Titanium in dentistry: historical development, state of the art and future perspectives

Anti-cancer property and DNA binding interaction of first row transition metal complexes: A decade update

Metal ions carry out a wide variety of functions, including acid-base/redox catalysis, structural functions, signaling, and electron transport. Understanding the interactions of transition metal complexes with biomacromolecules is essential for biology, medicinal chemistry, and the production of synthetic metalloenzymes. After the coincidental discovery of cisplatin, importance of the metal complexes in biochemistry became a top priority for inquiry. In this review, a decade update on various synthetic strategies to first row transition metal complex and their interaction with DNA through non-covalent binding are explored. Moreover, this effort provides an excellent analysis on the efficacy of theoretical and practical approaches to the systematic generation of new non-platinum based metallodrugs for anti-cancer therapeutics.

Biomedical Applications of Titanium Alloys: A Comprehensive Review

Titanium alloys have emerged as the most successful metallic material to ever be applied in the field of biomedical engineering. This comprehensive review covers the history of titanium in medicine, the properties of titanium and its alloys, the production technologies used to produce biomedical implants, and the most common uses for titanium and its alloys, ranging from orthopedic implants to dental prosthetics and cardiovascular devices. At the core of this success lies the combination of machinability, mechanical strength, biocompatibility, and corrosion resistance. This unique combination of useful traits has positioned titanium alloys as an indispensable material for biomedical engineering applications, enabling safer, more durable, and more efficient treatments for patients affected by various kinds of pathologies. This review takes an in-depth journey into the inherent properties that define titanium alloys and which of them are advantageous for biomedical use. It explores their production techniques and the fabrication methodologies that are utilized to machine them into their final shape. The biomedical applications of titanium alloys are then categorized and described in detail, focusing on which specific advantages titanium alloys are present when compared to other materials. This review not only captures the current state of the art, but also explores the future possibilities and limitations of titanium alloys applied in the biomedical field.

Subgingival titanium wire implantation induces weak inflammatory responses but does not promote substantial T cell activation

Titanium is a biocompatible material commonly used for dental treatments. However, the detailed mechanism underlying the weak biological activity of titanium has not been elucidated. We investigated both the inflammatory responses and T cell activation induced by solid titanium in the gingiva in mice. Both titanium and nickel wire implantation promoted neutrophil infiltration into the gingiva on day 2. Nickel, but not titanium, wire implantation enhanced proinflammatory cytokine expression and dendritic cell activity in gingival tissue by day 2. Nickel wire implantation enhanced the activity of T cells in draining lymph nodes on day 5. Moreover, T cell and neutrophil infiltration and elevated proinflammatory cytokine expression in the gingival tissue were still observed on day 5. However, no such augmented biological responses were observed after titanium wire implantation. These findings suggest that, unlike nickel, solid titanium does not induce sufficient inflammatory responses leading to T cell activation in gingival tissue.

Fusion of Ni Plating on CP-Titanium by Electron Beam Single-Track Scanning: Toward a New Approach for Fabricating TiNi Self-Healing Shape Memory Coating

The limited wear resistance of commercially pure titanium (CP-Ti) hinders its use in abrasive and erosive environments, despite its good strength-weight ratio and corrosion resistance. This paper reports the first study proposing a novel method for wear-resistant TiNi coating through Ni plating and electron beam (EB) irradiation in an in situ synthetic approach. Single-track melting experiments were conducted using the EB to investigate the feasibility of forming a TiNi phase by fusing the Ni plate with the CP-Ti substrate. Varying beam powers were employed at a fixed scanning speed to determine the optimal conditions for TiNi phase formation. The concentration of the melt region was found to be approximate as estimated from the ratio of the Ni-plate thickness to the depth of the melt region, and the region with Ni-48.7 at.% Ti was successfully formed by EB irradiation. The study suggests that the mixing of Ti atoms and Ni atoms was facilitated by fluid flow induced by Marangoni and thermal convections. It is proposed that a more uniform TiNi layer can be achieved through multi-track melting under appropriate conditions. This research demonstrates the feasibility of utilizing EB additive manufacturing as a coating method and the potential for developing TiNi coatings with shape memory effects and pseudoelasticity.

Structural Speciation of Ti(IV)-(α-Hydroxycarboxylic Acid) Complexes in Metabolism-Related (Patho)Physiology-In Vitro Approaches to (Pre)Adipocyte Differentiation and Mineralization

The prospect of developing soluble and bioavailable Ti(IV) complex forms with physiological substrates, capable of influencing (patho)physiological aberrations, emerges as a challenge in the case of metabolism-related pathologies (e.g., diabetes mellitus 1 and 2). To that end, pH-specific synthetic efforts on binary Ti(IV)-(α-hydroxycarboxylic acid) systems, involving natural physiological chelator ligands (α-hydroxy isobutyric acid, D-quinic acid, 2-ethyl-2-hydroxybutyric acid) in aqueous media, led to the successful isolation of binary crystalline Ti(IV)-containing products. The new materials were physicochemically characterized by elemental analysis, FT-IR, TGA, and X-ray crystallography, revealing in all cases the presence of mononuclear Ti(IV) complexes bearing a TiO₆ core, with three bound ligands of variable deprotonation state. Solution studies through electrospray ionization mass spectrometry (ESI-MS) revealed the nature of species arising upon dissolution of the title compounds in water, thereby formulating a solid-state-solution correlation profile necessary for further employment in biological experiments. The ensuing cytotoxicity profile (pre-adipocytes and osteoblasts) of the new materials supported their use in cell differentiation experiments, thereby unraveling their structure-specific favorable effect toward adipogenesis and mineralization through an arsenal of in vitro biological assays. Collectively, well-defined atoxic binary Ti(IV)-hydroxycaboxylato complexes, bearing bound physiological substrates, emerge as competent inducers of cell differentiation, intimately associated with cell maturation, thereby (a) associating the adipogenic (insulin mimetic properties) and osteogenic potential (mineralization) of titanium and (b) justifying further investigation into the development of a new class of multipotent titanodrugs.

