The Characterization of Titanium Particles Released from Bone-Level Titanium Dental Implants: Effect of the Size of Particles on the Ion Release and Cytotoxicity Behaviour

Abstract

Many studies are being carried out on the particles released during the implantoplasty process in the machining of dental implants to remove bacterial biofilms. However, there are no studies on the release of particles produced by the insertion of bone-level dental implants due to the high compressive frictional loads between the rough titanium implant and the bone tissue. This paper aims to characterize the released particles and determine the release of titanium ions into the physiological environment and their cytocompatibility. For this purpose, 90 dental implants with a neck diameter of 4 mm and a torque of 22 Ncm were placed in 7 fresh cow ribs. The placement was carried out according to the established protocols. The implants had a roughness Ra of 1.92 μm. The arrangement of the particles in the bone tissue was studied by micro-CT, and no particle clusters were observed. The different granulometries of 5, 15, and 30 μm were obtained; the specific surface area was determined by laser diffraction; the topography was determined by scanning electron microcopy; and the particles were chemically analysed by X-ray energy microanalysis. The residual stresses of the particles were obtained by X-ray diffraction using the Bragg-Bentano configuration. The release of titanium ions to the physiological medium was performed using ICP-MS at 1, 3, 7, 14, and 21 days. The cytocompatibility of the particles with HFF-1 fibroblast and SAOS-2 osteoblast cultures was characterized. The results showed that the lowest specific surface area (0.2109 m2/g) corresponds to the particles larger than 30 μm being higher than 0.4969 and 0.4802 m2/g of those that are 5 and 15 μm, respectively, observing in all cases that the particles have irregular morphologies without contamination of the drills used in the surgery. The highest residual stresses were found for the small particles, −395 MPa for the 5 μm particles, and −369 for the 15 μm particles, and the lowest residual stresses were found for the 30 μm particles with values of −267 MPa. In all cases, the residual stresses were compressive. The lowest ion release was for the 30 μm samples, as they have the lowest specific surface area. Cytocompatibility studies showed that the particles are cytocompatible, but it is the smallest ones that are lower and very close to the 70% survival limit in both fibroblasts and osteoblasts.

Influence of Zirconium on the Microstructure, Selected Mechanical Properties, and Corrosion Resistance of Ti20Ta20Nb20(HfMo)20−xZrx High-Entropy Alloys

“…For cp-Ti alloys, the presence of a self-passive titanium dioxide (TiO 2 ) layer ensured high corrosion resistance in different simulated body fluid environments [ 12 , 13 ]. Due to the presented properties of commercially pure titanium, their applications include dental implants [ 14 ].…”

Effect of the Size of Titanium Particles Released from Dental Implants on Immunological Response

“…In this work, particles of different sizes were isolated by simulating implantoplasty processes with more than 200 titanium dental implants, and they were classified into different mean sizes of 5 µm (Ti-5), 10 µm (Ti-10), 15 µm (Ti-15), and 30 µm (Ti-30). The reason for choosing these particle sizes is due to the fact that, in the literature, they are the most common ones found in the tissues after implantoplasty processes [20][21][22][23][24][25] and after the placement of bone-level dental implants caused by the friction of the collar on the cortical bone [26][27][28]. A limitation of this type of study is the difficulty in determining and characterizing particles smaller than 1 µm in size, although they can be observed in small quantities through field-emission electron microscopy observations and micro-CT characterization.…”

Diffusion of Vanadium Ions in Artificial Saliva and Its Elimination from the Oral Cavity by Pharmacological Compounds Present in Mouthwashes

“…However, as they are inserted into the oral cavity, they can be subjected to corrosion and wear phenomena, with consequent release of metal ions into the human body [ 4 , 5 , 6 ]. These released metal ions and particles may have deleterious systemic and local effects; for instance, they are related to the failure of implant-supported oral rehabilitations and thus matter of concern for the scientific community [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”

“…This standpoint is corroborated by Kunrath et al [ 12 ], who considered the long-term behavior of fragments of certain chemical elements in tissues or cells at the molecular level and indicated that this is still not well-understood. Ion release from metallic prosthetic devices is a current issue and the object of many recent studies [ 11 , 13 , 14 , 15 , 16 ].…”