Methodology

Strengths

The subject studied reinforces the issue about children living in poverty and extreme poverty need income redistribution policies because they are the most suffer, among other things, from oral diseases.

Weaknesses

It is a cross-sectional study and for that did not able to assess how much the students were benefited in their oral health by receiving bolsa família. A variable asking "how much time your family receive the benefit?" could be an estimator.

Major points

1- Considering the number of children enrolled in primary education in 2010 (44.7% in municipal schools, 43.1% in state schools and 12.2% in private schools), include nine municipal schools, six state schools and five private schools does not seem to reflect the proportion of the types of schools in the municipality. Table 1 does not show the “n” or percentage of private school pupils, public school pupils not receiving the BFP and public school pupils receiving the BFP.

Minor topics

1-The sample was obtained using a two stages cluster: schools and pupils, however, were randomly selected one year, between 2nd and 6th grade, of each school to the sample. In each school year selected all pupils were included or a randomly select was did again? It is not clearly defined in the text. 2- The study does not present intra-examiner concordance for dental caries. 3- Data collection was done in 2010. A child examined in January, for example, were 12 years old and in December the same child could already be 13 years old. At time of exam was the cutoff point for date of birth defined? It is not in the text. 4- The updated list of the beneficiary pupils of the BFP could be obtained in other ways. It was only 104 students, why you chose to exclude these pupils? 5- Fear of the dentist in methods section was categorized into yes or no, however in table 2 this variable has 4 categories. How was this data collected? 6- The benefit of Bolsa Família is defined from per capita family income. Was this data collected? What you think, would it be more interesting to introduce income per capita instead of only family income?

Data and Results

Strengths

The results are align with the aim of the study. Tables with titles are relevant and clearly presented.

Weaknesses

Major points

1. Results (text or table) is not mention number of children by category: private school pupils, public school pupils not receiving the BFP and public school pupils receiving the BFP.

Minor points

1. In abstract I suggest change those phrases: “Final model adjusted showed that caries prevalence was twice as high (PR 2.00; 95%CI 1.47;2.69) in schoolchildren benefiting from the Bolsa Família compared to school children from private. The other final model adjusted also showed that schoolchildren benefiting from the program presented greater severity of dental caries compared to school children from private schools (RR 1.53; 95%CI 1.18;2.00).
2. The authors verified if there is some child from private school receiving Bolsa Família. It is not probable but it is possible, right?
3. The statistically significant result is clear in tables but is not in text.
4. I suggest modify this phrase: “Pupils in public schools not receiving the BFP had a higher prevalence of caries (PR 1.76; 95%CI 1.32;2.34) compared to school children from private, although less severe, compared with those receiving the BFP (Table 2)”.
5. I suggest modify this phrase: “The final model for the outcome severity of dental caries (Table 3), after adjusting for maternal schooling, age and presence of dental plaque, shows that pupils receiving the BFP had more severe forms of the disease than those in private schools (MR 1.53; 95%CI 1.18;2.00), and those in public schools not receiving the BFP (MR 1.48; 95%CI 1.17;1.87) compared to school children from private.