Method: Forty-nine patients with MIH, aging from 6 to 9 years old, had 196 first molars and 392 incisors clinically examined by visual and tactile inspection, and data were compiled at baseline, 6 and 12 months concerning dental health, DMFT index and treatment needs. All patients received preventive and curative treatment according to EAPD criteria. Descriptive analysis and qui-square test were performed.
Result: A significant association between treatment needs and MIH was found at the baseline (p<0,000), 6-month (p=0,008) and 12-months (p=0,004). Significant association were also found between MIH and DMFT index different of 0 (p<0,001) in all periods of examination.
Conclusion: The teeth with molar-incisor-hypomineralization presented 12 times more treatment needs and dental decay.