Exploring fibroblast interactions on nanocrystalline surfaces in physiological environments through a phenomenological lens

The cytological behaviour and functional dynamics (adhesion, spreading, synthesis of proteins) of fibroblasts when interacting with biomedical surfaces are intricately influenced by the inherent nature of surface (nanocrystalline or microcrystalline), where the nanocrystalline (NC) surface is preferred in relation to the microcrystalline (MC) surface. This preference is a direct consequence of the distinct differences in physical and chemical characteristics between NC and MC surfaces, which include crystal boundary bio-physical attributes, electron work function, surface energy, and charge carrier density. The observed variances in cytological behaviour at the interfaces of NC and MC bio-surfaces can be attributed to these fundamental differences, particularly accounting for the percentage and nature of crystal boundaries. Recognising and understanding these physical and chemical characteristics establish the groundwork for formulating precise guidelines crucial in the development of the forthcoming generation of biomedical devices.

Development of ZTA (80% Al2O3/20% ZrO2) pre-sintered blocks for milling in CAD/CAM systems

The present work aims to develop a production method of pre-sintered zirconia-toughened-alumina (ZTA) composite blocks for machining in a computer-aided design and computer-aided manufacturing (CAD-CAM) system. The ZTA composite comprised of 80% Al2O3 and 20% ZrO2 was synthesized, uniaxially and isostatically pressed to generate machinable CAD-CAM blocks. Fourteen green-body blocks were prepared and pre-sintered at 1000 °C. After cooling and holder gluing, a stereolithography (STL) file was designed and uploaded to manufacture disk-shaped specimens projected to comply with ISO 6872:2015. Seventy specimens were produced through machining of the blocks, samples were sintered at 1600 °C and two-sided polished. Half of the samples were subjected to accelerated autoclave hydrothermal aging (20h at 134 °C and 2.2 bar). Immediate and aged samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Optical and mechanical properties were assessed by reflectance tests and by biaxial flexural strength test, Vickers indentation and fracture toughness, respectively. Samples produced by machining presented high density and smooth surfaces at SEM evaluation with few microstructural defects. XRD evaluation depicted characteristic peaks of alpha alumina and tetragonal zirconia and autoclave aging had no effect on the crystalline spectra of the composite. Optical and mechanical evaluations demonstrated a high masking ability for the composite and a characteristic strength of 464 MPa and Weibull modulus of 17, with no significant alterations after aging. The milled composite exhibited a hardness of 17.61 GPa and fracture toughness of 5.63 MPa m1/2, which remained unaltered after aging. The synthesis of ZTA blocks for CAD-CAM was successful and allowed for the milling of disk-shaped specimens using the grinding method of the CAD-CAM system. ZTA composite properties were unaffected by hydrothermal autoclave aging and present a promising alternative for the manufacture of infrastructures of fixed dental prostheses.

Aging processes in dental thermoplastics - Thermoanalytical investigations and effects on Vickers as well as Martens hardness

OBJECTIVE

The influence of various aging protocols, representing and accelerating influences present in the dental context, on possible changes in the microstructure and mechanical properties of thermoplastics was investigated. In order to minimize the complexity of the systems, first pure polymers and then later the equivalent dental polymeric materials were analyzed.

MATERIALS AND METHODS

Pure polymers (Poly(methyl methacrylate) - PMMA, Polyoxymethylene homopolymer - POM-H, Polyether ether ketone - PEEK, Nylon 12 - PA12, Polypropylene - PP) were analyzed before as well as after applying different aging protocols relevant to the oral environment (ethanol, thermocycling, alkaline and acidic setting) by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermoanalytical parameters used were glass transition temperature (Tg), melting peak and crystallization peak temperature (Tpm, Tpc) and decomposition behavior. In a second step selected commercially available dental products (Telio CAD - PMMAD, Zirlux Acetal - POMD, Juvora Natural Dental Disc - PEEKD) aged by the protocol that previously showed strong effects were examined and additionally tested for changes in their Vickers and Martens hardness by Mann-Whitney-U test.

RESULTS

The combinations of pure polymers and viable aging protocols analyzed within this study were identified via TGA or DSC as PA12 & thermocycling, POM-H & denture cleanser/lactic acid/ethanol, PP & lactic acid. The dental polymeric materials PMMAD and POMD due to aging in lactic acid showed slight but significantly (p < 0.01) reduced Vickers and partly Martens hardness. PEEK showed the greatest material resistance within this study.

Orthodontic adhesive loaded with different proportions of ZrO2 silver-doped nanoparticles: An in vitro μTBS, SEM, EDX, FTIR, and antimicrobial analysis

Zirconium dioxide silver-doped nanoparticles (ZrO2AgDNPs) impacts the adhesive material in terms of its physical characteristics, antimicrobial properties, degree of conversion (DC), and micro-tensile bond strength (μTBS) of orthodontic brackets to the enamel surface. A comprehensive methodological analysis utilizing a range of analytical techniques, including scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, DC analysis, and μTBS testing. A light-curable orthodontic adhesive, specifically Transbond XT, was combined with ZrO2AgDNPs at 2.5% and 5%. As a control, an adhesive with no incorporation of ZrO2AgDNPs was also prepared. The tooth samples were divided into three groups based on the weightage of NPs: group 1: 0% ZrO2AgDNPs (control), group 2: 2.5 wt% ZrO2AgDNPs, and group 3: 5 wt% ZrO2AgDNPs. EDX graph demonstrated silver (Ag), Zirconium (Zr), and Oxygen (O2), The antibacterial efficacy of adhesives with different concentrations of NPs (0%, 2.5%, and 5%) was assessed using the pour plate method. The FTIR spectra were analyzed to identify peaks at 1607 cm-1 corresponding to aromatic CC bonds and the peaks at 1638 cm-1 indicating the presence of aliphatic CC bonds. The μTBS was assessed using universal testing machine (UTM) and bond failure of orthodontic brackets was seen using adhesive remanent index (ARI) analysis. Kruskal-Wallis test assessed the disparities in survival rates of Streptococcus mutans. Analysis of variance (ANOVA) and post hoc Tukey multiple comparisons test calculated μTBS values. The lowest μTBS was observed in group 1 adhesive loaded with 0% ZrO2AgDNPs (21.25 ± 1.22 MPa). Whereas, the highest μTBS was found in group 3 (26.19 ± 1.07 MPa) adhesive loaded with 5% ZrO2AgDNPs. ZrO2AgDNPs in orthodontic adhesive improved μTBS and has acceptable antibacterial activity against S mutans. ZrO2AgDNPs at 5% by weight can be used in orthodontic adhesive alternative to the conventional method of orthodontic adhesive for bracket bonding. RESEARCH HIGHLIGHTS: The highest μTBS was found in orthodontic adhesive loaded with 5% ZrO2AgDNPs. ARI analysis indicates that the majority of the failures fell between 0 and 1 among all investigated groups. The colony-forming unit count of S. mutans was significantly less in orthodontic adhesive loaded with nanoparticles compared with control. The 0% ZrO2AgDNPs adhesive showed the highest DC.

Transglutaminase enables highly hydrolytically and proteolytically stable crosslinking of collagen on titanium surfaces and promotes osteogenic differentiation of human mesenchymal stem cells

Collagen with its bioactive ligand motives would be predestined as coating on bone implant surfaces like titanium hip stems to facilitate receptor-mediated cell adhesion and thereby improve early osseointegration. Unfortunately, collagen as coating exhibits very low proteolytic resistance in vivo. To overcome this limitation, different crosslinking methods of collagen (transglutaminase, GTA, EDC/NHS, riboflavin, and lysyl oxidase) with silanized titanium alloy (Ti6Al4V) were investigated in terms of degradation resistance, hydrolysis stability, tensile strength, and metabolic cell activity. The in vitro osteogenic differentiation ability of human mesenchymal stem cells (hMSCs) induced by the surface modification was evaluated by immunofluorescence of early osteogenic markers, Alizarin red staining, and energy dispersive X-ray spectroscopy. The expression of the adhesion-related protein vinculin was analyzed on the different functionalized surfaces. The results revealed that the enzymatic crosslinker transglutaminase offered high degradation resistance, tensile strength, and hydrolysis stability compared to the other crosslinking reagents tested. Remarkably, the adhesion sequences within the collagen were accessible to the hMSCs despite the transglutaminase crosslinking procedure. In conclusion, the organochemical functionalization of Ti6Al4V surfaces with collagen using transglutaminase holds great potential to facilitate an enhanced interaction with attached bone cells and thereby could potentially improve and accelerate osseointegration of a titanium-based bone implant in vivo.

Trueness, physical properties, and surface characteristics of additive-manufactured zirconia crown

OBJECTIVE

This study aimed to conduct a comparison of trueness and physical and surface properties among five distinct types of additive manufactured (AM) zirconia crowns and zirconia crowns produced using the subtractive manufacturing (SM).

MATERIAL AND METHODS

Zirconia crowns were fabricated using five distinct techniques, each varying in the method of slurry transfer and photocuring source. Each experimental group utilized either one of the four digital light processing (DLP)-based techniques (DLP spreading, DLP spreading gradation, DLP vat and DLP circular spreading) or the stereolithography (SLA)-based technique (SLA spreading). The control (CON) group employed SM. To assess accuracy, trueness was measured between the scan and reference data. To analyze the physical properties, voids were examined using high-energy spiral micro-computed tomography scans, and the crystal structure analysis was performed using X-ray diffraction (XRD). Surface roughness was assessed through laser scanning microscopy.

