Titanium Surface Research Articles

Development of Microstructure on Titanium Implant Surface Using CO2 Laser Processing

Background: Dental biomaterials made of titanium are commonly used. It depends on the implant surface texture to improve fixation and prevent the unwanted adhesion of bone cells. This study aimed to investigate whether continuous laser beam carbon dioxide (CNC - CO2) lasers produce specific textures on titanium surfaces with micrometer-sized indentations that influence cell behavior. Materials and method: (CNC - CO2) red laser device; with a fundamental wavelength of λ=10600 nm and power pulses of 34 W were applied, and textures on the surface of titanium discs were achieved. Results: Excellent degrees of uniformity and repeatability were achieved for the desired portions of the surface by creating different surface textures. The surface topography and chemical composition of the specimens were investigated by scanning electron microscopy, electron dispersive spectroscopy, X-ray diffraction, and surface roughness measurements. Also, a laser power of 34 watts raised the surface roughness, Ra (1.71 nm), and Rz (1.99 nm). Conclusion: Titanium surface textures with unique qualities can be formed in response to an increased heat input. When excessive laser power was used, the measured roughness increased because of instantaneous re-melting. The use of a right continuous-wave (CNC - CO2) laser on titanium used in dental implants can form specific surface textures.

Microbiological and Imaging-Based Evaluations of Photodynamic Therapy Combined with Er:YAG Laser Therapy in the In Vitro Decontamination of Titanium and Zirconia Surfaces.

The oral cavity's soft and hard tissues create a conducive environment for microbial proliferation and biofilm development, facilitating the colonization of prosthodontic and implant materials such as titanium (Ti) and zirconia (Zr). This study aimed to compare the efficacy of conventional decontamination methodologies (i.e., chemical and mechanical, using 0.12% digluconate chlorhexidine (CHX) solution-treatment and airflow) to adjunctive laser-based interventions on Ti and Zr substrates inoculated with Staphylococcus (S.) aureus ATCC 25923. Additionally, this investigation sought to elucidate the impact of these treatments on temperature variations and surface integrity, analyzing the laser irradiation effects on these prevalent dental materials. Experimental configurations were delineated for both Ti and Zr samples across four groups: (1) a conventional treatment group (CV); (2) a photodynamic therapy group (PDT); (3) an Er:YAG laser treatment group (Er); (4) a combined PDT and Er:YAG treatment group (PDTEr). Also, a negative control group (C) that received no treatment was considered. The decontamination of the inoculated disc samples was evaluated by quantifying the microbial colonies in colony-forming units per milliliter (CFU/mL). Temperature variations on the surface of the samples were determined during laser treatments. Surface modifications were investigated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). For statistical analysis, Fisher 95% confidence intervals, Hsu's MCB method, and the Kruskal-Wallis test were applied. With regard to the 105 CFU/mL of the negative control group, results indicated average values equal for each study group to (1) 2.66 CFU/mL for Ti and 2 CFU/mL for Zr for the CV group; (2) 0.33 CFU/mL for Ti and 1 CFU/mL for Zr for the PDT group; (3) 1.25 CFU/mL for Ti and 0 CFU/mL for Zr for the Er group; (4), and 0 CFU/mL for both Ti and Zr for the PDTEr group. Therefore, the combined PDT and Er:YAG treatment (PDTEr) and the singular PDT modality outperformed conventional decontamination methods in eradicating S. aureus biofilms from both Ti and Zr surfaces. Notably, the PDTEr regime achieved a comprehensive elimination of microbial colonies on treated substrates. Surface examination employing OCT demonstrated discernible alterations in the surface morphology of samples subjected to Er:YAG and combined PDT and Er:YAG treatments. Temperature checks during treatments showed no major changes, suggesting the applied laser methods are safe. In conclusion, PDTEr and PDT eliminated bacteria more effectively, but Zr surfaces were more resilient, making them better for microbe-controlling applications. Also, the study demonstrated that the (less costly but lower resolution) OCT method can replace SEM for such investigations.

