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Calcium phosphate-based bioscaffolds are used for bone tissue regeneration because of their physical and chemical resemblance to human bone. Calcium, phosphate, sodium, potassium, magnesium, and silicon are important components of human bone. The successful biomimicking of human bone characteristics involves incorporating all the human bone elements into the scaffold material. In this work, Mg-Whitlockite (WH) and Calcium Silicate (CS) were selected as matrix and reinforcement respectively, because of their desirable elemental composition and regenerative properties. The magnesium in WH increases mineralization in bone, and the silicon ions in CS support vascularization. The Mg-WH was synthesized using the wet chemical method, and powder characterization tests were performed. Response surface methodology (RSM) is used to design the experiments with a combination of material compositions, infill ratios (IFs), and sintering temperatures (STs). The WH/CS bioceramic composite is 3D printed in three different compositions: 100/0, 75/25, and 50/50 wt%, with IFs of 50%, 75%, and 100%. The physical and mechanical characterization study of printed samples is conducted and the result is optimized using RSM. ANOVA (Analysis of Variance) is used to establish the relationship between input parameters and responses. The optimized input parameters were the WH/CS composition of 50/50 wt%, IF of 50%, and ST of 1150 °C, which bring out the best possible combination of physical and mechanical characteristics. The RSM optimized response was a density of 2.27 g cm -3 , porosity of 36.74%, wettability of 45.79%, shrinkage of 25.13%, compressive strength of 12 MPa, and compressive modulus of 208.49 MPa with 92% desirability. The biological characterization studies were conducted for the scaffold samples prepared with optimized input parameters. The biological studies confirmed the capabilities of the WH/CS composite scaffolds in bone regenerative applications., (© 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Objectives: A new abutment-free implant connection allows for direct screwing of FDPs on implants to avoid complications caused by cement rests or screw loosening, which may affect to screw torque and load distribution. The objective of this study was to test the initial (Fi) and final failure (Ff) loads and torque changes of abutment-free monolithic zirconia CAD-CAM fixed dental prostheses (FDPs) compared to titanium FDPs on different abutment designs., Methods: Three-unit screw-retained FDPs (n = 50) on two implants (n = 100) were divided into groups (n = 10) based on the implant-abutment connection and material of the supra-structure: (1) abutment-free monolithic CAD-CAM zirconia FDP (Abut-free-Zr), (2) abutment-free veneered titanium FDPs (Abut-free-Ti), (3) monolithic zirconia FDPs with titanium base abutments (Zr-Ti-Base), (4) monolithic zirconia FDPs on multi-unit abutments (Zr-MU), (5) veneered titanium FDP on multi-unit abutments (Ti-MU). All specimens were subjected to thermo-mechanical aging (1'200'000 Cycles, 49 N, 1.67 Hz, 5º to 50º C, dwelling time 120 s). Torque of the screws was measured, and static loading was performed. Data were tested using ANOVA and Tukey's tests (p < 0.05)., Results: After thermo-mechanical aging, all screws showed reduced torque, Ti-MU significantly more reduction compared to Abut-Free-Ti (p = 0.0021). Titanium groups showed significantly lower Fi (N) values (171.4-230 vs 1272-1358,) due to veneering porcelain fractures (p = 0.0001) and significantly higher Ff (N) (2922 -3029 N vs. 1272-1358) values than zirconia groups (p < 0.0001)., Conclusions: Three-unit abutment-free monolithic zirconia FPDs showed similar failure loads compared to other zirconia groups, while the titanium groups exhibited superior final failure loads. Different abutment designs did not seem to affect the failure loads., Clinical Significance: The specific design of the novel implant interface allows for the fabrication of implant supported FDPs with personalized design directly on implant level without abutments. The monolithic zirconia FDPs on abutment-free implant connection can be used with good confidence since they exhibit similar mechanical stability as monolithic zirconia FDPs on titanium-base or multi-unit abutments., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: T.S., K.M, M.Ö., and J.H. report no financial interests related to any products involved in this study. R.J. is a patent-holder of the implant connection design of the tested implant (MaTRIx implant, TRI Dental Implants Int. AG, Zürich, Switzerland). Study implant materials such as implants and abutments were provided by TRI Dental Implants for free. Zirconia and titanium materials for the fixed dental prostheses were provided by ZirkonZahn. R.J. received lecture fees and research support from TRI Dental Implants in the past., (Copyright © 2025. Published by Elsevier Ltd.)

