This chapter aims to give the reader a broad understanding of the key aspects of dental public health. It covers the diseases, the epidemiology, oral health inequalities, older people, fluoridation, and current challenges and opportunities in dentistry. There are two main dental diseases – tooth decay and gum disease. These diseases cause pain and discomfort in most of the population at some time during their lives but interestingly they are both preventable. Despite this, the majority of the population suffers decay and/or gum disease to some degree at some stage in their life. Tooth decay is the most common reason for general anaesthetics in children as the diseased teeth are often extracted. Despite the dramatic changes, children still suffer unnecessary levels of tooth decay that can lead to pain and suffering and in some cases to children having teeth extracted under general anaesthetic.