Question

During APF therapy or bleaching treatments, a lubricant should be used to protect the surfaces of all of the following restorations EXCEPT one. Which one is the EXCEPTION?

1) Composite restorations
2) Amalgam restorations
3) Porcelain restorations
4) Gold restorations

Answer 1

The exception is Gold restorations; they don't require lubricant protection during APF therapy or bleaching as they are highly resistant to corrosion and tarnish.

Step-by-step explanation:

The exception to the rule when using a lubricant during APF therapy or bleaching treatments to protect the surfaces of restorations is: Gold restorations.

APF (acidulated phopshate fluoride) therapy and bleaching treatments can be harsh on certain dental restorative materials, potentially causing surface roughness or color changes. Because of this, a lubricant is often applied to protect the surfaces of restorations such as composite, amalgam, and porcelain restorations.

However, gold restorations are known for their excellent corrosion resistance and do not typically require the same level of protection from these procedures. Gold is a noble metal with high biocompatibility and resistance to tarnish and corrosion, which allows it to withstand the acidic environment of APF gels and the oxidizing agents in bleaching treatments without the need for a protective lubricant.