Crystallographic plane-induced selective mineralization of nanohydroxyapatite on fibrous-grained titanium promotes osteointegration and biocorrosion resistance.

The (002) crystallographic plane-oriented hydroxyapatite (HA) and anatase TiO2 enable favorable hydrophilicity, osteogenesis, and biocorrosion resistance. Thus, the crystallographic plane control in HA coating and crystalline phase control in TiO2 is vital to affect the surface and interface bioactivity and biocorrosion resistance of titanium (Ti) implants. However, a corresponding facile and efficient fabrication method is absent to realize the HA(002) mineralization and anatase TiO2 formation on Ti. Herein, we utilized the predominant Ti(0002) plane of the fibrous-grained titanium (FG Ti) to naturally form anatase TiO2 and further achieve a (002) basal plane oriented nanoHA (nHA) film through an in situ mild hydrothermal growth strategy. The formed FG Ti-nHA(002) remarkably improved hydrophilicity, mineralization, and biocorrosion resistance. Moreover, the nHA(002) film reserved the microgroove-like topological structure on FG Ti. It could enhance osteogenic differentiation through promoted contact guidance, showing one order of magnitude higher expression of osteogenic-related genes. On the other hand, the nHA(002) film restrained the osteoclast activity by blocking actin ring formation. Based on these capacities, FG Ti-nHA(002) improved new bone growth and binding strength in rabbit femur implantation, achieving satisfactory osseointegration within 2 weeks.

Preparation and characterization of mesoporous HA coating with paclitaxel loaded lignin nanospheres on titanium surface.

Background: Primary malignant bone tumor is a disease that can lead to death. The usually applied clinical treatment strategy is surgical resection of the primary tumor. However, tumor cells are difficult to clean up, easy to make the tumor recurrence, and the bone defect caused by surgical resection also hindered the postoperative recovery. Materials and methods: Herein, in this work, mesoporous hydroxyapatite (HA) coating with petal-structure was prepared on titanium (Ti) implant surfaces by micro-arc oxidation (MAO) to accelerate the bone growth, and then paclitaxel (PTX) loaded lignin nanospheres were deposited into the HA coatings to get a sustained release for killing residual tumor cells. Results: The results showed that many gaps and holes of micro-scale were formed in the petal-structured HA coatings, they worked as traps for the PTX loaded nanospheres to enhance the deposited amount and immobilization stability, playing good role of drug loading platform. The encapsulation of PTX by lignin ensured a lower release rate and a higher sustaining release time when compared with the PTX without encapsulation. In addition, the HA coating with PTX loaded lignin nanospheres showed higher killing effect to tumor cells than to osteoblast. Conclusion: The mesoporous HA coating with paclitaxel loaded lignin nanospheres endowed the titanium surface with good biological property and tumor cell-killing effect, so the obtained Ti-based material had a highly hopeful application as the localized implant for therapy of primary malignant bone tumor.

Silver-quercetin-loaded honeycomb-like Ti-based interface combats infection-triggered excessive inflammation via specific bactericidal and macrophage reprogramming.

Excessive inflammation caused by bacterial infection is the primary cause of implant failure. Antibiotic treatment often fails to prevent peri-implant infection and may induce unexpected drug resistance. Herein, a non-antibiotic strategy based on the synergy of silver ion release and macrophage reprogramming is proposed for preventing infection and bacteria-induced inflammation suppression by the organic-inorganic hybridization of silver nanoparticle (AgNP) and quercetin (Que) into a polydopamine (PDA)-based coating on the 3D framework of porous titanium (SQPdFT). Once the planktonic bacteria (e.g., Escherichia coli, Staphylococcus aureus) reach the surface of SQPdFT, released Que disrupts the bacterial membrane. Then, AgNP can penetrate the invading bacterium and kill them, which further inhibits the biofilm formation. Simultaneously, released Que can regulate macrophage polarization homeostasis via the peroxisome proliferators-activated receptors gamma (PPARγ)-mediated nuclear factor kappa-B (NF-κB) pathway, thereby terminating excessive inflammatory responses. These advantages facilitate the adhesion and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs), concomitantly suppressing osteoclast maturation, and eventually conferring superior mechanical stability to SQPdFT within the medullary cavity. In summary, owing to its excellent antibacterial effect, immune remodeling function, and pro-osteointegration ability, SQPdFT is a promising protective coating for titanium-based implants used in orthopedic replacement surgery.

