In general, there is a paucity of studies on dental caries with children in the mixed dentition phase [12, 20, 31]. In Brazil, a study using the same instrument was developed with 112 poor 8- to 10-year-old children. This previous study demonstrated that children with untreated dental caries have a greater prevalence ratio of having a negative perception of their oral health status than those without dental caries . The present study has a clear advantage over this previous study because of its case-control design. It provides stronger evidence than cross-sectional studies. There is a case-control study on dental caries and quality of life; however, it evaluated 415 children aged 3–5 years enrolled in public and private preschools. This previous study showed that caries severity impacted the OHRQoL of preschool children . The present study demonstrated that higher caries experience was associated with a greater negative impact on quality of life. In this way, children in the mixed dentition stage with high caries experience must be one of the priorities in the planning and implementation of public health policies for the prevention, control, and treatment of this disease.