Final answer:
Calcium hydroxide has a pH between 12 and 13, which is a range that stimulates the formation of secondary dentin when it comes into contact with dental pulp tissue due to its strong basicity.
Step-by-step explanation:
Calcium hydroxide is a material known to stimulate the formation of secondary dentin when in direct contact with pulp tissue. This stimulation only occurs within a specific pH range. Calcium hydroxide has a pH between 12 and 13 when dissolved in an aqueous solution. Since water at a neutral pH of 7 increases to a pH of 12 to 13 with the addition of 0.010M to 0.10M calcium hydroxide, this indicates that calcium hydroxide is a strong base in solution.
It is important to understand that pH is a scale that measures how acidic or alkaline a substance is, with values below 7 indicating acidity and values above 7 indicating alkalinity. Calcium hydroxide, with its high pH, provides an environment that can resist acidic conditions, such as those produced by bacterial acid waste on tooth enamel, which can lead to dental cavities. By creating a strongly basic pH, calcium hydroxide shifts the solubility equilibrium to favor remineralization rather than dissolution of hydroxyapatite, the mineral component of tooth enamel.