RESULTS

Differences in the trueness of internal surfaces of crowns were found among the groups (P < 0.05). Trueness varied across the measurement surfaces (occlusal, lateral, and marginal) in all the groups except for the DLP spreading gradation group (P < 0.05). Voids were observed in all AM groups. All groups showed similar XRD patterns. All AM groups showed significantly greater surface roughness compared to the CON group (P < 0.001).

CONCLUSION

The AM zirconia crowns showed bubbles and a rougher surface compared to the SM crowns. All groups exhibited typical zirconia traits and trueness levels within clinically acceptable limits, suggesting that current zirconia AM techniques could be suitable for dental applications.

Aging effects of titanium dioxide on Cu toxicity to Daphnia magna: Exploring molecular docking and significance of surface properties

Cosmetics and personal care products containing titanium dioxide nanoparticles (TiO2 NPs) may enter aquatic environments, where the surface coatings of TiO2 NPs may change with aging due to environmental factors such as light, and potentially affect their bioaccumulation and toxicity. This study examined how aging impacted the physicochemical properties of three commercially available TiO2 NPs and subsequent influence on the bioaccumulation and toxicity of copper (Cu) in Daphnia magna (D. magna). We demonstrated that aging significantly affected the hydrophobicity of TiO2 NPs, which affected their binding to water molecules and adsorption of Cu. Changes of bioaccumulation of TiO2 NPs and Cu in D. magna ultimately affected the activities of intracellular antioxidant enzymes such as SOD, CAT, GSH-Px, and the transmembrane protein Na+/K+-ATPase. Molecular docking calculations demonstrated that changes of activities of these biological enzymes were due to the interaction between TiO2 NPs, Cu, and amino acid residues near the sites with the lowest binding energy and active center of the enzyme. Such effect was closely related to the hydrophobicity of TiO2 NPs. Our study demonstrated the close relationship between surface properties of TiO2 NPs and their biological effects, providing important evidence for understanding the behavior of nanomaterials in aquatic environments.

Friction and wear behavior of a mechanical oscillating strip system used for interproximal enamel reduction: a quantitative and qualitative scanning electronic microscope evaluation

OBJECTIVES

To evaluate wear and friction properties of oscillating strips in order to validate the importance of a standardized interproximal enamel reduction (IPR) sequence to preserve their efficiency and lifetime.

MATERIALS AND METHODS

Fifteen complete oscillating IPR sequences were tested by means of tribological tests (Linear Reciprocating Tribometer, C.S.M. Instruments, Peseaux, Switzerland). Fifteen single 0.2-mm metallic strips underwent a long continuous cycle of 240 minutes. Strip surface roughness and waviness measurements were assessed by means of a contact probe surface profiler (TalySurf CLI 2000; Taylor Hobson, Leicester, UK) and TayMap software. Statistical analysis was performed with independent-samples t-test. Significance was at the P < .05 level. Scanning electronic microscopy analysis of strip surfaces was conducted with an FEI Quanta 200 (Hillsboro, Ore) in high vacuum at 30.00 kV.

RESULTS

Resin strips revealed a significant reduction in surface roughness (Ra, Rt, RDq) and a significant increase in waviness parameters (Wa, Wt). Rt and RDq values significantly decreased upon use of the metallic strips. Significantly higher values of Wa (+ 2.84 µm) and Wt (+0.1 µm) were observed only for the 0.2-mm metallic strips. Higher friction values were observed when the metallic strips were tested singularly rather than within the entire sequence. Lower Ra and Rt values were revealed when 0.2-mm metallic strips were tested up to 240 minutes.

CONCLUSIONS

The application of a standardized oscillating sequence allows for more efficient wear performance of the strips with a significant impact on their abrasive power and lifetime.

Size, Surface Properties, and Ion Release of Zinc Oxide Nanoparticles: Effects on Cytotoxicity, Dopaminergic Gene Expression, and Acetylcholinesterase Inhibition in Neuronal PC-12 Cells

The extensive applications of zinc oxide nanoparticles (ZnO NPs) have resulted in a substantial risk of human exposure. However, the knowledge of the toxicity of these NPs in the nervous system is still limited. A comparative analysis of ZnO NPs of various sizes and NPs of the same size, with and without surface coating, and the potential role of released zinc ions is yet to be thoroughly explored. As a result, we have studied the cellular toxicity of two different-sized ZnO NPs, ZnO-22 (22 nm) and ZnO-43 (43 nm), and NPs with similar size but with polyvinylpyrrolidone coating (ZnO-P, 45 nm). The findings from our study suggested a time-, size-, and surface coating-dependent cytotoxicity in PC-12 cells at a concentration ≥ 10 μg/ml. ZnO NP treatment significantly elevated reactive oxygen and reactive nitrogen species, thereby increasing oxidative stress. The exposure of ZnO-22 and ZnO-43 significantly upregulated the expression of monoamine oxidase-A and downregulated the α-synuclein gene expression associated with the dopaminergic system. The interaction of NPs enzymes in the nervous system is also hazardous. Therefore, the inhibition activity of acetylcholinesterase enzyme was also studied for its interaction with these NPs, and the results indicated a dose-dependent inhibition of enzyme activity. Particle size, coating, and cellular interactions modulate ZnO NP's cytotoxicity; smaller sizes enhance cellular uptake and reactivity, while coating reduces cytotoxicity by limiting direct cell contact and potentially mitigating oxidative stress. Furthermore, the study of released zinc ions from the NPs suggested no significant contribution to the observed cytotoxicity compared to the NPs.

In vitro comparison of one-step, two-step, and three-step polishing systems on the surface roughness and gloss of different resin composites

OBJECTIVES

This laboratory study evaluated the effect of three polishing systems on the surface roughness and gloss of resin composites.

MATERIALS AND METHODS

Thirty specimens (6 mm Ø × 8 mm) were fabricated from each of three resin composites: Z 350 XT (nanofill), Harmonize (nanohybrid), and Estelite Omega (supranonofill). All specimens were photopolymerized using a multi-peak LED curing unit (VALO-Standard mode), having a exitance irradiance of approximately 1000 mW/cm2 against a polyester strip (PS). 2 mm was then removed from the irradiated end (finished) using #320 abrasive paper (F). Specimens were then randomly polished (P) using a one-step (1S) (OneGloss), two-step (2S) (EVE Diacomp Twist Basic CA), or 3-step (3S) (Astropol P) system (n = 10). For PS, F, and P groups, surface roughness (Ra) was measured using a surface roughness tester, and surface gloss was measured with a glossmeter. For each specimen, the percent recovery to the PS value (%R) of surface roughness and surface gloss were calculated. Data were analyzed using two-way ANOVA, followed by Tukey's test. Surface roughness and gloss values were submitted to Pearson's correlation test (α = 0.05). All statistical testing was performed using a pre-set alpha of 0.05.

RESULTS

The interaction term [resin composite × polishing system] was significant for both surface roughness (p = 0.001) and gloss (p = 0.0001). For all resin composites, the 2S and 3S systems provided a higher %R of surface roughness and gloss compared to those of the 1S system. There was a negative correlation between surface roughness and gloss, but only a few combinations showed strong correlations.

CONCLUSIONS

The 2S and 3S polishing systems provided surfaces having greater smoothness and gloss compared to the 1S system. The ability to recover surface roughness and gloss was dependent on type of resin composite filler classification.

CLINICAL SIGNIFICANCE

The 3S and 2S polishing systems were more effective in achieving PS values than was the 1S system for all tested resin composites. However, individual polishing systems performed differently depending on type of resin composite.

Changes in physical properties of universal composites and CAD/CAM materials after bleaching and antioxidant applications: Scanning electron microscope and atomic force microscope evaluation

To evaluate the effects of vital bleaching agents and the subsequent application of ascorbic acid (AA) to universal composites and resin-based CAD/CAM blocks on the physical properties of materials. In the study; G-enial A'chord (GCA), Filtek Ultimate (FU), Clearfil Majesty (CM) composites, and LAVA Ultimate (LU), Cerasmart (GCC) CAD/CAM blocks were used. The materials were divided into two subgroups based on the applied bleaching type (n = 30/group): office bleaching (OB) and home bleaching (HB). After bleaching, AA was applied to the samples. Surface roughness, microhardness, and color change values of all samples were measured at three stages: initial (I), post-bleaching (B), and post-bleaching+AA application (BA). Statistical analysis was performed using 3-way Mixed ANOVA with Bonferroni correction (p < .05). The BA of the HB group of CM; the B of the HB group of LU; the B roughness values of both the OB and HB groups of GCC were significantly lower than I. The microhardness values of all the materials examined decreased significantly after both bleaching (p < .05). With regard to the AA application, it significantly decreased Ra values in the HB group of CM. In addition, it significantly increased the microhardness values in the HB groups of CM and GCC. Also, the ΔE001 and ΔE002 values for the FU and GCC HB groups were significantly higher than in the OB groups (p < .05). Bleaching and AA application affected the physical properties of the materials. The physical properties of the materials either remained unchanged or improved with the application of AA after bleaching. RESEARCH HIGHLIGHTS: This article presents in vitro results of a new approach that has not been studied before. Ascorbic acid, used to increase the bond strength between the material-tooth after bleaching, was used to eliminate the adverse effects of bleaching on the physical properties of aesthetic restorative materials. Additionally, the effects of all procedures on the materials were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). As a result of the study, it was concluded that the application of ascorbic acid after bleaching improved the physical properties of some of the materials.

