Cariology & Caries Management MCQ

Operative dentistry begins with reading the lesion. The microbiology of caries lives in another section; here the work is diagnostic and decision-making: detect caries early, judge its activity and the patient's risk, and decide whether to remineralize, arrest, or restore. The organizing idea is the caries balance (demineralization versus remineralization) and the surgical threshold, which is cavitation. Restore what is cavitated, and remineralize or arrest what is not.

Detecting and Diagnosing Caries

• The white spot lesion is the earliest clinical sign of enamel caries: a subsurface demineralization that is non-cavitated and can be remineralized, so it is treated, not drilled.
• Bitewing radiographs are the standard for detecting proximal (interproximal) caries, which is hidden below the contact and hard to see directly.
• A sharp explorer should not be forcibly stuck into a suspicious pit or fissure: it can damage a remineralizable surface and does not reliably diagnose caries. Visual inspection (clean, dry tooth) and gentle assessment are preferred, with adjuncts such as transillumination or fluorescence devices.
• Recurrent (secondary) caries forms at the margins of an existing restoration and is the most common reason restorations are replaced; it must be distinguished from stain or normal marginal appearance.

Classifying Caries and Judging Activity

• G.V. Black's classification sorts lesions by location (Class I pits and fissures, Class II proximal posterior, Class III and IV proximal anterior, Class V cervical, Class VI incisal or cusp tip), which guides detection and design.
• A lesion is incipient (non-cavitated, often remineralizable) or cavitated (the surface is broken into dentin, generally requiring restoration); cavitation is the surgical threshold.
• Activity matters: an active lesion is typically soft, light, and matte, while an arrested lesion is hard, dark, and shiny and can be monitored rather than restored.
• Lesions are also primary (new) or secondary (recurrent, at a restoration margin), and root surface caries on exposed cementum behaves differently from enamel caries.

Caries Risk Assessment

• Caries is multifactorial, so management is risk-based. Key risk factors include frequent fermentable carbohydrate intake, reduced salivary flow (xerostomia), existing and recent lesions or many restorations, inadequate fluoride exposure, heavy plaque, and social determinants.
• The frequency of sugar exposure matters more than the total amount, because each exposure restarts an acid attack before saliva can buffer and remineralize.
• A patient's risk level (often categorized low, moderate, or high) determines the intensity of prevention and the recall interval.
• Protective factors push the balance the other way: fluoride, adequate saliva, sealants, good hygiene, and a diet with infrequent fermentable carbohydrate.

Managing Caries: Remineralize, Arrest, or Restore

• Non-cavitated incipient lesions are managed non-surgically: topical fluoride, diet and plaque control, and sealants to protect at-risk pits and fissures (minimal intervention dentistry).
• Silver diamine fluoride (written out in full to avoid confusion with the Structural Decision Framework) is a liquid that arrests active caries without drilling; it stains the arrested lesion black and is valuable for high-risk, elderly, young, or uncooperative patients and for root caries.
• Cavitated lesions are restored, because the biofilm can no longer be removed from a cavitated surface by cleaning alone; the goal is to remove disease conservatively and seal the tooth.
• Fluoride works by promoting remineralization (forming acid-resistant fluorapatite) and inhibiting demineralization, the chemical basis of non-surgical caries control.