Background: Due to the launch of new self-etching and self-adhesive sealing materials combined with the release of bioactive ions in the dental market, this in vitro study aimed to compare physical values of surface roughness (RS), vickers microhardness (VM), compositional energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), microbiological tests (inhibition halo-HI and surface microbial adhesion-MAS) and mechanical microshear bond strength (MBS)., Methods: The following groups were analyzed: Beautisealant® self-etching sealant (Shofu)(G1), FluroShield® conventional sealant (Dentsply)(G2- Control Group), Flow Constic® self-adhesive/self-etching resin (DMG)(G3) and Beautifil Flow Plus F03® conventional resin (Shofu)(G4). For the physical and compositional tests, specimens were molded and submitted to finishing/polishing in a metallographic polisher. RS and VM were measured through 5 readings. For the HI test, specimens were exposed to S. mutans for 24 h in brain-heart infusion (BHI) agar under microaerophilic conditions, with the diameter of the HI (mm) measured by digital caliper. For the MAS test, a bacterial biofilm of S. mutans was induced for five days in BHI broth + 5% sucrose and measurement of CFU/ml (log 10 from serial dilutions). For the MBS test, specimens were made in bovine enamel with the addition of the experimental group FluroShield® (Dentsply) + Single Bond Universal® adhesive (3 M)(G5) and measured in a universal testing machine. Data were submitted to ANOVA and Tukey's post hoc tests (p < 0.05) using the SPSS software., Results: Different compositions proven in the EDS test were not determinants of the promotion of different RS: G1 = 0,19 (± 0,07), G2 = 0,15 (± 0,053), G3 = 0,13 (± 0,046), G4 = 0,14 (± 0,056); HI: G1 = 17,7 (± 1,36), G2 = 18,7 (± 3,47), G3 = 18,9 (± 4,87), G4 = 17,9 (± 3,61) and MAS: G1 = 5,22 (± 0,12), G2 = 5,15 (± 0,15), G3 = 5,12 (± 0,20), G4 = 5,06 (± 0,24). However, statistically influenced the values of VM: G1 = 16,71 (± 1,93), G2 = 16,28 (± 4,91), G3 = 26,11 (± 3,46), G4 = 37.9 (± 4.87), promoted lesser bacterial adhesion (G4 = 5.06 ± 0.24), and demonstrated fluoride ion only in the G4. Higher MBS was found in the conventional materials G5 = 8.38 (± 2.05) and G2 = 6.28 (± 1.35)., Conclusions: Bioactive materials and self-adhesive/self-etching for sealing pits and fissures did not demonstrate superior mechanical and antimicrobial properties performance compared to conventional techniques., Competing Interests: Declarations. Ethics approval and consent to participate: Non-applicable for this in vitro study. Consent to participate: Non-applicable for this in vitro study. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Metallic biomaterials, such as cobalt chrome molybdenum (CoCrMo), Ti-6Al-4V, and 316L stainless steel are commonly used in orthopedic implant devices. Damage modes such as corrosion and wear are associated with the use of these alloys. One solution to limit wear and corrosion damage is to apply a surface coating to the medical device. In this study, using the low-energy electron beam (LEEB) of scanning electron microscopy (SEM), we induced a highly scratch-resistant oxygen and silicon-rich amorphous carbon film to grow on each of the above metallic biomaterials. LEEB interaction with adventitious surface carbon, silicone, and oxygen deposited on the above three alloys resulted in the layered-deposition formation (LEEB-LD) of a surface coating. Coating chemistry, morphology, and nano-scratch wear properties on each of the three alloys were characterized using atomic force microscopy (AFM) scratch testing and SEM/Energy dispersive spectroscopy (EDS) analysis. We hypothesized that LEEB-LD coatings could be deposited on these three metallic biomaterials with improved tribological properties than the underlying metal substrate. First, we generated coatings on all three biomaterials and documented the coating morphology (thickness and heterogeneity) and chemistry as a function of alloy, exposure time, and scan rate with coating thicknesses generated between 5 and 50 nm after 60 min of treatment, with each factor affecting the thickness. EDS maps showed high amounts of carbon, oxygen, and silicon in the modified