Final answer:
Xylitol is delivered to patients through means such as chewing gum, nasal sprays, and inhalation, but not through injection, as it is meant to act within the oral cavity.
Step-by-step explanation:
Xylitol can be delivered to the patient by all of the following means except injection. Xylitol is a sugar alcohol used as a sweetener and is known to be effective at preventing dental caries, especially when included as an ingredient in toothpaste. It is commonly delivered via chewing gum, where it can have direct contact with the teeth and oral tissues for its caries-preventive action. Nasal sprays and other forms of inhalation of medication can be effective for the delivery of certain drugs, particularly those targeting the respiratory system or for vaccine delivery, such as the intranasal influenza vaccine. However, these delivery mechanisms are typically not used for substances like xylitol that are meant to act locally within the oral cavity, and there is no common practice of delivering xylitol via injection.