Australian Dental Council (ADC) Test 2025 – 400 Free Practice Questions to Pass the Exam

The presence of a lactobacilli concentration of 10^-5 is a significant indicator of rapidly progressive root caries. Lactobacilli are highly acidogenic and aciduric bacteria found in dental plaque, particularly in carious lesions. A high concentration of these bacteria signifies a cariogenic environment, characterized by low pH, which promotes the demineralization of tooth structure, especially in vulnerable areas such as exposed root surfaces.

Rapidly progressive root caries often occurs in individuals with a high-risk profile for caries, including those with reduced salivary flow, poor oral hygiene, or systemic conditions that negatively impact oral health. The presence of lactobacilli at elevated levels suggests an active carious process and correlates with the potential for rapid deterioration of tooth structure, making it a reliable indicator for diagnosing and predicting the progression of root caries.

The other options provide various metrics related to salivary secretion, Streptococcus mutans concentration, and plaque composition, but they do not specifically indicate a rapid progression of root caries. While stimulated salivary secretion rates and S. mutans concentrations might reflect overall caries risk, they do not directly correlate with the fast-paced development of root caries in the same way