Caries severity declined besides persistent untreated primary teeth over a 22-year period: Trends among children in Goiania, Brazil

Background Evidence of time trends in early childhood caries in low- and middle-income countries in the second decade of the year 2000 is scarce. Aim To assess the trends in early childhood caries prevalence and severity in 2- to 5-year-old children over a 22-year period (1993-2015) in Goiania, Midwest Brazil. Additionally, we aimed to investigate the changes regarding affected dental arches and teeth. Design A time-lag analysis of trends in caries was carried out using data from three cross-sectional studies based on the World Health Organization diagnostic criteria, in 1993 (N = 1362), 2001 (N = 1620), and 2015 (N = 548). Results Caries prevalence declined from 45.1% in 1993 to 29.0% in 2015. Prevalence of severe caries (dmft >= 6) in 2015 was nearly one-third of that found in 1993, and the SiC index (mean dmft of the highest tertile) decreased from 4.55 to 3.32. Decline was higher in the 1993-2001 than in the 2001-2015 time-lag. Posterior teeth and second molars had the greatest reductions. High proportions of untreated caries were found in all ages and survey years. Conclusion There were significant changes in caries prevalence and severity, marked by a striking decline from 1993 to 2001, followed by a less prominent decrease up to 2015, and high levels of untreated caries.