Which bacteria is primarily responsible for dental caries?

Streptococcus mutans is primarily responsible for dental caries, which are the result of tooth decay. This bacterium is a gram-positive, facultative anaerobic organism that is found in the oral cavity and is known for its ability to metabolize carbohydrates, particularly sucrose, to produce acid. As S. mutans metabolizes sugars, it generates acid that lowers the pH in the dental plaque and leads to demineralization of tooth enamel, a process that is critical in the development of cavities.

S. mutans is particularly effective at colonizing the tooth surface and forming biofilms, which play a crucial role in the carious process. Its ability to form sucrose-dependent glucans contributes to its adherence to dental surfaces, promoting the accumulation of plaque. The more plaque that gathers and the higher the sugar intake, the greater the acid production, leading to increased risk of enamel erosion and, subsequently, caries formation.

While other bacteria listed can play roles in oral health and disease, none are as directly implicated in the initial stages of caries development as S. mutans. For instance, although Lactobacillus casei is associated with the progression of existing carious lesions and contributes to the acidity in the mouth,