The aim of this study was to evaluate the associations between occupational health behaviors and occupational dental erosion. Using data for 943 workers among 34 factories, selected by three-stage stratified cluster sampling from 888 factories using acids, two sets of modified case-control studies were performed. The cases were 242 workers with any dental erosion (G1-5) and 78 with severe dental erosion (G3-5); the controls were 701 workers with no erosion (GO) and 864 workers with no or mild erosion grades, GO-2, respectively. The main explanatory variables were behaviors such as wearing a respiratory mask and gargling at work. The results were adjusted for employment, age, sex, knowledge, and opinion about occupational health, attrition, and abrasion. Bivariate and multivariate logistic regression analyses were conducted. The odds of overall occupational dental erosion (G1-5) was 0.63 (95% CI = 0.42, 0.94) for respiratory mask wearers compared to nonwearers; the odds of severe occupational dental erosion (G3-5) was not significantly less in respiratory mask wearers (OR = 0.94; 95% CI = 0.53, 1.67). Gargling did not show a significant association with occupational dental erosion in this study. Among occupational health behaviors, wearing personal protective respiratory masks in work was significantly associated with less overall occupational dental erosion.