Minimal Invasive Post Endodontic Monoblock Restorations, II- Sharonlay Crown: Review

Abstract

The loss of tooth structure owing to caries, iatrogenic cavity preparation, and dentin drying compromises the structural integrity of root canal treated teeth. Because the quantity of remaining tooth structure and the ability to resist occlusal forces have a direct link, it is critical to offer a post endodontic restoration that allows cuspal covering as soon as possible after completion. The decision to place a full crown or an onlay is based on the remaining tooth structure; an onlay can be inserted if the cuspal width to length ratio is 1:2 or above. A full crown must be planned when the ratio is less than 1:2. Cast post and core or a prefabricated post can provide fracture resistance with equivalent outcomes in single-rooted teeth requiring post-endodontic repair. In the case of premolars, however, contrary to the common practice of just providing cuspal covering through onlays, cervical reinforcement would be required to counteract horizontal stresses acting in the cervical region. Only full crown or onlay does not prevent horizontal fracture of tooth that occurs due to shear forces of mastication so many a times radicular support is taken to retain coronal restoration and strengthening of cervical region of tooth. Sharonlay is one of the newer ways being developed by researchers to improve the function of teeth and repair in such circumstances. Sharonlay is a new onlay patented design with I.P. no 1956475 dated 27/04/2010 that has a post extending into the radicular section of the premolar giving the required strengthening in a conservative manner while also protecting it against both vertical and horizontal stresses. It is a potential post-endodontic restoration option for premolars, and it may be indicated in a multirooted tooth primarily for retention, particularly when the clinical crown is too short to support an onlay, crown, or endocrown.