Formulation of silver-loaded zeolitic imidazole framework-67 and its antibacterial coating on titanium surface for bioimplant applications

Artificial bioimplant infections caused by bacteria have been a persistent problem that requires re-surgery and is harmful to human tissue. A facile, inexpensive and stable antibacterial agent coating can be a significant alternative. The present study attempted to construct titanium (Ti) implant coated with silver loaded zeolitic imidazole framework (ZIF)-67 (Ag@ZIF-67)-chitosan composite through a casting technique. The as-prepared nanocomposite and its coating were subjected to various characterization techniques, including XPS, XRD, SEM, and TEM to understand the material properties. Antibacterial activity was assessed through a standard spread-plate method, and the cytocompatibility of the fabricated materials was examined upon the skin fibroblast (L929) cell line. Corrosion studies were performed by using anodic polarization and impedance methods. The bactericidal efficacy of the coating was validated in vivo by utilizing a subcutaneous mouse model. The nanocomposite and coating exhibited a significant antibacterial efficiency of above 95 % against S. aureus and E. coli as the combined release of Co2+ and Ag+ ions entailed cellular membrane disintegration. The Ag@ZIF-67 composite revealed negligible cytotoxicity and its coating exhibited strong bone cell attachment. In contrast to pure Ti surface, the Ag@ZIF-67-chitosan coated Ti exhibited a minor reduction in corrosion resistance and modifications to its passivation properties as a result of the formation of a galvanic cell. A remarkable antibacterial effect was evinced through the in vivo experiments demonstrating a complete disinfection with 99 % of S. aureus lysis with no bacterial growth in the nearby healthy tissues. In conclusion, the current results demonstrated that the fabricated Ag@ZIF-67 could be applied as an antibacterial coating material of Ti for bioimplant applications.

On the Use of Nanoparticles in Dental Implants.

Results obtained in physics, chemistry and materials science on nanoparticles have drawn significant interest in the use of nanostructures on dental implants. The main focus concerns nanoscale surface modifications of titanium-based dental implants in order to increase the surface roughness and provide a better bone-implant interfacial area. Surface coatings via the sol-gel process ensure the deposition of a homogeneous layer of nanoparticles or mixtures of nanoparticles on the titanium substrate. Nanotubular structures created on the titanium surface by anodic oxidation yield an interesting nanotopography for drug release. Carbon-based nanomaterials hold great promise in the field of dentistry on account of their outstanding mechanical properties and their structural characteristics. Carbon nanomaterials that include carbon nanotubes, graphene and its derivatives (graphene oxide and graphene quantum dots) can be used as coatings of the implant surface. Their antibacterial properties as well as their ability to be functionalized with adequate chemical groups make them particularly useful for improving biocompatibility and promoting osseointegration. Nevertheless, an evaluation of their possible toxicity is required before being exploited in clinical trials.

Titanium surface treatments and their effects on the roughness factor

The surface pretreatment of a Ti substrate to produce metal oxide electrodes with electrocatalytic properties is of fundamental importance. The preparation of the substrate prior to the application of the coating critically affects the properties of the coating, including its surface roughness, adhesion, and corrosion resistance. In this work, different treatments were applied to the surfaces of Ti discs and their effects on surface roughness were studied. The treatments applied to Ti consisted of three stages: (1) mechanical treatment, (2) degreasing, and (3) chemical treatment. The first stage was carried out with 120 grit SiC abrasive sandpaper, the second stage was carried out with acetone (group A) or sodium hydroxide (NaOH) solution (group B), and the third stage was conducted using hydrochloric acid (HCl), oxalic acid, a mixture of hydrofluoric acid (HF)/phosphoric acid (H3PO4), or a sequence of all three chemical treatments (i.e., HCl, oxalic acid, and HF/H3PO4). The morphological properties, surface composition, and electrochemical behavior of the treated Ti discs were characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD) and cyclic voltammetry (CV) in a 0.5 M H2SO4 solution, respectively. The electroactive surface area (Aes) and roughness factor (frs) of each Ti disc were estimated from capacitance measurements of the electrochemical double layer. The morphology and voltammetric behavior of Ti varied markedly depending on the surface treatment applied. In addition, the XRD results showed that Ti surfaces subjected to different treatments exhibited different crystallographic planes. The trend in surface roughness with respect to the chemical reagent used was as follows: Group A: oxalic acid > HF/H3PO4 > global treatment > acetone > HCl; Group B: oxalic acid > HF/H3PO4 > NaOH > HCl > global treatment. The most severe chemical attack on the substrate was induced by oxalic acid, which led to the largest electroactive area and roughness factor among the treated Ti samples investigated in this study.

