Oops, it doesn't look like 'prosthodontics day' is a national day..

Other days

fiancee

Fiancee Day
gum

Gum Day
hannah

Hannah Day
cat girl

Cat Girl Day
bubble bath

Bubble Bath Day
cursing

Cursing Day
coffee

Coffee Day
stud

Stud Day
self care

Self Care Day
lisp

Lisp Day