Design optimization of implant geometrical characteristics enhancing primary stability using FEA of stress distribution around dental prosthesis

The main objective of this study was to investigate the influence of implant geometrical characteristics: diameter, length and thread's pitch, on stress distribution around dental prosthesis. A set of numerical simulations using FEM were conducted and responses surfaces were generated. With the aim of optimizing the equivalent stresses responses; desirability function approach was adopted to solve this multi-objective problem. Results showed that implant diameter had most significant influence on generated stresses and high concentration of stresses were identified in the lower part of the implant. This study is helpful in choosing the optimal dental implant for clinical application.

Mandibular bone remodeling around osseointegrated functionally graded biomaterial implant using three dimensional finite element model

Dental implantation surgery has been progressed as one of the most efficient prosthetic technologies, however, it still fails very often and one of the main causes is the large difference between implant mechanical properties and those in welcoming bony tissues, making it problematical in osseointegration and bone remodeling. Biomaterial and tissue engineering research shows that there is a requirement in developing implants with Functionally Graded Materials (FGM). Indeed, the great potential of FGM lies not only in the field of bone tissue engineering but also in dentistry. To improve the acceptance of dental implants inside the living bone, FGM were proposed to step up the challenge of ensuring a better match of mechanical properties between biologically and mechanically compatible biomaterials. The aim of the present work is to investigate mandibular bone remodeling induced by FGM dental implant. Three-dimensional (3D) mandibular bone structure around an osseointegrated dental implant has been created to analyze the biomechanical behavior of the bone-implant system depending on implant material composition. In order to implement the numerical algorithm into ABAQUS software, UMAT subroutines and user-defined material were employed. Finite element analysis have been conducted to determine the stress distributions in implant and bony system, and to evaluate bone remodeling induced by the use of various FGM and pure titanium dental implants over the period of 48 months.

Agglomeration effect on biomechanical performance of CNT-reinforced dental implant using micromechanics-based approach

Dental implants have long played an important role in restoring lost teeth, but there are still concerns about their durability and long-term success. Commercial dental implants have traditionally been made of metallic and ceramic materials like titanium and zirconia; however, each kind of material has restrictions regarding osseointegration and mechanical characteristics that differ between native bone and the implant material, limiting the implant's longevity and reliability. To address these concerns, this research explores the use of carbon nanotubes (CNTs) in restorative dentistry, their excellent properties make them an ideal candidate for promoting bone growth around implanted device and ensuring long-lasting success. The objective of this study was to understand how CNT properties when incorporated into the titanium matrix may be able to better adapt to the oral environment taking into consideration the CNT agglomeration effects when designing reinforced nanocomposite materials for dental implant. A mathematical formulation of the micromechanics model was developed and improved to extend its application for the case of CNT-based composite materials for dental implants. A three dimensional (3D) model of bone structure around the osseointegrated dental implant was established considering different compositions of implant material. Finite Element Analysis (FEA) were conducted to assess the aggregation effect of implant incorporating CNTs into the titanium matrix, considering CNTs with both spherical inclusions (CNT clusters), and randomly dispersive ones (CNTs) in the titanium matrix, on osseointegration and bone remodeling around the dental implant and supporting bone system over a period of 48 months. Firstly, the effects of CNT-Ti implantation on time-dependent performance are evaluated in a computational remodeling framework. Then, Von Mises equivalent stresses are investigated to evaluate the stress distributions and micromotions in jaw bones of loaded implant with different composition of prosthetic material. Three agglomeration patterns are considered, particularly without agglomeration (ζ = ξ), partial and complete agglomeration (ζ < ξ, ξ = 1). Further, the influence of CNTs volume fraction variation is taken into account to predict the mechanical response of the bony system after CNT-reinforced dental implantation. It can be inferred that the agglomeration of CNTs reduces the elastic stiffness of the matrix. This is due to the fact that when CNTs are agglomerated, the inter-tube contacts are reduced and the effective stiffness of the matrix is decreased.