TNF-α-licensed exosome-integrated titaniumaccelerated T2D osseointegration by promoting autophagy-regulated M2 macrophage polarization

Type 2 diabetes (T2D) is on a notable rise worldwide, which leads to unfavorable outcomes during implant treatments. Surface modification of implants and exosome treatment have been utilized to enhance osseointegration. However, there has been insufficient approach to improve adverse osseointegration in T2D conditions. In this study, we successfully loaded TNF-α-treated mesenchymal stem cell (MSC)-derived exosomes onto micro/nano-network titanium (Ti) surfaces. TNF-α-licensed exosome-integrated titanium (TNF-exo-Ti) effectively enhanced M2 macrophage polarization in hyperglycemic conditions, with increased secretion of anti-inflammatory cytokines and decreased secretion of pro-inflammatory cytokines. In addition, TNF-exo-Ti pretreated macrophage further enhanced angiogenesis and osteogenesis of endothelial cells and bone marrow MSCs. More importantly, TNF-exo-Ti markedly promoted osseointegration in T2D mice. Mechanistically, TNF-exo-Ti activated macrophage autophagy to promote M2 polarization through inhibition of the PI3K/AKT/mTOR pathway, which could be abolished by PI3K agonist. Thus, this study established TNF-α-licensed exosome-immobilized titanium surfaces that could rectify macrophage immune states and accelerate osseointegration in T2D conditions.

The effect of surface modification strategies on biological activity of titanium implant

The surface morphology of titanium metal is an important factor affecting its hydrophilicity and biocompatibility, and exploring the surface treatment strategy of titanium metal is an important way to improve its biocompatibility . In this study , titanium (TA4) was firstly treated by large particle sand blasting and acid etching (SLA) technology, and then the obtained SLA-TA4 was treated by single surface treatments such as alkali-heat, ultraviolet light and plasma bombardment. According to the experimental results, alkali-heat treatment is the best treatment method to improve and maintain surface hydrophilicity of titanium. Then, the nanowire network morphology of titanium surface and its biological property, formed by further surface treatments on the basis of alkali-heat treatment, were investigated. Through the cell adhesion experiment of mouse embryonic osteoblast cells (MC3T3-E1), the ability of titanium material to support cell adhesion and cell spreading was investigated after different surface treatments. The mechanism of biological activity difference of titanium surface formed by different surface treatments was investigated according to the contact angle, pit depth and roughness of the titanium sheet surface. The results showed that the SLA-TA4 titanium sheet after a treatment of alkali heat for 10 h and ultraviolet irradiation for 1 h has the best biological activity and stability. From the perspective of improving surface bioactivity of medical devices, this study has important reference value for relevant researches on surface treatment of titanium implantable medical devices.

Effects of nanomodified titanium surfaces considering bacterial colonization and viability of osteoblasts and fibroblasts.

This study investigates nanostructured titanium surfaces (Ti2 spikes) that promote the viability of osteoblasts and fibroblasts and prevent bacterial colonisation. Helium ion irradiation was adopted to produce nanometric-sized cones on titanium. Human osteoblasts (hFOB) and human gingiva fibroblasts (hGF) were used for analysis. A viability and a cytotoxicity assay were conducted to evaluate the lactate dehydrogenase (LDH) activity and assess cell damage in Ti2 spikes compared to titanium discs with a sandblasted and acid-etched (Ti2 SLA) surface. The antibacterial activity was investigated against Escherichia coli, Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis. In the course of the cultivation, both hGF and hFOB demonstrated significantly reduced viability on the Ti2 spikes surface. hGF cells exhibited a slight but significant increase in LDH release. In contrast, hFOB showed reduced cytotoxicity on this surface. On the Ti2 spikes surface, hGF cells exhibited a significant reduction in gene expression of VCL, Src-1, and ITGα5. However, the integrin subunits ITGα1 and ITGα3 showed upregulation on the Ti2 spikes surface. The Ti2 spikes surface significantly increased the expression of almost all osteogenic markers. The results of conventional culturing demonstrated a statistically significant decrease in the number of viable cells for S. mutans, F. nucleaum, and greater quantities of P. gingivalis on Ti2 spikes surface compared to control. However, no such reduction was detected for E. coli. The long-term success of implants relies on establishing and maintaining hard and soft peri-implant tissues. Ti2 spikes represent a novel and promising approach to enhance osseointegration and optimize biocompatibility.

