Objective: To conduct a systematic review of the literature on risk factors for dental caries in deciduous teeth of children aged six years and under, to give a scientific framework for the international collaborative studies on inequalities in childhood caries.
Method: Accepted guidelines were followed. Studies were identified by electronic searching and reviewed on the basis of key words, title and abstract by two reviewers to assess whether inclusion criteria were met. Copies of all articles were obtained and assessed for quality according to the study design.
Results: 1029 papers were identified from the electronic search, 260 met the prima facie inclusion criteria. 183 were excluded once full copies of these papers were obtained. Of the 77 studies included, 43 were cross sectional, 19 cohort studies, 8 case control studies and 7 interventional studies. Few obtained the highest quality scores. 106 risk factors were significantly related to the prevalence or incidence of caries.
Conclusion: There is a shortage of high quality studies using the optimum study design, i.e. a longitudinal study. The evidence suggests that children are most likely to develop caries if Streptococcus Muttans is acquired at an early age, although this may be partly compensated by other factors such as good oral hygiene and a non-cariogenic diet. Diet and oral hygiene may interact so that if there is a balance of 'good' habits by way of maintaining good plaque control and 'bad' habits by way of having a cariogenic diet, the development of caries may be controlled.