[Dental caries prevalence and mean dmf-t among 12 to 13-years old schoolchildren between 1971 and 1997, Southern Brazil].
BACKGROUND
Cross-sectional surveys carried out in Brazil during the last decade have showed a significant decrease in both prevalence and severity of dental caries. However, the validity of these studies is questioned. Different methodologies as well as diagnosis criteria were used. Thus, a study was carried out with the purpose of comparing the prevalence and severity of caries among schoolchildren aged 12 and 13 years in a region of Brazil.


METHODS
Two cross-sectional surveys were carried out. All 12 and 13 year old children enrolled in a primary school were examined by a single dentist in 1971 (n=202) and 1997 (n=175), following the same protocol. The original criteria for the diagnosis of caries proposed by Klein and Palmer in 1937 were used both in 1971 and 1997. A total of 202 and 175 children were examined in 1971 and 1997 respectively.


RESULTS
The response rate was 100%. Intra-examiner agreement was very high. Kappa test was performed on a tooth by tooth basis and all values were above 0.86. The prevalence of caries was 98% and 93. 7% in 1971 and 1997 respectively. Comparison of the severity of caries experience expressed as changes in the mean DMF-T scores showed a reduction from 9.2 to 6.2 between 1971 and 1997 in the study group.


CONCLUSIONS
There was a significant reduction in dental caries prevalence and severity between 1971 to 1997 in the study population. The observed reduction of caries was not a statistical artifact as the same methodology and diagnostic criteria were applied in both cross-sectional surveys.
Freysleben
G R
GR
Secretaria Estadual de Saúde de Santa Catarina. Florianópolis, SC, Brasil.
Peres
M A
MA
Marcenes
W
W
D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012720:Severity of Illness Index