**4. Results**

The data presented in the dental literature to answer the question of the efficacy of toothpastes with fluoride concentrations between 440 and 550 ppm in dental caries prevention in children are very limited. Four randomized controlled clinical trial were selected from five references yielded by electronic and hand searches. The studies included in the meta-analysis are listed in chronological order in Table 1. The included trials comprised a total of 5657 participants under similar conditions regarding variables, such as no systemic fluoridation and positive participation in oral health programs. Baseline caries levels were reported in all studies. Winter et al.(37) did not report specific baseline caries data. they explained that they decided to conduct the trial on 2-year-old children based on the expectation that most would be caries free given that according to epidemiological evidence very few children aged 2 years or less have caries which would be limited to the main lesions affecting the upper incisors. Of the 2177 children examined only 32 (1.5 per cent) had caries of this type with a difference of only 2 children between the groups. As a further analysis on the validity of the approach, they repeated the analysis of data related to dental caries, omitting the 32 children, with no effect on the outcome.
