Which condition indicates high caries activity?

The indication of high caries activity is exemplified by a high lactobacillus count in saliva. Lactobacillus are acidogenic bacteria that thrive in low pH environments, which are often created by the presence of fermentable carbohydrates in the diet. When there is a high count of these bacteria, it signifies an increase in acid production, which can lead to demineralization of the tooth structure if not neutralized by saliva. This microbiological marker reflects an imbalance in the oral ecosystem, suggestive of an environment conducive to caries development.

In contrast, while low salivary flow can contribute to caries risk by reducing the mouth's buffering capacity and its ability to remineralize enamel, it alone does not directly indicate caries activity. Excessive tooth wear may result from various factors, including abrasion or erosion, but it does not specifically correlate to the presence of carious lesions. Gum sensitivity relates to periodontal conditions and may indicate underlying issues that do not directly reflect caries activity. Thus, high lactobacillus counts effectively highlight an active caries process in the mouth.