This study by Kim et al from March 2011 has had a summary prepared by the Centre for Reviews and Dissemination (CRD) at the University of York.
The CRD summary of the paper states:-
This study examined the cost-effectiveness of strategies for the management of a tooth after failed root canal treatment, including non-surgical or surgical re-treatment, or replacement with an implant-supported restoration or a fixed partial denture. The authors concluded that endodontic microsurgery was the most cost-effective strategy, followed by non-surgical re-treatment and restoration, then extraction with a fixed partial denture, and finally extraction with an implant-supported restoration. The study had some methodological limitations that might affect the validity of the authors’ conclusions.
Kim SG, Solomon C. Cost-effectiveness of endodontic molar retreatment compared with fixed partial dentures and single-tooth implant alternatives. J Endod. 2011 Mar;37(3):321-5. PubMed PMID: 21329815