Journal of the korean academy of Pediatric Dentistry (대한소아치과학회지)

Korean Academy of Pediatric Dentistry (대한소아치과학회)
권호 표지

COMPENSATION EFFECT OF EXPOSURE TIME INCREASE TO DECREASED LIGHT INTENSITY OF VISIBLE-LIGHT CURING UNIT

가시광선 중합기의 조사강도 감소에 대한 조사시간 증가의 보상효과

  • Yoon, Tae-Won (Dept. of Pediatric Dentistry, College of Dentistry, Chosun University) ;
  • Lee, Chang-Seop (Dept. of Pediatric Dentistry, College of Dentistry, Chosun University) ;
  • Lee, Sang-Ho (Dept. of Pediatric Dentistry, College of Dentistry, Chosun University)
  • 윤태원 (조선대학교 치과대학 소아치과학교실) ;
  • 이창섭 (조선대학교 치과대학 소아치과학교실) ;
  • 이상호 (조선대학교 치과대학 소아치과학교실)
  • Published : 1997.02.28
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Abstract

The purpose of this study was to evaluate the compensation effect of exposure duration increase to decreased light intensity of visible-light curing unit. The specimen with 2mm thickness was made of Restorative $Z-100^{TM}$ (A2 shade, 3M Dental Products, U.S.A.) and cured with $Optilux^{TM}$ (Demetron Research Co. U.S.A.). The light intensity was controlled to 420 $mW/cm^2$, 540 $mW/cm^2$, 630 $mW/cm^2$ and curing time, also, controlled to 40, 60, 80 seconds. Cured specimen was stored in a light-proof container for 24 hours to post-irradation was completed. Microhardness of top and bottom surface of specimen were measured to evaluate the depth of cure. The obtained results were as follows: 1. The microhardness of top and bottom surface of the composite resin specimen was increased significantly as light intensity and exposure time was increased (P<0.01). 2. Light intensity was more correlated with bottom microhardness(${\gamma}{\geq}$0.438) than top microhardness(${\gamma}{\geq}$0.213), and exposure time was more correlated with top microhardness (${\gamma}{\geq}$0.424) than bottom microhardness(${\gamma}{\geq}$0.335). 3. The regressive equation was obtained in this study as follows : $H=0.07{\times}D+0.012{\times}I+76$ (H : Microhardness(KHN), D : Exposure time, I : Light intensity)

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