A patient presents with flattened occlusal surfaces on their teeth occurring on opposing surfaces. The wear pattern results from tooth-to-tooth contact. What is the most likely diagnosis?

Attrition is defined as the loss of tooth structure resulting from tooth-to-tooth contact (occlusal friction), without the involvement of any external abrasive agents. It presents as flattened, shiny, polished facets on the occlusal and incisal surfaces of opposing teeth that fit together precisely. Erosion results from chemical dissolution of tooth structure by acids (not tooth contact). Abrasion is caused by an external mechanical agent (e.g., aggressive toothbrushing). Abfraction involves stress-related cervical lesions from occlusal loading. The key feature of attrition is the occlusal wear from direct tooth-to-tooth contact, often associated with bruxism.