sentence-end-base

sentence-end-base is a variable defined in `paragraphs.el'.
Its value is

"[.?!][]\"'”)}]*"

• This variable is safe as a file local variable if its value
  satisfies the predicate `stringp'.

Documentation:
Regexp matching the basic end of a sentence, not including following space.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 22.1 of Emacs.