Evaluation of Fracture Resistance of Endocrown using Three Novel Esthetic Materials with Two Preparation Designs

Abstract

Restoration of endodontically treated teeth continues to be a challenge in reconstructive dentistry. A common protocol of restoring such teeth has been to build up the tooth with a post and core to aid the retention of an overlying crown. Nowadays, endocrowns are a type of restoration consisting of the entire core and crown as a single unit (ie, monoblock). Endocrowns use the available surface of the pulp chamber axial walls as macroretentive resources and adhesive resin cement as a means of micromechanical retention where selection of the material that will restore the endodontically treated teeth having a great effect on the durability and the longevity of the restoration. Moreover, endocrowns have the advantage of preserving tooth structure, reducing the need for auxiliary macroretentive features, and saving patient’s and operator’s time due to fewer clinical steps. Also modification of basic preparation guidelines as extension of finish line axially for restoring endodontically treated teeth by endocrown are needed in order to get more information regarding their potential clinical uses. Therefore this study was conducted to evaluate fracture resistance of endocrown using three novel esthetic materials with two preparation designs. In this study forty two mandibular extracted molars were collected and endodontically treated then divided into three groups according to the material used, group 1 Emax, group 2 peek and group 3 vita enamic then each group was further subdivided into two subgroups, subgroup 1 (design 1 butt margin) and subgroup 2 (design 2 butt margin with extension finish line all around) where teeth were prepared using a computerized Numerical Control (CNC) milling machine and Endocrown restoration were fabricated using open cad /cam system which includes the following: Exocad software, Identica blue scanner and Vhf milling machine.