Humans have two sets of dentitions (teeth)- the milk or the deciduous set and the adult or the permanent set. The deciduous dentition consists of twenty teeth (ten in each arch) and are the first ones to erupt in the mouth at the age of six to seven months. As the child ages, these are replaced by the permanent ones. The permanent dentition consists of thirty-two teeth in total with sixteen in each arch and usually begin to erupt around the age of seven years and continue erupting till teenage years. The wisdom teeth or third molars may or may not erupt. Their eruption time may vary and could be delayed up to twenty-four years of age or even further. A tooth has two segments- crown and root. Crown is that part of the tooth that is visible in the mouth. It is this portion that is usually susceptible to cavities. Root is that part of the tooth that attaches the tooth to the bone. This is not seen in the mouth and is covered by a layer called the cementum. This is very sensitive i