Question

Which of the following can be used as a base under CaOH2 when the remaining dentin thickness is less than 1 mm?

• A. ZnOE
• B. Resin modified GIC
• C. Polycarboxylate
• D. ZnPO4

Hint:

Resin modified GIC is preferred when the dentin thickness is minimal, as it offers both mechanical support and good bonding.

Answer 1

The Correct Option is B

In conservative dentistry and endodontics, selecting the appropriate base material under calcium hydroxide (CaOH₂) is crucial, especially when the remaining dentin thickness is less than 1 mm. The concern is to provide an effective protective layer that supports the restorative material, protects the pulp, and ensures longevity.

Here's the reasoning for selecting Resin modified glass ionomer cement (GIC) as the appropriate base:

1. Dentin and Pulpal Protection: When the remaining dentin is thin, there is a potential risk to the pulp due to chemical irritation or thermal conductivity. Resin modified GIC offers better adhesion and provides a seal that helps in protecting the dentinal tubules effectively compared to other materials.
2. Fluoride Release: Resin modified GIC has the additional benefit of releasing fluoride, which aids in remineralization and provides antibacterial properties, thus offering an additional protective measure against caries.
3. Adhesion and Compatibility: This material provides excellent bonding with dentin and also with the overlying restorative materials, ensuring that the restoration remains intact. This is particularly important in cases where there's reduced dentin thickness.

Let's rule out the other options:

• ZnOE (Zinc Oxide Eugenol): While ZnOE is known for its sedative properties on the pulp, it is less commonly used under composites due to the potential for interference with polymerization. It is not the best choice when thin dentin is present.
• Polycarboxylate: This material has good biocompatibility but offers less favorable mechanical properties and adhesion compared to Resin modified GIC.
• ZnPO4 (Zinc Phosphate): Zinc phosphate cement provides good physical strength but does not bond well to dentin, and there is no fluoride release. It is also more acidic initially, which could irritate the pulp under thin dentin.

Given these considerations, Resin modified GIC stands out as the optimal choice for use under calcium hydroxide when the remaining dentin thickness is less than 1 mm.

Therefore, the correct answer is: Resin modified GIC.