BACKGROUND: Demarcated hypomineralization lesions are not uncommon in second primary molars. Data on the prevalence of hypomineralized second primary molars (HSPM) are scarce. AIM: To investigate the prevalence of HSPM, assess the relationship between HSPM and first permanent molars previously diagnosed with demarcated lesions and to determine the severity of HSPM in relation to dental caries severity. DESIGN: A cluster sample of 809, 7- to 9-year-old children was examined. The scoring criteria proposed by the European Academy of Paediatric Dentistry for hypomineralization in permanent dentition were adapted to score HSPMs. The International Caries Detection and Assessment System was used to assess caries status in the second primary molar of the children diagnosed with demarcated defects. The examination was carried out in schools by a calibrated dentist. RESULTS: Of the children examined, 53 (6.6%) had hypomineralization defects in at least one second primary molar. Combinations of affected first permanent and second primary molars were reported in 21 (39.6%) of cases. Severe carious lesions were found mostly in teeth with enamel breakdown. CONCLUSIONS: The prevalence of HSPM was 6.6%. Over one-third of affected second primary molars were associated with demarcated lesions in the first permanent molars. The chance of severe caries increased with the increase in the demarcated lesion severity.
BACKGROUND: Demarcated hypomineralization lesions are not uncommon in second primary molars. Data on the prevalence of hypomineralized second primary molars (HSPM) are scarce. AIM: To investigate the prevalence of HSPM, assess the relationship between HSPM and first permanent molars previously diagnosed with demarcated lesions and to determine the severity of HSPM in relation to dental caries severity. DESIGN: A cluster sample of 809, 7- to 9-year-old children was examined. The scoring criteria proposed by the European Academy of Paediatric Dentistry for hypomineralization in permanent dentition were adapted to score HSPMs. The International Caries Detection and Assessment System was used to assess caries status in the second primary molar of the children diagnosed with demarcated defects. The examination was carried out in schools by a calibrated dentist. RESULTS: Of the children examined, 53 (6.6%) had hypomineralization defects in at least one second primary molar. Combinations of affected first permanent and second primary molars were reported in 21 (39.6%) of cases. Severe carious lesions were found mostly in teeth with enamel breakdown. CONCLUSIONS: The prevalence of HSPM was 6.6%. Over one-third of affected second primary molars were associated with demarcated lesions in the first permanent molars. The chance of severe caries increased with the increase in the demarcated lesion severity.