Calcipex II has been widely used for root canal irrigation in endodontic treatment. It is a product of calcium oxide-based water soluble paste containing fine granular resin materials1). It was known that these granular materials were hardly dissolved in tissue and subsequently elicited foreign body granuloma by recruiting macrophages. Sometimes serious complications involving regional osteomyelitis and maxillary sinusitis were followed in long time after the endodontic treatment using Calcipex II materials2,3). And then the removed surgical specimen should be carefully examined to detect whether there exists Calcipex II material-related foreign body reaction or not. As the fine granular materials are too small in size, about 1 μm in diameter, and slightly translucent, it is difficult to find out the fine granular materials scattered throughout the granulomatous lesion even in the high magnification view. Here, we firstly found that the fine granular materials of Calcipex II showed bright birefringence under the polarizing microscope, and that the Calcipex II granules dispersed in chronic granulomatous lesion could be easily detected by their bright birefringence. The present study demonstrated a case of peri-implantitis involved with Calcipex II granule-related periapical granuloma, exhibiting numerous bright birefringence spots in the polarizing microscope observation.

Field sequential 액정 디스플레이(FSLCD)는 컬러필터를 사용하지 않아 높은 투과율 특성을 보이고 광 원으로 LED를 사용함으로써 색재현성이 매우 우수하다. 하지만 FSLCD(60Hz 구동)를 실현하기 위해서는 액정의 응답속도가 5ms이하로 고속응답 특성을 보여야 한다. 따라서 본 논문에서는 고속응답 ECB(electrically controlled birefringence) 셀의 최적 구조를 연구하여 5ms 이하의 응답시간을 얻었다. 그리고 ECB 모드에서 높은 구동전압과 시야각을 개선하기 위해 필름 보상을 연구하였다. 판상형 액정필름(discotic film)과 TAC(triacetyl cellulose) 필름의 위상차 값을 최적화함으로써 구동전압을 5V로 낮추고 상하좌우에서 160° 이상(CR>10:1)의 시야각을 실현하였다.