StartFill 2B was specifically developed for the directed shrinkage technique of posterior composite placement, first described by Dr. Raymond Bertolotti. StartFill 2B is also ideal for luting posts, core buildups, crowns, veneers and any application where light transmission is in question. Being a dual cure, StartFill 2B can be rapidly cured with a light. Startfill 2B contains 61% filler by weight (41% by volume).