The aims of this study were to detect whether recommendations concerning oral hygiene practices for children among Brazilian health agencies are consistent and to verify whether possible inconsistencies in these recommendations might be associated with an apparent gap in the scientific evidence. Fifty-four Brazilian health agencies were contacted by mail or electronic mail and were asked to send any material containing recommendations on oral hygiene practices aimed at children. A search was subsequently carried out on the Cochrane Oral Health Review Group and PubMed-Clinical Queries websites in order to assess the scientific evidence available on this subject. Forty (74%) agencies answered and 21 materials containing oral hygiene recommendations were obtained. Eleven pertinent systematic reviews were identified. This preliminary study detected some conflicting and not evidence-based oral hygiene messages, which emphasizes the need to carry out and disseminate systematic reviews on these controversial issues in order to bridge the gap between knowledge and practice.