True or False: If used as a base, zinc phosphate requires the use of a liner first.

When zinc phosphate is used as a base, it is indeed important to place a liner first, particularly in cases where thermal sensitivity or pulpal irritation could be a concern. Zinc phosphate is quite acidic upon initial placement, which can pose a risk of pulp irritation if applied directly to the dental pulp or very close to it. The liner serves to provide a barrier that protects the pulp from this acidity, reducing the likelihood of sensitivity and potential damage.

Liners typically include materials like calcium hydroxide or glass ionomer, which have properties that not only insulate the pulp but also promote healing and provide a protective barrier against chemical irritation. By using a liner first, the restorative process ensures a safer interface between the tooth structure and the potentially irritating base material, making the use of zinc phosphate as a base safer and more effective.

Understanding this process is crucial for dental assistants and practitioners, as it directly impacts patient comfort and treatment outcomes.