Should oral implants be splinted in a mandibular implant-supported fixed complete denture? A 3-dimensional-model finite element analysis Angel Alvarez-Arenal, DDS, PhD, a Aritza Brizuela-Velasco, DDS, b Hector DeLlanos-Lanchares, DDS, c and Ignacio Gonzalez-Gonzalez, DDS, PhD d School of Dentistry, University of Oviedo, Oviedo, Spain Statement of problem. The design of a mandibular fixed complete denture can influence periimplant bone loss. However, the design that transfers the greatest stress to the periimplant bone is not well documented. Purpose. The purpose of this study was to assess the stress distribution associated with splinted and nonsplinted implant-supported mandibular fixed complete denture designs. Material and methods. Three-dimensional finite element models simulating 6 osseointegrated implants were created in the mandible to support a cobalt-chromium alloy and feldspathic porcelain veneering framework. One model simulated a 1-piece framework, and the other models simulated 2-piece and 3-piece frameworks. Axial and oblique loads were applied to the frameworks. Results. For all the models, the greatest stress values were recorded in the periimplant bone of posterior implants, with differences between the left and right sides. The axial load transferred greater stress values to the periimplant bone than did the oblique load. The lowest periimplant bone stress values were observed in the 3-piece framework model at all implant locations, with the exception of implants placed in the canine region. Conclusions. A framework separated into 3 pieces transfers the least stress to the periimplant bone. (J Prosthet Dent 2014;-:---) Clinical Implications A 3-piece framework provides more favorable results in the treatment of an edentulous mandible with an implant-supported complete-arch fixed mandibular prosthesis than a 2-piece structure or a 1-piece structure that splints all the implants. Progressive bone loss around im- plants is the main factor in implant- supported restoration failure. Bone loss may be caused by either me- chanical (occlusal overload) or biologic (periimplantitis) elements, or by a combination of both. Regardless of periimplantitis, several in vivo and in vitro studies have found the influence of occlusal overload in the loss of periim- plant marginal bone. 1-4 Occlusal force generates a certain amount of stress on the framework, which, in turn, is transferred to the implant and the per- iimplant bone. However, the stress/ strain values transmitted to the implant and the alveolar bone depend on several parameters. The most important are occlusal force characteristics (in- tensity, direction, duration, speed), implant factors (number, diameter, length), implant-abutment connection, bone quality and density, and pros- thetic restoration material and design. With regard to prosthetic design, the position and number of implants and whether they are splinted are im- portant factors in planning the treat- ment of an implant-supported fixed mandibular complete-arch prosthesis to avoid the effect of cantilevers. Nev- ertheless, prospective studies have re- ported that cantilevers do not adversely a Professor and Head, Department of Prosthodontics and Occlusion. b Clinical Assistant Professor, Department of Prosthodontics and Occlusion. c Clinical Assistant Professor, Department of Prosthodontics and Occlusion. d Associate Professor, Department of Prosthodontics and Occlusion. Alvarez-Arenal et al