Authors
Bouillaguet S., Rocca G. T.
Title
Crown and corono-radicular restorations of endodontically treated teeth.
Journal
Chapitre 13 in “Endodontie”, Simon S., Machtou P., Pertot W., CDP Edn, 2013
Link
Abstract
ABSTRACT While the construction of prosthetic crowns supported by metal posts or inlay-cores remains the most commonly used technique for restoring endodontically treated teeth, recent studies highlight the limitations of this approach (Dietschi & Bouillaguet, 2011). Endodontic literature shows that long-term clinical success of non-vital teeth depends on the complete elimination of bacterial infection within the root canal system. Success rates can approach 95% in cases of irreversible pulpitis or necrosis without periapical complications, but healing rates decrease significantly when root infection is accompanied by a radiographically visible periapical lesion (Farzaneh et al., 2004; Friedman, 2008). It is therefore accepted that the nature and extent of bacterial infection influence endodontic healing. It has also been demonstrated that the quality of the coronal restoration significantly affects endodontic treatment outcomes, as poor sealing increases failure rates even when the root canal filling appears radiographically adequate (Ray & Trope, 1995). Based on these observations, it is clear that conventional restoration techniques—which require multiple laboratory steps (fabrication of an inlay-core, placement of a provisional crown, creation of the final prosthetic crown)—introduce intermediate steps that increase the risk of bacterial reinfection and long-term endodontic complications. The placement of a prosthetic crown may be indicated to restore aesthetics and function in non-vital teeth with extensive coronal destruction. Some studies show that cuspal coverage provided by a prosthetic crown improves long-term prognosis for endodontically treated teeth (Salehrabi & Rotstein, 2004). When a crown is indicated, practitioners typically place a post (inlay-core) to retain the future crown. For decades, metal posts of varying shapes have been used. Contrary to common belief, placing an intraradicular post does not increase the mechanical strength of the tooth root; in fact, it can weaken it (Robbins, 2001). Notably, the shape of a metal post only partially matches the anatomical shapes of root canals (Grandini et al., 2005). Therefore, reshaping the canal to ensure friction and post retention requires additional tissue removal, increasing the risk of root fracture. Other studies criticize the mutilating nature of this type of reconstruction and suggest less invasive restorative techniques based on bonded restorations (Krejci et al., 2003). Current trends favor maximal preservation of residual tooth structure, as this approach positively affects the longevity of dental restorations (Manhart et al., 2004). The aim of this chapter is to present the principles of a modern therapeutic approach grounded in minimal invasiveness, aiming to restore both aesthetics and function in non-vital teeth. The physical characteristics of non-vital teeth will be discussed to support these new treatment options.
