What key substance is primarily responsible for the mineralization of calculus in periodontal disease?

The key substance primarily responsible for the mineralization of calculus in periodontal disease is calcium phosphate. This compound plays a critical role in the formation of calculus (tartar) by contributing to its mineral content. During the process of calculus formation, organic materials in the dental plaque become calcified through the precipitation of minerals, particularly calcium and phosphate ions, from saliva and gingival crevicular fluid.

Calcium phosphate, in its various forms such as hydroxyapatite, is the most prevalent mineral in calculus and is crucial for its structural integrity. The presence of calcium ions promotes the aggregation of plaque matrices, leading to the calcification process, while phosphate ions help in crystallization, which further strengthens the calculus formation.

The other substances listed do not play a significant role in this specific process of mineralization in the context of periodontal disease. Sodium chloride, while it has its uses in biological systems, does not contribute to the mineralization of calculus. Potassium nitrate and magnesium carbonate also lack a direct involvement in this mineralization process in periodontal contexts. Therefore, understanding the role of calcium phosphate in calculus mineralization is essential in comprehending periodontal disease progression and its relationship with calculus formation.