An expandable interbody device for implantation within an intervertebral space is provided, together with methods and tools for use therewith. The interbody devices of the present invention include upper and lower bearing members configured to expand via an expansion mechanism configured to allow the insertion of osteoconductive materials and other structures into the interior of the interbody device before and after implantation, and before and after expansion of the interbody device. The insertion tool is configured expand the interbody device and to allow insertion of materials into the interbody device through a protected pathway.