A more traditional approach to retreatment thinking was given to me courtesy of Ken Serota with this first algorithm. The focus of the decision making is on the quality of the root filling. Decision making with such a matrix often results in retreatment without necessarily improving patient centered outcomes. The second algorithm is restorativley driven with the expressed interest in improving patient centered outcomes and meeting treatment planning objectives. The other pillars of restoratively driven endodontics are present as well including conservation of tooth structure, and determination of restorability based on remaining tooth structure.