Drag increase behavior of micro-textured concave titanium surface generated by oblique laser etching

Titanium alloy has been widely used in the clinical preparation of artificial jawbone implants due to its excellent mechanical properties and biocompatibility. Artificial bone implantation drug-carrying research can realize the targeted release of drugs at the lesion, however, it is still at the technical bottleneck in inhibiting the sudden release of drugs. In this paper, based on the typical wettability model, a drug-loading and release-retarding method for artificial titanium jawbone drug-storage microcapacitor has been proposed by studying the oblique laser etching process of the inner surface of the drug-storage capsule and by investigating the resistance-enhancing mechanism of the texturization of concave surface of the inner wall. Using the oblique laser etching texture, the contact angle measurement reveals that when the laser frequency is 40KHz, the laser pulse width is 11 ns, the scanning speed is 130 mm/s, and the laser incidence angle is kept at 30° and the number of processing is one, the minimum surface contact angle can be obtained is only 8°. By combining the “3 + 2″ nanosecond laser etching device with the laser depth of focus theory, a curved surface laser etching process method was proposed. A titanium alloy jawbone with drug-carrying cavities was printed using SLM 3D printing technology, and the drag-enhancing effect of the texture was verified using sodium fluorescein labeling method, and it was found that the hydrophilic microtexture had a significant drag-enhancing effect on the liquid flow in the microfluidic channel.

Preliminary Evaluation of Bioactive Collagen-Polyphenol Surface Nanolayers on Titanium Implants: An X-ray Photoelectron Spectroscopy and Bone Implant Study.

To endow an implant surface with enhanced properties to ensure an appropriate seal with the host tissue for inflammation/infection resistance, next-generation bone implant collagen-polyphenol nanolayers were built on conventional titanium surfaces through a multilayer approach. X-ray Photoelectron Spectroscopy (XPS) analysis was performed to investigate the chemical arrangement of molecules within the surface layer and to provide an estimate of their thickness. A short-term (2 and 4 weeks) in vivo test of bone implants in a healthy rabbit model was performed to check possible side effects of the soft surface layer on early phases of osteointegration, leading to secondary stability. Results show the building up of the different nanolayers on top of titanium, resulting in a final composite collagen-polyphenol surface and a layer thickness of about 10 nm. In vivo tests performed on machined and state-of-the-art microrough titanium implants do not show significant differences between coated and uncoated samples, as the surface microroughness remains the main driver of bone-to-implant contact. These results confirm that the surface nanolayer does not interfere with the onset and progression of implant osteointegration and prompt the green light for specific investigations of the potential merits of this bioactive coating as an enhancer of the device/tissue seal.

Influence of Current Duty Cycle and Voltage of Micro-Arc Oxidation on the Microstructure and Composition of Calcium Phosphate Coating

The micro-arc oxidation (MAO) technique was employed to produce calcium phosphate coatings on titanium surfaces using an electrolyte composed of hydroxyapatite and calcium carbonate in an aqueous solution of orthophosphoric acid. The coatings’ morphology and composition were regulated by adjusting electrical parameters, specifically the duty cycle and voltage. This study examined the effects of the duty cycle and voltage during the MAO process on the microstructure and composition of calcium phosphate coatings on VT1–0 titanium substrates. Scanning electron microscopy (SEM) was utilized to analyze the microstructure and thickness of the coatings, while X-ray diffraction (XRD) was employed to determine their phase composition. The findings reveal that the surface morphology of the calcium phosphate coatings transitions from a porous, sponge-like structure to flower-like formations as the duty cycle and voltage increase. A linear increase in the voltage within the applied duty cycles led to a rise in the size of the forming particles of amorphous/crystalline structures containing phases of monetite (CaPO3(OH)), monocalcium phosphate monohydrate (Ca(H2PO4)2·H2O), and calcium pyrophosphate (γ–Ca2P2O7).

Enhanced Antibacterial Properties of Titanium Surfaces through Diversified Ion Plating with Silver Atom Deposition.

