Which of the following is NOT a factor that prevents the formation of calculus?

Mastication is not a factor that prevents the formation of calculus. Instead, it is primarily the mechanical action of chewing food, which can aid in the natural cleaning of teeth by dislodging food particles and reducing plaque accumulation temporarily. However, it does not directly influence the biochemical processes that lead to calculus formation.

In contrast, factors like tooth shape play a significant role in calculus prevention because certain shapes promote easier oral hygiene practices, affecting the accumulation of plaque. Similarly, tooth inclination and crowding can create areas that are harder to clean, thereby promoting plaque buildup and potential calculus formation. Salivary flow is crucial because saliva contains minerals and enzymes that can help wash away food particles and reduce plaque; low salivary flow can significantly increase the risk of calculus formation.