well, its not possible to to restrict teeth from an includes search for tee without adding some way to the search term to tell it to look for the word boundary.
the includes search does not work on word boundaries, that is not the way SQL searches work unless you add the boundry to the search term.
how is the search configured? is it a key word search? what is used for the OR separator? is the or separator a space? that would explain why adding the space to the search is not working. is trying to add an or comparison.