Objectives: Oral health inequality in children is a widespread and well-documented problem in oral healthcare. However, objective and reliable methods to determine these inequalities in all oral health aspects, including both dental attendance and oral health, are rather scarce. Aims: To explore oral health inequalities and to assess the impact of socioeconomic factors on oral health, oral health behaviour and dental compliance of primary school children. Methods: Data collection was executed in 2014 within a sample of 2216 children in 105 primary schools in Flanders, by means of an oral examination and a validated questionnaire. Intermutual Agency database was consulted to objectively determine individuals' social state and frequency of utilisation of oral healthcare services. Underprivileged children were compared with more fortunate children for their mean DMFt, DMFs, plaque index, care index (C, restorative index (RI), treatment index (TI), knowledge and attitude. Differences in proportions for dichotomous variables (RI100%, TI100% and being a regular dental attender) were analysed. The present study was approved by the Ethics Committee of the University Hospital Ghent (2010/061). All parents signed an informed consent form prior to data collection. All schools received information about the study protocol and agreed to participate. Children requiring dental treatment or periodic recall were referred to the local dentist. Results: Underprivileged children had higher D1MFT (95% CI 0.87 to 1.36), D3MT (95% CI 0.30 to 0.64), plaque scores (95% CI 0.12 to 0.23) and lower care level (p< 0.02). In the low- income group, 78.4% was caries-free, compared with 88.4% for the other children. Half of the low- income children could be considered as regular dental attenders, while 12.6% did not have any dental visit during a 5-year period. Conclusion: Oral health, oral hygiene, oral healthcare level and dental attendance patterns are negatively affected by children's social class, leading to oral health inequalities in ...