Hide buffer left, right or both fringes. Read mode documentation or/and source code for more details. Examples:
;; M-x fringe-hide-mode
;; M-x fringe-hide
(fringe-hide-mode 1)
(fringe-hide-mode -1)
(fringe-hide "left")
(fringe-hide "right-margin")
(fringe-hide "both")
(fringe-hide "show")