Do Titanium Dioxide Particles Stimulate Macrophages to Release Proinflammatory Cytokines and Increase the Risk for Peri-implantitis?

PURPOSE

Titanium dioxide (TiO₂) particles detached from titanium dental implants by tribocorrosion can be phagocytosed by macrophages, releasing various proinflammatory cytokines at the implant sites that may trigger peri-implantitis. The study objective was to measure the association between peri-implantitis and the presence of non-allergy-related proinflammatory cytokines associated with TiO₂ particles.

METHODS

The investigators implemented a retrospective cross-sectional study and enrolled a sample of 60 subjects from a dental practice. Subjects were excluded if the plaque index was grade 3 (Silness and Löe). The predictor variable was a positive or negative TiO₂ stimulation test, an in vitro macrophage proinflammatory response test. The outcome variable was peri-implantitis status defined as present or absent. Three groups were considered: control group with 20 patients without dental implants (group 1), 2 groups of patients with titanium dental implants, one without peri-implantitis (group 2), and the other with peri-implantitis (group 3) (n = 20 each). For patients with implants, depth of the gingival pockets of the implants were measured, and existing bleeding and suppuration were determined to assess peri-implantitis. Radiographs were taken if one or more factors applied to confirm the diagnosis of peri-implantitis. Further covariates were age, sex, duration of implant wear, and number of implants which were analyzed descriptively. Inferential analyses were undertaken using χ² test, Kruskal-Wallis-, Wilcoxon-two-sample tests, and logistic regressions.

RESULTS

The sample was composed of 35 female and 25 male patients with a mean age of 54.2 years (standard deviation = 14.76). The overall TiO₂ stimulation test positivity frequency was 28.3% and were 30.0%, 5.0%, and 50.0% in the control, implants without peri-implantitis, and implants with peri-implantitis groups. No statistically significant differences could be seen in the frequencies of the TiO₂ stimulation test results between control group and combined groups 2 and 3 (P-value = .84). The risk for positive TiO₂ patients with a titanium implant of developing peri-implantitis was statistically significant and higher compared to negative TiO₂ patients (odds ratio, 19.0 with 95% confidence interval [2.12,170.38]; P-value< .01).

CONCLUSIONS

The data in this study showed a statistically significant relationship between a positive TiO₂ stimulation test and peri-implantitis. Further studies with larger numbers of subjects are recommended to confirm this result.

Focal adhesion formation of primary human gingival fibroblast on hydrothermally and in-sol-made TiO2 -coated titanium

Optimal cell adhesion of the gingival fibroblasts to dental implants is important for maintaining good implant integration. The aim of this study was to discover, if the nanoporous TiO₂ -coating on titanium alloy substrates is able to increase the cell adhesion of the human gingival fibroblasts (HGF). The study consisted of three differently produced titanium groups: hydrothermally produced TiO₂ -coating (HT), novel TiO₂ -coating made in sol (SOL), and noncoated control group. Primary HGF cells were initiated from gingival biopsies from patients having a third molar extraction. HGF were cultivated on titanium discs for 2 and 24 h to determine the initial attachment with confocal microscope. The cell spreading and adhesion protein signals were measured. In addition, expression of adhesion proteins vinculin, paxillin, and focal adhesion kinase (FAK) were measured after 3 days of cultivation by using Western Blotting. Higher protein levels of paxillin, vinculin, and FAK were induced on both coated discs compared to noncoated discs. The difference was statistically significant (p < 0.05) concerning expression of paxillin. The cell spreading was significantly larger on SOL discs after 2 and 24 h when comparing to noncoated controls. The confocal microscope analyses revealed significantly higher adhesion protein signals on both HT- and SOL-coated titanium compared to control group. This study showed, that both methods to produce TiO₂ -coatings are able to increase HGF adhesion protein expression and cell spreading on titanium surface. Accordingly, the coatings can potentially improve the gingival attachment to titanium implant surfaces.

Exploring the Usability of α-MSH-SM-Liposome as an Imaging Agent to Study Biodegradable Bone Implants In Vivo

Novel biodegradable metal alloys are increasingly used as implant materials. The implantation can be accompanied by an inflammatory response to a foreign object. For studying inflammation in the implantation area, non-invasive imaging methods are needed. In vivo imaging for the implanted area and its surroundings will provide beneficiary information to understand implant-related inflammation and help to monitor it. Therefore, inflammation-sensitive fluorescent liposomes in rats were tested in the presence of an implant to evaluate their usability in studying inflammation. The sphingomyelin-containing liposomes carrying alpha-melanocyte-stimulating hormone (α-MSH)-peptide were tested in a rat bone implant model. The liposome interaction with implant material (Mg-10Gd) was analyzed with Mg-based implant material (Mg-10Gd) in vitro. The liposome uptake process was studied in the bone-marrow-derived macrophages in vitro. Finally, this liposomal tracer was tested in vivo. It was found that α-MSH coupled sphingomyelin-containing liposomes and the Mg-10Gd implant did not have any disturbing influence on each other. The clearance of liposomes was observed in the presence of an inert and biodegradable implant. The degradable Mg-10Gd was used as an alloy example; however, the presented imaging system offers a new possible use of α-MSH-SM-liposomes as tools for investigating implant responses.