In this study, we investigate the antibacterial effect of silver atoms implanted into a thin surface layer of titanium at low energies using an alternative ion plating technology called Diversified Ion Plating. Silver atoms were incorporated into titanium samples using reactive low-voltage ion plating at 2 keV and 4 keV. Surface modifications and morphology were evaluated using wettability, profilometry measurements, and energy-dispersive spectroscopy. For a precise determination of the quantity and depth of implanted silver atoms on titanium surfaces, a combination of experimental techniques such as Rutherford Backscattering Spectrometry along with Monte Carlo simulations were utilized. To assess the antibacterial effects of the silver atoms incorporated into pure titanium surfaces, bacterial suspension immersion tests were performed with a standard strain of Staphylococcus aureus (ATCC 12600). The outcomes indicate that titanium surfaces implanted with silver atoms were more effective in inhibiting the growth of Staphylococcus aureus than pure titanium surfaces. Better results were found when the deposition was performed at 4 keV, indicating that a deeper implantation of silver, spanning a few nanometers, can result in a longer and more effective release of silver atoms. These findings suggest the potential for the development of new, cost-effective biomaterials, paving the way for improved implant materials in various health-related applications.

The Effect of Implantoplasty on the Fatigue Behavior and Corrosion Resistance in Titanium Dental Implants.

Implantoplasty is a technique increasingly used to remove the biofilm that causes peri-implantitis on dental implants. This technique of mechanization of the titanium surface makes it possible to eliminate bacterial colonies, but it can generate variations in the properties of the implant. These variations, especially those in fatigue resistance and electrochemical corrosion behavior, have not been studied much. In this work, fatigue tests were performed on 60 dental implants without implantoplasty, namely 30 in air and 30 in Hank's solution at 37 °C, and 60 with implatoplasty, namely 30 in air and 30 in Hank's solution at 37 °C, using triaxial tension-compression and torsion stresses simulating human chewing. Mechanical tests were performed with a Bionix servo-hydraulic testing machine and fracture surfaces were studied by scanning electron microcopyElectrochemical corrosion tests were performed on 20 dental implants to determine the corrosion potentials and corrosion intensity for control implants and implantoplasty implants. Studies of titanium ion release to the physiological medium were carried out for each type of dental implants by Inductively Coupled-Plasma Mass Spectrometry at different immersion times at 37 °C. The results show a loss of fatigue caused by the implantoplasty of 30%, observing that the nucleation points of the cracks are in the areas of high deformation in the areas of the implant neck where the mechanization produced in the treatment of the implantoplasty causes an exaltation of fatigue cracks. It has been observed that tests performed in Hank's solution reduce the fatigue life due to the incorporation of hydrogen in the titanium causing the formation of hydrides that embrittle the dental implant. Likewise, the implantoplasty causes a reduction of the corrosion resistance with some pitting on the machined surface. Ion release analyses are slightly higher in the implantoplasted samples but do not show statistically significant differences. It has been observed that the physiological environment reduces the fatigue life of the implants due to the penetration of hydrogen into the titanium forming titanium hydrides which embrittle the implant. These results should be taken into account by clinicians to determine the convenience of performing a treatment such as implantoplasty that reduces the mechanical behavior and increases the chemical degradation of the titanium dental implant.

NP-12 peptide functionalized nanoparticles counteract the effect of bacterial lipopolysaccharide on cultured osteoblasts

ObjectiveTo evaluate whether nanoparticles (NPs) functionalized with Tideglusib (TDg, NP-12), and deposited on titanium surfaces, would counteract the effect of bacterial lipopolysaccharide (LPS) on osteoblasts. MethodsExperimental groups were: (a) Titanium discs (TiD), (b) TiD covered with undoped NPs (Un-NPs) and (c) TiD covered with TDg-doped NPs (TDg-NPs). Human primary osteoblasts were cultured onto these discs, in the presence or absence of bacterial LPS. Cell proliferation was assessed by MTT-assay and differentiation by measuring the alkaline phosphatase activity. Mineral nodule formation was assessed by the alizarin red test. Real-time quantitative polymerase chain reaction was used to study the expression of Runx-2, OSX, ALP, OSC, OPG, RANKL, Col-I, BMP-2, BMP-7, TGF-β1, VEGF, TGF-βR1, TGF-βR2, and TGF-βR3 genes. Osteoblasts morphology was studied by Scanning Electron Microscopy. One-way ANOVA or Kruskal-Wallis and Bonferroni multiple comparisons tests were carried out (p < 0.05). ResultsTDg-NPs enhanced osteoblasts proliferation. Similarly, this group increased ALP production and mineral nodules formation. TDg-NPs on titanium discs resulted in overexpression of the proliferative genes, OSC and OSX, regardless of LPS activity. In the absence of LPS, TDg-NPs up-regulated Runx2, COL-I, ALP, BMP2 and BMP7 genes. OPG/RANKL gene ratios were increased about 2500 and 4,000-fold by TDg-NPs, when LPS was added or not, respectively. In contact with the TDg-NPs osteoblasts demonstrated an elongated spindle-shaped morphology with extracellular matrix production. SignificanceTDg-NPs on titanium discs counteracted the detrimental effect of LPS by preventing the decrease on osteoblasts proliferation and mineralization, and produced an overexpression of proliferative and bone-promoting genes on human primary osteoblasts.

