EFFECT OF TIME AND TEMPERATURE ON THE MARGINAL FIT OF PROVISIONAL RESIN CROWN DURING POLYMERIZATION

임시 수복물 중합시 시간과 중합온도가 변연 적합도에 미치는 효과

  • Youn Seung-Hwan (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Oh Nam-Sik (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Kim Il-Kyu (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Oh Sung-Seop (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Choi Jin-Ho (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Kim Wang-Sik (Department of Prosthodontics, College of Medicine, In-Ha University) ;
  • Rim Young-Il (Department of Prosthodontics, College of Medicine, In-Ha University)
  • 윤승환 (인하대학교 의과대학 치과보철학교실) ;
  • 오남식 (인하대학교 의과대학 치과보철학교실) ;
  • 김일규 (인하대학교 의과대학 치과보철학교실) ;
  • 오성섭 (인하대학교 의과대학 치과보철학교실) ;
  • 최진호 (인하대학교 의과대학 치과보철학교실) ;
  • 김왕식 (인하대학교 의과대학 치과보철학교실) ;
  • 임영일 (인하대학교 의과대학 치과보철학교실)
  • Published : 2001.10.01

Abstract

The purpose of this study was to compare the marginal fit of provisional restorations by differentiating the removal time and setting temperature during resin polymerization. After mixing autopolymerizing methyl methacrylate resin, the material was placed in a preformed resin shell crown. The crown was seated on a die with 1mm shoulder margin. Crowns were removed after 3, 4, 5, 6 minutes and polymerization was continued under the following conditions : $25^{\circ}C$ air, $30^{\circ}C,\;40^{\circ}C,\;50^{\circ}C,\;60^{\circ}C,\;70^{\circ}C$ water. After polymerization. the crown was sectioned. The marginal & occlusal discrepancies were measured. The mean marginal discrelpancies at 3 minutes, 4 minutes, 5 minutes and 6 minutes of removing time were $96.6{\mu}m.\;84.6{\mu}m,\;86.7{\mu}m$ and $105.6{\mu}m$. The mean occlusal discrepancies at 3 minutes, 4 minutes, 5 minutes and 6 minutes of removing time were $106.7{\mu}m,\;89.3{\mu}m,\;98.6{\mu}m$ and $127.7{\mu}m$. There was significant difference between 4 minutes group and 6 minutes group in occlusal discrepancies. The mean marginal & occlusal discrepancies for crowns polymerized in $25^{\circ}C$ air were $98.2{\mu}m$ and $124.1{\mu}m$. The crowns polymerized in $50^{\circ}C$ water demonstrated the smallest marginal & occlusal. discrepancies. The mean value of marginal & occlusal discrepancies in $50^{\circ}C$ water were $73.1{\mu}m$ and $77.5{\mu}m$. These values were smaller than that of $25^{\circ}C$ air. There were significant differences in the occlusal discrepancies between $25^{\circ}C$ air and water conditions of $50^{\circ}C$ water (${\alpha}=0.05$) but. no significant difference in marginal discrepancies. There was no significant difference in the interaction between time and temperature. 4 minutes waiting time & $50^{\circ}C$ water polymerizing condition produces the best fit at the margin of the provisional crown.

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