What primarily causes dental diseases such as caries and periodontal disease?

The primary cause of dental diseases, such as caries and periodontal disease, is the presence of various types of bacteria found in dental plaque. Dental plaque is a sticky film that forms on the teeth and consists of bacteria that feed on sugars and carbohydrates present in the diet. When these bacteria metabolize sugars, they produce acids as a byproduct, which can demineralize the tooth enamel and lead to caries. Additionally, some bacteria in plaque can cause inflammation and destruction of the supporting structures of the teeth, leading to periodontal disease.

While excessive sugar consumption contributes to the environment that fosters bacterial growth, and infrequent dental check-ups can delay diagnosis and treatment, the root cause of the diseases lies in the harmful bacteria themselves and their activities within the dental plaque. Genetic predisposition can influence an individual's susceptibility to these conditions, but it is the action of the bacteria that fundamentally drives the development of caries and periodontal disease. Thus, the role of bacteria in plaque is central to understanding these dental diseases.