## **Core Concept**
The question pertains to the management of hypersensitivity in a tooth filled with glass ionomer cement. Glass ionomer cements are commonly used dental restorative materials known for their adhesive properties to tooth structure and fluoride release. However, hypersensitivity can still occur due to various reasons such as microleakage, incomplete sealing of the dentinal tubules, or changes in the dentinal fluid.

## **Why the Correct Answer is Right**
The correct approach to managing hypersensitivity in a tooth filled with glass ionomer cement involves identifying and addressing the underlying cause. If the hypersensitivity is due to microleakage or incomplete sealing, a suitable desensitizer or a resin-based restoration might be considered. However, if the glass ionomer filling is still intact and the hypersensitivity is likely due to the dentin's response, applying a desensitizing agent or a resin-modified glass ionomer cement could be beneficial. The correct answer, ., implies that replacing the glass ionomer with another material might not always be necessary and could potentially be harmful.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option suggests a specific treatment but without details, it's hard to assess its correctness directly. However, if it implies an overly invasive approach like root canal treatment without trying simpler desensitization methods, it would be incorrect.
- **Option B:** This could imply a non-invasive approach such as applying a desensitizing agent. If this option does not address the potential causes of hypersensitivity effectively or is not suitable for a glass ionomer filled tooth, it would be incorrect.
- **Option C:** If this option suggests doing nothing, it would be incorrect because some form of intervention is usually required to alleviate patient symptoms.
- **Option D:** If this option suggests an inappropriate or overly aggressive treatment for hypersensitivity, such as immediate extraction, it would clearly be incorrect.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that hypersensitivity in a tooth with a glass ionomer filling can often be managed with conservative treatments before considering replacement of the filling. Desensitizing agents, varnishes, or even resin-based restorations can be effective. It's crucial to diagnose the cause of hypersensitivity accurately to choose the most appropriate treatment.

## **Correct Answer:** .