Porous structure design and properties of dental implants

At present, selective laser melting (SLM) 3D printing technology can accurately control the internal pore structure and complex cell shape. Three types of reticulated meshes with cubic, G7 and composite structure cell shapes were fabricated by the SLM 3D printing technology using Ti-6Al-4V alloy powders. The bone stresses around the implant and the stresses in the implant were analyzed by ANSYS finite element software, which comprehensively evaluated the effect of porous dental implants with different spatial porosity characteristics on osseointegration. The results show that porous dental implants with composite structure of pore characteristics have improved mechanical and biological properties and can better promote the growth and integration of bone tissue.

Investigation of the mucin-nanoparticle interactions via real-time monitoring by microbalance and kinetic model simulation

Interactions between nanoparticles and the mucus layer are crucial to understand the behaviours in biological environments and design drug delivery systems. In this study, we developed a kinetic deposition model for the dynamic mucin-nanoparticle interactions using quartz crystal microbalance with dissipation (QCM-D). We investigated the effects of the physiochemical properties of several nanoparticles (including size, charge, and shape) and the physiological conditions on the mucin-nanoparticle interaction. Interestingly, layered double hydroxide (LDH) nanoparticles showed stronger interactions with the mucus layer compared to other types of nanoparticles due to their unique plate-like morphology. In specific for sheet-like LDH nanoparticles, our model found that their equilibrium adsorption capacity (Qe) followed the Langmuir adsorption isotherm, and the adsorption rate (k1) increased proportionally with the nanoparticle concentration. In addition, the particle size and thickness affected Qe and the surface coverage. Furthermore, bovine serum albumin (BSA) coating dramatically increased k1 of LDH nanoparticles. We proposed a novel mechanism to elucidate mucin-nanoparticle interactions, shedding light on the synergistic roles of drag force (Fd), repulsive force (Fr), and adsorptive force (Fa). These findings offer valuable insights into the complex mucin-nanoparticle interactions and provide guidance for the design of drug delivery systems.

The capacity of conservative preparations for lithium disilicate glass-ceramic laminates luted with different resin cements to mask different substrate shades: A minimally invasive esthetic approach

OBJECTIVE

Demonstrate the ability of 0.5 mm thickness lithium disilicate laminates associated with resin cement to mask different substrate saturations.

METHODS

60 specimens (n = 5) were prepared with CAD/CAM lithium disilicate glass-ceramic IPS e.max CAD, 0.5 mm thick, in three degrees of translucency (HT, MT and LT); cemented by Variolink Esthetic LC Light+ (L) and Neutral (N) on composite resin substrates A1 and A4 shades. Color measurements were performed by a spectrophotometer (CM-3700d -Konica Minolta). The L*, a*, b* parameters of the tri-layer structure (laminate/ resin cement/ substrate) were used to calculate color difference ( ∆ E 00 ) by CIEDE2000 formula and Translucency Parameter (TP 00 ). This study adopted ∆ E 00 = 0.8, as perceptibility threshold (PT), and ∆ E 00 = 1.8, as acceptability threshold (AT). Statistical analyses were performed by one-way ANOVA and Tukey tests (a = 0.05).

RESULTS

Color difference between resin cement shades showed statistical differences (p < 0.0001) and ∆ E 00 > 1.8 for all groups. Color difference between substrates saturations showed a significant statistical difference (p < 0.0001) and ∆ E 00 values above AT for all groups. TheTP 00 demonstrated significant statistical differences (p < 0.0001). The LTL combination, the opaquest set, showed the smallest ∆ E 00 values between substrate shades differences, however, above AT.

CONCLUSION

The translucency of the lithium disilicate, the substrate saturation and the resin cement opacity influenced final color of restoration. The ceramic translucency impact on final color was reduced by opaque resin cement. Furthermore, the LT lithium disilicate and the Light+ resin cement reduced the translucency of the restoration, contributing to mask saturated substrate.

CLINICAL RELEVANCE

This study shows the influence of conservative lithium disilicate laminates with different degrees of translucency associated with resin cement on final color of saturated substrate restorations. A minimally invasive esthetic protocol for masking substrates is demonstrated by associating low translucency ceramic laminates and opaque resin cement.

Particle abrasion as a pre-bonding dentin surface treatment: A scoping review

OBJECTIVE

This scoping review aims to assess the influence of air abrasion with aluminum oxide and bioactive glass on dentin bond strength.

MATERIALS AND METHODS

An electronic search was conducted in three databases (PubMed, Cochrane Library, and Embase), on March 3rd, 2023, with previously identified MeSH Terms. A total of 1023 records were screened. Exclusion criteria include primary teeth, air abrasion of a substrate other than sound dentin, use of particles apart from aluminum oxide or bioactive glass, and studies in which bond strength was not assessed.

RESULTS

Out of the 1023 records, title and abstract screening resulted in the exclusion of 895 and 67 studies, respectively, while full-text analysis excluded another 25 articles. In addition, 5 records were not included, as full texts could not be obtained after requesting the authors. Two cross-references were added. Thus, 33 studies were included in this review. It is important to emphasize the absence of standardization of air abrasion parameters. According to 63.6% of the studies, air abrasion does not influence dentin bond strength. Moreover, 30.3% suggest improving bonding performance, and 6.1% advocate a decrease.

CONCLUSIONS

Air abrasion with aluminum oxide does not enhance or impair dentin bond strength. The available data on bioactive glass are limited, which hinders conclusive insights.

CLINICAL SIGNIFICANCE

Dentin air abrasion is a widely applied technique nowadays, with numerous clinical applications. Despite the widespread adoption of this procedure, its potential impact on bonding performance requires a thorough analysis of the existing literature.

Enhancement of in vitro antibacterial activity and bioactivity of iodine-loaded titanium by micro-scale regulation using mixed-acid treatment

Postoperative infection and subsequent device loss are serious complications in the use of titanium dental implants and plates for jawbone reconstruction. We have previously reported that NaOH-CaCl2 -thermal-ICl3 -treated titanium (NaCaThIo) has a nano-scale surface and exhibits antibacterial activity against Staphylococcus aureus. The present study examined the surface properties of mixed-acid treated and then iodine-treated titanium (MA-NaCaThIo), and evaluated oral antibacterial activity and cytotoxicity compared with the results obtained with NaCaThIo. MA-NaCaThIo formed a surface layer with a nano-scale network structure having microscale irregularities, and both the thickness of the surface layer (1.49 ± 0.16 μm) and the average surface roughness (0.35 ± 0.03 μm) were significantly higher than those of NaCaThIo. Furthermore, MA-NaCaThIo maintained high hydrophilicity with a contact angle of 7.5 ± 1.7° even after 4 weeks, as well as improved apatite formation, iodine ion release, and antibacterial activity against Prevotella intermedia compared to NaCaThIo. Cell culture test revealed that MA-NaCaThIo exhibited no cytotoxicity against MG-63 and Vero cells, while increased cell proliferation, ALP activity and mineralization of MG-63 compared to NaCaThIo. This treated titanium is expected to be useful for the development of next-generation titanium devices having both bone-bonding and antibacterial properties.

Critical attributes of fine excipient materials in carrier-based dry powder inhalation formulations: The particle shape and surface properties

The potential of fine excipient materials to improve the aerodynamic performance of carrier-based dry powder inhalation (DPI) formulations is well acknowledged but not fully elucidated. To improve the understanding of this potential, we studied two fine excipient materials: micronized lactose particles and silica microspheres. Inhalation formulations, each composed of a coarse lactose carrier, one of the two fine excipient materials (0.0-15.0 % w/w), and a spray-dried drug (fluticasone propionate) material (1.5 % w/w) were prepared. The physical structure, the flow behavior, the aerosolization behavior, and the aerodynamic performance of the formulations were studied. The two fine excipient materials similarly occupied carrier surface macropores. However, only the micronized lactose particles formed agglomerates and appeared to increase the tensile strength of the formulations. At 2.5 % w/w, the two fine excipient materials similarly improved drug dispersibility, whereas at higher concentrations, the micronized lactose material was more beneficial than the silica microspheres. The findings suggest that fine excipient materials improve drug dispersibility from carrier-based DPI formulations at low concentrations by filling carrier surface macropores and at high concentrations by forming agglomerates and/or enforcing fluidization. The study emphasizes critical attributes of fine excipient materials in carrier-based DPI formulations.

Peptide-based self-assembled monolayers (SAMs): what peptides can do for SAMs and vice versa

Self-assembled monolayers (SAMs) represent highly ordered molecular materials with versatile biochemical features and multidisciplinary applications. Research on SAMs has made much progress since the early begginings of Au substrates and alkanethiols, and numerous examples of peptide-displaying SAMs can be found in the literature. Peptides, presenting increasing structural complexity, stimuli-responsiveness, and biological relevance, represent versatile functional components in SAMs-based platforms. This review examines the major findings and progress made on the use of peptide building blocks displayed as part of SAMs with specific functions, such as selective cell adhesion, migration and differentiation, biomolecular binding, advanced biosensing, molecular electronics, antimicrobial, osteointegrative and antifouling surfaces, among others. Peptide selection and design, functionalisation strategies, as well as structural and functional characteristics from selected examples are discussed. Additionally, advanced fabrication methods for dynamic peptide spatiotemporal presentation are presented, as well as a number of characterisation techniques. All together, these features and approaches enable the preparation and use of increasingly complex peptide-based SAMs to mimic and study biological processes, and provide convergent platforms for high throughput screening discovery and validation of promising therapeutics and technologies.

