Regenerative endodontic procedures to be widely available and predictable, endodontists have to depend on tissue engineering therapies to regenerate pulp dentin tissue. One of the most challenging aspects of developing a regenerative endodontic therapy is to understand how the various component procedures can be optimized and integrated to produce the outcome of a regenerated pulp-dentin complex. The future development of regenerative endodontic procedures will require a comprehensive research program directed at each of these components and their application to our patients.