The cariogenicity of commercial infant formulas: a systematic review

Aim To systematically evaluate the cariogenic potential of various commercially available infant formulas. Materials and methods A literature search was conducted using Pubmed and Scopus databases for articles published between 1966 and November 2014. Reference lists of all eligible studies were searched. Only human studies were included. Data extraction and risk of bias assessments were performed. Results Seven of the 83 articles identified were included in this review, of which six studies employed plaque harvesting methods, while one study utilised an intra-oral cariogenicity/in situ model. Three studies compared milk-based formulas (MBFs) and soy-based formulas (SBFs), two compared protein hydrolysate formulas (PHFs) with MBFs and SBFs, four compared formulas with various types of sugar, and two studies compared formulas with varying casein content. Based on a single study, SBFs were significantly more cariogenic than MBFs. Formulas containing only non-milk extrinsic sugars (NMES) and those containing lactose + NMES were found to be significantly more cariogenic than formulas containing only lactose. No significant correlation was found between cariogenicity and casein content in infant formula. The results of studies comparing PHFs with MBFs and SBFs were contradictory. Risk of bias assessment revealed that five studies were at moderate risk of bias, and two were assessed to be at high risk of bias. Conclusion The result for cariogenicity of various types of infant formulas remains inconclusive, thus no concrete recommendations can be made. Further well-designed studies are needed to clarify the effect of casein content on cariogenicity.