Three-dimensional finite element analysis of occlusal splint and implant connection on stress distribution in implant-supported fixed dental prosthesis and peri-implantal bone.

The aim of this study was to investigate the influence of occlusal splint therapy on the stress distribution of implant-supported fixed dental prosthesis (FDP) and peri-implantal bone structures using three-dimensional (3D) finite element analysis (FEA). The system consisted of two implants (positioned on region of second premolar and second molar) as retainers of fixed porcelain-fused-to-metal 3-unit FDP (first molar as pontic element). Two implant connections systems (external and internal hexagon) were tested. Static axial loads simulating functional (100N) and overloaded (300N) chewing were applied on the occlusal surface of the FDP covered or not with the occlusal splint. Maximum von Mises stress and bioperformance were accessed for the implants and bone tissues (cortical and cancellous) models. Analytic results indicated that independently of the load condition, implant region, and connection type, the presence of the occlusal splint decreased the stress developed in the implants. Both bone tissues showed increased levels of von Mises stress, and the bioperformance index was far from their maximum yield strength. The internal hexagon implants presented lower stress on premolar and molar regions than external hexagon implants under functional load and overload. The presence of the occlusal splint device over implant-supported FDP may be clinically useful for forwarding stresses towards the bone structure to maintain implants for long term.