DIGITAL SUBTRACTION RADIOGRAPHIC EVALUATION OF THE STANDARDIZED PERIAPICAL INTRAORAL RADIOGRAPHS

규격화된 구내 표준 방사선사진의 계수 공제 방사선학적 평가

  • Cho Bong-Hae (Department of Oral Radiology, College of Dentistry, Pusan National University) ;
  • Nah Kyung-Soo (Department of Oral Radiology, College of Dentistry, Pusan National University)
  • 조봉혜 (부산대학교 치과대학 치과방사선학교실) ;
  • 나경수 (부산대학교 치과대학 치과방사선학교실)
  • Published : 1993.06.01

Abstract

The geometrically standardized intraoral radiographs using 5 occlusal registration materials were taken serially from immediate, 1 day, 2, 4, 8, 12, and 16 weeks after making the bite blocks. And the resultant images were digitally subtracted using the immediately taken film as reference images. The qualities of those subtracted images were evaluated to check the degree of reproducibility of each impression material. The results were as follows: 1. The standard deviations of the grey scales of the overall subtracted images were 4.9 for Exal1ex, 7.2 for Pattern resin, 9.0 for Tooth Shade Acrylic, 12.2 for XCP only, 14.8 for Impregum. the lesser the standard deviation, the better the quality of the subtracted images. 2. The standard deviation of the grey scales of the overall subtracted images were grossly related to those of the localized horizontal line of interest. 3. Exaflex which showed the best subtracted image quality had 15 cases of straight, 14 cases of wave, 1 case of canyon shape. Impregum which showed the worst subtracted image quality had 4 cases of straight, 8 cases of wave, 18 cases of canyon shape respectively.

Keywords