Micromotion analysis of immediately loaded implants with Titanium and Cobalt‐Chrome superstructures. 3D finite element analysis

Abstract

Objective: The aim of this study was to evaluate the amount of micromotion of dental implants under immediate loading supported by Titanium (Ti) and Cobalt-Chrome (Co-Cr) superstructures. Material and methods:A model of tridimensional half-edentulous maxilla with three dental implants was made using the Finite Element Analysis (FEA). Two standard and one zygomatic implants were connected to a superstructure with an elliptic section of 6x 3 mm (mm). Two study models were established. Model A: Titanium (Ti) alloy superstructure; Model B: Cobalt-Chrome (Co-Cr) alloy superstructure. To simulate an immediate-loading situation, a friction coefficient of 0.71 was applied between the implant and the bone surface. An axial load of 252.04 [N] was applied on standard and zygomatic implants.Results: The Micromotion of dental implants was similar in both superstructure situations. The amount of micromotion was slightly higher in B1 and B3 models (Co-Cr alloy-superstructure) compared with A1 and A3 models (Titanium alloy superstructure). The micromotion values in two groups were greater than 150 μm in the incisive region (standard implant) and molar region (zygomatic). In general, the micromotion was higher on the implant that received the load with respect to the other implants.The greater difference was observed when the load was applied on the standard implant A1 (Model A1 = 189.12 μm) compared with standard implant B1(Model B1 = 263.25 μm).Conclusions: Within the limits of present study, all implants on different load application points showed micromotion; in general, the amount of micromotion was slightly higher in the implants connected with Co-Cr alloy superstructure.

Stress Distribution Pattern in Zygomatic Implants Supporting Different Superstructure Materials

“…Mini-conical abutments, as well as their corresponding screws, were designed for each implant. Subsequently, zygomatic implants with a tilted head, monoblock conical form and with apical threads (3.6 × 33.5 mm) were designed and positioned bilaterally in the molar sites [ 2 ]. For the zygomatic implants, abutments were not used.…”

“…Dental implants remain the ideal treatment option for supporting prosthetic restorations in patients with partial and/or complete edentulism [ 1 ]. Unfortunately, in the atrophic edentulous maxilla, poor bone quantity and quality may inhibit the use of conventional dental implants [ 2 ]. In certain situations, bone augmentation with biomaterials may be required to improve the bone volume, enabling the clinician to perform more conventional rehabilitation treatment options with standard dental implants [ 3 , 4 ].…”

“…In certain situations, bone augmentation with biomaterials may be required to improve the bone volume, enabling the clinician to perform more conventional rehabilitation treatment options with standard dental implants [ 3 , 4 ]. However, in the case of severe maxillary atrophy, the use of zygomatic implants may be the only viable alternative available for full-arch rehabilitation, which may also reduce the requirement for bone graft procedures [ 2 , 5 , 6 ].…”

“…Traditional protocols recommended a healing phase, to allow for the proper osseointegration between the bone and implant [ 2 , 3 ]. During healing, the application of occlusal forces should be minimized [ 7 ].…”

“…With the application of CAD/CAM, there are several superstructure materials that are suggested for implant-supported, full-arch rehabilitations, such as a cobalt–chrome alloy [ 2 ], a titanium alloy [ 7 ], zirconia [ 15 , 16 ], carbon-fiber polymers [ 17 , 18 ] and the polyaryletherketone family [ 14 , 19 ]. Despite the extensive literature on the effects of superstructure materials for conventional implants [ 6 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ], the data regarding biomechanical behavior of zygomatic implants are limited [ 2 , 6 , 21 , 22 ].…”