A patient presents with cupped-out concavities on the occlusal surfaces, with restorations standing above the surrounding tooth structure. What is the most likely cause?

Correct answer: C. Erosion

• A. Attrition is tooth-to-tooth wear, producing FLAT, shiny, matching wear facets on opposing surfaces, with restorations worn level with the tooth rather than standing above it.
• B. Abrasion is mechanical wear from an external agent, producing notched, often V-shaped cervical lesions or wear in the pattern of the causative habit — not smooth occlusal cupping with proud restorations.
• C. CORRECT. 'CUPPING' of occlusal surfaces — smooth, rounded, shallow concavities in cusp tips and occlusal fossae, with amalgam or composite restorations left standing PROUD of the dissolved surrounding tooth structure — is the classic sign of EROSION. Restorative materials are acid-resistant while enamel and dentin are not, so the difference in level is diagnostic of chemical dissolution rather than mechanical wear. Investigate diet (citrus, carbonated and sports drinks), gastroesophageal reflux, and vomiting.
• D. Abfraction refers to proposed cervical stress lesions at the cementoenamel junction, not occlusal cupping.