Size-Dependent Effect of Titania Nanotubes on Endoplasmic Reticulum Stress to Re-establish Diabetic Macrophages Homeostasis.

In patients with diabetes, endoplasmic reticulum stress (ERS) is a crucial disrupting factor of macrophage homeostasis surrounding implants, which remains an obstacle to oral implantation success. Notably, the ERS might be modulated by the implant surface morphology. Titania nanotubes (TNTs) may enhance diabetic osseointegration. However, a consensus has not been achieved regarding the tube-size-dependent effect and the underlying mechanism of TNTs on diabetic macrophage ERS. We manufactured TNTs with small (30 nm) and large diameters (100 nm). Next, we assessed how the different titanium surfaces affected diabetic macrophages and regulated ERS and Ca2+ homeostasis. TNTs alleviated the inflammatory response, oxidative stress, and ERS in diabetic macrophages. Furthermore, TNT30 was superior to TNT100. Inhibiting ERS abolished the positive effect of TNT30. Mechanistically, topography-induced extracellular Ca2+ influx might mitigate excessive ERS in macrophages by alleviating ER Ca2+ depletion and IP3R activation. Furthermore, TNT30 attenuated the peri-implant inflammatory response and promoted osseointegration in diabetic rats. TNTs with small nanodiameters attenuated ERS and re-established diabetic macrophage hemostasis by inhibiting IP3R-induced ER Ca2+ depletion.

In vitro evaluation of surface roughness of titanium abutments after air polishing with different abrasive powders

AbstractObjectivesThe purpose of this study was to evaluate the effects of air polishing with sodium bicarbonate and erythritol powders on surface roughness and morphological changes in titanium abutments.MethodsA total of 45 grade V titanium discs were divided in three groups: Group A (Control) air polished with air/water; Group B, air polished with sodium bicarbonate powder; and Group C, air polished with erythritol powder. After air polishing, the samples' roughness (Sa) in micrometres were analysed with an optical profilometer. The samples' surface morphology study was conducted via scanning electronic microscope (SEM). Data were described using mean and standard deviation of roughness values (Sa). Inferential analysis was performed using the ANOVA multiple comparison test followed by Tukey's post hoc test. Both tests used a 5% level of significance.ResultsAfter air polishing, average roughness of group A, B and C were 0.036, 0.046 and 0.037 μm, respectively, with statistically significant differences between groups A and B (p &lt; 0.05). No statistically significant differences were found between group A and group C, as well as between group B and C (p &gt; 0.05). As for the morphology analysis, damages to the titanium surface were only observed in group B.ConclusionsThe study indicates that air polishing with erythritol powder maintains titanium abutment integrity better than sodium bicarbonate, which increased surface roughness and caused damage. Erythritol is preferable for minimizing surface alterations and maintaining morphological stability.

Injectable Platelet-Rich Fibrin and Advanced Platelet-Rich Fibrin Demonstrate Enhanced Anti-Biofilm Effect Compared to Enamel Matrix Derivatives on Decontaminated Titanium Surfaces.

The search for effective antimicrobial agents to mitigate peri-implant infections remains a crucial aspect of implant dentistry. This study aimed to evaluate and compare the antimicrobial efficacy of i-PRF, A-PRF+, and enamel matrix derivative (EMD) on decontaminated rough and smooth titanium (Ti) discs. Rough and smooth Ti discs were coated with multispecies biofilm and thoroughly debrided using a chitosan-bristled brush. Subsequently, i-PRF, A-PRF+, and EMD were applied. Untreated discs served as control. Residual adherent bacteria present on the treated Ti discs were visualized by SEM and quantified using culture technique, and colony-forming units (CFUs) were measured after 48 h and 7 days. i-PRF demonstrated better antimicrobial effectiveness on both smooth and rough implant surfaces as compared to A-PRF+ and EMD (p < 0.001). In all the experimental groups, smooth Ti discs displayed a greater reduction in microbes compared to rough Ti discs when treated with the biologics. The major reduction in CFU values was determined after seven days. i-PRF as a regenerative material may also be suitable for decontaminating implant surfaces, which could influence tissue healing and regenerative outcomes positively.