surface which depended on the alloy (e.g., CoCrMo and SS had similar compositions while Ti had higher oxygen in the coatings). Coated and uncoated surfaces were then subjected to diamond scratch testing in an AFM at increasing force until the coating delaminated from the surface. Scratch-depth versus load and nominal Hertzian stress were plotted for both the uncoated and coated surfaces. We found that scratch depths were 40%, 75%, and 38% smaller on CoCrMo, Ti, and SS coatings, respectively, at the peak contact stresses tested (⍺ < 0.05), indicating higher hardness and wear resistance for the coatings. These results support the hypothesis that controlled thickness LEEB-LD oxygen and silicon-rich amorphous carbon coatings can be systematically generated using low-power electron beams and that these coatings have increased tribological (scratch-resistance) properties compared to the substrate metal., (© 2025 The Author(s). Journal of Biomedical Materials Research Part A published by Wiley Periodicals LLC.)

Background: A decrease in oral pH levels may have detrimental effects on vacuum-formed retainers since an acidic oral environment could impact the mechanical and physical properties of these retainers. The present In vitro study aimed to evaluate the effect of simulated gastric acid at pH 4 and 1.2 on the surface microhardness, flexural strength, and color change of three different types of orthodontic retainer materials., Methods: A total of 144 vacuum-formed commercially available retainer materials: copolyesters, polypropylene, and PET-G (n = 48/group) were evaluated. Each specimen was immersed in distilled water, and then the specimens were divided into two subgroups: those with a pH of 4 and those with a pH of 1.2. The microhardness test was performed using Innovatest, the flexural strength was evaluated by a universal testing machine, and the color change was analyzed using a spectrophotometer. The data were analyzed using One-Way ANOVA and independent sample t test at a significance value of P ≤ 0.05., Results: Our findings indicated a significant decrease in flexural strength in all the experimental groups after immersion in pH 1.2 and 4 solutions (P < 0.001), with PET-G being the most affected material, followed by copolyester and polypropylene. Only copolyester demonstrated a significant decrease in surface microhardness following immersion in a pH 4 solution (P = 0.025). All materials exhibited the greatest degree of color alteration CP (P = 0.006), PP (P = 0.001), and PET-G (P = 0.009) respectively., Conclusion: The study concluded that copolyester adversely affects flexural strength, surface microhardness, and color when subjected to immersion in simulated gastric acid. Therefore, care is recommended for patients diagnosed with gastroesophageal reflux disease., Competing Interests: Declarations. Ethics approval and consent to participate: This study did not involve animal or human experiments. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Objectives: The growing trend of minimally invasive approaches has encouraged the application of partial coverage designs in restorative dentistry. This study aimed to evaluate the cyclic fatigue performance of different CAD-CAM materials used in various partial coverage designs for premolar restorations., Methods: A freshly extracted upper premolar was prepared using a high-speed handpiece to create mesio-occluso-distal (MOD) cavities with standardized dimensions. Three preparation designs were investigated: onlay, overlay, and vonlay. CAD software was used to create digital models of the restorations, which were milled into one of four CAD-CAM materials: Zr - zirconia polycrystals (4Y-PSZ); EX - lithium disilicate glass-ceramic; VS - zirconia-reinforced lithium silicate glass-ceramic; GB - nanohybrid composite. Partial coverage restorations were bonded to tooth replicas and subjected to step-stress cyclic fatigue testing using a chewing simulator device (n = 10). The number of cycles-to-failure and fatigue fracture resistance (N) were recorded and analysed with Kaplan-Meier survival statistics and Weibull analysis, respectively. Fracture surfaces were analysed using fractography., Results: Zr exhibited significantly