Journal of Dental and Oral Health www.scientonline.org J Dent Oral Health Volume 5 • Issue 1 • 128 Research Article ISSN: 2369-4475 Scient Open Access Exploring the World of Science Clinical Evaluation of The Marginal Integrity, and Internal Fit of E-Max Endocrown Restorations with Different Marginal Preparation Designs. Ex-Vivo Study Inas A. Elalem 1 *, Rabab M. Ibraheem 2 , Ahmed M. Hamdy 3 1 Lecturer of Conservative and Fixed Prosthodontics at Dr.Haider A.Shaf dental college, Al-Azhar University, Gaza Strip, Palestine 2 Professor of Fixed Prosthodontics, Faculty of Dentistry, Cairo University, Cairo, Egypt 3 Professor of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, October University Modern Science and Arts, Cairo, Egypt *Corresponding Author: Inas A. Elalem, Dr. Haider A.Shafi dental college, Al-Azhar University, Gaza Strip, Palestine. Address, Rimal, Gaza, Gaza Strip, Palestine, Tel:00970599448344, Email: inas.alalem@gmail.com Introduction One of the conservative approaches that has been developed with the advances of adhesive and bonding techniques is the endocrown restoration, which is a monoblock restoration that has the ability to restore a severely destructed endodontically posterior teeth. It follows the concept of minimal invasive preparation as it gains its retention and stability from anchoring to the internal part of the pulp chamber and the cavity margins [1,2]. Endocrown restorations have two different marginal preparation designs, either with a finish line, or with a butt joint. Both designs are supra- gingival cervical margins that have the advantages of preservation of sound tooth structure, and the periodontium, as well as the facilitation of teeth preparation and impression taking [3]. Endocrown restoration approach has gained more popularity, due to its advantages in providing better esthetic, better mechanical performance, less removing of sound tooth tissues, and less clinical time [4]. Endocrown restoration has been considered as a reliable alternative to the conventional restoration of severely damaged posterior teeth [3-5]. Lithium disilicate glass ceramic has been widely used in the dental practice because it had satisfied the requirements of both dentists and patients. It is a highly aesthetic material, and can be easily and simply bond to the tooth structure with resin cement after being treated with hydrofluoric acid and silane coupling agents. Along with the surface treatment of tooth structure by acid etching and application of bonding agents [6]. It also has adequate mechanical and sufficient strength to be used in the fabrication of single and short span bridges up to premolar areas combined This article was published in the following Scient Open Access Journal: Journal of Dental and Oral Health Received May 27, 2019; Accepted June 10, 2019; Published June 17, 2019 Abstract Purpose: The aim of this study was to evaluate clinically the marginal integrity, and internal ft of endodontically treated molar teeth restored with endocrown restorations with two diferent preparation designs. Materials and Methods: Seventeen patients had a twenty endocrown restorations which were constructed of lithium disilicate (IPS E.max press ceramic). The endocrown restorations were randomly and equally divided into two groups regarding the marginal preparation designs; group 1: had a butt joint preparation and group 2: had a circumferential preparation with deep chamfer fnish line. Evaluation of the marginal integrity and the internal ft were performed using silicon replica technique, each replica was sectioned into four segments and each segment had fve reference points to be measured using digital microscope at 35X magnifcation. The data were analyzed using Two-way ANOVA and Post-hoc tests. Results: The marginal gaps of both groups were within the clinical acceptable range, but group 1 (73.49±5.29µm) was statistically signifcantly higher than group 2 (59.81±3.42 µm), meanwhile there was no signifcant diference regarding the internal ft of both groups as group 1(83.05±11.72 µm) had slightly higher mean value than group 2 (80.29±10.59 µm). Conclusion: Endocrown restorations with diferent preparation designs showed a clinical acceptable range of marginal and internal ft. Keywords: Endocrown Restorations, Marginal Preparation Designs, Marginal Integrity, Internal Fit.