Nanochemistry of gold: from surface engineering to dental healthcare applications

Advancements in nanochemistry have led to the development of engineered gold nanostructures (GNSs) with remarkable potential for a variety of dental healthcare applications. These innovative nanomaterials offer unique properties and functionalities that can significantly improve dental diagnostics, treatment, and overall oral healthcare applications. This review provides an overview of the latest advancements in the design, synthesis, and application of GNSs for dental healthcare applications. Engineered GNSs have emerged as versatile tools, demonstrating immense potential across different aspects of dentistry, including enhanced imaging and diagnosis, prevention, bioactive coatings, and targeted treatment of oral diseases. Key highlights encompass the precise control over GNSs' size, crystal structure, shape, and surface functionalization, enabling their integration into sensing, imaging diagnostics, drug delivery systems, and regenerative therapies. GNSs, with their exceptional biocompatibility and antimicrobial properties, have demonstrated efficacy in combating dental caries, periodontitis, peri-implantitis, and oral mucosal diseases. Additionally, they show great promise in the development of advanced sensing techniques for early diagnosis, such as nanobiosensor technology, while their role in targeted drug delivery, photothermal therapy, and immunomodulatory approaches has opened new avenues for oral cancer therapy. Challenges including long-term toxicity, biosafety, immune recognition, and personalized treatment are under rigorous investigation. As research at the intersection of nanotechnology and dentistry continues to thrive, this review highlights the transformative potential of engineered GNSs in revolutionizing dental healthcare, offering accurate, personalized, and minimally invasive solutions to address the oral health challenges of the modern era.

Effect of Aging on Fracture Load and Reliability of Cemented Glass-Ceramics

PURPOSE

To evaluate the influence of aging on the fracture load (Lf) and reliability of glass-ceramics after different etching protocols.

MATERIALS AND METHODS

Specimens were fabricated and divided according to the etching Ame (10% hydrofluoric acid [HF] for 20 seconds, 40 seconds, and 60 seconds). Etched surfaces were examined under microscopy. The ceramics were resin-cemented to a dentin analog material. Samples were split into two groups (n = 20 each) and tested after 24 hours (I) or stored in 37° water for 1 year (A). A compressive load (0.1 mm/minute) was applied to the samples unAl failure was detected by acoustic emission. The influence of aging on the Lf was tested by two-way ANOVA and Tukey tests (α = .05). The characteristic fracture load (L0) and Weibull modulus (m) values were calculated.

RESULTS

Lithium silicate (LS) etching for 20 seconds resulted in the highest immediate Lf, which was significantly decreased after aging (P ≤ .05). Water storage had no effect on the Lf of glass-ceramic etched for 40 and 60 seconds (P > .05). For lithium disilicate (LD), the etching time had no significant effect on the immediate or aged Lf (P > .05). The Lf was significantly reduced after aging (A) for LD (P ≤ .05). Radial cracks were the predominant failure mode. Surface topography was more regular after lower etching times for LD and after higher times for LS.

CONCLUSIONS

After 1 year of water-assisted aging, the evaluated etching times had no influence on the load-bearing capacity and structural reliability of resin-bonded glass-ceramics.

Effect of Simulated Gastric Acid on the Interface Between Zirconia and Resin Cement

PURPOSE

To evaluate the effect of simulated gastric acid solution (SGAS) and resin cement composition on the shear bond strength (SBS) of zirconia-based materials with different levels of translucency to composite resin.

MATERIALS AND METHODS

A total of 40 medium-opacity (MO; 3Y-TZP) and 40 medium-translucency (MT; 4Y-PSZ) zirconia slabs were distributed into four groups according to the composition of the resin luting system (MDP free or with MDP [primer + Panavia V5]) and storage method (distilled water or SGAS [5% hydrochloric acid]). Composite resin cylinders were cemented on the zirconia surface and stored for 91 hours. SBS, failure mode, and surface characterization analyses via scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were performed. SBS data were analyzed using three-way ANOVA and Tukey tests, and failure mode was assessed using one-way ANOVA (P < .05).

RESULTS

Storage media (P = .180), resin cement (P = .110), zirconia (P = .404), and their interactions did not affect SBS values. Bond strength ranged from 21.41 to 26.11 MPa. SEM images showed that SGAS modified the surface topography of zirconia and resin cement. The presence of chlorine and silicon (wt%) were higher after SGAS storage than after water storage in both cements used, while barium was higher only for the MDP cement. There was a prevalence of mixed failures for most of the groups.

CONCLUSIONS

The SBS between both types of zirconia and resin cement was not affected by SGAS, although changes in zirconia topography were observed after SGAS exposure. The presence of MDP in the cement layer had no effect on the SBS challenged by SGAS.

Effect of acidic environment on color and translucency of different indirect restorative materials

PURPOSE

The aim of the current study was to evaluate the effect of simulated gastric acid on the color and translucency of different indirect restorative materials.

MATERIALS AND METHODS

A total of 36 disc-shaped samples were cut by using an isomet saw and divided into four equal groups (n = 9) according to the material type: Group Z: translucent zirconia (Ceramill® Zolid ht.+ preshade, Amann Girrbach, Koblach, Austria); Group E: lithium disilicate (IPS e.max CAD, Ivoclar Vivadent AG, Schaan, Liechtenstein); Group C: resin nanoceramic (Cerasmart, GC, Tokyo, Japan); Group P: polyether ether ketone (PEEK) (Bettin Zirconia Dentale Italy) veneered with indirect high impact polymer composite (HIPC) (breCAM HIPC, Bredent GmbH & Co. KG, Germany). The samples were immersed in simulated gastric acid (HCl, pH 1.2) for 96 hours at 37 °C in an incubator. The color change (ΔE00) and translucency (RTP00) were measured every 9.6 hours (one-year clinical simulation) of immersion in simulated gastric acid.

RESULTS

For color change (∆E00) and translucency (RTP00) among the tested materials, there was a highly statistically significant difference (P < 0.001) after every year of follow-up. The color change in both Z and G groups was the lowest after 1 year of acid immersion, followed by that in group H, and the highest change in color was recorded in group P.

CONCLUSION

High translucent zirconia is recommended in patients who are concerned about esthetic, especially with acidic oral environment.

The effect of deviations in sintering temperature on the translucency and color of multi-layered zirconia

OBJECT

This study aimed to investigate the changes in the translucency and color of four different multi-layered zirconia materials when the sintering temperature were inaccurate.

MATERIALS AND METHODS

Two hundred zirconia samples (11 × 11 × 1.0 mm) of four multi-layered zirconia, Upcera TT-GT (UG), Upcera TT-ML (UM), Cercon xt ML (CX), and Lava Esthetic (LE), were divided into five subgroups according to the sintering temperature: L1 (5% lower temperature), L2 (2.5% lower temperature), R (recommended sintering temperature), H2 (2.5% higher temperature), H1 (5% higher temperature). After sintering, color coordinates were measured. Then the translucency parameter (TP) values, and the color differences (between the inaccurate sintering temperature and the recommended temperature) of each zirconia specimen were calculated. Statistical analysis was performed by using three-way ANOVA tests, the one-way ANOVA, and Tukey's post hoc test.

RESULTS

Three-way ANOVA results showed that material type, sintering temperature, specimen section, and their interactions significantly influenced the TP values (except for the interactions of specimen section and sintering temperature) (P < .05). TP values of zirconia specimens were significantly different in the inaccurate sintering temperatures (P < .05), except for the cervical and body sections of UG group (P > .05). Compared with recommended sintering temperature, higher sintering temperature caused higher TP values for CX, but lower for LE. Three-way ANOVA results showed that material type, sintering temperature, and their interactions significantly influenced the ∆E00 values (P < .05). There were no significant differences in ∆E00 values of UM and CX groups at different inaccurate sintering temperatures, and were clinical imperception (except for UM-L1) (∆E00 < 1.25). ∆E00 values of all zirconia specimens showed clinically acceptable (∆E00 < 2.23).

CONCLUSION

The deviations in sintering temperature significantly influenced the translucency and color of tested multi-layered zirconia. The trends of translucency in the multi-layered zirconia depended on material type and the color changes of all zirconia materials were clinically acceptable at inaccurate sintering temperatures.

[Effect of printing orientation on physical and mechanical properties of 3D printing prosthodontic base resin materials]

OBJECTIVE

To analyze the influence of forming direction on the surface characteristics, elastic modulus, bending strength and fracture toughness of printed parts and the relationship between forming direction and force direction, and to provide scientific basis and guidance for the clinical application of oral denture base resin materials.

METHODS

The 3D printing technology was used to print denture base resin samples. The shape and size of the samples referred to the current standard for testing conventional denture base materials. The samples used for physical performance testing were cylindrical (with a diameter of 15 mm and a thickness of 1 mm) and printed at different angles along the Z axis (0°, 45°, 90°). Scanning electron microscope was used to observe the microscopic topography of the different samples. The color stability of different samples was observed by color stabilizer. The surface roughness of the samples was analyzed by using surface roughness tester. The Vickers hardness was measured to analyze the hardness of the samples. The samples used for mechanical performance testing were rectangular (elastic modulus and bending strength: A length of 64 mm, a width of 10 mm, and a height of 3.3 mm; fracture toughness: A length of 39 mm, a width of 8 mm, and a height of 4 mm), divided into two groups: W group and H group. The W group was printed from the bottom up along the Z axis with the length × width as the bottom surface parallel to the X, Y axis plane, while the H group printed from the bottom up along the Z axis with the length × height as the bottom surface parallel to the X, Y axis plane. The forming angles of both groups were equally divided into 0°, 45°, and 90°. The elastic modulus, bending strength and fracture toughness of different samples were studied through universal mechanical testing machine. SPSS 22.0 software was used for statistical analysis.

