A supragingival margin is placed above the gum line, making it easier to access for cleaning and plaque control. This reduces the risk of gingival irritation and periodontal disease compared to subgingival margins. The visibility and ease of instrumentation facilitate routine oral hygiene and professional maintenance, which are critical for long-term restoration success. Therefore, supragingival margins promote better oral health by allowing patients and clinicians to keep the area clean more effectively.

Reference: Principles and Practice of Fixed Prosthodontics, Shillingburg WK Jr., 4th Edition.