Estimation of Mercury Emission from Incineration of Extracted Teeth with Dental Amalgam Fillings in South Korea

This study is aimed to estimate the levels of mercury emission related to amalgam fillings at dental institutions in order to provide basic data for establishing a management protocol for extracted mercury-containing amalgam fillings. We conducted a cross-sectional study at a dental clinic of a general hospital (City of Daegu), a dental hospital (City of Daegu), and five private dental clinics (one in the South and four in the North Gyeongsang Province). The extracted anterior and posterior teeth (N = 1208) were separated, and the amalgam filling rate of the posterior teeth was assessed. After cutting out the amalgam from filled posterior teeth, the weight of the amalgam was measured, and the estimated mercury emission was calculated based on the equation, where annual number of extracted posterior teeth × amalgam filling rate (%) × mean amalgam weight (g) × 0.5 (the proportion of mercury in amalgam). We found that 48.86 kg (95% confidence interval [CI] 41.53–58.63 kg) of mercury had been incinerated along with the extracted teeth. After applying the dental institution weights, the estimated amount of mercury was 42.53 kg (95% CI 34.11–52.17 kg). The amount of mercury incinerated with extracted posterior teeth at Korean dental institutions is therefore about 42.53–48.86 kg/year.