Tooth sensitivity happens when the protective outer layers of a tooth thin out or the gums recede, exposing the softer dentin underneath. Dentin is threaded with microscopic channels leading to the nerve, so cold, sweet, or acidic triggers reach it easily.
Common causes
Brushing too hard with a stiff brush; enamel erosion from acidic drinks (soda, seltzer, citrus, sports drinks); gum recession; nighttime grinding or clenching; recent dental work (temporary and normal); or a cracked tooth or cavity — which is why new or worsening sensitivity deserves an exam rather than guesswork.
What you can do today
Switch to a soft-bristled brush and lighten your grip — hold it like a pen, not a hammer. Use a desensitizing toothpaste with potassium nitrate or stannous fluoride twice daily; give it two to four weeks of consistent use to build its effect. Limit acidic drinks, use a straw, and rinse with water afterward rather than brushing immediately.
How we can help
In the office we can apply fluoride varnish to strengthen enamel, seal exposed root surfaces with bonding, or fit a night guard if grinding is the culprit. If a cavity or crack is behind the sensitivity, treating it resolves the symptom at the source. Sensitivity is your tooth asking for attention — it’s worth a mention at your next visit even if it seems minor.