Day 0 — Baseline. Pristine. Enamel is the hardest thing the body makes. It is also the only part that never grows back.
Year 1 — Sugar, coffee. Consumption. Acid softens the surface a little each day. The shine is the first thing to go.
Year 4 — Tar. Smoking. Nicotine settles into the microscopic grooves. The stain is not on the tooth. It is in it.
Year 7 — Nothing. Neglect. Plaque hardens into shelter for bacteria. The first cavities open quietly, without pain.
Year 10 — Rot. Decay. Past a certain depth, a tooth cannot be saved. It can only be removed.
Two minutes, twice a day, would have been enough.