Which of the following is NOT a common sign of gingivitis?

In the context of gingivitis, common signs include contour changes, consistency alterations, and color changes in the gum tissue. Contour changes refer to the swelling or rounding of the gums that occurs as a response to inflammation. Consistency alterations involve the gums becoming softer or more friable due to the inflammatory process and the presence of bacteria. Color changes are also prominent, as healthy gums are typically a light pink and, in gingivitis, they may appear red or darker due to increased blood flow and inflammation.

The absence of pain is notable in the context of gingivitis because many individuals may not experience pain even when they have the condition. Unlike periodontitis, which can lead to more severe symptoms, gingivitis can often exist without noticeable discomfort. This fact allows the condition to remain undetected, making it crucial for regular dental check-ups for detection and treatment. Therefore, not experiencing pain is indeed characteristic of gingivitis.