The article discusses questions related to the means by which dentists can prolong the lifespan of endodontically treated teeth. Several opportunities for future research are described, which include research into the factors of endodontic treatment which affect the behavior of the dental hard tissues, the microtensile properties of the bond of various dental adhesives to root dentin, and data regarding the adhesion of endodontic sealers to root dentin for extended periods of time.