Ti3+/Ti4+ and Co2+/Co3+ redox couples in Ce-doped Co-Ce/TiO2 for enhancing photothermocatalytic toluene oxidation.

Cerium and cobalt loaded Co-Ce/TiO2 catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation. Based on catalyst characterizations (XPS, EPR and H2-TPR), redox cycle between Co and TiO2 (Co2+ + Ti4+ ↔ Co3+ + Ti3+) results in the formation of Co3+, Ti3+ and oxygen vacancies, which play important roles in toluene catalytic oxidation reaction. The introduction of Ce brings in the dual redox cycles (Co2+ + Ti4+ ↔ Co3+ + Ti3+, Co2+ + Ce4+ ↔ Co3+ + Ce3+), further promoting the elevation of reaction sites amount. Under full spectrum irradiation with light intensity of 580 mW/cm2, Co-Ce/TiO2 catalyst achieved 96% of toluene conversion and 73% of CO2 yield, obviously higher than Co/P25 and Co/TiO2. Co-Ce/TiO2 efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination. Photothermal catalytic reaction displays improved activities compared with thermal catalysis, which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.

Dynamic analysis of a NiTi rotary file by using finite element analysis: Effect of cross-section and pitch length.

This study assessed stress distribution, maximum stress values and fatigue life of experimentally designed NiTi rotary files with different cross-sectional geometry and pitch length using finite element analysis (FEA). Four cross-sectional shapes (Convex triangle, S-shaped, Triple helix and Concave triangle) and two pitch lengths (2 mm and 3 mm) were tested in simulated root canals with curvatures of 30°, 45° and 60°. The FEA results indicated that convex triangle and triple helix geometries exhibited lower stress values compared to the S-shaped and concave triangle designs. Increasing the canal curvature angle resulted in higher stress values, with the S-shaped instrument showing the most significant increase (up to 12%). Instruments with shorter pitch lengths showed more even stress distribution enhancing fatigue life. The maximum stress was concentrated 5-8 mm from the tip, varying across cutting edges, with S-shaped sections experiencing the lowest forces but higher stress due to lower moments of inertia.

Titanium Cages vs PEEK Cages in Interbody Fusions: A Meta-Analysis of Clinical and Radiographic Outcomes.

BACKGROUND: The most widely adopted materials for interbody fusion implants are titanium and polyetheretherketone (PEEK), both of which have their potential advantages and disadvantages. Despite the differences between PEEK and titanium, there is no consensus on which material provides better clinical and radiological outcomes. Therefore, the purpose of this meta-analysis is to analyze the clinical and radiographic outcomes between the two cages. METHODS: Four databases (PubMed, Cochrane, Embase and Google Scholar (page 1-20)) were queried since December 2001 up until December 2023,. The clinical outcomes evaluated included the rates of adverse events, radiographic outcomes, and PROs. RESULTS: Higher rates of subsidence and revision were reported in PEEK cages in the lumbar spine (p=0.0006, and p=0.006 respectively). In the cervical spine, no difference was observed between PEEK and titanium in any analysis. CONCLUSION: In the lumbar spine, titanium cages were shown to have a lower rate of subsidence and revision compared to PEEK. As for the cervical spine, the difference between cages did not reach statistical significance in any of the analyzed outcomes.

