European Journal of Prosthodontics and Restorative Dentistry (2019) 27, 1–7 ejprd.org - Published by Dennis Barber Journals. Copyright ©2019 by Dennis Barber Ltd. All rights reserved. ARTICLE IN PRESS •••••••••••••••••••••••••••••••• EJPRD Influence of Ceramic Materials on Biomechanical Behavior of Implant Supported Fixed Prosthesis with Hybrid Abutment ABSTRACT Purpose: This study evaluated the stress distribution in different cement-retained implant-supported prostheses with a hybrid abutment. Materials and Methods: Two factors were evaluated: restorative material for the crown and hybrid abutment - zir- conia, lithium disilicate and hybrid ceramic, yielding 9 combinations. For finite ele- ment analysis, a monolithic crown cemented on a hybrid abutment was modeled and cemented on a titanium base (Ti base). An oblique load (45°, 300 N) was applied to the fossa bottom and system fixation occurred on the bone’s base. Results: Each struc- ture was evaluated separately to find the possible weaknesses in geometry and fail- ure criteria. In this context, results demonstrated a significant decrease of maximum principal and von-Mises stresses concentration when crowns with high elastic modu- lus are cemented onto a hybrid abutment with lower elastic modulus. Conclusions: Considering this theoretical study for a Morse taper implant, the association of a rigid crown with a more resilient hybrid abutment reduces the tensile stress concentration in the restoration cervical region. INTRODUCTION Dental ceramics have excellent mechanical properties, 1 aesthetics, 2 bio- compatibility and chemical stability, 1,3 promoting excellent clinical per- formance to this material 4 in manufacturing dental prostheses. Zirconia stabilized by yttria (Y 2 O 3 ), also known as Y-TZP (yttria tetragonal zirco- nia polycrystals), has an interesting combination of properties among ceramic materials such as high fracture toughness, 5 high hardness and wear resistance, chemical stability and biocompatibility. 6 The transfor- mation toughness mechanism of Y-TZP, which is responsible for high re- sistance to fracture, allows the preparation of partial fxed prostheses and prosthetic abutments for implants. 1 Lithium disilicate is a type of ceramic containing vitreous phase and lithi- um oxide in its composition, unlike polycrystalline ceramics such as zirconia, whose composition is formed by sintered crystals and absence of a vitreous matrix. 5 Although lithium disilicate has an elastic modulus of 64 GPa 7 and fracture strength lower than Y-TZP (210-400 MPa and 700 GPa, respectively), it is able to offer a more appropriate aesthetic result when resistance is not the most relevant factor. Hybrid ceramics that are polymer infltrated Keywords Dental Implants Finite Element Analysis Material Testing Dental Ceramics Dental Implant-Abutment Design Authors Dr. João Paulo Mendes Tribst* (DDS, MSc, PhD student) Dr. Amanda Maria de Oliveira Dal Piva* (DDS, MSc, PhD student) Prof. Mutlu Özcan § (DDs, MSc, PhD, Professor) Prof. Alexandre Luiz Souto Borges* (DDS, MSc, PhD, Professor) Prof. Marco Antonio Bottino* (DDS, MSc, PhD, Professor) Address for Correspondence Dr. Amanda Maria de Oliveira Dal Piva* Email: amodalpiva@gmail.com * Post-Graduate Program in Restorative Dentistry (Prosthodontic), Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp/SJC), Institute of Science and Technology, Brazil § University of Zürich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich, Switzerland Received: 25.04.2018 Accepted: 25.03.2019 doi: 10.1922/EJPRD_01829Tribst07