OBJECTIVETo explore whether the dental restoration of nickel-chromium (Ni-Cr) based alloys will lead to extra excretions of urinary Ni and Cr.

METHODSUrinary Ni and Cr were repeatedly measured in 33 patients before and 2 months after the dental restoration of Ni-Cr alloys. The associations between alloy restoration and urinary Ni or Cr were analyzed by paired t test and general linear model of repeated measures.

RESULTSA slightly higher urinary Ni was found in patients after 2 month of the alloy restoration, but the difference was not statistically significant (before: 46.4 microg x mol(-1) crea; after: 67.6 microg x mol(-1) crea; P=0.063). This difference was only in female subjects (before: 44.8 microg x mol(-1) crea; after: 73.7 microg x mol(-1) crea; P=0.068). A significant higher urinary Cr was found in patients after 2 month of the alloy restoration (before: 57.0 microg x mol(-1) crea; after: 99.4 microg x mol(-1) crea; P=0.024). This significant difference was only in female subjects (before: 59.8 microg x mol(-1) crea; after: 124.4 microg x mol(-1) crea; P=0.023). General linear models of repeated measurements showed that urinary excretions of Ni and Cr were associated with the number of restoration and the area of metal basis uncovered with porcelain.

CONCLUSIONDental restoration of Ni-Cr alloy might lead to the enhanced excretions of urinary Ni and Cr.

Chromium ; Chromium Alloys ; Dental Porcelain ; Female ; Follow-Up Studies ; Humans ; Male ; Nickel ; Prospective Studies

Objective To understand the epidemiological characteristics of new occupational pneumoconiosis in Zigong City from 2018 to 2022, and to provide the basis for further prevention and treatment of local pneumoconiosis. Methods The information of newly diagnosed and reported cases of pneumoconiosis in Zigong City from 2018 to 2022 was collected through the occupational disease and occupational health information monitoring system, and the characteristics of the distribution of pneumoconiosis in three regions, the composition of diseases and the length of service of exposure to dust were analyzed. Results From 2018 to 2022, the top 3 newly diagnosed pneumoconiosis diseases in Zigong City were silicosis, coal workers' pneumoconiosis and asbestosis. Silicosis cases were mainly distributed in small and medium-sized employers, accounting for 81.41%. Coal workers' pneumoconiosis was mainly distributed in large and medium-sized employers, accounting for 97.24%. Asbestosis mainly distributed in large scale employers, accounting for 96.36%. There was significant difference in dust handling age of different scale employers (H=11.453, P<0.05). The median ages of silicosis, coal workers' pneumoconiosis and other pneumoconiosis were 47.0 years, 52.0 years and 48.2 years, respectively. The median age of dust handling was 3.3 years, 22.0 years and 23.2 years, respectively. The age of onset of coal workers' pneumoconiosis was higher than that of silicosis and other pneumoconiosis (H=72.547, P<0.05), and the age of dust exposure of silicosis was shorter than that of coal workers' pneumoconiosis and other pneumoconiosis (H=10.453, P<0.05). Conclusion The current situation of pneumoconiosis in Zigong City is still severe, with obvious clustering in disease types and industries. Prevention and treatment of pneumoconiosis in key industries should be further strengthened to protect the health rights and interests of workers.