Titanium and titanium alloys in dentistry: current trends, recent developments, and future prospects

Many implant materials have been used in various dental applications depending on their efficacy and availability. A dental implant must possess the required characteristics, such as biocompatibility, corrosion & wear resistance, adequate mechanical properties, osseointegration, etc., to ensure its safe and optimum use. This review analyzes various aspects of titanium (Ti) and Ti alloys, including properties, manufacturing processes, surface modifications, applications as dental implants, and limitations. In addition, it also presents a perception of recent advances in Ti-based implant materials and the futuristic development of innovative dental implants.

Effect of Currently Available Nanoparticle Synthesis Routes on Their Biocompatibility with Fibroblast Cell Lines

Nanotechnology has acquired significance in dental applications, but its safety regarding human health is still questionable due to the chemicals utilized during various synthesis procedures. Titanium nanoparticles were produced by three novel routes, including Bacillus subtilis, Cassia fistula and hydrothermal heating, and then characterized for shape, phase state, size, surface roughness, elemental composition, texture and morphology by SEM, TEM, XRD, AFM, DRS, DLS and FTIR. These novel titanium nanoparticles were tested for cytotoxicity through the MTT assay. L929 mouse fibroblast cells were used to test the cytotoxicity of the prepared titanium nanoparticles. Cell suspension of 10% DMEM with 1 × 104 cells was seeded in a 96-well plate and incubated. Titanium nanoparticles were used in a 1 mg/mL concentration. Control (water) and titanium nanoparticles stock solutions were prepared with 28 microliters of MTT dye and poured into each well, incubated at 37 °C for 2 h. Readings were recorded on day 1, day 15, day 31, day 41 and day 51. The results concluded that titanium nanoparticles produced by Bacillus subtilis remained non-cytotoxic because cell viability was >90%. Titanium nanoparticles produced by Cassia fistula revealed mild cytotoxicity on day 1, day 15 and day 31 because cell viability was 60−90%, while moderate cytotoxicity was found at day 41 and day 51, as cell viability was 30−60%. Titanium nanoparticles produced by hydrothermal heating depicted mild cytotoxicity on day 1 and day 15; moderate cytotoxicity on day 31; and severe cytotoxicity on day 41 and day 51 because cell viability was less than 30% (p < 0.001). The current study concluded that novel titanium nanoparticles prepared by Bacillus subtilis were the safest, more sustainable and most biocompatible for future restorative nano-dentistry purposes.

Epithelial cell attachment and adhesion protein expression on novel in sol TiO2 coated zirconia and titanium alloy surfaces

An adequate mucosal attachment is important when it comes to preventing peri-implant inflammation. The aim of this study was to compare epithelial cell adhesion and adhesion protein expression on in sol TiO₂ -coated and non-coated zirconia and titanium alloy surfaces. Fifty-six zirconia and titanium discs were cut, and half of them were coated with bioactive TiO₂ -coating. To study the epithelial cell attachment, human gingival keratinocytes were cultivated on discs for 1, 3, 6, and 24 h. The cell proliferation was detected by cultivating cells for 1, 3, and 7 days. In addition, the levels of adhesion proteins laminin y2, integrin α6, β4, vinculin, and paxillin were detected with Western Blot method. Furthermore, high-resolution imaging of the actin cytoskeleton and focal adhesion proteins was established. Longer-term cell culture (1-7 days) revealed higher cell numbers on the coated zirconia and titanium discs compared to non-coated discs. The difference was statistically significant (p < .05) after 24 h on coated zirconia and after 3 and 7 days on coated titanium discs compared to non-coated discs. Clear induction in the protein levels of laminin y2 and integrin α6 were detected on both coated samples, meanwhile integrin β4 were clearly induced on coated titanium alloy. The microscope evaluation showed significantly increased cell spreading on the coated discs. According to this study, the in sol induced TiO₂ -coating increases keratinocyte attachment and the expression of adhesion proteins on coated zirconia and titanium in vitro. Consequently, the coating has potential to enhance the mucosal attachment on implant surfaces.

Overview of the Influence of Silver, Gold, and Titanium Nanoparticles on the Physical Properties of PEDOT:PSS-Coated Cotton Fabrics

Metallic nanoparticles have been of interest to scientists, and they are now widely used in biomedical and engineering applications. The importance, categorization, and characterization of silver nanoparticles, gold nanoparticles, and titanium nanoparticles have been discussed. Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) is the most practical and reliable conductive polymer used in the manufacturing of conductive textiles. The effects of metallic nanoparticles on the performance of PEDOT:PSS thin films are discussed. The results indicated that the properties of PEDOT:PSS significantly depended on the synthesis technique, doping, post-treatment, and composite material. Further, electronic textiles known as smart textiles have recently gained popularity, and they offer a wide range of applications. This review provides an overview of the effects of nanoparticles on the physical properties of PEDOT:PSS-coated cotton fabrics.