higher number of cycles-to-failure and greater characteristic fracture load (L 0 ) than the other materials, for onlay and overlay designs. For vonlay design, Zr, VS and EX had similar and greater number of cycles-to-failure than GB. When comparing different designs for the same material, Zr had lower number of cycles-to-failure for vonlay in comparison to onlay and overlay, while the other materials had similar values among the different designs. Weibull modulus was similar among experimental groups., Significance: The findings of this study emphasize the critical role of material selection and preparation design in optimizing the mechanical performance and clinical success of partial coverage restorations. 4Y-PSZ is recommended for high-stress areas due to its superior fatigue and fracture resistance. Overlay designs provide better fatigue resistance, making them more suitable for clinical scenarios requiring higher durability. Understanding the fatigue performance of different materials and designs aids in making informed decisions to enhance the longevity and success of partial coverage restorations in premolars., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: To proof the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C through investigating the degree and durability of the colour changes, and testifying whether surface, mechanical and biological properties are influenced by the treatment., Methods: 222 nm UV-C light (Irradiance: 1.870 mW/cm 2 ) was used to treat 3Y-TZP for durations from 15 min to 24 h. ΔE*, TP, crystalline structure, surface morphology, S a , BFS and biological activities were investigated before and after irradiation. SPSS 28.0 was used for statistical analysis (α = 0.05)., Results: 222 nm UV-C irradiation was capable to shade white 3Y-TZP into tooth colours. With the increase of ΔE*, TP decreased, such that the longer the irradiation time, the higher the ΔE* (logarithmic relationship) and lower the TP. Despite the induced optical changes being prone to fade, the process can be predicted by inversely proportional relationships between ΔE*, TP and the testing points. The treated surface exhibited enhanced hydrophilicity, while the recovery phenomenon was observed. Other properties were not altered by the treatment., Significance: This is the seminal study demonstrating the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C. The new relationship between the colour centre and E g of 3Y-TZP was established, whereas the induced optical changes were stabilised after a certain period and were highly predictable by controlling the irradiation periods. The irradiation was only correlated to the electron excitation and oxygen vacancies, and would not lead to any changes of other properties. A simple, safe and promising approach to achieve satisfactory colours on 3Y-TZP in clinical practice can be developed., Competing Interests: Declaration of Competing Interest There are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to enhance the anti-bacterial adhesion effect against Streptococcus mutans (S. mutans) of fluorinated dimethacrylate (DF MA) based dental resin composites (DRCs) by using silicone dimethacrylate (SMA-MEO)., Method: The SMA-MEO was added into mixture of DFMA and tricyclo (5.2.1.0) decanedimethanol diacrylate (SR833s) (DFMA/SR833s = 50 wt./50 wt.) with mass ratios of 10 wt% and 20 wt% to form resin matrix both with fluorinated and silicon containing dimethacrylates, and then DRCs named DS+ 10 %SMA-MEO and DS+ 20 %SMA-MEO were prepared by mixing the resin matrix with silaned BaAlSiO 2 filler particles at a mass ratio of 30 wt./70 wt. Double bond conversion, volumetric shrinkage and shrinkage stress, flexural strength and modulus, water sorption and solubility, contact angle and surface free energy, anti-bacterial adhesion effect against Streptococcus mutans (S. mutans), and cytotoxicity of prepared DRCs were investigated according to standard or referenced methods. Fluorinated dimethacrylate (DFMA) based DRC named DS and 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl)-phenyl]propane (Bis-GMA) based DRC named BT were used as controls., Results: Adding SMA-MEO into DFMA based DRC could lead to higher double bond