Which method involves creating physical replicas of the dentition to compare wear over time?

• A. Study models
• B. Photographs
• C. Radiographs
• D. Clinical examination

Answer: (A)

Study models are physical replicas of the dentition created from impressions. They let you capture an exact snapshot of tooth surfaces at one point in time, and because these casts are durable and can be stored, you can take a second impression later and pour a new model to compare with the original. By aligning stable reference points on the two models, you can detect and measure wear facets, cusp height loss, or changes in occlusal relationships. This makes wear over time visible in a repeatable, objective way, which is much harder to achieve with photographs alone (records appearance at one moment), radiographs (show internal structures, not surface wear), or a live clinical examination (one-time assessment without a lasting, measurable record). So the method of creating physical replicas provides the best means to track wear over time.