Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Caries Res 2012;46:581–588 DOI: 10.1159/000342170 Impact of National Income and Inequality on Sugar and Caries Relationship M. Masood a Y. Masood b T. Newton c a Center of Studies for Community Dentistry and b Center of Studies for Oral and Maxillofacial Surgery, Faculty of Dentistry, Universiti Teknologi MARA, Shah Alam, Malaysia; c Unit of Dental Public Health and Oral Health Services Research, King’s College Dental Institute, King’s College London, London, UK 0.17), whereas countries with a low income and high income inequality have a strong positive relationship between DMFT and per capita sugar consumption (B = –0.89, R 2 = 0.20). Con- clusion: The relationship between per capita consumption of sugar and dental caries is modified by the absolute level of income of the country, but not by the level of income in- equality within a country. Copyright © 2012 S. Karger AG, Basel Dental caries is characterized as a pandemic and is considered a highly prevalent chronic disease that afflict humans of all ages and in all regions of the world, par- ticularly in developing and underdeveloped countries [Harel-Raviv et al., 1996; Masood et al., 2012]. It has pro- found significance for both individuals and the commu- nity because of its often severe, though nonfatal, conse- quences [Edelstein, 2006]. Eradicating dental caries is considered a major challenge for oral health care profes- sionals because of the complex interplay of social, behav- ioral, cultural, dietary, and biological risk factors that are associated with its initiation and progression [Ismail et al., 1997; Barondess, 2000]. A wealth of evidence from many different types of investigation, including human Key Words Dental caries  Income inequality  National income Abstract Objective: The aim of this study was to examine the impact that national income and income inequality in high and low income countries have on the relationship between den- tal caries and sugar consumption. Methods: An ecological study design was used in this study of 73 countries. The mean decayed, missing, or filled permanent teeth (DMFT) for 12-year-old children were obtained from the WHO Oral Health Country/Area Profile Programme. United Nations Food and Agricultural Organization data were used for per capita sugar consumption. Gross national incomes per capi- ta based on purchasing power parity and the Gini coefficient were obtained from World Bank data. Bivariate and multi- variate linear regression analysis was performed to estimate the associations between mean DMFT and per capita sugar consumption in different income and income inequality countries. Results: Bivariate and multivariate regression analysis showed that countries with a high national income and low income inequality have a strong negative associa- tion between sugar consumption and caries (B = –2.80, R 2 = Received: June 5, 2012 Accepted after revision: July 26, 2012 Published online: September 21, 2012 Mohd Masood Center of Studies for Community Dentistry, Faculty of Dentistry Universiti Teknologi MARA Shah Alam (Malaysia) E-Mail drmasoodmohd  @  gmail.com © 2012 S. Karger AG, Basel 0008–6568/12/0466–0581$38.00/0 Accessible online at: www.karger.com/cre