How should pulpal protection be managed when using a glass ionomer liner?

• A. Use liner as the sole restoration without base.
• B. Do not use liner.
• C. Apply liner to protect pulp and achieve a seal, followed by an adequate base if needed.
• D. Use liner only if patient has allergies.

Answer: (C)

Protecting the pulp with a glass ionomer liner is about using the liner to shield the pulp and seal the prepared dentin, then adding a base if more thickness or insulation is needed. The liner creates a biochemical and physical barrier over the dentin, helping to block microleakage and reduce sensitivity. It also bonds to dentin and releases fluoride, which can aid remineralization and further sealing against irritants. However, the liner alone doesn’t provide the bulk or mechanical strength required for many restorations, especially in posterior teeth. That’s why, when the remaining dentin thickness is thin or more decay removal has weakened structure, an adequate base is placed after the liner to build up height, provide thermal insulation, and support the final restorative material. Not using a liner misses that protective seal and barrier, whereas using a liner only for special cases like suspected allergies isn’t the standard approach. The best practice is to apply the liner to protect the pulp and achieve a seal, followed by an adequate base if needed.