Restorative Dentistry and Endodontics

The Korean Academy of Conservative Dentistry (대한치과보존학회)
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EFFECT OF RESIN AND FILLER TYPE ON THE FRACTURE TOUGHNESS OF UTMA-BASED LIGHT-CURED COMPOSITES

기질레진 필러가 UTMA계 광중합형 복합레진의 파괴인성에 미친는 영향

  • Ahn, Yun-Sil (Department of Conservative Dentistry and Institute for Oral Bioscience, College of Dentistry, Chonbuk National University) ;
  • Hwang, Su-Jin (Department of Conservative Dentistry and Institute for Oral Bioscience, College of Dentistry, Chonbuk National University) ;
  • Bae, Tae-Sung (Department of Dental Materials and Institute for Oral Bioscience, College of Dentistry, Chonbuk National University) ;
  • Lee, Kwang-Won (Department of Conservative Dentistry and Institute for Oral Bioscience, College of Dentistry, Chonbuk National University)
  • 안연실 (전북대학교 치과대학 치과보존학교실 및 구강생체과학연구소) ;
  • 황수진 (전북대학교 치과대학 치과보존학교실 및 구강생체과학연구소) ;
  • 배태성 (전북대학교 치과대학 치과재료학교실 및 구강생체과학연구소) ;
  • 이광원 (전북대학교 치과대학 치과보존학교실 및 구강생체과학연구소)
  • Published : 1999.12.02
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Abstract

This study was performed to evaluate the effect of resin and filler type on the fracture toughness of light-activated composites. Experimental composites were prepared using urethane tetramethacrylate(UTMA) and bisphenol glycidylmethacrylate(Bis-GMA) monomers and five different types of silica fillers. Fracture toughness was measured by a single edge V-notched beam(SEVNB) method, which was discussed from ASTM E399-78. Rectangular bars of $2.5{\times}5{\times}26mm$ were prepared with experimental composites and a notch about 2.25mm deep was carved at the center of the long axis of the specimen using a dental diamond disk driven by a dental micro engine. The flexural test was carried out at a crosshead speed of 0.05mm/min and fracture surfaces were observed under scanning electron microscope. The results obtained were summarized as follows: 1. The fracture toughness values of UTMA-based composites were relatively higher than those of Bis-GMA-based composites. 2. The highest fracture toughness value was observed in the UTMA-based composite containing the $1.5{\mu}m$-spherical fillers. 3 Aging in the distilled water at $37^{\circ}C$ for 10 days showed the increase of fracture toughness, which was severer in the Bis-GMA-based composites than those of UTMA-based composites. 4. The AE amplitude occurring during the fracture toughness tests was the highest at the point of macroscopic fracture.

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