RESULTS

The microscopic topography and roughness of different samples were closely related to the printing direction, with significant differences between the 0°, 45°, and 90° specimens. The 0° specimens had the smoothest surface (roughness < 1 μm). The surface of the 45° specimen was the roughest (roughness>3 μm). The microhardness of the 0° sample was the best [(196.13±0.20) MPa], with a significant difference compared with the 90° sample [(186.62±4.81) MPa, P < 0.05]. The mechanical properties of different samples were also closely related to the printing direction. The elastic modulus, bending strength, and fracture toughness of the 45° samples in the W group were the highest compared with the other groups. The results of elastic modulus showed that in the H group, the 45° specimens had the highest elastic mo-dulus, which was significantly different from the 0° and 90° specimens (P < 0.05). The elastic modulus of 0° and 45° specimens in the W group were higher than those in 90° specimens (P < 0.05). The bending strength results showed that there was no significant difference between the specimens from dif-ferent angles in the H group. The bending strength of the 90° specimens in the W group was the smallest, and there was a significant difference between 90° and the 0° and 45° specimens (P < 0.05); And the bendind strength of the 0° and 45° specimens in the W group was significantly higher than that of the 0° and 45° specimens in the H group (P < 0.05). The fracture toughness results showed that the fracture toughness of the H group specimens was lower than 1.9 MPa m1/2, which was specified in the denture base standard. The 45° samples in the W group were the highest, with significant differences compared with the 0° and 90° samples (P < 0.05). And the 90° samples of the W group specimens were lower than 1.9 MPa m1/2. And the fracture toughness of the 45° specimen in the W group was significantly higher than that of all the specimens in the H group (P < 0.05).

CONCLUSION

The 0° samples had relatively better physical properties. The 45° samples had the best mechanical properties. But the fracture toughness of specimens (H group and 90° samples of W group) did not yet meet clinical requirements. That indicated that the characteristics of the 3D printing denture base resin were affected by the printing direction. Only when the performance of the printed samples in all directions met the minimum requirements of the standard, they could be used in clinical practice.

Structure of Human Serum Albumin at a Foam Surface

Proteins can be adsorbed on the air-water interface (AWI), and the structural changes in proteins at the AWI are closely related to the foaming properties of foods and beverages. However, how these structural changes in proteins at the AWI occur is not well understood. We developed a method for the structural assessment of proteins in the foam state using hydrogen/deuterium exchange mass spectrometry. Adsorption sites and structural changes in human serum albumin (HSA) were identified in situ at the peptide-level resolution. The N-terminus and the loop (E492-T506), which contains hydrophobic amino acids, were identified as adsorption sites. Both the structural flexibility and hydrophobicity were considered to be critical factors for the adsorption of HSA at the AWI. Structural changes in HSA were observed after more than one minute of foaming and were spread widely throughout the structure. These structural changes at the foam AWI were reversible.

Corrosion and Biological Behaviors of Biomedical Ti-24Nb-4Zr-8Sn Alloy under an Oxidative Stress Microenvironment

Biomaterials can induce an inflammatory response in surrounding tissues after implantation, generating and releasing reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). The excessive accumulation of ROS may create a microenvironment with high levels of oxidative stress (OS), which subsequently accelerates the degradation of the passive film on the surface of titanium (Ti) alloys and affects their biological activity. The immunomodulatory role of macrophages in biomaterial osteogenesis under OS is unknown. This study aimed to explore the corrosion behavior and bone formation of Ti implants under an OS microenvironment. In this study, the corrosion resistance and osteoinduction capabilities in normal and OS conditions of the Ti-24Nb-4Zr-8Sn (wt %, Ti2448) were assessed. Electrochemical impedance spectroscopy analysis indicated that the Ti2448 alloy exhibited superior corrosion resistance on exposure to excessive ROS compared to the Ti-6Al-4V (TC4) alloy. This can be attributed to the formation of the TiO2 and Nb2O5 passive films, which mitigated the adverse effects of OS. In vitro MC3T3-E1 cell experiments revealed that the Ti2448 alloy exhibited good biocompatibility in the OS microenvironment, whereas the osteogenic differentiation level was comparable to that of the TC4 alloy. The Ti2448 alloy significantly alleviates intercellular ROS levels, inducing a higher proportion of M2 phenotypes (52.7%) under OS. Ti2448 alloy significantly promoted the expression of the anti-inflammatory cytokine, interleukin 10 (IL-10), and osteoblast-related cytokines, bone morphogenetic protein 2 (BMP-2), which relatively increased by 26.9 and 31.4%, respectively, compared to TC4 alloy. The Ti2448 alloy provides a favorable osteoimmune environment and significantly promotes the proliferation and differentiation of osteoblasts in vitro compared to the TC4 alloy. Ultimately, the Ti2448 alloy demonstrated excellent corrosion resistance and immunomodulatory properties in an OS microenvironment, providing valuable insights into potential clinical applications as implants to repair bone tissue defects.

Flexural strength of repaired denture base materials manufactured for the CAD-CAM technique

PURPOSE

To evaluate the flexural properties of repaired poly(methylmethacrylate) (PMMA) denture base materials for computer-aided design/computer-aided manufacturing (CAD-CAM) and to compare them with heat-activated polymerized PMMA.

METHODS

A total of 288 specimens (65 × 10 × 2.5 mm) were prepared using both CAD-CAM and conventional blocks and repaired using autopolymerizing and visible-light polymerizing (VLC) materials. Microwave energy, water storage and hydroflask polymerization were applied as additional post-polymerization cycles after the repair process. The flexural strength (FS) of the specimens was evaluated using the three-point bending test. Data were evaluated statistically using 2-way ANOVA followed by Bonferroni's correction to determine the significance of differences between the groups (P ≤ 0.05).

RESULTS

The FS of the denture base materials for CAD-CAM was significantly higher than that for the heat-activated group (P ≤ 0.05). The FS was significantly highest when microwave energy was used for the post-polymerization cycle. The FS values for all groups repaired with VLC resin were significantly lower than for the autopolymerization group (P ≤ 0.05).

CONCLUSION

The flexural properties of denture base materials for CAD-CAM repaired using autopolymerizing acrylic resins can recover by 50-70%. Additional post-polymerization cycles for autopolymerizing repair resin can be suggested to improve the clinical service properties of repaired dentures.

Bottom-up production of injectable itraconazole suspensions using membrane technology

Bottom-up production of active pharmaceutical ingredient (API) crystal suspensions offers advantages in surface property control and operational ease over top-down methods. However, downstream separation and concentration pose challenges. This proof-of-concept study explores membrane diafiltration as a comprehensive solution for downstream processing of API crystal suspensions produced via anti-solvent crystallization. It involves switching the residual solvent (N-methyl-2-pyrrolidone, NMP) with water, adjusting the excipient (d-α-Tocopherol polyethylene glycol 1000 succinate, TPGS) quantity, and enhancing API loading (solid concentration) in itraconazole crystal suspensions. NMP concentration was decreased from 9 wt% to below 0.05 wt% (in compliance with European Medicine Agency guidelines), while the TPGS concentration was decreased from 0.475 wt% to 0.07 wt%. This reduced the TPGS-to-itraconazole ratio from 1:2 to less than 1:50 and raised the itraconazole loading from 1 wt% to 35.6 wt%. Importantly, these changes did not adversely affect the itraconazole crystal stability in suspension. This study presents membrane diafiltration as a one-step solution to address downstream challenges in bottom-up API crystal suspension production. These findings contribute to optimizing pharmaceutical manufacturing processes and hold promise for advancing the development of long-acting API crystal suspensions via bottom-up production techniques at a commercial scale.

Bacteroid cerium oxide particles promote macrophage polarization to achieve early vascularization and subsequent osseointegration around implants

The establishment of an osseointegration is crucial for the long-term stability and functionality of implant materials, and early angiogenesis is the key to successful osseointegration. However, the bioinertness of titanium implants affects osseointegration, limiting their clinical application. In this study, inspired by the rapid polarization of macrophages following the phagocytosis of bacteria, we developed bacteroid cerium oxide particles; these particles were composed of CeO2 and had a size similar to that of Bacillus (0.5 μ m). These particles were constructed on the implant surfaces using a hydrothermal method. In vitro experiments demonstrated that the particles effectively decreased the reactive oxygen species (ROS) levels in macrophages (RAW264.7). Furthermore, these particles exerted effects on M1 macrophage polarization, enhanced nitric oxide (NO) secretion to promote vascular regeneration, and facilitated rapid macrophage transition to the M2 phenotype. Subsequently, the particles facilitated human umbilical vein endothelial cell (HUVEC) migration. In vivo studies showed that these particles rapidly stimulated innate immune responses in animal models, leading to enhanced angiogenesis around the implant and improved osseointegration. In summary, the presence of bacteroid cerium oxide particles on the implant surface regulated and accelerated macrophage polarization, thereby enhancing angiogenesis during the immune response and improving peri-implant osseointegration.

