National Board Dental Hygiene Examination (NBDHE) Dental Hygienist Practice Test

If a tooth becomes wet due to saliva contact during sealant preparation, what is the next correct step?

1. Use air/water syringe to re-rinse and dry the tooth

2. Use air/water syringe to dry the tooth

3. Re-etch for the full amount of time

4. Re-etch for a shorter amount of time

The correct answer is: Re-etch for a shorter amount of time

When a tooth becomes wet due to saliva contact during the preparation for sealants, it is important to re-etch the surface to ensure proper bonding and adhesion of the sealant material. The correct approach is to re-etch for a shorter amount of time. The purpose of re-etching is to remove any contaminating saliva and modify the surface of the enamel to enhance the bonding surface for the sealant. A shorter re-etching time is effective because it allows for the cleansing of the area without overexposing the tooth to the etching agent, which could potentially damage the enamel. It’s essential to note that while it might seem logical to re-etch for the full amount of time initially prescribed, excessive etching could lead to over-etching, which can adversely affect the tooth structure. This is why the consideration for a shorter time is optimal, just enough to ensure the surface is prepared without causing harm. Using an air/water syringe may help dry the tooth but won’t adequately address the contamination from saliva. Therefore, solely drying the tooth or re-rinsing it wouldn’t provide the necessary surface reconditioning that comes from re-etching.