Effect of Cage Material and Size on Fusion Rate and Subsidence Following Biportal Endoscopic Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: Biportal endoscopic transforaminal lumbar interbody fusion (BE-TLIF) is an emerging, minimally invasive technique performed under biportal endoscopic guidance. However, concerns regarding cage subsidence and sufficient fusion during BE-TLIF necessitate careful selection of an appropriate interbody cage to improve surgical outcomes. This study compared the fusion rate, subsidence, and other radiographic parameters according to the material and size of the cages used in BE-TLIF. METHODS: In this retrospective cohort study, patients who underwent single-segment BE-TLIF between April 2019 and February 2023 were divided into 3 groups: group A, regular-sized three-dimensionally (3D)-printed titanium cages; group B, regular-sized polyetheretherketone cages; and group C, large-sized 3D-printed titanium cages. Radiographic parameters, including lumbar lordosis, segmental lordosis, anterior and posterior disc heights, disc angle, and foraminal height, were measured before and after surgery. The fusion rate and severity of cage subsidence were compared between the groups. RESULTS: No significant differences were noted in the demographic data or radiographic parameters between the groups. The fusion rate on 1-year postoperative computed tomography was comparable between the groups. The cage subsidence rate was significantly lower in group C than in group A (41.9% vs. 16.7%, p=0.044). The severity of cage subsidence was significantly lower in group C (0.93±0.83) than in groups A (2.20±1.84, p=0.004) and B (1.79±1.47, p=0.048). CONCLUSION: Cage materials did not affect the 1-year postoperative outcomes of BE-TLIF; however, subsidence was markedly reduced in large cages. Larger cages may provide more stable postoperative segments.

The enhanced antibacterial and antibiofilm properties of titanium dioxide nanoparticles biosynthesized by multidrug-resistant Pseudomonas aeruginosa.

The emergence of Multidrug-resistant (MDR) bacteria are becoming a major worldwide health concern, encouraging the development effective alternatives to conventional antibiotics. The study identified P. aeruginosa and assessed its antimicrobial sensitivity using the Vitek-2 system. Carbapenem-resistant genes were detected through Polymerase chain reaction (PCR). MDR- P. aeruginosa isolates were used to biosynthesize titanium dioxide nanoparticles (TiO2NPs) and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM). A study involving 78 P. aeruginosa isolates revealed that 85.8% were MDR, with meropenem and amikacin showing effectiveness against 70% of the isolates. The most prevalent carbapenemase gene was blaOXA-48, present in 83% of the isolates. Majority of the isolates formed biofilms, and biosynthesized TiO2NPs were able to reduce biofilm formation by 94%. TiO2NPs exhibited potent antibacterial action against MDR-Gram-negative bacilli pathogens and showed synergistic activity with antibiotics, particularly piperacillin, with a significant fold increase in areas (283%). A new local strain of P. aeruginosa, identified as ON678251 in the World GenBank, was found capable of producing TiO2NPs. Our findings demonstrate the potential of biosynthesized TiO2NPs to manage antibiotic resistance and regulate the formation of biofilms. This presents a promising direction for the creation of novel antimicrobial agents or substitutes for use in clinical settings, particularly in the management of isolates capable of resisting multiple drugs.

Three-dimensional printed titanium chest wall reconstruction for tumor removal in the sternal region.

Resection of thoracic wall tumors results in significant defects in the chest wall, leading to various complications. In recent years, the use of three-dimensional (3D) printed titanium alloy prostheses in clinical practice has demonstrated enhanced outcomes in chest wall reconstruction surgery. A cohort of seven patients with sternal tumors was identified for this study. Following a helical CT scan, a digital model was generated for the design of the prosthesis. Subsequently, the tumors were then removed together with the affected sternum and ribs. The chest wall was then reconstructed using 3D-printed titanium alloy prosthesis for bone reconstruction, mesh for pleural reconstruction, and flap for soft tissue reconstruction. Patients were monitored for a period of one year post-surgery. In the seven cases examined, the tumors were found in various locations with varying degrees of invasion. Based on the scope of surgical resection and the size of the defect, 3D-printed titanium alloy prosthesis was custom-designed for chest wall reconstruction. Prior to bone reconstruction, pleural reconstruction was achieved with Bard Composix E/X Mesh, while soft tissue repair involved muscle flap and musculocutaneous flap procedures. A one-year follow-up assessment revealed that the utilization of the 3D-printed titanium alloy prosthesis led to secure fixation, favorable histocompatibility, and enhanced lung function. The findings demonstrate that the utilization of 3D printed titanium alloy prostheses represents a significant advancement in the field of chest wall reconstruction and thoracic surgical procedures.

