The relation between fluoride concentration in drinking water and dental caries may have occurred throughout the history but was scientifically reported only at the beginning of the last century. The epidemiology of enamel fluorosis and its relation to dental caries has a rich history dating back to 1900s. It serves as an illustration of the power of epidemiology to uncover significant health relations and to establish the safety and effectiveness of specific interventions well in advance of an understanding of the underlying mechanisms of action.
The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Last date updated on July, 2014