with a plasma arc curing light (전단접착강도와 관련된 Plasma Arc Curing Light의 중합효율평가)

  • Kwon, Young-Chul;Kim, Sun-Young;Chung, Sae-Joon;Han, Young-Chul;Lee, In-Bog;Son, Ho-Hyun;Um, Chung-Moon;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.213-223
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    • 2008
  • The objective of this study was to compare dentin shear bond strength (DSBS) of dentin bonding agents (DBAs) cured with a plasma arc (PAC) light curing unit (LCU) and those cured with a light emitting diode (LED) LCU. Optical properties were also analyzed for Elipar freelight 2 (3M ESPE); LED LCU, Apollo 95E (DMT Systems); PAC LCU and VIP Junior (Bisco); Halogen LCU. The DBAs used for DSBS test were Scotchbond Multipurpose (3M ESPE), Singlebond 2 (3M ESPE) and Clearfil SE Bond (Kuraray). After DSBS testing, fractured specimens were analyzed for failure modes with SEM. The total irradiance and irradiance between 450 nm and 490 nm of the LCUs were different. LED LCU showed narrow spectral distribution around its peak at 462 nm whereas PAC and Halogen LCU showed a broad spectrum. There were no significant differences in mean shear bond strength among different LCUs (P > 0.05) but were significant differences among different DBAs (P < 0.001)

Effect of infection control barrier thickness on light curing units (감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향)

  • Chang, Hoon-Sang;Lee, Seok-Ryun;Hong, Sung-Ok;Ryu, Hyun-Wook;Song, Chang-Kyu;Min, Kyung-San
    • Restorative Dentistry and Endodontics
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    • v.35 no.5
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    • pp.368-373
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    • 2010
  • Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

TEMPERATURE TRANSMISSION OF PAC UNIT THROUGH DENTIN (상아질을 통한 플라즈마 아크 광중합기의 온도 전달)

  • Park, Ho-Won;Kim, Ji-Hun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.4
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    • pp.707-714
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    • 2003
  • Plasma Arc Curing(PAC) units operate at relatively high intensity and claimed to result in optimum properties of composite resin in a short curing time, so the interest of pediatric dentists about PAC units have been increased recently. But PAC units used for polymerizing restorative resins produce heat during operation. The purpose of this study was to evaluate temperature transmission through dentin of various depths using two types of PAC units(Flipo, Q-Lux plasma 100). The results from the present study can be summarized as follows : 1. When PAC be used continuously, temperature on tip was increased as curing times, and Q-Lux showed greater temperature rising(p<0.001). 2. Compared temperature transmission as dentin depth, temperature rising rate was decreased as dentin thickened(0.5, 1.0, 1.5, 2.0mm)(p<0.05). 3. Compared temperature transmission as resin depth, temperature rising rate was also decreased as resin thickened(1.0, 2.0mm)(p<0.05).

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Evaluation of New LED Curing Light on Resin Composite Polymerization (발광 다이오드 광중합기의 복합레진 중합 평가)

  • Kang, Jieun;Jun, Saeromi;Kim, Jongbin;Kim, Jongsoo;Yoo, Seunghoon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.41 no.2
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    • pp.152-156
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    • 2014
  • The purpose of this study is to compare efficiency of broad spectrum LEDs ($VALO^{(R)}$, Ultradent, USA) with conventional LED curing lights ($Elipar^{TM}$ Freelight 2, 3M ESPE, USA) using a microhardness test. The light curing units used were $VALO^{(R)}$ in three different modes and $Elipar^{TM}$ Freelight 2. The exposure time was used according to the manufacturer's instructions. After cured resin specimens were stored in physiological saline at $37^{\circ}C$ for 24 hours, microhardness was measured using Vickers microhardness tester. The microhardness of upper and lower sides of the specimens were analyzed separately by the ANOVA method (Analysis of Variance) with a significance level set at 5%. At upper side of resin specimens, an increased microhardness was observed in the broad spectrum LED curing light unit with a high power mode for 4 seconds and plasma emulation mode for 20 seconds (p < 0.05). However, at the lower side of resin specimens, there were no significant differences in microhardness between broad spectrum LED curing light unit and conventional LED curing light unit.

Shear bond strength of orthodontic adhesive to amalgam surface using light-cured resin (광중합형 레진으로 아말감 면에 브라켓 접착 시 전단결합강도)

  • Cho, Ji-Young;Lee, Dong-Yul;Lim, Yong-Kyu
    • The korean journal of orthodontics
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    • v.35 no.6 s.113
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    • pp.443-450
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    • 2005
  • This study was performed to compare the shear bond strength of orthodontic adhesive to amalgam according to different light sources (halogen-based light and light emitting diode (LED)) and amalgam surface treatments. Ninety extracted human premolars were randomly divided into 6 groups (4 experimental and 2 control groups) of 15 by light sources and surface treatments. Orthodontic brackets were bonded and shear bond strength was measured with an Instron universal testing machine. The findings were as follows: The bond strength of adhesive to amalgam surface was 3-5.5 MPa which was lower than that of acid-etched enamel (19 MPa) control. In the sandblasted amalgam surface, the shear bond strength of the halogen light group was higher than that of the LED group (p < 0.05) but. in the non-treated amalgam surface. there was no significant difference in the shear bond strength according to the light sources (p> 0.05). Within the same light source. sandblasting had no significant effect on the shear bond strength of the adhesive bonded to amalgam surface (p > 0.05). There was no significant difference in shear bond strength according to the light sources in acid-etched enamel control groups. This results suggest that there can be a limit in using light curing adhesives when brackets are bonded to an amalgam surface. Additional clinical studies are necessary before routine use of halogen light and LED light curing units can be recommended in bonding brackets to an amalgam surface.

IN VITRO PULP CHAMBER TEMPERATURE CHANGE DURING COMPOSITE RESIN CURING WITH VARIOUS LIGHT SOURCES (복합레진 중합 광원에 따른 치수강 온도 변화에 대한 생체외 연구)

  • Lee, Ji-Young;Kim, Dae-Eop;Lee, Kwang-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.1
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    • pp.85-91
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    • 2004
  • The purpose of this study was to observe in vitro pulp chamber temperature rise during composite resin polymerization with various light-curing sources. The kinds of light-curing sources were plasma arc light(P), low heat plasma arc light, traditional low intensity halogen light, low intensity LED(L-LED), and high intensity LED(H-LED). Temperature at the tip of light guide was measured by a digital thermometer using K-type thermocouple. Occlusal cavities$(2{\times}2{\times}1.5mm)$ were so prepared in extracted human premolars as to the remaining dentin thickness was 1mm. Dentin adhesive was applied to all cavities. Experimental groups consisted of no base group, ionomer glass base group, and calcium hydroxide base group. Temperature before and after resin filling was measured. Temperature at the light guide tip was the highest with P and the lowest L-LED. Temperature before resin filling was the highest with H-LED and the lowest with L-LED. Temperature after resin filling was the highest with H-LED and the lowest with L-P and with L-LED. The lining of base partially reduced the temperature rise.

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