Enhanced adsorption-photodegradation of tetracycline using Ce-N-co-doped AC/TiO2 photocatalyst: isotherms, kinetics, mechanism, and thermodynamic insight.

Excessive use of tetracycline (TC) is alarming owing to its increased detection in water systems. In this study, a photocatalyst was developed to degrade TC using a Ce-N-co-doped AC/TiO2 photocatalyst, denoted as Ce/N-AC/TiO2, prepared using the sol-gel method assisted by microwave radiation, speeding up the synthesis process. Ce/N-AC/TiO2 achieved maximum TC degradation of 93.1% under UV light with optimum sorption system conditions of an initial concentration of 10 mg L-1, pH 7, and 30 ℃, under 120 min. Scavenger experiments revealed that holes and superoxide radicals were the active species influencing the photodegradation process. The TC degradation was appropriately fitted with Langmuir isotherms and a pseudo-second-order (PSO) kinetic model. The change in enthalpy (ΔH) (2.43 kJ mol-1), entropy (ΔS) (0.024 kJ mol-1), and Gibbs free energy (ΔG) (- 4.941 to - 5.802 kJ mol-1) suggested that the adsorption process was spontaneous, favourable, and endothermic. Electrostatic interaction, hydrogen bonding, pore-filling, cationic-π, n-π, and π-π interaction were among the interactions involved between TC and Ce/N-AC/TiO2. Furthermore, Ce/N-AC/TiO2 stability was confirmed through 80% removal efficiency even after the fifth reuse cycle. Notably, this work provides new insight into the production of efficient, reusable, and enhanced photocatalysts using a rapid and cost-effective microwave-assisted synthesis process for pollutant remediation.

Evaluation of Nickel and Titanium Releasing from Titanium-coated Stainless Steel Crowns Regarding Trimming: An In Vitro Study.

Introduction: Stainless steel crowns (SSCs) are the most durable and effective restorations for primary teeth. Titanium-coated SSCs are newer on the market, and this study was conducted to assess the amount of nickel (Ni) and titanium ions released from titanium-coated SSCs, with and without trim, in artificial saliva. Materials and methods: A total of 60 titanium-coated SSCs were divided into two groups-group I (n = 30, without trim) and group II (n = 30, with trim) and were immersed in 5 mL artificial saliva. The amount of Ni and titanium released in each group was measured by inductively coupled plasma-mass spectrometry on days 1, 7, and 21. Results: The amount of Ni ion released in group I on day 1 was 0.0096 ppm and reduced on day 7 (0.0091 ppm) and day 21 (0.0088 ppm). Whereas the amount of Ni ion released in group II was the same for all 3 days (0.0096 ppm). The amount of titanium ion released in both groups was the same on all 3 days (0.00108 ppm). Conclusion: There was no significant difference seen in the mean Ni and titanium ion release between the two groups on all 3 days. The cumulative release of metals from titanium-coated SSCs in each of the groups was significantly lower than the level required to produce any harmful effects. Any of the groups of commercially available SSCs can be used in pediatric dentistry. How to cite this article: Biradar R, Siaddaiah SB, Bhat PK. Evaluation of Nickel and Titanium Releasing from Titanium-coated Stainless Steel Crowns Regarding Trimming: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(5):524-527.

Impact of instrumentation material on local recurrence: a case-matched series using carbon fiber-PEEK vs. titanium.

