Which type of fluoride should not be used on small children?

The type of fluoride that should not be used on small children is a rinse. Fluoride rinses require children to swish and spit, which can be challenging for young children who may not have fully developed the motor skills necessary to do this effectively. It also increases the risk of swallowing excess fluoride, potentially leading to dental fluorosis or other adverse effects.

In contrast, topical gels, varnishes, and sprays are typically applied by a dental professional or used in a manner that minimizes ingestion. Varnish, in particular, is often recommended for young children as it can be painted directly onto the teeth and is designed to be safe in the event that a small amount is swallowed. This makes varnish a more suitable option for preventing cavities in young children's teeth compared to rinses, which involve the risk of unintended ingestion.