Which organism is primarily responsible for causing dental caries?

The primary organism responsible for causing dental caries is Streptococcus mutans. This bacterium is a significant contributor to tooth decay because it metabolizes sugars to produce acid, leading to demineralization of tooth enamel. S. mutans adheres to tooth surfaces and forms part of the dental plaque biofilm. When dietary sugars are present, these bacteria produce acids that erode the hard tissues of the teeth, resulting in cavities. This process is commonly referred to in the context of cariogenesis.

Other bacteria, although they may also be present in the oral cavity, play different roles in oral health and disease. For example, Streptococcus pyogenes is primarily associated with pharyngitis and skin infections but not with dental caries. Staphylococcus aureus and Staphylococcus epidermidis are typically associated with skin infections and other conditions unrelated to dental decay. Thus, the role of Streptococcus mutans in the pathophysiology of dental caries is well established and directly linked to the disease process.