PURPOSE: Spine metastases are a major burden of oncologic care, contributing to substantial morbidity. A well-established treatment paradigm for patients with metastatic epidural spinal cord compression includes separation surgery followed by stereotactic body radiotherapy (SBRT). Innovations in implant technology have brought about the incorporation of Carbon fiber-reinforced polyetheretherketone (CFR-PEEK) instrumentation for spinal fixation. We present our experience of CFR-PEEK instrumentation, comparing outcomes and complication profiles with a matched cohort of titanium instrumented cases for spine metastatic disease. METHODS: Oncology patients who underwent spinal fusion for metastatic spine disease from 2012 to 2023 were retrospectively reviewed. Ninety-nine cases with CFR-PEEK fusions were case-control matched with 50 titanium controls (2:1 ratio) based upon primary tumor type and spinal instability neoplastic score (SINS) location. Demographic, clinical, radiographic and progression free survival (PFS) were analyzed. RESULTS: In the study years, 263 patients underwent spinal decompression and fusion, for which 148 patients met predetermined inclusion criteria. Of these, 49 had titanium instrumentation, and 99 had CFR-PEEK. Complication profiles, including hardware failure and infection were similar between the groups. There was no significant difference in PFS between all CFR-PEEK and titanium patients (143 days versus 214 days; p = 0.41). When comparing patients in which recurrence was noted, CFR-PEEK patients had recurrence detected two times earlier than titanium patients (94 days versus 189 days; p = 0.013). CONCLUSION: In this case matched cohort, CFR-PEEK demonstrated decreased overall PFS suggestive of earlier local recurrence identification. Long-term studies are warranted for better evaluation of the impact on survival and systemic disease progression.

The impact of collagen membrane fixation protocols on volume stability in horizontal ridge augmentation in the aesthetic area: A retrospective study.

OBJECTIVES: This study aimed to evaluate the impact of different collagen membran fixation protocols on the volume stability in horizontal ridge augmentation in the aesthetic area. METHODS: A total of 48 patients with 65 augmented sites were included in this study. Implants were placed in the aesthetic region, and simultaneous guided bone regeneration (GBR) surgery was performed for horizontal ridge augmentation. Participants were divided into four groups, each comprising 12 patients, based on different absorbable collagen membrane fixation protocols. Group 1: without fixation; Group 2: fixation with absorbable sutures; Group 3: fixation with titanium pins; Group 4: fixation with titanium pins and absorbable sutures. Cone beam computed tomography (CBCT) was performed immediately after surgery and at 6 months post-surgery, respectively. The horizontal thickness of the augmented region was analyzed for volume stability at the implant shoulder (H0) and 1-5 mm apical to the implant shoulder (H1-H5). Changes in labial thickness during bone healing were calculated as absolute values (mm) and relative values (%). RESULTS: After 6 months of bone healing, horizontal thickness was significantly reduced at all levels (H0-H5) in all groups compared to immediate post-surgery results (p < 0.05). At H1-H5, horizontal bone loss in group 1 was significantly higher than in the other three groups (p < 0.05). Group 4 exhibited significantly less horizontal bone loss compared to group 2 at H0-H2 (p < 0.05) and group 4 compared to group 3 at H0-H1 (p < 0.05). No significant difference in horizontal bone loss between groups 2 and 3 was detected at H0-H5 (p > 0.05). CONCLUSION: Guided bone regeneration in the aesthetic area with additional membrane fixation demonstrated superior volume stability of the augmented region compared to cases without fixation. There was no significant difference in bone volume stability between membrane fixation with titanium pins and fixation with absorbable sutures. However, the combined use of pins and absorbable sutures yielded superior volume stability.

Antibacterial and cytocompatible silver coating for titanium Boston Keratoprosthesis.

