You should also check if part of the name matches each key. You can do that by checking if find(scorePlayerName.Text, ProfanityFilterDictionary.CurrentValue) is different from -1. If it is, it means the key is included in that player's name and should be filtered, if it is equal to -1 the key was not found and the name is fine.
Your method would detect if a player used "Fuck" as name, but would not detect if he used "Fuck1"
The find method above would return 0 for both "Fuck" and "Fuck1", meaning the key was found and should be filtered.
Also, you should save all keys in lowercase and test the lowercase(scorePlayerName.Text) against them. This would avoid players from getting away with it by writing "fUcK" for instance.