What is a notable feature of plasma cell gingivitis?

A notable feature of plasma cell gingivitis is its sensitive reaction to allergens. This condition is characterized by a hypersensitivity response in the gingival tissue, often triggered by external irritants such as dental materials, certain oral hygiene products, or foods. The presence of plasma cells indicates an immune response, particularly an increased production of antibodies, reflecting the body's attempt to combat an allergic reaction. This sensitivity is central to the diagnosis and understanding of the condition, as it distinguishes plasma cell gingivitis from other periodontal diseases that may not have such an allergic component. The management often involves identifying and eliminating the allergen to allow for healing of the gingival tissue.

The other choices do not depict primary features of plasma cell gingivitis. The presence of calculus is more associated with chronic periodontitis and doesn’t directly correlate with this specific type of gingivitis. Sudden tooth mobility is typically indicative of acute conditions or advanced periodontal disease, not plasma cell gingivitis. Gradual tissue recovery would be more expected in chronic conditions rather than a condition triggered by acute allergic reactions, where the initial presentation may involve significant inflammation and sensitivity.