The WHO Global Oral Data Bank (GODB) demonstrates wide varieties of dental caries levels. During the last 10 years, dental caries prevalence in many countries has decreased from very high and high to moderate and low levels. However, there also are countries where dental caries has increased from very low and low to a moderate level. In total in 1993, of the 158 countries for which the WHO GODB has data available, 16 countries indicate a very low level (69 - low, 53 - moderate, 17 - high), and only three a very high level of dental caries. Very high levels of dental caries have been recorded in Costa Rica, Jamaica, and Uruguay. All these data, based on the weighted mean of DMF in 12-year-old children, have been obtained from national surveys or collected from published papers on oral health surveys conducted in selected areas of the countries. Very often, these papers indicated an increase (or decrease) in dental caries in people living in different areas of a particular country; however, the DMF weighted mean at the national level is still without change. One of the most populated countries in the world, China, shows clear evidence from several recent epidemiological studies that the level of dental caries in the urban population is persistently increasing. Dental caries still remains one of the most common diseases affecting a substantial number of children and adults around the world. There is evidence that water or
