Several epidemiological studies have analyzed the association between oral health and social development. However, the use of different variables assessing socioeconomic status impairs the comparative analysis of their findings. The present study describes how recent dental studies have classified population segments according to categories of social stratification. We selected 86 papers on social determinants of dental caries or periodontal conditions, and published in MEDLINE-indexed journals from 1990 to 2001. The studies used different strategies to stratify populations, but occupation, schooling, and income were the most frequently assessed variables. Ethnic differentials, characteristics of households and schools, and access to material resources were also frequently appraised. We also observed a large portion of Brazilian studies focusing on socioeconomic differentials in the distribution of caries and periodontal disease. Knowledge of strategies for social stratification can improve the understanding of factors associated with dental diseases, fostering further studies and allowing the comparison of their results.