OBJECTIVES: To clarify whether high tooth wear of employees in a mining industry that extracts the mineral olivine could be associated with airborne dust exposure in their working environment. METHOD: The cumulative exposure to airborne mineral dust for the workers in the company was calculated on the basis of their period of employment multiplied by the airborne olivine-dust concentrations, which have been monitored continuously during the past 20 years for all divisions of the company. After invitation, 85% of the employees (n = 191) were examined clinically and their dentitions were photographed and duplicated in plaster casts. Four clinicians, working independently, examined the sets of casts/photographs for tooth wear and ranked these from most to least. Two groups of employees were compared with regard to tooth wear, i.e. the 30% with the highest (case) and the lowest (control) estimated dust exposure levels. Tooth wear in the case and control groups was compared using a non-parametric test based on rankings (Mann-Whitney test). RESULTS: Tooth wear differed significantly between the workers in the low and the high mineral dust exposure groups (p < 0.001). The differences were also apparent within three age subsets, although statistical significance was reached only in the 34-44 years subset (p = 0.002). Considerable individual variation was noted within the three exposure groups. CONCLUSION: Workers with high exposure to airborne olivine dust may contract considerable tooth wear.
OBJECTIVES: To clarify whether high tooth wear of employees in a mining industry that extracts the mineral olivine could be associated with airborne dust exposure in their working environment. METHOD: The cumulative exposure to airborne mineral dust for the workers in the company was calculated on the basis of their period of employment multiplied by the airborne olivine-dust concentrations, which have been monitored continuously during the past 20 years for all divisions of the company. After invitation, 85% of the employees (n = 191) were examined clinically and their dentitions were photographed and duplicated in plaster casts. Four clinicians, working independently, examined the sets of casts/photographs for tooth wear and ranked these from most to least. Two groups of employees were compared with regard to tooth wear, i.e. the 30% with the highest (case) and the lowest (control) estimated dust exposure levels. Tooth wear in the case and control groups was compared using a non-parametric test based on rankings (Mann-Whitney test). RESULTS:Tooth wear differed significantly between the workers in the low and the high mineral dust exposure groups (p < 0.001). The differences were also apparent within three age subsets, although statistical significance was reached only in the 34-44 years subset (p = 0.002). Considerable individual variation was noted within the three exposure groups. CONCLUSION: Workers with high exposure to airborne olivine dust may contract considerable tooth wear.