Answer:
If by "Dene" you mean Dine Bizaad (Navajo), the word yá'át'ééh is used for hello, good afternoon or good evening.
If you really mean Dene (Chipewyan) the word hóʔą is a greeting used to welcome someone to your dwelling (literally = there's room). The term é-kla-netʔé-a means "how are you" and is used as a greeting.