The Boston Keratoprosthesis (BKPro) serves as a medical solution for restoring vision in complex cases of corneal blindness. Comprising a front plate made of polymethylmethacrylate (PMMA) and a back plate of titanium (Ti), this device utilizes the beneficial biomaterial properties of Ti. While BKPro demonstrates promising retention rates, infection emerges as a significant concern that impacts its long-term efficacy. However, limited research exists on enhancement of BKPros through intrinsic infection-preventing mechanisms. In this regard, metal ions, especially the well-known Ag+ ions, are a promising alternative to obtain implants with innate antibacterial properties. However, little information is available about the effects of Ag in corneal tissue, especially within human corneal keratocytes (HCKs). In this work, an electrodeposition treatment using a constant pulse is proposed to attach Ag complexes onto rough Ti surfaces, thus providing antibacterial properties without inducing cytotoxicity. Complete physicochemical characterization and ion release studies were carried out with both control and Ag-treated samples. The possible cytotoxic effects in the short and long term were evaluated in vitro with HCKs. Moreover, the antibacterial properties of the silver-treated surfaces were tested against the gram-negative bacterial strain Pseudomonas aeruginosa and the gram-positive strain Staphylococcus epidermidis, that are common contributors to infections in BKPros. Physicochemical characterization confirmed the presence of silver, predominantly in oxide form, with low release of Ag+ ions. Ag-treated surfaces demonstrated no cytotoxicity and promoted long-term proliferation of HCKs. Furthermore, the silver-treated surfaces exhibited a potent antibacterial effect, causing a reduction in bacterial adhesion and evident damage to the bacterial cell walls of P. aeruginosa and S. epidermidis. The low release of Ag+ ions suggested reactive oxygen species (ROS)-mediated oxidative stress imbalance as the bactericidal mechanism of the silver deposits. In conclusion, the proposed electrodeposition technique confers antibacterial protection to the Ti backplate of BKPro, mitigating implant-threatening infections while ensuring non-cytotoxicity within the corneal tissue.

Vacancy-Induced Symmetry Breaking in Titanium Dioxide Boosts the Photocatalytic Hydrogen Production from Methanol Aqueous Solution.

The key to optimizing photocatalysts lies in the efficient separation and oriented migration of the photogenerated carriers. Herein, we report that breaking continuous TiO6 tetragonal (D4h) symmetry in titanium dioxide material by oxygen vacancy engineering could induce a dipole field within the bulk phase and thus facilitate the separation and transfer of photogenerated electron-hole pairs. After further loading of Cu single-atom co-catalysts, the obtained catalyst attained a hydrogen (H2) yield rate of 15.84 mmol g-1 h-1 and a remarkable apparent quantum yield of 12.67% at 385 nm from methanol aqueous solution. This catalyst also demonstrated impressive stability for at least 24 h during the photocatalytic tests. The innovative concept of producing dipole fields in semiconductors by breaking the crystal symmetry offers a new perspective for designing photocatalysts.

Inflammatory and adhesion profile of gingival fibroblasts to lithium disilicate ceramic surfaces.

OBJECTIVES: Lithium disilicate (LS) ceramic emerges as a compelling option for customized implant abutments. However, ensuring its safety and reliability requires clarification on key aspects, notably its impact on inflammation and potential for cell adhesion. This study delves into these considerations, examining the influence of LS ceramic on cytokine release and the transcriptional profile of human gingival fibroblasts (hGFs) in direct contact with various LS surfaces. METHODS: hGFs were cultured on LS disks featuring three distinct surfaces (unpolished, polished, and polished glaze), while titanium disks served as reference material and cells cultured directly on plates as controls. The surface of the disks was analyzed using a scanning electron microscope. The cell metabolism was analyzed by MTT test, cytokine release by MAGPIX and the expression of genes related to cell adhesion was evaluated by qPCR. RESULTS: The disks exhibited similar topography with smooth surfaces, except for the unpolished LS disks, which had an irregular surface. Contact with LS surfaces did not substantially reduce cell metabolism. Moreover, it generally decreased cytokine release compared to controls, particularly pro-inflammatory mediators like IL-1ß, IL-6, and TNF-α. Significantly increased expression of genes related to cell adhesion to LS was observed, comparable to titanium, the gold standard material for implant abutments. SIGNIFICANCE: This study unveils that LS ceramic not only fails to trigger pro-inflammatory cytokine release, but also significantly enhances gene expression associated with cell adhesion. These mechanisms are closely linked to gene pathways such as PTK2, SRC, MAPK1, and transcription factors ELK-1 and MYC. In summary, the findings underscore LS ceramic's potential as a biocompatible material for implant abutments, shedding light on its favorable inflammatory response and enhanced cell adhesion properties.

