WHITER teeth are the desire of many. To understand whitening, one needs to first understand how our teeth stain. Teeth are protected by an outer layer of enamel that serves as a barrier against plaque infiltration and it also gives our teeth a whiter appearance. Enamel is made of hydroxy appetite crystals that form microscopic hexagonal rods, thus the enamel layer is porous which can allow staining agents to work their way down into the tooth. When we put stuff in our mouth via eating, cigarette smoking, tea/coffee, beetle-nut chewing, etc. another layer forms on top of the enamel layer which can be removed by good dental hygiene and regular scaling and polishing by a dental professional, however, when that layer sits on the teeth for a prolonged period, the foreign material gets into the enamel and this is when teeth whitening can be effective. Teeth whiteners use bleaching agents to get down into the enamel and set off a chemical reaction that removes the staining compounds. Northwick Dental Centre invites you for a dental assessment and oral hygiene programme to suit your family’s needs. — Dr Sudhir Rathiram (BDT UKZN-Westville, BDS Medunsa).