Wettability and Bactericidal Properties of Bioinspired ZnO Nanopillar Surfaces

Nanomaterials of zinc oxide (ZnO) exhibit antibacterial activities under ambient illumination that result in cell membrane permeability and disorganization, representing an important opportunity for health-related applications. However, the development of antibiofouling surfaces incorporating ZnO nanomaterials has remained limited. In this work, we fabricate superhydrophobic surfaces based on ZnO nanopillars. Water droplets on these superhydrophobic surfaces exhibit small contact angle hysteresis (within 2-3°) and a minimal tilting angle of 1°. Further, falling droplets bounce off when impacting the superhydrophobic ZnO surfaces with a range of Weber numbers (8-46), demonstrating that the surface facilitates a robust Cassie-Baxter wetting state. In addition, the antibiofouling efficacy of the surfaces has been established against model pathogenic Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli). No viable colonies of E. coli were recoverable on the superhydrophobic surfaces of ZnO nanopillars incubated with cultured bacterial solutions for 18 h. Further, our tests demonstrate a substantial reduction in the quantity of S. aureus that attached to the superhydrophobic ZnO nanopillars. Thus, the superhydrophobic ZnO surfaces offer a viable design of antibiofouling materials that do not require additional UV illumination or antimicrobial agents.

Effects of surface glazing on the mechanical and biological properties of 3D printed permanent dental resin materials

Purpose This study aimed to determine the surface glazing effect on the mechanical and biological properties of three-dimensional printed dental permanent resins.Methods Specimens were prepared using Formlabs, Graphy Tera Harz permanent, and NextDent C&B temporary crown resins. Specimens were divided into three groups: samples with untreated surfaces, glazed surfaces, and sand-glazed surfaces. The flexural strength, Vickers hardness, color stability, and surface roughness of the samples were analyzed to identify their mechanical properties. Their cell viability and protein adsorption were analyzed to identify their biological properties.Results The flexural strength and Vickers hardness of the samples with sand glazed and glazed surfaces were significantly increased. The color change was higher for surface untreated samples than that for the samples with sand-glazed and glazed surfaces. The surface roughness of the samples with sand-glazed and glazed surfaces was low. The samples with sand-glazed and glazed surfaces have low protein adsorption ability and high cell viability.Conclusions Surface glazing increased the mechanical strength, color stability, and cell compatibility, while reducing the Ra and protein adsorption of 3D-printed dental resins. Thus, a glazed surface exhibited a positive effect on the mechanical and biological properties of 3D-printed resins.

Evaluation of High-Performance Polyether Ether Ketone Polymer Treated with Piranha Solution and Epigallocatechin-3-Gallate Coating

Background

Dental implantation has become a standard procedure with high success rates, relying on achieving osseointegration between the implant surface and surrounding bone tissue. Polyether ether ketone (PEEK) is a promising alternative to traditional dental implant materials like titanium, but its osseointegration capabilities are limited due to its hydrophobic nature and reduced surface roughness.

Objective

The aim of the study is to increase the surface roughness and hydrophilicity of PEEK by treating the surface with piranha solution and then coating the surface with epigallocatechin-3-gallate (EGCG) by electrospraying technique.

Materials and Methods

The study includes four groups intended to investigate the effect of piranha treatment and EGCG coating: a control group of PEEK discs with no treatment (C), PEEK samples treated with piranha solution (P), a group of PEEK samples coated with EGCG (E), and a group of PEEK samples treated with piranha solution and coated with EGCG (PE). Surface roughness, wettability, and microhardness were assessed through statistical analysis.

Results

Piranha treatment increased surface roughness, while EGCG coating moderated it, resulting in an intermediate roughness in the PE group. EGCG significantly improved wettability, as indicated by the reduced contact angle. Microhardness increased by about 20% in EGCG-coated groups compared to noncoated groups. Statistical analysis confirmed significant differences between groups in all tests.

Conclusion

This study demonstrates the potential of EGCG coating to enhance the surface properties of PEEK as dental implants. The combined piranha and EGCG modification approach shows promise for improved osseointegration, although further vivo research is necessary. Surface modification techniques hold the key to optimizing biomaterial performance, bridging the gap between laboratory findings and clinical implementation in dental implantology.

Effect of filler contents on the bond strength of CAD/CAM resin crowns: New resin primer versus conventional silane agents

Purpose This study aims to evaluate the effects of resin primers containing methyl methacrylate (MMA) and silane agent on the bonding effectiveness of indirect resin composite blocks with three different filler contents.Methods A commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) resin composite block and two experimental resin composite blocks with different filler contents were alumina-blasted and two surface treatments (primer and silane agent) were applied. The resin cement was built up, and the micro-tensile bond strength (μTBS) was measured after 24 hours, 1 month or 3 months of water storage (n = 24 per group). The fracture surfaces after μTBS measurements and resin block/cement interface were observed by scanning electron microscopy (SEM).Results The primer treatment group showed a significantly higher bond strength than the silane group only in F0 (filler content 0 wt%) group (P < 0.001). In the primer group, F0 and F41 (filler content 41 wt%) groups showed significantly higher bond strengths than F82 (filler content 82 wt%) group (P < 0.001). In contrast, in the silane group, F41 group showed significantly higher bond strength than F0 and F82 groups (P < 0.001), and F82 group showed significantly higher bond strength than F0 group (P < 0.001). SEM revealed that the matrix resin was partially destroyed on the fracture surface of the primer group, and an uneven interface surface was observed compared with that of the silane group.Conclusions MMA-containing primers showed higher bonding effectiveness to CAD/CAM resin composite blocks than the silane treatment.

Effects of various functional monomers' reaction on the surface characteristics and bonding performance of polyetheretherketone

PURPOSE

Polyetheretherketone (PEEK) is a new polymeric material that has received significant attention in dentistry because of its mechanical properties, biocompatibility, and aesthetics. However, the bonding performance of PEEK to other materials is not preferable. This study aimed to analyze the variations in the surface characteristics of PEEK under the chemical action of primers containing different functional monomers or polymers and to evaluate the bonding performance of PEEK and dental cement.

METHODS

Disk-shaped PEEK samples were prepared by dental milling, blasting with alumina oxide, and covering with primers containing functional monomers or polymers. The surface characteristics of the samples were analyzed by microscopy and spectroscopy. The shear bond strength (SBS) between PEEK and dental cement, with and without thermocycling, was tested using a universal testing machine. Finally, the data were statistically analyzed and compared.

RESULTS

Functional monomers or polymers were successfully bonded to the surface of PEEK. This treatment significantly improved its hydrophilicity and surface free energy (P < 0.05). The primer containing pentaerythritol triacrylate had the highest SBS without thermocycling (13.89 MPa). Meanwhile, the primers containing urethane dimethacrylate (UDMA) and methyl methacrylate (MMA) (abbreviated as the HC group) showed the highest SBS and lowest reduction (25.51%) after thermocycling. Notably, all the testing groups achieved the ISO10477 standard of 5 MPa. After thermocycling, adhesive failure accounted for the largest proportion of failures in all the groups except the HC group.

CONCLUSIONS

The chemical priming treatment can significantly improve the SBS of PEEK and dental cement. Moreover, a primer containing both UDMA and MMA can provide improved bonding for PEEK materials.

Influence of stress-relieving heat treatments on the efficacy of Co-Cr-Mo-W alloy copings fabricated using selective laser melting

Purpose This study aimed to evaluate the influence of stress-relieving heat treatments on the metal-ceramic bond strength and fitness accuracy of selective laser melting (SLM)-fabricated Co-Cr alloy copings.Methods SLM-manufactured Co-Cr samples were stress-relieved at 750 (Ht-750) and 1150 °C (Ht-1150). The microstructure, surface roughness, metal-ceramic bond strength, marginal and internal fit, Vickers hardness, and residual stress were then compared with those of the non-heat-treated group (As-built). The results were analyzed using one-way ANOVA and post-hoc tests (Tukey's or Student's t test) (P = 0.05).Results The microstructure of the Ht-1150 samples had a brittle oxide layer and lower surface roughness, resulting in significantly lower bond strength values than those of the other groups. The As-built group exhibited significantly lower marginal gap values than the Ht-750 and Ht-1150 groups. Therefore, the post-heat treatments degraded the marginal fitness. The surface residual stress in all sample groups were compressive because of the sandblasting effect. The compressive stresses were larger in Ht-1150 than in As-built and Ht-750 owing to their low hardness values.Conclusions Stress-relief annealing porcelain-fused-to-metal single crowns does not improve bond strength and degrades fitness accuracy because additional post-heat treatments induce thermal distortion. These findings are expected to facilitate the direct application of As-built SLM single crowns in dentistry to minimize post-manufacturing costs and time.

Effects of ceramic thickness, ceramic translucency, and light transmission on light-cured bulk-fill resin composites as luting cement of lithium disilicate based-ceramics

PURPOSE

To assess the effects of ceramic thickness, ceramic translucency, and light transmission on restorative composites used as luting cement for lithium disilicate-based ceramics.

METHODS

Four luting types of cement were tested (n=8); a dual-cured resin cement (Multilink N), a light-cured conventional flowable composite (Tetric N-Flow), and two light-cured bulk-fill flowable composites (Tetric N-Flow Bulk Fill and X-tra base). The 20 s- or 40 s-light (1000 mW/cm2) was transmitted through 1- or 2-mm-thick high- or low-translucency (HT- or LT-) ceramic discs (IPS e.Max press) to reach the 1-mm-thick luting cement. Light transmitted to cement without ceramic served as a control. Vickers hardness number (VHN), flexural strength (FS), fractography, and degree of conversion (DC) were evaluated. One-way and multi-way analysis of variance was conducted to determine the effects of factors on VHN and FS.

RESULTS

Ceramic thickness, light transmission time, and cement type significantly affected the VHN of the luting cement (P < .000). Only Multilink N (LT- and HT-1mm) and Tetric N-Flow (HT-1mm) reached 90% VHN of corresponding control by 20 s-light transmissions, but Tetric N-Flow exhibited lowest VHN and approximately 1/3-1/2 VHN of Multilink N (P < 0.05). X-tra base expressed superior physicochemical properties to Tetric N-Flow Bulk Fill (P < 0.05) and reached >90% VHN of control in all conditions with 40 s-light transmissions except for LT-2 mm. DC, FS, and fractography supported these findings.

