INFLUENCE OF LIGHT SOURCE AND CURING TIME ON SURFACE HARDNESS OF RESIN COMPOSITES

Bae, Sang-Man; Lee, Kwang-Hee; Kim, Dae-Eup; Ahn, Ho-Young

Journal of the Korean Academy of Pediatric Dentistry 2001;28(2):199-206.
Published online May 31, 2001.

INFLUENCE OF LIGHT SOURCE AND CURING TIME ON SURFACE HARDNESS OF RESIN COMPOSITES

Sang-Man Bae, Kwang-Hee Lee, Dae-Eup Kim, Ho-Young Ahn

Department of Pediatric Dentistry, College of Dentistry, Wonkwang Dental Research Institute Wonkwang University

중합 광원과 중합 시간이 복합레진의 표면 경도에 미치는 영향

배상만, 이광희, 김대업, 안호영

원광대학교 치과대학 소아치과학교실.원광치의학연구소

Abstract

The purpose of study was to compare the plasma arc light with the halogen light in compostie resin curing. Three composite resin materials(Z-100, 3M, USA; Tetric Ceram, Vivadent, Liechtenstein; SureFil, Dentsply, USA) were filled in the teflon molds (4mm in diameter and 2, 3, 4, 5mm in thickness) and cured with either the conventional low-intensity light curing unit with a halogen lamp (Optilux 360, Demetron, U.S.A.) for duration of 40 seconds or with the high-intensity light curing unit with a plasma arc lamp (Flipo, Lokki, France) for duration of 3, 6, and 9 seconds. The intensity of halogen light was about 370mW/cm² and that of plasma light was about 1,900mW/cm². After one week, the surface hardnesses of both the top and the bottom of the resin samples were measured with a microhardness tester(MXT70, Matsuzawa, Japan). There were significant differences in the hardness between the top and the bottom of the resin samples except the 2mm thickness samples cured by halogen light for 40s or by plasma light for 9s. There was no significant difference between the hardness values of the top surfaces of the thickness groups. The hardness values of the bottom surfaces decreased as the curing time decreased and as the thickness of resin samples increased, and the three kinds of resin composites showed similar patterns. The results suggest that the halogen light for 40 seconds might be able to cure greater depth of resin composites than the plasma light for 3, 6, or 9 seconds.

Key Words: Plasma, Halogen, Light-curing, Composite resin, Surface hardness