Dental Erosion in Workers Exposed to Sulfuric Acid in Lead Storage Battery Manufacturing Facility

Abstract

Dental erosion, and specifically its symptoms, has long been studied in Japan as an occupational dental disease. However, in recent years, few studies have investigated the development of this disease or labor hygiene management aimed at its prevention. As a result, interest in dental erosion is comparatively low, even among dental professionals. Our investigation at a lead storage battery factory in 1991 found that the work environmental sulfuric acid density was above the tolerable range (1.0mg/m 3 ) and that longterm workers had dental erosion. Therefore, workers handling sulfuric acid were given an oral examination and rates of dental erosion by tooth type, rates of erosion by number of working years and rates of erosion by sulfuric acid density in the work environment investigated. Where dental erosion was diagnosed, degree of erosion was identified according to a diagnostic criterion. No development of dental erosion was detected in the maxillary teeth, and erosion was concentrated in the anterior mandibular teeth. Its prevalence was as high as 20%. Rates of dental erosion rose precipitously after 10 working years. The percentages of workers with dental erosion were 42.9% for 10-14 years, 57.1% for 15-19 years and 66.7% for over 20 years with 22.5% for total number of workers. The percentages of workers with dental erosion rose in proportion to work environmental sulfuric acid density: 17.9% at 0.5-1.0, 25.0% at 1.0-4.0 and 50.0% at 4.0-8.0mg/m 3 . This suggests that it is necessary to evaluate not only years of exposure to sulfuric acid but also sulfuric acid density in the air in factory workers.

Dental Erosion and Sulfuric Ion Exposure Levels in Individuals Working with Sulfuric Acid in Lead Storage Battery Manufacturing Plant Measured with Mouth-rinse Index

“…In an earlier study, we reported that cadmium concentrations in the saliva and mouth rinse of employees working with cadmium had a high correlation with the work environment, and that mouth rinse could be used as an index for individual exposure 17) . In our earlier study 18) , sulfuric ion concentrations in mouth rinse obtained from employees working with sulfuric acid were approximately twice those of employees not working with sulfuric acid. The average sulfuric ion concentration in the work environment of the battery-charging area of the plant was approximately double that of the other work environments investigated.…”

“…However, in a lead storage battery factory where dental erosion had been identified in the past, local sulfuric ion concentration in the work environment was found to be above the maximum permissible concentration (1.0 mg/m 3 ) 18) . Therefore, in our previous study 18) , workers handling sulfuric acid were given an oral examination and rates of dental erosion by tooth type, number of working years and sulfuric acid density in the work environment investigated. Where dental erosion was diagnosed, the degree for each case was identified according to a diagnostic criterion.…”

Erosão dental ocupacional: aspectos clínicos e tratamento

“…Suyama et al, 17,18 verificaram maior concentração de erosão nos dentes anteriores inferiores de profissionais expostos ao ácido sulfúrico. O mesmo grupo de pesquisadores publicou um estudo avaliando bochechos coletados de trabalhadores que lidam com este ácido a…”

“…12 Tais ácidos podem significar efeitos irritantes nos tecidos mucosos membranosos e epiteliais além de efeito químico corrosivo nos dentes, conhecido como erosão dental. 17,18 Algumas características clínicas representam a erosão dental causada por ácidos industriais e a diferem das causadas por alimentos ácidos e ácidos intrínsecos. O quadro 2 descreve detalhes que auxiliam o diagnóstico diferencial.…”

“…Entretanto, sugeriram novos trabalhos para maior acurácia da metodologia. 17,18 A acidez dos vinhos varia entre 3.0 e 3.8 o que justifica que exposições de longo prazo a esta bebida podem resultar em erosão dental severa. Relata-se que provadores profissionais de vinho suecos experimentam de vinte a cinquenta tipos diferentes de vinho por dia e trabalham cinco dias por semana.…”