What is the primary risk associated with calculus in dental health?

The primary risk associated with calculus in dental health is its ability to cause inflammation of the gum tissue, a condition known as gingivitis. When plaque, a soft film of bacteria, accumulates on the teeth and is not removed through regular brushing and dental cleanings, it can harden into calculus or tartar. This hardened substance can irritate the gums, leading to redness, swelling, and potential bleeding. If left untreated, gingivitis can progress to more severe periodontal disease, which can result in tooth loss and other health issues.

While the other options mention various health conditions, they do not relate to the consequences of calculus on dental health. Uneven pupil size is not connected to dental issues, nor is calculus directly indicative of heart disease or respiratory problems, which involve separate physiological mechanisms and health factors. Thus, inflammation of gum tissue stands out as the key risk related to the presence of calculus in dental health.