Stretch blocks assist in re-establishing the cervical contour of the crown if distorted by scissors while trimming. It also slightly flares the cervix of the crown to assist passage over shoulder preparations. Assists in re-establishing the cervical contour of a crown if distorted by scissors while trimming. Bicuspid and molar selections for use with posterior crowns. Suggested Application: Re-establishing the cervical contour of a crown if distorted by scissors while trimming. Slightly flaring the cervex of the crown to assist passage over shoulder preparations.