Studying the Insulating Properties of Oxide Films Obtained on the Ti6A14V Alloy in Tartaric Acid Solutions Using the Method of Electrochemical Decoration by Copper

The investigation data of the formation peculiarities of oxide films on the Ti6A14V alloy in tartaric acid solutions have been given. It is shown that the behavior of alloy forming dependences is conditioned by the anode current density. At ja < 0.5 A∙dm-2 the continuous oxide film is not formed on the alloy surface and the preset value of the final voltage on the cell is not reached. With an increase in ja > 0.5 A∙dm-2, alloy forming dependences show a linear behavior that is indicative of the formation of low porous films. In these conditions, the oxide film formation rate is in direct proportion to the value of ja. The electrochemical oxidation of Ti6A14V alloy in tartaric acid solutions results in the formation of interference-colored oxide films. The oxide film ultimate thickness and color are defined by the preset voltage and are independent of the current density and electrolyte concentration. The isolating properties of obtained films were studied by the way of the cathode polarization of oxidized specimens in the sulfate copper-plating electrolyte. The research done allows us to make a conclusion that electrochemical copper deposition is a convenient tool for the detection of defective spots in oxide films. It is shown that due to the specific features of the reduction kinetics of Cu2+ ions on the oxidized titanium it is reasonable to use for the studies the initial sections of polarization dependences that correspond to ΔE = 0.2–0.25 V. The alloy polarization dependences allow us to establish unavailability of apparent dependences between the oxidation current density, the electrolyte concentration, the cell final voltage value and the polarization that occurs during the Cu2+ ion reduction. The anodic connection of copper-coated specimens conditions the reversible dissolution of a greater portion of the specks of copper deposits. It is indicative of the electron conduction of film defects. The obtained data allow us to vary the electrolysis parameters in a wide range with no significant influence of the treatment mode of Ti6A14V alloy on the quality of oxide coatings.

Metal Oxide Nanoparticles and Nanotubes: Ultrasmall Nanostructures to Engineer Antibacterial and Improved Dental Adhesives and Composites

Advances in nanotechnology have unlocked exclusive and relevant capabilities that are being applied to develop new dental restorative materials. Metal oxide nanoparticles and nanotubes perform functions relevant to a range of dental purposes beyond the traditional role of filler reinforcement-they can release ions from their inorganic compounds damaging oral pathogens, deliver calcium phosphate compounds, provide contrast during imaging, protect dental tissues during a bacterial acid attack, and improve the mineral content of the bonding interface. These capabilities make metal oxide nanoparticles and nanotubes useful for dental adhesives and composites, as these materials are the most used restorative materials in daily dental practice for tooth restorations. Secondary caries and material fractures have been recognized as the most common routes for the failure of composite restorations and bonding interface in the clinical setting. This review covers the significant capabilities of metal oxide nanoparticles and nanotubes incorporated into dental adhesives and composites, focusing on the novel benefits of antibacterial properties and how they relate to their translational applications in restorative dentistry. We pay close attention to how the development of contemporary antibacterial dental materials requires extensive interdisciplinary collaboration to accomplish particular and complex biological tasks to tackle secondary caries. We complement our discussion of dental adhesives and composites containing metal oxide nanoparticles and nanotubes with considerations needed for clinical application. We anticipate that readers will gain a complete picture of the expansive possibilities of using metal oxide nanoparticles and nanotubes to develop new dental materials and inspire further interdisciplinary development in this area.

Comparative study of bacterial microfiltration in the implant-abutment interface, with straight and conical internal connections, in vitro

OBJECTIVE

to determine the presence of marginal bacterial microfiltration in the IAI in different implant/abutment systems, in vitro.

MATERIAL AND METHODS

Fifty-six implants from seven different brand names, 4 with cone and 3 with straight connections were used, implant and abutment were connected using the Ncm tightening as indicated by each of the manufacturers and then were sealed. The samples were subjected occlusal load and thermal cycling, a first sample of each group was observed by micro CT and in a second sample (both samples randomly selected) length of connection was measured, while the rest of the samples were mounted on devices according to the bacterial microfiltration model with Porphyromonas gingivalis.

RESULTS

Two of the conical connection system groups did not present bacterial microfiltration, one of the three straight connection groups only microfiltered in one sample, while the other two conical as well as the two straight connection samples showed different and important levels of bacterial microfiltration, all groups presented a direct relationship between the implant-abutment adjustment determined by micro-CT and bacterial microfiltration levels, not related to the connection length.

CONCLUSION

Only two conical connection systems presented no bacterial microfiltration.

Evaluation of serum metal ion levels in dental implant patients: A prospective study

Introduction:

Titanium is the most commonly used bio-inert implant material. Nevertheless, there is a possibility of systemic release of metal ions, which could have clinical implications like implant failure and toxicity. This prospective study focuses on the evaluation of serum metal ion levels in patients receiving dental implants. The aim of the study is to evaluate the release of titanium, aluminium, and vanadium from dental implants by comparing the preoperative and postoperative serum levels of these ions.

Methodology:

Serum samples were collected from 30 patients undergoing dental implant placement preoperatively and postoperatively at intervals of 6 weeks, 3, 6, and 12 months. These samples were analyzed for titanium, aluminium, and vanadium levels using Inductively Coupled Plasma Optical Emission Spectrometry. The difference in preoperative and postoperative serum levels was measured and statistically analyzed using the paired t-test.

Results:

There was a slight difference in the postoperative levels of titanium and aluminium (2.30 and 4.07 mg/dl) as compared to the preoperative levels (2.28 and 2.30 mg/dl), which was statistically insignificant (P > 0.5). The serum levels of vanadium were too insignificant to be detected by the instrument (<0.0088 mg/dl).

