Tooth discoloration is frequently seen by dental practitioners and is considered an aesthetic problem. There are two types of teeth discoloration; intrinsic discoloration which is related to intrinsic factors such as congenital and inherited conditions and extrinsic discoloration which occurs due to the formation of pigments on the enamel surface (Prskalo et al., 2017).~Black stain is a specific type of external tooth discoloration. It is clinically diagnosed as dark dots on the gingival third of the tooth that may coalesce and form a complete dark line following gingival contour or can also impregnate pits, fissures, and grooves (França-Pinto et al., 2012).~Black stains are a common finding in children and are seen equally in both genders (Zyła et al., 2015). When children's smiles do not fit the esthetic criteria, it can have negative social and psychological consequences causing embarrassing situations for the child, including school bullying. Their guardians may also be affected as people could judge it as bad oral health and question the care given to these children .(Fernando Pessoa, n.d.)~The etiology of black stains is multifactorial . Chromogenic anaerobic bacteria have been considered one of the etiological factors by their production of hydrogen sulfide that interacts with iron present in saliva and forms insoluble ferric sulfate which is the main component of these pigments (Elelmi et al., 2021).~Rational:~Although black stains have been considered a protective factor against caries, they are considered a common aesthetic problem. According to the systematic review of Asokan et al., 2020, there is conflicting data on the relation between tooth stains and dental caries as some studies showed a positive association between black stains and caries and other studies showed a negative association between them, and therefore, further studies are needed to completely understand the nature, risk factors of black stains and their relation with caries experience.
To assess the prevalence of black tooth stains and their relation with caries experience in the primary dentition of 3-5-year-old children.