The story
From tooth + paste. Compare Saterland Frisian Tuskepasta (“toothpaste”), West Frisian toskpoetserguod (“toothpaste”), Dutch tandpasta (“toothpaste”), German Zahnpasta, Zahnpaste (“toothpaste”), Danish tandpasta (“toothpaste”), Swedish tandpasta (“toothpaste”), Icelandic tannkrem (“toothpaste”).
Etymology from Wiktionary, CC BY-SA 4.0.