Discussion:

Mild increase in the titanium and aluminium levels in blood serum was noted. These metallic ion levels might increase significantly due to which further clinical research with larger sample sizes and a long-term follow-up period is required to evaluate the clinical effects of metallic ion release from dental implants. There is no significant difference in the serum metal ion levels before and after the implant placement, although a little increase is observed in the aluminium ion levels after the implant placement.

Effect of Multi-Phosphonate Coating of Titanium Surfaces on Osteogenic Potential

The aim of this study was to evaluate the impact of a novel multi-phosphonate (MP) coating strategy of dental implant surfaces on the expression of osteogenesis-related factors in vitro. MG-63 human osteoblast-like cells, bone marrow mesenchymal stem cells (BM-MSCs), and human periodontal ligament stem cells (hPDLSCs) were cultured separately on titanium disks with and without MP coating. Cell attachment was visualized by focal adhesion and actin cytoskeleton staining. The proliferation and gene expression of the markers related to osteogenesis and bone turnover were measured after 48 and 120 h of cell culture. Actin cytoskeleton assembly and focal adhesion were similar between test surfaces within each cell type but differed from those on tissue culture plastic (TCP). The proliferation of MG-63 cells and PDLSCs was comparable on all surfaces, while BM-MSCs showed an increase on tissue culture plastic (TCP) versus titanium. The gene expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand was higher in MG-63 cells grown on MP-coated surfaces. At the same time, osteocalcin was decreased compared to the other surfaces. Collagen type I gene expression after 120 h was significantly lower in hPDLSCs cultivated on MP-coated surfaces. Within the limitations of this study, MP coating on titanium surfaces might have a slight beneficial effect on bone turnover in vitro.

Titanium Alloys for Dental Implants: A Review

The topic of titanium alloys for dental implants has been reviewed. The basis of the review was a search using PubMed, with the large number of references identified being reduced to a manageable number by concentrating on more recent articles and reports of biocompatibility and of implant durability. Implants made mainly from titanium have been used for the fabrication of dental implants since around 1981. The main alloys are so-called commercially pure titanium (cpTi) and Ti-6Al-4V, both of which give clinical success rates of up to 99% at 10 years. Both alloys are biocompatible in contact with bone and the gingival tissues, and are capable of undergoing osseointegration. Investigations of novel titanium alloys developed for orthopaedics show that they offer few advantages as dental implants. The main findings of this review are that the alloys cpTi and Ti-6Al-4V are highly satisfactory materials, and that there is little scope for improvement as far as dentistry is concerned. The conclusion is that these materials will continue to be used for dental implants well into the foreseeable future.

Comparing maximal forces in resorbable poly-L-lactic acid and titanium plates for mandibular fracture fixation

Treatment for mandibular fractures is commonly performed via open reduction fixation with mini titanium or resorbable plates and screws. The investigators hypothesized differences in maximum mechanical stress forces and deflection with each plating material; however, it was proposed that the experimental forces withstood by the resorbable system would be enough to withstand normal forces produced during mastication. The sample was composed of fresh cadaver mandibles that were harvested, fractured, and fixated with plates and screws. The predictor variable was fracture fixation and included a titanium plating or resorbable poly-L-lactide plating system. The primary outcome measure was maximum load withstood before plating failure measured in Newtons (N). Descriptive and bivariate statistics were computed, P value was set at .05. The sample was composed of six mandibles with and grouped by type of fixation modality, Titanium (T) (n = 3) and Resorbable (n = 3). There was a statistically significant correlation between the T group and increased maximum load (N) before failure as compared to the R group, (P = 0.023). The results suggest that fracture fixation with titanium plates and screws can withstand greater maximum forces before failure; however, the resorbable plating system withstood forces similar to/or greater than the maximum forces produced during normal mastication.

Evaluation of the Effect of Fluoride-containing Luting Cements on Titanium and Its Effect on the Shear Bond Strength

Context:

The most appropriate luting agent for titanium crowns is yet to be determined. Commonly used cements for luting titanium restorations give off leachable ions which may cause surface interaction with the titanium.

Aims:

The purpose of this study was to determine the shear bond strength of four grades of commercially pure titanium and Ti 6Al 4V with different cements and to examine for any surface physical changes.

Settings and Design:

The three luting cements, i.e., zinc polycarboxylate cement, glass ionomer cement, and zinc phosphate cement, were used to evaluate their effect on titanium. Ni Cr was used as a control.

Methods and Material:

The metal rods were milled to discs of 6 mm diameter and 4 mm height. Freshly extracted maxillary first molars, mounted in resin blocks, were sliced horizontally at occlusal third of the tooth. The discs were cemented to the sliced surface of the tooth with the three luting cements. The models were subjected to the shear bond strength test. Statistical analysis used: The data collected were analyzed statistically with one way ANOVA. A representative specimen of each group was observed under a scanning electron microscope.

Results:

The mean values ranged from 0.31 to 15.6 MPa. The shear bond strength values of the zinc polycarboxylate cement group were significantly high (P < 0.05). Corrosion of the titanium alloy luted with zinc polycarboxylate cement was observed.

Conclusions:

Cementation with zinc polycarboxylate cement provided high shear bond strength, but showed corrosion on titanium.

Vestibuloplasty covering titanium mesh with grafted free gingiva on anterior mandible: technical report and rationale

This paper describes a patient with an insufficient vestibular depth for a removable partial denture who underwent vestibuloplasty with a free gingival graft using a titanium mesh in the anterior mandible. Free gingiva was harvested from the palatal mucosa, and a partial thickness flap was elevated at the recipient site. After minimal suturing for the graft, a titanium mesh was fixed over the graft. The mesh was removed four weeks after surgery. The patient obtained an adequate vestibular depth and keratinized gingiva eight weeks after surgery without any complications. In this case, an appropriate vestibular depth and keratinized gingiva were easily obtained by vestibuloplasty using a titanium mesh.

