What is typically the first step in treating a sensitive tooth with no visible caries?

The first step in treating a sensitive tooth with no visible caries usually involves the application of fluoride varnish. Fluoride varnish is effective in strengthening the enamel and may help to alleviate sensitivity by promoting the remineralization of the tooth structure. This treatment is non-invasive and can provide immediate benefits to the patient, often addressing issues such as dentin hypersensitivity that may arise from enamel erosion or gum recession.

Observing the tooth and educating the patient is also an important part of the process, but it typically follows initial treatment such as fluoride application. More invasive options, such as placing a new filling or performing a root canal, are usually reserved for situations where there's clear decay or damage that requires more extensive intervention. Thus, starting with fluoride varnish reflects a cautious and preventive approach consistent with modern dental practice.