Restorative Dentistry and Endodontics
- Volume 18 Issue 2
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- Pages.357-367
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- 1993
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- 2234-7658(pISSN)
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- 2234-7666(eISSN)
AN EXPERIMENTAL STUDY ON THE FRACTURE STRENGTH OF CLASS II POSTERIOR RESTORATIONS
II급 와동에서 각종 구치용 수복물의 파절강도에 관한 실험적 연구
- Lee, Kye-Hyuck (Department of Conservative Dentistry, College of Dentistry, Chosun University) ;
- Hur, Seung-Myun (Department of Conservative Dentistry, College of Dentistry, Chosun University) ;
- Cho, Young-Gon (Department of Conservative Dentistry, College of Dentistry, Chosun University)
- Published : 1993.09.10
Abstract
The purpose of this study was to evaluate the fracture strength of class II restored premolars with amalgam, posterior composite, amalgam - Ketac silver, resin - Ketac silver restorations at marginal ridge. Fifty extacted maxillary and mandibular premolar teeth that were caries free, fracture free, and restoration free were selected and randomly divided into five groups : Group 1 : 10 intact teeth, Group 2 : 10 teeth with class II cavities and restored with, amalgam, Group 3: 10 teeth with class II cavities and restored with posterior resin, Group 4 : 10 teeth with class II cavities and restored with amalgam - ketac silver, Group 5 : 10 teeth with class II cavities and restored with resin - Ketac silver. All teeth were mounted in base of dental stone within metal rings of 2cm diameter, exposing only the crown portion. Class II mesio - occlusal or disto - occlusal cavities were prepared into specimens of Group 2 through 5 by using a No. 710 fissure bur. The occlusal portion was prepared to a faciolingual width of 1.5mm and a pulpal depth of 1.5mm. The proximal protion was prepared to a faciolingual width of 4mm, a occlusogingival height of 4mm, and a gingival floor of 1.5mm. The teeth in Group 2 and 3 were resotored with silver amalgam apd posterior resin respectively. In Group 4 and 5, proximal portions were first filled with Ketac silver 1.5mm gingivally and remaining cavities were restored with amalgam and posterior resin respectively. All specimens were stored in 100 % relative humidity at
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