Off-Stoichiometric Reactions at the Cell-Substrate Biomolecular Interface of Biomaterials: In Situ and Ex Situ Monitoring of Cell Proliferation, Differentiation, and Bone Tissue Formation

The availability of osteoinductive biomaterials has encouraged new therapies in bone regeneration and has potentially triggered paradigmatic shifts in the development of new implants in orthopedics and dentistry. Among several available synthetic biomaterials, bioceramics have gained attention for their ability to induce mesenchymal cell differentiation and successive bone formation when implanted in the human body. However, there is currently a lack of understanding regarding the fundamental biochemical mechanisms by which these materials can induce bone formation. Phenomenological studies of retrievals have clarified the final effect of bone formation, but have left the chemical interactions at the cell-material interface uncharted. Accordingly, the knowledge of the intrinsic material properties relevant for osteoblastogenesis and osteoinduction remains incomplete. Here, we systematically monitored in vitro the chemistry of mesenchymal cell metabolism and the ionic exchanges during osteoblastogenesis on selected substrates through conventional biological assays as well as via in situ and ex situ spectroscopic techniques. Accordingly, the chemical behavior of different bioceramic substrates during their interactions with mesenchymal cells could be unfolded and compared with that of biomedical titanium alloy. Our goal was to clarify the cascade of chemical equations behind the biological processes that govern osteoblastogenic effects on different biomaterial substrates.

A review of materials for managing bone loss in revision total knee arthroplasty

In 2014-2015, 61,421 total knee arthroplasties (TKAs) were performed in Canada; an increase of about 20% over 2000-2001. Revision total knee arthroplasties (rTKAs) accounted for 6.8% of TKAs performed between 2014 and 2015, and this is estimated to grow another 12% by 2025. rTKAs are typically more complicated than primary TKAs due to the significant loss of femoral and tibial bone stock. The escalating demand and limitations associated with total knee arthroplasty and their revision drives the development of novel treatments. A variety of materials have been utilized to facilitate regeneration of healthy bone around the site of a knee arthroplasty. The selection of these materials is based on the bone defect size and includes bone grafts, graft substitutes and cements. However, all these materials have certain disadvantages such as blood loss, disease transmission (bone grafts), inflammatory response, insufficient mechanical properties (bone graft substitutes) thermal necrosis and stress shielding (bone cement). Recently, the use of metal augments for large bone defects has attracted attention, however they can undergo fretting, corrosion, and stress shielding. All things considered, this review indicates the necessity of developing augments that have structural integrities and biodegradation rates similar to that of human bone. Therefore, the future of bone loss management may lie in fabricating novel bioactive glass augments as they can promote bone healing and implant stability and can degrade with time.

What is the Optimal Material for Implant Prosthesis?

Implant dentistry has shifted to prosthetically guided implant planning and placement. This shift has influenced the range of available dental materials to restore single crowns and partially and fully edentulous jaws with dental implants. This article presents an overview of the available options to restore dental implants. The qualities that define an ideal restoring material are discussed along with the most commonly used materials with their advantages and limitations. Because clinicians face different clinical scenarios in their practice, the discussion sums up the best techniques and materials that are useful in addressing these nonideal situations.

Retrospective Study of 18 Titanium Alloy Crowns Produced by Computer-Aided Design and Manufacturing in Dogs

Computer-aided design (CAD) and computer-aided manufacturing (CAM) technology is routinely used in various fields of human dentistry, particularly prosthodontics. Reverse engineering and additive manufacturing allow the technician to create an easier, faster and more accurate restoration, with a natural design and adequate strength. Eighteen titanium alloy full crowns were produced for canine teeth of 7 working dogs using CAD/CAM technology (3D BioCare, Nobel Biocare). Reasons for crown therapy included abrasion, enamel infraction, and crown fracture. Crown preparation was routinely performed, and impressions were delivered to the laboratory where digital impressions were performed with a lab scanner. Using 3D dental design software, the metal crown was designed and sent for manufacture. Each prosthodontic crown was then carved from a solid titanium alloy block to obtain the final crown. All prosthodontic crowns were an adequate fit, and cementation was routinely performed. Crowns were lost from 2 canine teeth during the dogs' normal working activity, in one case, for 2 times. In all cases, replicas were requested. In the first case, the second cementation was successful. In the second case, the second crown was again lost and only the third cementation was successful. Follow up of all cases range from 12 to 62 months. Mean survival time for the crowns was 58.0 months. Here, CAD/CAM technology is shown to be a useful tool for manufacturing accurate prosthodontic crowns for veterinary patients. Moreover, CAD/CAM enables the production of prosthodontic crown replicas in a very short time and at relatively low cost compared to traditional methods, consequently eliminating the need for at least one anesthetic procedure in the incidence of crown cementation failure.

General review of titanium toxicity

Background

Titanium is a commonly used inert bio-implant material within the medical and dental fields. Although the use of titanium is thought to be safe with a high success rate, in some cases, there are rare reports of problems caused by titanium. In most of these problematic reports, only individual reports are dominant and comprehensive reporting has not been performed. This comprehensive article has been prepared to review the toxicity of titanium materials within the medical and dental fields.

