Teeth are tools that have evolved to ensure survival of species.Food comes in many forms and different consistency.Teeth serve the function of gathering, cutting, grinding and admixing food with saliva in order to prepare it for swallowing and its journey through the alimentary digestive system and conversion into energy for bodily needs.Enamel tissue by virtue of its unique biological properties is highly susceptible to environmental agents. Dental caries is one of the most commonly encountered oral disease. Caries is a Latin word for "rot" or "rotten". It should be noted that dental caries is an infectious, disease resulting in destruction of tooth structure by acid forming bacteria found in dental plaque, an intraoral biofilm, in the presence of sugar. In order to make a continued progress in eliminating this common disease, new strategies will be required to provide improved and early Diagnosis of Caries.The book provides a overview of history and recent advances till date in the diagnosis of Caries. So , that we can early diagnosis and prevent its spread.