Methodological heterogeneity in dental fluorosis investigations: a critical review

Abstract

Objectives The purpose of this investigation was to conduct a comprehensive and critical review of pertinent literature concerning dental fluorosis in order to examine the methodology used in different studies and report the potential sources of heterogeneity among identified reports. Methods The PubMed database was searched using Medical Subject Headings (MeSH) for articles in English language, published between January 2000 and December 2016. The search was limited to human studies and having abstract available. Subsequently, potential sources of heterogeneity were categorized. Results Through PubMed search, a total of 56 articles were selected out of 2369 initially identified papers. Subsequently, 17 out of the 56 articles were excluded due to being irrelevant or no full text available. Likewise, genetic studies, in-vitro reports and those studies with no evidence of association were excluded as well. Therefore, 39 remaining articles were critically analyzed in order to identify the potential sources of heterogeneity in dental fluorosis studies. Quality assessment of the reviewed papers demonstrated the following categories as potential sources of heterogeneity in dental fluorosis investigations: “Different methods of fluoride exposure by children”, “Different characteristics of study samples under investigation”, “Methodological flaws in the fluorosis research design”. Conclusion Given the existing methodological heterogeneity, a consensus development is highly crucial for the standard diagnosis of fluorosis and improvement in homogeneity in future fluorosis investigations globally. Keywords dental, enamel, fluorosis, dental fluorosis, methodology