conversion (p < 0.05), higher hydrophobicity (p < 0.05), and lower surface free energy (p < 0.05). Only DS+ 10 %SMA-MEO had better anti-bacterial adhesion effect against S. mutans than DS (p < 0.05). The SMA-MEO had no influence on volumetric shrinkage, shrinkage stress, flexural modulus, water sorption and solubility of DRC (p > 0.05), but could reduce flexural strength of dry DRC (p < 0.05). After water immersion, SMA-MEO containing DRCs had comparable flexural strength as DS (p > 0.05). Compared with BT, DS and SMA-MEO containing DRCs had better or comparable physicochemical properties, and lower amount of adherent S. mutans. All of DRCs had comparable cytotoxicity (p > 0.05)., Significance: DRCs with both DFMA and SMA-MEO could have better anti-bacterial adhesion effect against S. mutans than DRC only with DFMA due to increased hydrophobicity and decreased Surface free energy, and the optimal mass fraction of SMA-MEO in DFMA based resin matrix was 10 wt%., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study aimed to investigate the efficacy and durability of bioactive glass-based dental resin infiltrants. Resin infiltrants were formulated by combining photoinitiated dimethacrylate monomers with three variations of bioactive glass: 45S5 Bioglass (RIS), boron-substituted (RIB), fluoride-substituted (RIF), and pure resins (PR), whereby TOOTH group (TH) and ICON (CN) served as commercial control groups. Teeth samples were prepared, and experimental and control infiltrants were applied on demineralized human-extracted teeth. All the samples were subjected to immersion in artificial saliva and pH cycling for 30 days. The samples from another group underwent tooth brushing simulation for 9600 cycles. Following artificial saliva immersion, the samples' hardness values showed that RIB had the highest values (318.44 ± 3.83) while PR (212.52 ± 9.02) had the lowest values. After immersing into the pH cycling solution, the RIF showed the highest hardness (286.86 ± 5.11), while the lowest values for the CN (143.76 ± 3.50). After the tooth brushing simulation, the teeth samples with RIB showed maximum microhardness values (312.06 ± 16.30) and the weakest for the TH (189.60 ± 6.43). The commercial and experimental enamel resin infiltrants showed almost similar results overall, with RIB demonstrating better microhardness and comparable surface roughness. In contrast, RIF proved more resistant to pH cycling, exhibited higher microhardness, and performed better in surface roughness analysis. These findings suggest that resin infiltrant materials, especially RIF, have promising potential for effectively and esthetically managing white spot lesions., (© 2024 Wiley Periodicals LLC.)

Objective: To evaluate the effect of build orientation on the fabrication trueness and fit of additively manufactured 2-piece zirconia abutments when compared with those manufactured subtractively in 3 mol% and 4 mol% yttria-stabilized zirconia (3Y-TZP and 4Y-TZP)., Methods: A titanium-base (Ti-base) abutment was digitized with a scan body and an industrial scanner to design a 2-piece zirconia abutment with a 50 µm cement gap. This design was used to manufacture zirconia abutments additively in different orientations (0-degree, AM-0; 15-degree, AM-15; 30-degree, AM-30; 45-degree, AM-45; 180-degree, AM-180) and subtractively from 3Y-TZP and 4Y-TZP (SM-3 and SM-4) (n=5). An intraoral scanner was used to digitize all abutments, when they were seated on the Ti-base, and only the Ti-base. Abutments' trueness (overall, external, intaglio, and marginal) was analyzed with the root mean square (RMS) method, and their fit was assessed with the triple-scan protocol. Data were analyzed with 1-way analysis of variance and Tamhane's T2 tests (α = 0.05)., Results: SM-3 abutments had the lowest overall and external RMS (P ≤ 0.023). SM-3 and SM-4 abutments mostly had lower intaglio and AM-0 abutments mostly had lower gingival RMS (P ≤ 0.013). Except for AM-0 and SM-3 (P ≥ 0.930), SM-4 abutments had the lowest average gaps (P ≤ 0.041)., Conclusions: SM-3 abutments mostly had higher fabrication trueness, while AM-0 abutments had trueness similar to or higher than the other additively manufactured abutments. AM-0, SM-3, and