Methods

We used online searching tools including MEDLINE (PubMed), Embase, Cochrane Library, and Google Scholar by combining keywords such as “titanium implant toxicity,” “titanium implant corrosion,” “titanium implant allergy,” and “yellow nail syndrome.” Recently updated data has been collected and compiled into one of four categories: “the toxicity of titanium,” “the toxicity of titanium alloys,” “the toxicity of titanium implants,” and “diseases related to titanium.”

Results

Recent studies with regard to titanium toxicity have been increasing and have now expanded to the medical field in addition to the fields of environmental research and basic science. Problems that may arise in titanium-based dental implants include the generation of titanium and titanium alloy particles and ions deposited into surrounding tissues due to the corrosion and wear of implants, resulting in bone loss due to inflammatory reactions, which may lead to osseointegration failure of the dental implant. These titanium ions and particles are systemically deposited and can lead to toxic reactions in other tissues such as yellow nail syndrome. Additionally, implant failure and allergic reactions can occur due to hypersensitivity reactions. Zirconia implants can be considered as an alternative; however, limitations still exist due to a lack of long-term clinical data.

Conclusions

Clinicians should pay attention to the use of titanium dental implants and need to be aware of the problems that may arise from the use of titanium implants and should be able to diagnose them, in spite of very rare occurrence. Within the limitation of this study, it was suggested that we should be aware the rare problems of titanium toxicity.

A comparison of panoramic radiography and cone beam computed tomography in the detection of osteosynthesis complications in sheep mandibular angle fractures

OBJECTIVE

The aim of this study was to compare the diagnostic efficacy of panoramic radiography (PANO) and cone beam computed tomography (CBCT) in detecting simulated complications of plate osteosynthesis applied to mandibular angle fractures (MAFs).

STUDY DESIGN

Unfavorable MAFs were created in 100 fresh sheep hemimandibles. Fractures were fixed with 4-hole titanium miniplates and screws. Bone necrosis around the screws, penetration of the screw into the inferior alveolar canal, screw loosening, and plate breakage were simulated. The diagnostic efficacy of the imaging techniques was compared by using intra- and interobserver agreement scores and area under the receiver operating characteristic curve (AUC) values. Examination time (ET), confidence scores (CS), and planar preference (PP) in CBCT evaluation were assessed.

RESULTS

Intra- and interobserver agreement scores varied between 0.61 and 0.91. AUCs for screw penetration into the inferior alveolar canal and screw loosening were significantly higher in CBCT than in PANO (P < .05). CBCT presented significantly higher ET and CS values compared with PANO (P < .05). PP showed significant differences among types of complications (P < .05).

CONCLUSIONS

PANO provided acceptable outcomes in the detection of bone necrosis and broken plates around the screw, but CBCT was more likely to enable detection of all simulated types of complications with higher confidence.

Molecular analysis of biocompatibility of anodized titanium with deposited silver nanodendrites

Titanium (>99.6% purity) and its anodically oxidized modifications, with and without deposited silver nanodendrites regarding its biocompatibility were evaluated. In human gingival fibroblasts and osteoblast cell lines grown on tested samples, the level of expression of genes encoding αV (ITGAV) and β1 (ITGB1) integrin subunits also genes encoding focal adhesion (FAK) and extracellular-signal regulated (ERK) kinases was assessed. For this purpose, the qualitative and quantitative PCR technique was used. The expression of studied genes was dependent on the origin of cell lines and the type of evaluated material. The high expression of PBGD and ITGAV genes in fibroblasts grown on the surface of anodically modified titanium with deposited silver nanodendrites indicates potentially high biocompatibility of these samples for soft tissue cells. The high expression of the ITGB1 and ERK1 genes and the enhanced expression of the FAK gene in osteoblasts cells grown on the tested material was also observed. Summarizing, the nanocrystalline Ti modified with silver deposits showed higher biocompatibility in comparison with the conventional pure Ti samples.

Effect of chemical surface treatment of titanium on its bond with dental ceramics

STATEMENT OF PROBLEM

Airborne-particle abrasion of titanium is a clinically accepted method of surface preparation. As a side effect of airborne-particle abrasion, particles of the abrasive material get embedded into the surface. How particle presence or removal from the titanium surface affects the strength of the titanium-ceramic bond is unclear.

PURPOSE

The purpose of this in vitro study was to determine the effect of removing Al₂O₃ particles embedded into the surface by means of chemical surface treatment on the strength of the titanium-ceramic bond.

MATERIAL AND METHODS

Titanium (TritanCpTi 1, Dentaurum, 99.5% Ti) disks were airborne-particle abraded with 110 μm Al₂O₃ at a pressure of 0.4 MPa and an angle of approximately 45 degrees. The surface was etched chemically using 1 of 8 reagents, and the veneering ceramic applied and fired. The strength of the metal-ceramic bond was determined using the shear strength test. Further, the effect of thermal fatigue on the bond strength was evaluated. The results were analyzed with 2-way ANOVA and the Tukey honest significant difference (HSD) test (α=.05). Fractographic investigations and microscopic tests were also performed to determine the quality of the titanium-ceramic bond.

RESULTS

Effective etching of the titanium surface and removal of Al₂O₃ particles included a 30% water solution of HNO₃ + 3% HF, a mixture of HNO₃ + HF + glycerin, a 4% solution of HF in H₂O₂, and a 4% solution of HF in H₂O. A statistically significant difference (of about 50%) in bond strength was found between the groups subjected to chemical etching and the control group (P<.05). Additionally, a statistically significant difference (about 25%) was found after thermocycling (P<.05).