Titanium surfaces loaded with puerarin and exosomes derived from adipose stem cells promote the proliferation and differentiation of pre-osteoblasts.

The study is to evaluate the effects of collagen/hyaluronic acid coating with or without puerarin and exosomes (Exos) derived from adipose stem cells (ADSCs-Exos) on pre-osteoblast proliferation and differentiation on the surface of titanium materials. Titanium materials with different coatings were prepared by layer-by-layer technique, evaluating the surface characterization. Cell functions were assessed by cell biology experiments. Related genes and proteins were assessed by RT-qPCR and Western blot. Puerarin or ADSCs-Exos coating had better effects on promoting the adhesion, proliferation and differentiation of pre-osteoblasts, and the strongest effect was found after their co-coatings, manifesting as the up-regulations of alkaline phosphatase (ALP) activity, collagen type I alpha 1 (Col1a1), runt-related transcription factor 2 (Runx2), osterix and activating transcription factor-2 (ATF-2). Levels of phosphorylated-P38 (p-P38) and p-ATF-2 were up-regulated in pre-osteoblasts grown on puerarin and ADSCs-Exos-loaded titanium surfaces. Titanium surfaces loaded with puerarin and ADSCs-Exos promotes the proliferation and differentiation of pre-osteoblasts.

Influence of Porosities of 3D Printed Titanium Implants on the Tensile Properties in a Rat Tendon Repair Model.

BACKGROUND: There is a desire in orthopaedics to have soft tissue, particularly tendon, grow into metallic implants. With the introduction of three-dimensional (3D) printed porous metal implants, we hypothesized that tendons could directly attach to the implants. However, the effects of the porous metal structure on tissue growth and penetration into the pores are unknown. Using a rat model, we investigated the effect of pore size on tendon repair fixation using 3D printed titanium implants. METHODS: There were three experimental groups of eight Sprague Dawley rats (n = 24) plus control (n = 3). Implants had defined pore sizes of 400µm (n = 8), 700µm (n = 8), and 1000µm (n = 8). A defect was created in the Achilles tendon and the implant positioned between cut ends and secured with suture. Specimens were harvested at twelve weeks. Half the specimens underwent mechanical testing to assess tensile load to failure. The remaining specimens were fixed and processed for hard tissue histological analysis. RESULTS: The average load to failure was 72.6N for controls (SD 10.04), 29.95N for 400µm (SD 17.95), 55.08N for 700µm (SD 13.47), and 63.08N for 1000µm (SD 1.87). The load to failure was generally better in the larger pore sizes. The 700µm and 1000µm specimens performed similarly, while the 400µm showed significant differences vs control (p = 0.039), vs 1000µm (p = 0.010), and approached significance vs 700µm (p = 0.066). There was increasing ingrowth as pore size increased. Histology showed fibrous tendon tissue within and around the implants, with collagen fibers organized in bundles. CONCLUSIONS: Tendon repair utilizing implants with 700µm and 1000µm pores exhibited similar load to failure as controls. Using a defined pore structure at the attachment points of tendons to implants may allow predictable tendon ingrowth onto/into an implant at the time of revision arthroplasty.

Role of the novel aloe vera-based titanium dioxide bleaching gel on the strength and mineral content of the human tooth enamel with respect to age.

