Dental caries called as tooth decay is basically a disease in which bacterial processes changes carbohydrate to acid. This acid then dematerializes the hard tooth structure. They are produced when demineralization amount exceeds the remineralization amount. Streptococcus mutans and Lactobacillus are the bacteria responsible for the dental caries. This article throws light on the dental caries disease, its sign and symptoms, treatment, prevention and risk factors associated with it. A review of some patents on dental caries is also provided that summarizes the recent technical advancements taken place in this area.