Cascade catalysis nanozyme for interfacial functionalization in combating implant infections associated with diabetes via sonodynamic therapy and adaptive immune activation

Innovative solutions are required for the intervention of implant associated infections (IAIs), especially for bone defect patients with chronic inflammatory diseases like diabetes mellitus (DM). The complex immune microenvironment of infections renders implants with direct antibacterial ability inadequate for the prolonged against of bacterial infections. Herein, a synergistic treatment strategy was presented that combined sonodynamic therapy (SDT) with adaptive immune modulation to treat IAIs in diabetes patients. A multifunctional coating was created on the surface of titanium (Ti) implants, consisting of manganese dioxide nanoflakes (MnO2 NFs) with cascade catalytic enzyme activity and a responsive degradable hydrogel containing a sonosensitizer. The reactive oxygen species (ROS) generated by glucose-hydrogen peroxide (H2O2) cascade catalysis and ultrasound (US) activation sonosensitizer helped kill bacteria and release bacterial antigens. Meanwhile, Mn2+ facilitated dendritic cells (DCs) maturation, enhancing antigen presentation to activate both cellular and humoral adaptive immunity against bacterial infections. This approach effectively eliminated bacteria in established diabetic IAIs model and activated systemic antibacterial immunity, providing long-term antibacterial protection. This study presents a non-antibiotic immunotherapeutic strategy for fighting IAIs in chronic diseases.

Alendronate as Bioactive Coating on Titanium Surfaces: An Investigation of CaP-Alendronate Interactions.

The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the bioactivity and osseointegration properties are strongly dependent on the physicochemical properties of the implant surface. A surface coating with bioactive molecules that stimulate the formation of a mineral calcium phosphate (CaP) layer has a positive effect on the bone bonding process, as biomineralization is crucial for improving the osseointegration process and rapid bone ingrowth. In this work, the spontaneous deposition of calcium phosphate on the titanium surface covered with chemically stable and covalently bound alendronate molecules was investigated using an integrated experimental and theoretical approach. The initial nucleation of CaP was investigated using quantum chemical calculations at the density functional theory (DFT) level. Negative Gibbs free energies show a spontaneous nucleation of CaP on the biomolecule-covered titanium oxide surface. The deposition of calcium and phosphate ions on the alendronate-modified titanium oxide surface is governed by Ca2+-phosphonate (-PO3H) interactions and supported by hydrogen bonding between the phosphate group of CaP and the amino group of the alendronate molecule. The morphological and structural properties of CaP deposit were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. This integrated experimental-theoretical study highlights the spontaneous formation of CaP on the alendronate-coated titanium surface, confirming the bioactivity ability of the alendronate coating. The results provide valuable guidance for the promising forthcoming advancements in the development of biomaterials and surface modification of dental implants.

Cementum and enamel surface mimicry influences soft tissue cell behavior.

To test whether titanium surface roughness disparity might be used to specifically guide the behavior of gingiva fibroblasts and keratinocytes, thereby improving the quality of soft tissue (ST) integration around abutments. Titanium discs resembling the roughness of enamel (M) or cementum (MA) were created with normal or increased hydrophilicity and used as substrates for human fibroblasts and keratinocytes. Adhesion and proliferation assays were performed to assess cell-type specific responses upon encountering the different surfaces. Additionally, immunofluorescence and qPCR analyses were performed to study more in depth the behavior of fibroblasts and keratinocytes on MA and M surfaces, respectively. While enamel-like M surfaces supported adhesion, growth and a normal differentiation potential of keratinocytes, cementum-emulating MA surfaces specifically impaired the growth of keratinocytes. Vice versa, MA surfaces sustained regular adhesion and proliferation of fibroblasts. Yet, a more intimate adhesion between fibroblasts and titanium was achieved by an increased hydrophilicity of MA surfaces, which was associated with an increased expression of elastin. The optimal titanium implant abutment might be achieved by a bimodal roughness design, mimicking the roughness of enamel (M) and cementum with increased hydrophilicity (hMA), respectively. These surfaces can selectively elicit cell responses favoring proper ST barrier by impairing epithelial downgrowth and promoting firm adhesion of fibroblasts.