CONCLUSIONS

The light-cured bulk-fill composite served as a luting cement for lithium-disilicate-based ceramics in a product-dependent manner. Light transmission time is crucial to ensure sufficient luting cement polymerization.

Research Progress in Structure Synthesis, Properties, and Applications of Small-Molecule Silicone Surfactants

Silicone surfactants have garnered significant research attention owing to their superior properties, such as wettability, ductility, and permeability. Small-molecular silicone surfactants with simple molecular structures outperform polymeric silicone surfactants in terms of surface activity, emulsification, wetting, foaming, and other areas. Moreover, silicone surfactants with small molecules exhibit a diverse and rich molecular structure. This review discusses various synthetic routes for the synthesis of different classes of surfactants, including single-chain, "umbrella" structure, double chain, bolaform, Gemini, and stimulus-responsive surfactants. The fundamental surface/interface properties of the synthesized surfactants are also highlighted. Additionally, these surfactants have demonstrated enormous potential in agricultural synergism, drug delivery, mineral flotation, enhanced oil recovery, separation, and extraction, and foam fire-fighting.

The effect of linseed oil/canola oil blend on the coating and thermal properties of waste PET-based alkyd resins

This study aims to prepare oil-modified alkyd resins using a linseed oil/canola oil (LO/CO) blend and waste PET depolymerization product, suitable for environmentally friendly coating applications. Waste PET flakes obtained from grinding post-consumer water bottles were depolymerized by the aminoglycolysis reaction at high pressure. Raw depolymerization product (DP) was used in the synthesis of four components, 50% oil alkyd resins by monoglyceride method. DP has partly replaced the dibasic acid component in the PET-based alkyd formulations. Besides PET-based alkyds, reference alkyds without DP were also synthesized for comparison. Then, the surface coating properties and thermal behaviors of alkyd films were determined. The effect of DP usage and the changing ratios of LO/CO blend on coating properties and thermal behaviors of alkyd films were investigated. In addition, the optimum LO/CO blend ratio which is compatible with alkyd formulation was attempted to be determined. At the end of this study, glossy, soft/medium-hard films were obtained with excellent adhesion, impact strength, and chemical resistance. Thermal resistance and final thermal oxidative degradation temperature increased with adding DP to the alkyd formulation. Using LO/CO blend in the formulations affected oxidation rate and ratio, hence, drying time/degree and oxidative stability of alkyd films.

Short curing time bulk fill composite systems: volumetric shrinkage, degree of conversion and Vickers hardness

This study aimed to evaluate volumetric polymerization shrinkage, degree of conversion and Vickers hardness of four bulk-fill resin composites light-activated with their dedicated light curing units (LCUs). Four groups were evaluated, according to the type of composite and curing mode: Tetric EvoCeram Bulk-fill (TEBO) and Tetric EvoFlow Bulk-fill (TEBF) were light-activated with Bluephase Style 20i (20s, in high-mode), while Tetric Powerfill (TEPO) and Tetric Powerflow (TEPF) were light-activated with Bluephase PowerCure (3s). Volumetric polymerization shrinkage test (n = 6) was performed in standardized box-shaped class-I cavities of extracted third molars (4 x 4 x 4 mm). Teeth were scanned before and after resin composite application by micro-computed tomography, and acquired data were evaluated with Amira software. Degree of conversion (n = 5) was evaluated at the top and bottom surfaces of composite cylindric samples (4 mm diameter, 4 mm thickness) using an FT-IR spectrometer (spectra between 1,500 and 1,800 cm-1, 40 scans at a resolution of 4 cm-1). Three Vickers indentations (50 g / 15 s), spaced 500 μm apart, were performed on the top and bottom composite surfaces and averaged. One-way ANOVA was used for data evaluation. TEPF showed the lowest volumetric polymerization shrinkage (p < 0.05), while the other composites were not significantly different within each other (p > 0.05). All materials presented a significant decrease in degree of conversion and Vickers hardness when compared top to bottom surfaces (p < 0.05). Bottom to top surface ratios for degree of conversion ranged from 0.8 (TEBO and TEPO) to 0.9 (TEBF and TEPF), and from 0.4 (TEPO) to 0.7 (TEBF and TEPF) for hardness. In conclusion, resinous materials present a decrease in hardness and degree of conversion from top to bottom even when a higher power is used, while the flowable material TEPF showed the lowest volumetric shrinkage values compared to the other materials.

Ion-incorporated titanium implants for staged regulation of antibacterial activity and immunoregulation-mediated osteogenesis

Antibacterial properties and osteogenic activity are considered as two crucial factors for the initial healing and long-term survivability of orthopedic implants. For decades, various drug-loaded implants to enhance biological activities have been investigated extensively. More importantly, to control the drug release timing is equally significant due to the sequential biological processes after implantation. Hence, developing a staged regulation system on the titanium surface is practically significant. Here, we prepared TiO2 nanotubes (TiO2 NTs) on the titanium surface by anodization, followed by the incorporation of zinc (Zn) and strontium (Sr) sequentially through a hydrothermal process. Surface characterization confirmed the successful fabrication of Zn and Sr-incorporated TiO2 NTs (Zn-Sr/TiO2) on the titanium surface. The ion release results exhibited the differential release characteristic of Zn and Sr, which meant the early-stage release of Zn and the long-term release of Sr. It was exactly in accord with  the biological process after implantation, laying the basis of staged regulation after implantation. Zn-Sr/TiO2 showed favorable anti-early infection properties both in vitro and in vivo. Its inhibition effect on bacterial biofilm formation was attributed to the resistance against bacteria's initial adhesion and the killing effect on planktonic bacteria. Additionally, the release of Sr could alleviate infection-induced damage via immunoregulation. The biocompatibility and osteogenic activity mediated by M2 macrophage activation were confirmed with in vitro and in vivo studies. Therefore, it exhibited great potential in staged regulation for antibacterial activity in the early stage and the M2 activation-mediated osteogenic activity in the late stage. The staged regulation process was based on the differential release of Zn and Sr to achieve the early antibacterial effect and the long-term immune-induced osteogenic activity, to prevent implant-related infection and achieve better osseointegration. These two kinds of ions played their roles synergistically and complement mutually. This work is expected to provide an innovative idea for realizing sequential regulation after implantation.

Bonding Effectiveness of Saliva-Contaminated Monolithic Zirconia Ceramics Using Different Decontamination Protocols

Objective

This research study investigated the effect of new decontamination protocols on the bonding capacity of saliva-contaminated monolithic zirconia (MZ) ceramics cemented with two different monomer-containing self-adhesive resin cements.

Materials and Methods

Standardized tooth preparations (4 mm. axial height) were performed for eighty human maxillary premolars under constant water cooling system. Eighty monolithic zirconia crowns (Whitepeaks Supreme Monolith) (n = 8/10 groups) were manufactured by CAD-CAM. Specimens were kept in the artificial saliva at pH = 7.3 for 1 minute at 37°C except control groups. The specimens have not been prealumina blasted and grouped according to cleaning methods and resin cements: control groups (C) (no saliva contamination + GPDM + 4-META (N) (CN) and 10-MDP (M) containing resin cement (CM), alumina blasted (AL) + GPDM + 4-META (ALN) and 10-MDP containing resin cement (ALM), zirconium oxide containing universal cleaning agent (IC) applied + GPDM + 4-META (N) (ICN) and 10-MDP containing resin cement (ICM), pumice (P) applied + GPDM + 4-META (PN) and 10-MDP containing resin cement (PM), and air-water spray (AW) applied + GPDM + 4-META (AWN) and 10-MDP containing resin cement (AWM)). Monobond Plus was applied to all surfaces for 40 seconds before cementation. The thermal cycle was applied at 5,000 cycles after cementation. The crowns were tested in tensile mode at a speed of 1 mm/min. The mode of failure was recorded. SEM examinations were carried out at different magnifications. Data were analyzed using rank-based Kruskal-Wallis and Mann-Whitney tests.

Results

No significant differences were found between the surface treatments and between the two types of resin cements. Interaction effects between surface treatments and resin cements were found to be significant by two-way ANOVA analysis. ICM group resulted in significantly better bond strength results compared with CN. ICM was found to result in better bond strength results compared with PM. The combination of universal cleaning agent and 10-MDP containing resin cement had significantly the highest cementation bond strength values. The increasing order of mean tensile bond strength values of decontamination protocols was C < AW < P < AL < IC. The mean tensile bond strength of 10-MDP containing resin cement was slightly higher than GPDM + 4-META containing resin cement.

Conclusions

Universal cleaning agents can be preferred as an efficient cleaning method with 10-MDP-containing cement after saliva contamination for better adhesive bond strength of 4 mm crown preparation height of monolithic zirconia ceramics.

