Dental Assistant State Licensing Examination (DASLE) Practice Exam

A contraindication for sealant placement is the presence of decay on an interproximal surface, as this suggests that the tooth has an active cavity that could worsen if a sealant is applied. Sealants are designed to protect healthy teeth from decay by providing a physical barrier over the occlusal surfaces. If decay is already present, particularly on interproximal surfaces, sealing over the decayed area would not only fail to address the existing problem but could potentially trap bacteria and lead to further complications and deterioration of the tooth structure.

The other scenarios, such as having a rough occlusal surface and a patient with a history of caries, do not prevent the application of sealants. A rough occlusal surface may require some smoothing before sealant application but does not exclude it. A history of caries indicates a risk factor for future decay, however, it doesn't directly contraindicate sealant placement. Lastly, if the surface is well-cleaned, it is actually a positive condition for sealant application, as a clean surface allows for better bonding and effectiveness of the sealant.