OBJECTIVE: This study aims to describe the primary care services carried out by Oral Health Teams (OHTs) in Brazil, and to understand the nuances that lead to different levels of OHT performance. MATERIAL & METHODS: A mixed-methods study with a sequential explanatory design was developed. In the quantitative phase, secondary data from a national survey (PMAQ-AB) was used to describe the work of 12,403 OHTs. Item response theory (IRT) was applied, to evaluate the psychometric qualities of 20 oral health questions from PMAQ-AB and to identify the performance of OHT. The quantitative results guided the selection of the qualitative sample. An extreme case sampling strategy was used (opposite results). OHTs were selected from Belo Horizonte metropolitan region in Brazil using scores measured by IRT. Data were collected through semi-structured interviews. Data analysis was conducted using deductive and inductive thematic analysis. RESULTS: Quantitative results showed that there are OHT with high and low performance in Brazil. The IRT analysis showed that items related to prostheses and oral cancer tend to discriminate high-performance OHTs from other OHTs. Qualitative results deepened the understanding of accessing oral health services and found several access barriers, such as the insufficient number of OHTs for the population, and a very long waiting time for dental consultations other than urgency. The qualitative results confirmed that high-performance OHTs tend to emphasize oral cancer surveillance and deliver prostheses in PHC services. CONCLUSION: Despite the expansion of oral health in PHC in Brazil in recent years, OHTs still face many challenges such as: access barriers; failures in prevention, early diagnosis and follow-up of oral cancer cases; and insufficient rehabilitation with prostheses.