Purpose: a survey of the current knowledge about the clinical approach of restoring endodontically treated teeth
Summary:
Significance of remaining coronal tooth structure
-Most important predictor of clinical success
-To ensure functional longevity, endodontically treated teeth must have at least 5 mm of tooth structure coronal to the crestal bone, 3mm are needed to maintain a healthy soft tissue complex and 2mm of coronal tooth structure incisal to the preparation finish line are necessary to ensure structural integrity
-A 1:1 crown-to-root ratio has been advocated as the minimum ratio for resisting lateral forces
-A retrospective study of 400 teeth during a 9-years period found that endodontically treated teeth with cuspal coverage were six times more likely to survive than those with intracoronal restorations (Aquilino SA, Caplan DJ.2002)
-When direct bonded restorations are not suitable, a core build-up followed by a partial or a complete crown coverage will be considered and the presence of a ferrule is needed
–Significance of occlusal forces
-Endodontically treated teeth can withstand a maximum bite force comparable to natural teeth, being therefore able to regain a level of masticatory function similar to that in sound teeth (Woodmansey KF, Ayik M, 2009)
-Endodontically treated teeth retain the natural periodontal ligament, allows physiologic movement and adapt to functional occlusal forces -Continuous loading as in clenching is more destructive than cyclic loading as in chewing
–The basic principles in the restoration of endodontically treated teeth
– Cuspal coverage restorations appear to grant higher longevity to posterior teeth with RCT
-Bonded restorations represent the main choice for conservatively restoring anterior teeth with minimal loss
-Maximum preservation of coronal and radicular sound tooth structure is recommended
-When a tooth has more than 50% of its coronal structure missing, the use of a post-and- core is recommended
-Posts indicated only when there is inadequate tooth structure to retain a core
-An adequate ferrule is considered to need a minimum of 2 mm of vertical height and 1 mm of dentin thickness.