In vivo validation of highly customized cranial Ti-6AL-4V ELI prostheses fabricated through incremental forming and superplastic forming: an ovine model study

Cranial reconstructions are essential for restoring both function and aesthetics in patients with craniofacial deformities or traumatic injuries. Titanium prostheses have gained popularity due to their biocompatibility, strength, and corrosion resistance. The use of Superplastic Forming (SPF) and Single Point Incremental Forming (SPIF) techniques to create titanium prostheses, specifically designed for cranial reconstructions was investigated in an ovine model through microtomographic and histomorphometric analyses. The results obtained from the explanted specimens revealed significant variations in bone volume, trabecular thickness, spacing, and number across different regions of interest (VOIs or ROIs). Those regions next to the center of the cranial defect exhibited the most immature bone, characterized by higher porosity, decreased trabecular thickness, and wider trabecular spacing. Dynamic histomorphometry demonstrated differences in the mineralizing surface to bone surface ratio (MS/BS) and mineral apposition rate (MAR) depending on the timing of fluorochrome administration. A layer of connective tissue separated the prosthesis and the bone tissue. Overall, the study provided validation for the use of cranial prostheses made using SPF and SPIF techniques, offering insights into the processes of bone formation and remodeling in the implanted ovine model.

Visible light-induced photocatalytic and antibacterial adhesion properties of superhydrophilic TiO2 nanoparticles

Bacterial infections triggered by patient or healthcare worker contact with surfaces are a major cause of medically acquired infections. By controlling the kinetics of tetrabutyl titanate hydrolysis and condensation during the sol-gel process, it is possible to regulate the content of Ti3+ and oxygen vacancies (OVs) in TiO2, and adjust the associated visible light-induced photocatalytic performance and anti-bacterial adhesion properties. The results have shown that the Ti3+ content in TiO2 was 9.87% at the calcination temperature of the reaction system was 300 °C and pH was 1.0, corresponding to optimal photocatalytic and hydrophilic properties. The formation of a hydrated layer on the superhydrophilic surface provided resistance to bacterial adhesion, preventing cross-contamination on high-touch surfaces. The excellent photocatalytic self-cleaning performance and anti-bacterial adhesion properties can be attributed to synergistic effects associated with the high specific surface area of TiO2 nanoparticles, the mesoporous structure, and the presence of Ti3+ and OVs. The formation of superhydrophilic self-cleaning surfaces under visible light can serve as the basis for the development of a new class of anti-bacterial adhesion materials.

Rapid and Mechanically Robust Immobilization of Proteins on Silica Studied at the Single-Molecule Level by Force Spectroscopy and Verified at the Macroscopic Level

Typical methods for stable immobilization of proteins often involve time-consuming surface modification of silicon-based materials to enable specific binding, while the nonspecific adsorption method is faster but usually unstable. Herein, we fused a silica-binding protein, Si-tag, to target proteins so that the target proteins could attach directly to silica substrates in a single step, markedly streamlining the immobilization process. The adhesion force between the Si-tag and glass substrates was determined to be approximately 400-600 pN at the single-molecule level by atomic force microscopy, which is greater than the unfolding force of most proteins. The adhesion force of the Si-tag exhibits a slight increase when pulled from the C-terminus compared to that from the N-terminus. Furthermore, the Si-tag's adhesion force on a glass surface is marginally higher than that on a silicon nitride probe. The binding properties of the Si-tag are not obviously affected by environmental factors, including pH, salt concentration, and temperature. In addition, the macroscopic adhesion force between the Si-tag-coated hydrogel and glass substrates was ∼40 times higher than that of unmodified hydrogels. Therefore, the Si-tag, with its strong silica substrate binding ability, provides a useful tool as an excellent fusion tag for the rapid and mechanically robust immobilization of proteins on silica and for the surface coating of silica-binding materials.

Anodization as a scalable nanofabrication method to engineer mechanobactericidal nanostructures on complex geometries

Bacterial contamination of implant surfaces is one of the primary causes of their failure, and this threat has been further exacerbated due to the emergence of drug-resistant bacteria. Nanostructured mechanobactericidal surfaces that neutralize bacteria via biophysical forces instead of traditional biochemical routes have emerged as a potential remedy against this issue. Here, we report on the bactericidal activity of titania nanotubes (TNTs) prepared by anodization, a well-established and scalable method. We investigate the differences in bacterial behavior between three different topographies and demonstrate the applicability of this technique on complex three-dimensional (3D) geometries. It was found that the metabolic activity of bacteria on such surfaces was lower, indicative of disturbed intracellular processes. The differences in deformations of the cell wall of Gram-negative and positive bacteria were investigated from electron micrographs Finally, nanoindentation experiments show that the nanotubular topography was durable enough against forces typically experienced in daily life and had minimal deformation under forces exerted by bacteria. Our observations highlight the potential of the anodization technique for fabricating mechanobactericidal surfaces for implants, devices, surgical instruments, and other surfaces in a healthcare setting in a cheap, scalable way.

Effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials: An in vitro investigation

The aim of the study was to evaluate the effects of erosion and abrasion on resin-matrix ceramic CAD/CAM materials [CERASMART (GC); VITA ENAMIC (VITA Zahnfabrik); Lava Ultimate (3 M)] in comparison to feldspar ceramic (VITABLOCS Mark II, VITA Zahnfabrik) and resin composite materials (ceram.x universal, Dentsply Sirona). Daily brushing and acid exposure were simulated using a brushing apparatus and a solution of 0.5 vol% citric acid. Microhardness, surface roughness, and substance loss were measured at baseline and after simulation of 1 and 3 years of function. All materials showed a decrease in microhardness after 3 years and an increase in surface roughness (Ra) after 1 and 3 years. The Ra increase was statistically significantly lower for the resin-matrix ceramics than for feldspar ceramic and similar to composite material. After 3 years, only feldspar ceramic showed no significant substance loss. In conclusion, resin-matrix ceramics demonstrate reduced roughening compared to feldspar ceramics, potentially improving restoration longevity by preventing plaque buildup, but differences in abrasion resistance suggest the need for further material-specific research. Future research should aim to replicate clinical conditions closely and to transition to in vivo trials.

In vitro wear resistance of conventional and flowable composites containing various filler types after thermomechanical loading

OBJECTIVE

To comparatively assess the wear resistance of conventional and flowable composites containing different filler types using thermomechanical chewing simulation.

MATERIALS AND METHODS

Six different composite resin materials were used: a conventional and flowable composite from each of three manufacturers respectively classified by different filler characterizations: (1), a nanohybrid conventional (G-aenial Posterior, GC) and flowable (G-aenial Universal Injectable, GC), (2) a nanofilled conventional (Filtek One Bulk-fill Restorative, 3M) and flowable (Filtek Ultimate Flow, 3M), and submicron-filled conventional (Estelite Posterior Quick, Tokuyama) and flowable (Estelite Bulk-Fill Flow, Tokuyama). The buccal surfaces of extracted human premolars were planarly abraded and used as control (n = 12). The prepared surfaces were subjected to wear using a thermocycler chewing simulator against 6-mm diameter steatite balls for 240,000 cycles, simulating 1 year of in vivo use. Digital profiles of treated sample surfaces were scanned using a laser scanner, and the volume loss and maximum depth of loss were calculated. Two-way MANOVA was used to compare the wear volume loss and depth according viscosity (conventional/flowable) and filler type (nanohybrid, nanofilled, submicron-filled), and multiple comparisons were performed using Duncan's test.

RESULTS

Wear volume loss and loss depth were significantly lower in enamel than in all composite resin groups. The wear volume loss and loss depth of nanofilled composites were significantly higher than the other composite filler types, with no significant difference in either parameter between the nanohybrid and submicron-filled composite groups. With respect to apparent viscosity, wear volume loss and loss depth of conventional composites were significantly lower than the flowable composites.

CONCLUSIONS

The type of composite filler and its apparent viscosity significantly influence the in vitro wear resistance of the material. All composite materials tested demonstrated a susceptibility to simulated wear that was two to three times greater than that of human enamel.

CLINICAL SIGNIFICANCE

Flowable composite resins provide a level of convenience in clinical application. Despite advancements in their wear characteristics, they continue to display inferior wear resistance compared to conventional composite resins. Nevertheless, all tested composite resins exhibited a significantly higher potential for wear than human enamel.

The biofilm removal effect and osteogenic potential on the titanium surface by electrolytic cleaning: An in vitro comparison of electrolytic parameters and five techniques

OBJECTIVES

To determine the optimal current and time of electrolytic cleaning (EC), compare its biofilm removal effect with generic treatments and evaluate the influence of EC to surface characteristics and osteogenic potential of SLA titanium (Ti) discs.

MATERIALS AND METHODS

The six-species biofilm-covered Ti discs were placed as cathodes in physiologic saline and subjected to various current and time treatments. The residual biofilms were evaluated to determine the optimal parameters. The contaminated Ti discs were randomized and treated by rotating Ti brush; ultrasonic-scaling with metal tips; ultrasonic-scaling with PEEK tips; air-polishing and EC. The residual biofilms were compared using a lipopolysaccharide kit (LPS), scanning electron microscope (SEM), confocal laser scanning microscopy and colony-forming unit counting. Non-contaminated Ti discs were treated and characterized. The bone marrow mesenchymal stem cells (BMSCs) were cultured on treated non-contaminated Ti discs. The adhesion, proliferation, alkaline phosphatase (ALP) activity and osteocalcin level of BMSCs were assessed.

RESULTS

The parameters at 0.6A5min were considered optimal. For LPS and SEM, EC promoted a significantly greater biofilm removal than the other groups. There were no changes in the Ti discs' colour, topography, roughness and chemical elements after EC, and the electrolysis-treated Ti discs obtained a super-hydrophilic surface. EC positively impacted the proliferation and ALP activity of BMSCs, surpassing the efficacy of alternative treatments.

CONCLUSIONS

EC achieves a near-complete eradication of contaminants on the SLA surface, causes no surface damage with improved hydrophilicity, and promotes the early osteogenic response of BMSCs, which makes it a promising treatment for peri-implantitis.