Chemical Stimuli occur as a result of what?

• A. Acidic materials, such as saliva, reaching pulpal tissues
• B. Bacteria from saliva contacting pulpal tissues
• C. Heat changes
• D. Vibrations from a handpiece

Answer: (A)

Chemical stimuli happen when acids or other chemicals diffuse through dentin and irritate the pulp. When acidic materials from the mouth—such as certain foods, drinks, or saliva that has become acidic—reach the pulpal tissue, the low pH activates the nerve endings inside the tooth, producing a chemical-type response. The other options involve different kinds of stimuli: heat changes elicit thermal responses, vibrations trigger mechanical responses, and bacteria contacting pulpal tissues relates more to infection and microbial irritation than a chemical irritant.