Topical anesthetics are less effective on which type of tissue?

Topical anesthetics are designed to provide localized numbing through application directly to the surface of mucosal tissues. Keratinized tissue, such as the hard palate and gingiva, is covered by a layer of keratin, which is a tough, protective protein. This keratinized layer acts as a barrier, limiting the absorption of the anesthetic agent into the underlying nerve endings. As a result, the efficacy of the topical anesthetic is diminished on keratinized tissues compared to non-keratinized tissues.

Non-keratinized tissues, such as the buccal mucosa or floor of the mouth, have a thinner outer layer making it easier for topical anesthetics to penetrate and produce a numbing effect effectively. Therefore, topical anesthetics are not as effective on keratinized tissue due to this protective barrier, highlighting their reduced effectiveness in such areas.