RESUMEN
Abstract The aims of this study were to describe the self-reported oral hygiene habits, dental visit frequency, and gingival bleeding perception in adult populations from three South American cities, and also to assess the association of these variables with sociodemographic data and with the clinical presence of plaque and gingival inflammation. Five-hundred and fifty adult subjects from each city (Porto Alegre, Brazil; Tucumán, Argentina; Santiago, Chile) received full mouth examinations to determine visible plaque and gingival index. A structured questionnaire on demographics, habits, attitudes and knowledge of oral health was also administered. The data were analyzed according to dental visit frequency, toothbrushing frequency, interproximal tooth cleaning frequency, subjects' perception of gum bleeding, and proportion of subject sites with VP and bleeding sites. Analysis of the association among the variables was performed using either a chi-square test or Fischer's exact test. Toothbrushing twice a day or more was reported by 84.2% of the subjects, but only 17.7% reported daily interdental cleaning, and 60.2% reported visiting a dental clinic only in an emergency. Only 2.97% had no bleeding sites, whereas 33.7% had 50% or more bleeding sites. Regular interdental self-cleaning and a dental visit every 3-6 months was associated with less plaque and less gingival bleeding. More than 12 years of education was associated with healthier habits, less bleeding and plaque scores. In conclusion, the oral health behavior of South American adult subjects from these cities is below the international recommendations, especially in relation to interdental cleaning and regular dental visits.