A STUDY OF THE MERCURY VAPOR MEASUREMENT DURING AMALGAM REMOVAL

충전(充塡)된 아말감 제거시(除去時) 발생(發生)되는 수은증기량(水銀蒸氣量) 측정(測定)에 관(關)한 연구(硏究)

The aim of this study was to examine the influence of the speed of grinding and coolants on mercury vaporization during amalgam removal. Forty amalgam filled stone dies were stored at $37^{\circ}C$ and 100% relative humidity for 7 days prior to the beginning of the mercury vapor experiment and were divided into 4 different groups; In Group I; Used by high speed without coolant & evacuator during amalgam removal. In Group II; Used by high speed with coolant & evacuator during amalgam removal. In Group III; Used by low speed without coolant & evacuator during amalgam removal. In Group IV; Used by low speed with coolant & evacuator during amalgam removal. The amalgam specimens were removed in a 30-second time period and mercury vapor was collected with membrane filter at 27mm from the site of removal and 45 degree above there. Samples in Group II, IV were removed with coolant spray at a flow rate of 30 ml/min with high-velocity evacuator. Mercury vapor collected membrane filter was analysed by Atomic Absorption Spectrophotometer using cold vapor method. The results were as follows; 1. The mercury vapor levels were obtained all of the Groups. 2. The mercury vapor levels of the Group II, IV (with coolant & evacuator) were less than that of the Group I, III (without coolant & evacuator). 3. The highest mercury vapor level recorded during amalgam removal procedure was Group I (used by high speed without coolant & evacuator) and its record was $0.78{\pm}0.09\;mg/m^3$, which exceed the T.L.V. by 15 times. 4. The mercury vapor level of the Group IV (used by low speed with coolant & evacuator) was more than that of the Group II (used by high speed with coolant & evacuator), but its difference was not significant, statistically. (p > 0.05)