CONCLUSIONS

Removing the Al₂O₃ particles embedded into the titanium surface after airborne-particle abrasion lowers the strength of the titanium-ceramic bond (P<.05). Thermocycling also weakens the strength of the titanium-ceramic bond, regardless of the surface preparation (P<.05).

Wear and Corrosion Interactions at the Titanium/Zirconia Interface: Dental Implant Application

PURPOSE

Dental implants have been shown to have predictable success, but esthetic complications often arise. To reduce tissue shadowing from titanium, zirconia abutments may be used; however, the literature suggests that the use of zirconia leads to greater destruction of the implant interface that may result in biological complications such as titanium tattoos and heavy metal toxicity. Previous studies have examined the mechanical aspects of this implant/abutment relationship, but they have not accounted for the corrosive degradation that also takes place in the dynamic environment of the oral cavity. This study investigated the combined effect of both wear and corrosion on the materials at the implant and abutment interface.

MATERIALS AND METHODS

Using a simulated oral tribocorrosive environment, titanium (Ti) and zirconia (Zr) abutment materials were slid against titanium and Roxolid implant alloys. The four couplings (Ti/Ti, Ti/Rox, Zr/Ti, Zr/Rox) were selected for the tribocorrosion tests (N = 3). The testing was conducted for 25K cycles, and the coefficient of friction (CoF) and voltage evolution were recorded simultaneously. Following the tribocorrosion assays, the wear volume loss was calculated, and surface characterization was performed. Statistical analysis was completed using a one-way ANOVA followed by post-hoc Bonferroni comparisons.

RESULTS

Zr/Ti groups had the highest CoF (1.1647), and Ti/Ti had the lowest (0.5033). The Zr/Ti coupling generated significantly more mechanical damage than the Ti/Ti group (p = 0.021). From the corrosion aspect, the Ti/Ti groups had the highest voltage drop (0.802 V), indicating greater corrosion susceptibility. In comparison, the Zr/Roxolid group had the lowest voltage drop (0.628 V) and significantly less electrochemical degradation (p = 0.019). Overall, the Ti/Ti group had the largest wear volume loss (15.1 × 10⁷ μm³ ), while the Zr/Ti group had the least volume loss (2.26 × 10⁷ μm³ ). Both zirconia couplings had significantly less wear volume than the titanium couplings (p < 0.001).

CONCLUSIONS

This study highlights the synergistic interaction between wear and corrosion, which occurs when masticatory forces combine with the salivary environment of the oral cavity. Overall, the zirconia groups outperformed the titanium groups. In fact, the titanium groups generated 5 to 6 times more wear to the implant alloys as compared with the zirconia counterparts. The best performing group was Zr/Ti, and the worst performing group was Ti/Ti.

Sandblasting and fibronectin-derived peptide immobilization on titanium surface increase adhesion and differentiation of osteoblast-like cells (MC3T3-E1)

Background/purpose

Various chemical titanium (Ti) surface modifications have been reported for enhancing cellular activities that promote early osseointegration. The purpose of this study was to determine if sandblasted Ti coated with or without fibronectin (FN) or FN-derived peptides stimulated osteoblast-like cell adhesion, spreading, proliferation, and differentiation.

Materials and methods

Osteoblast-like cells (MC3T3-E1) were cultured on sandblasted Ti disks immobilized with FN or FN-derived peptides [GRGDSP (Gly-Arg-Gly-Asp-Ser), PHSRN (Pro-His-Ser-Arg-Asn), or GRGDSP/PHSRN]. Surface topography, cell morphology, cell adhesion, cell proliferation, analysis of osteogenesis-related genes and protein expression, alkaline phosphatase, and alizarin red staining of mineralization were evaluated.

Results

The sandblasted Ti coated with FN or FN-derived peptides enhanced cell adhesion and cell proliferation. However, the Ti coated with FN or FN-derived peptides groups were similar in cell spreading. Osteogenic differentiation was observed in the peptide-modified Ti surface groups, compared with that of the noncoated Ti group. FN and GRGDSP/PHSRN coating enhanced the gene and protein expression of Runx2, osteocalcin, and bone sialoprotein. Alkaline phosphatase activity and matrix mineralization were also markedly enhanced in the Ti coated groups.

Conclusion

The sandblasted Ti coated with FN or FN-derived peptides (GRGDSP/PHSRN) markedly enhance adhesion, proliferation, and differentiation of osteoblast-like cells compared with uncoated sandblasted Ti.

A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials

In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively). IBS-R was designed as a specific cylindrical polytetrafluoroethylene (PTFE) system to evaluate attachment, proliferation and morphology of human gingival fibroblasts (HGFs) on grade V titanium and lithium disilicate glass-ceramic discs characteristics of dental prostheses. The number of cells, their covering on discs and their morphology were determined from MTS assays and microscopic fluorescent images after 24, 48 and 72 h. IBS-F was developed as a two components system to study HGFs behavior on guided bone regeneration polyester membranes. The viability and the membrane barrier effect were evaluated by metabolic MTS assays and by scanning electron microscopy. IBS-R and IBS-F were shown to promote (1) easy and rapid handling; (2) cell retention on biomaterial surface; (3) accurate evaluation of the cellular proliferation, spreading and viability; (4) use of non-toxic material. Moreover IBS-F allowed the study of the cell migration through degradable membranes, with an access to both faces of the biomaterial and to the bottom of culture wells for medium changing.