National Dental Assisting Examining Board (NDAEB) Practice Exam

What is a common characteristic of liners used in restorative dentistry?

1. They are highly acidic

2. They are used primarily for aesthetics

3. They can provide thermal insulation

4. They do not bond to teeth

The correct answer is: They can provide thermal insulation

In restorative dentistry, liners are materials applied in the cavity preparation before placing a restorative filling. A common characteristic of liners is that they can provide thermal insulation, which is crucial for protecting the dental pulp from thermal shock caused by external temperature variations. This insulation helps prevent discomfort or damage to the tooth pulp during and after the placement of restorative materials, particularly when using materials that can conduct temperature changes, like amalgam or composite resins. Thermal insulation is particularly important when dealing with deep cavities, where the sensitivity of the pulp to changes in temperature can lead to severe discomfort or even pulpal damage. Liners may also offer some degree of protection against chemical irritation from restorative materials, contributing to overall pulp health during treatment. This characteristic aligns them closely with their intended function in restorative procedures, emphasizing their role in enhancing patient comfort and treatment outcomes. The other options provided do not reflect the functions of liners effectively. Liners are not highly acidic; rather, they tend to be neutral or slightly basic to avoid pulp irritation. They're also not primarily used for aesthetics, as their purpose is more protective than cosmetic. While there are certain concepts regarding bonding, liners typically do not bond as strongly to the teeth as other restorative materials, but this is not their defining characteristic