Enamel defects and dental caries in 9-year-old children living in fluoridated and nonfluoridated areas of Auckland, New Zealand.
OBJECTIVE
This epidemiological study aims to investigate the developmental enamel defects and dental caries among 9-year-old children resident in fluoridated and nonfluoridated regions in Auckland, New Zealand.


METHODS
A stratified, two-stage random selection design where strata were defined by fluoridation status, school size, and school decile. After informed consent was obtained, parents completed oral health questionnaires and children underwent dental examinations at school clinics.


RESULTS
612 children from 38 schools participated in the study. Overall, 175 (29%) children had lived continuously in fluoridated areas, 149 (24%) had lived continuously in nonfluoridated areas, and 288 (47%) had resided intermittently in fluoridated areas. Diffuse opacities were present in 117 (19%) children and deciduous teeth dental caries was seen in 370 (60%) children. After adjustment for covariates, a strong dose-response relationship between diffuse opacity and fluoridation status was found, with children who lived continuously in fluoridated areas being 4.17 times as likely to have diffuse opacities as children who lived continuously in nonfluoridated areas (P < 0.001). Conversely, a strong protective dose-response relationship between caries experience and fluoridation status was seen, with children who lived continuously in fluoridated areas being 0.42 times as likely to have dental caries as children who lived continuously in nonfluoridated areas (P < 0.001).


CONCLUSIONS
Reticulated water fluoridation in Auckland reduces the risk of dental caries but increases the risk of diffuse opacities in 9-year-old children. Guidelines and health-promotion strategies that enable children to minimize their risk to diffuse opacities yet reduce their risk of dental caries should be reviewed.
Kanagaratnam
Sathananthan
S
Waitemata District Health Board, Auckland Regional Dental Service, Auckland, New Zealand.
Schluter
Philip
P
Durward
Callum
C
Mahood
Robyn
R
Mackay
Tim
T
D002327:Cariostatic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003743:Dental Enamel / Q000002:abnormalities*; D003744:Dental Enamel Hypoplasia / Q000453:epidemiology; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D016021:Epidemiologic Studies; D005260:Female; D005457:Fluoridation / Q000706:statistics & numerical data*; D005459:Fluorides / Q000008:administration & dosage / Q000627:therapeutic use; D005544:Forecasting; D006801:Humans; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D015995:Prevalence; D012923:Social Class; D013607:Tablets; D016388:Tooth Loss / Q000453:epidemiology; D014094:Tooth, Deciduous / Q000002:abnormalities / Q000473:pathology; D014100:Toothpastes / Q000627:therapeutic use; D044465:White People / Q000706:statistics & numerical data
D002327:Cariostatic Agents; D013607:Tablets; D014100:Toothpastes; D005459:Fluorides