There has been an increased demand for dental bleaching globally irrespective of age and gender. Main drawbacks associated with conventional tooth bleaching agents have been compromised strength and mineral-content of tooth enamel which results in sensitivity, discomfort, roughness, and structure loss of human teeth. Currently, nanoparticles synthesized by green synthesis have gained popularity especially in medical and dental applications because of their versatile and beneficial nano-scaled features. Titanium dioxide nanoparticles (TiO2Nps) in this study were prepared from green ecofriendly source using the aloe vera plant extract and were then characterized via dynamic light scattering (DLS), scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray (EDX), for size, shape, composition and true-phase. These TiO2 Nps were incorporated in commercial bleaching gel containing hydrogen peroxide to form a novel TiO2-bleaching gel which was used to bleach extracted anterior teeth belonging to four different age groups: 20-29 years, 30-39 years, 40-49 years and ≥50 years. These teeth were investigated for micro-hardness (Vickers microhardness tester) and mineral-content (EDX spectroscopy) including sodium, magnesium, phosphorus, calcium in an in-vitro environment both before and after bleaching. Results revealed that TiO2 Nps prepared by aloe vera plant were nanos-sized of about 37.91-49 nm, spherical shape, true anatase phase with pure titanium and oxygen in their composition. The values of Vickers micro-hardness and mineral-content (Na, Mg, P, Ca) of enamel specimens belonging to different age groups enhanced in a linear pattern before bleaching with the increase in age (p value < 0.05). There was negligible reduction observed in Vickers micro-hardness and mineral-content elements (Na, Mg, P, Ca) of all enamel specimens belonging to different ages after the bleaching (p value > 0.05). The novel TiO2-bleaching gel prepared was effective enough in preventing the declination in Vickers micro-hardness strength and mineral-content of all the enamel specimens belonging to different age groups even after the bleaching procedure which makes it a promising biomaterial.

Comparative Evaluation of the Effect of Microwave, 1% Sodium Hypochlorite, and Sodium Perborate Disinfection on the Color Stability of Two Nanoparticle-Reinforced Heat-Polymerized PMMA Denture Base Resins: An In Vitro Study.

Introduction Older adults experience significant improvement in their quality of life by using removable prosthetics to replace missing teeth. Poly(methyl methacrylate) (PMMA) has become the most popular material for denture bases due to its ease of use and affordability. Recently, scientists have started adding nanoparticles like titanium dioxide (TiO2) and zirconium oxide (ZrO2) to PMMA to enhance its physical properties. These resins with nanoparticles need to stay the same color after being disinfected in different ways if they are going to be used for a long time. So, the purpose of this investigation was to assess whether or not there exists any difference between two kinds of thermally cured acrylic resin for artificial tooth bases strengthened with nanoparticles when subjected to various chemical sterilizers alongside microwave irradiation, as well as determine their comparative colorfastness levels.  Materials and methods In this lab experiment, we tested how well 5% TiO2 and 7% ZrO2 nanoparticle-reinforced PMMA resins held their color when exposed to microwave irradiation, 1% sodium hypochlorite, or sodium perborate disinfection. We made 120 specimens shaped like discs; half were treated using one method, while the other half were treated using a different method. Color was measured at baseline (T0), after one cycle (T1), after five cycles (T2), and after six months (T3) using a reflectance spectrophotometer, which calculates the color difference (∆E). Results All three methods of disinfection caused significant color changes (p<0.001); however, sodium perborate caused the least amount of change, followed by 1% sodium hypochlorite and microwave irradiation. The mean ∆E values showed that after one day, there was a change in color by 1.1 due to microwave disinfection, which increased to 5.7 after five days; on the other hand, for 1% sodium hypochlorite, the change was recorded as 0.7 after one month and 1.6 after three months and finally reached up to 2.6 after six months, while sodium perborate showed the least amount of change, with ∆E values recorded as 0.2 after one month, 0.5 after three months, and 0.8 after six months. Conclusion Sodium perborate proved to be the most effective disinfectant for maintaining color stability in 5% TiO2 and 7% ZrO2 nanoparticle-reinforced PMMA resins, thus making it ideal for routine disinfection. Therefore, according to this study, sodium perborate should be used as a disinfection method because it results in minimal color change in nanoparticle-reinforced PMMA dentures.