RESUMEN
Objective: to evaluate the knowledge of parents and guardians of school-age children about oral hygiene and diet in a shelter and in a higher education institution. Material and Methods: a study with 82 parents and guardians of school-age children in the Teresa de Jesus Shelter (ATJ; n = 47) and the Veiga de Almeida University (UVA; n = 35) was conducted. A questionnaire with objective questions about hygiene and diet was used. The data were compiled in a database and analyzed using the SPSS 20.0 software (SPSS Inc, Il, USA). Descriptive analysis of data was conducted and normality was verified using the Shapiro-Wilk test (p <0.05). Categorical variables were compared using the χ2 test (p <0.05). Results: the mean age of children at ATJ was 4.9 (ñ 2.5) and those at UVA was 7.1 (ñ 2.7) (p <0.01). There was no difference between groups in relation to age (p = 0.71) and educational level of parents and/or guardians (p = 0.93); however, parents of children at UVA showed higher income (p = 0.02). Parents of children at ATJ had more information on oral health care (p <0.01). Most of the ATJ group (98.7%) claimed that visiting the dentist is also an important factor for the prevention of oral diseases compared to the UVA group (25.7) (p <0.01) and showed higher number of visits to the dentist (p = 0.03). ATJ parents associate more bacteria (p <0.01) and not going to the dentist as causal factors for dental caries (p = 0.03). Conclusion: despite the worse socio-economic conditions, parents and guardians of children at ATJ had more knowledge about oral hygiene and diet than respondents of UVA. It is likely that the educational activities held at ATJ have influenced this result.