What is an essential condition for sealant application?

For the application of dental sealants, it is crucial that the tooth surface is clean and dry. This condition ensures that the sealant material can properly bond to the enamel of the tooth, maximizing its effectiveness in preventing cavities. A clean surface free of debris, plaque, or saliva allows for a strong physical and chemical bond between the sealant and the tooth structure. If the tooth is not adequately dried, any moisture could hinder the sealing process and lead to potential sealant failure, resulting in inadequate protection against decay.

The other options do not support the successful application of sealants. A tooth does not need to be actively decayed for sealant application, as sealants are primarily preventative measures aimed at healthy teeth. Similarly, a moist environment in the mouth would compromise the bond of the sealant, and while it is important for patients to remain still during the procedure, it is not a fundamental condition for the actual application of sealants.