Which type of restoration is zinc phosphate cement considered least suitable for?

Zinc phosphate cement is considered least suitable for deep restoration due to its physical properties and setting characteristics. This type of cement is strong and provides good compressive strength, which makes it suitable for certain applications. However, it has limited adhesive properties and can be less effective in deep restorations where retention and bonding are essential.

In deep restorations, the tooth structure may be compromised, and the restoration may require materials that provide better adhesion or seal. Materials such as resin-modified glass ionomer or composite resins are often preferred for deep restorations because they can bond to tooth structure and provide better thermal insulation and moisture control. Additionally, the acidic nature of zinc phosphate may cause irritation to the dental pulp if used in deeper cavities without adequate liner or base, further reducing its suitability for such applications.

On the other hand, shallow and moderate restorations can benefit from zinc phosphate cement due to its strength and durability, making it an acceptable choice for those situations. Temporary restorations also do not typically necessitate the same physical properties that deep restorations require, allowing zinc phosphate to be used effectively in those cases.