Current perspective on dental black stain of bacterial origin: A narrative review

Dental black stain is a form of external discoloration appearing as a dark line or an incomplete coalescence of dark spots in the cervical third of the tooth. This review aims to provide an up-to-date clinical and biological summary of dental black stain of bacterial origin. Black stain is esthetically unwelcome to patients, and clinicians frequently attempt its removal. Dental black plaque has a prevalence rate of 2.4%-20% affecting both genders equally and may appear throughout the lifetime. Most studies investigating the microflora of black stain reveal that Actinomyces spp. are the most abundant species found. Most authors have found a correlation between black stain and a low caries incidence. Interestingly, individuals with black stain demonstrate higher salivary concentrations of iron, sodium, copper, and calcium/phosphate, higher pH, and lower salivary flow. Standard treatment involves repeated professional ultrasonic cleaning. Alternative treatments include photo-dynamic therapy, application of virgin coconut oil, peroxide therapy, lactoferrin, or oral probiotics. Our best interpretation of the causes implicates the involvement of oral bacteria, resulting in the deposition of iron ions in patients with altered salivary composition. The use of any treatments should be balanced against potential damage to the teeth as a result of the therapy.