SM-4 abutments had similar fit with average gaps lower than 50 µm., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: To examine whether the effectiveness of current dentin-priming approaches requiring solvated hydrophilic resins may be replicated by modifying the infiltration dynamics of neat methacrylate-based monomers into dry-etched dentin using dimethyl sulfoxide (DMSO) pretreatments., Methods: H 3 PO 4 -etched mid-coronal dentin surfaces from human molars were air-dried for 30 s and randomly pretreated with 50 %(v/v) ethanolic DMSO for 20 or 60 s. Untreated samples and an isolated wet-bonding group served as controls. Samples were bonded with a three-step etch-and-rinse adhesive or simply with the solvent-free hydrophobic-rich resin. Restored crown segments (n = 7/group) were stored in distilled water for 24 h and sectioned for microtensile bond strength testing. Resin-dentin beams (0.8 mm 2 ) were tested under tension until failure (0.5 mm/min) after 24 h or 2 years of storage in artificial saliva at 37 °C. Nanoleakage evaluation and hybrid layer characterization were performed by SEM. Bond strength data was examined by three-way ANOVA followed by Tukey and Dunnett's test (α = 0.05)., Results: Pretreatments significantly affected the ability of neat and solvated resins to bond to etched-dry dentin (p = 0.001). Ageing significantly lowered bond strengths depending on resin composition and DMSO-application times (p = 0.007). While hybridization of DMSO-treated dentin with the solvated resin produced no significant reductions in bond strengths after ageing (p < 0.05) improving hybrid layer integrity, direct bonding of the neat hydrophobic-rich resin matched the long-term bonding performance of the "gold standard" wet-bonding protocol (p > 0.05)., Significance: Lowering dentin's hydration state via DMSO-dry bonding allows direct coupling of neat methacrylate-based resins, which may contribute to developing new strategies to ultimately extend the durability of resin-dentin interfaces., (Copyright © 2024. Published by Elsevier Inc.)

Additive manufacturing for fabrication of patient-specific oral and maxillofacial implants enables optimal fitting, significantly reducing surgery time and subsequent costs. However, it is still common to encounter hardware- or biological-related complications, specifically when radiation treatment is involved. For mandibular reconstruction plates, irradiated patients often experience plate loosening and subsequent plate exposure due to a decrease in the vascularity of the irradiated tissues. We hypothesize that an acceleration of the bone ingrowth prior to radiation treatment can increase the survival of such plates. In this work, a new design of a mandibular reconstruction plate is proposed to promote osseointegration, while providing the necessary mechanical support during healing. In this regard, six different Triply Periodic Minimal Surface (TPMS) structures were manufactured using laser-powder bed fusion. Three-point bending and in-vitro cell viability tests were performed. Mechanical testing demonstrated the ability for all structures to safely withstand documented biting forces, with favorable applicability for the Gyroid structure due its lower flexural modulus. Finally, cell viability tests confirmed high cell proliferation rate and good cell adhesion to the surface for all TPMS structures. Overall, the new design concept shows potential as a viable option for plates with improved functionality and higher survival rate., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: The purpose of this study was to evaluate the effects of air polishing with sodium bicarbonate and erythritol powders on surface roughness and morphological changes in titanium abutments., Methods: A total of 45 grade V titanium discs were divided in three groups: Group A (Control) air polished with air/water; Group B, air polished with sodium bicarbonate powder; and Group C, air polished with erythritol powder. After air polishing, the samples' roughness (S a ) in micrometres were analysed with an optical profilometer. The samples' surface morphology study was conducted via scanning electronic microscope (SEM). Data were described using mean and standard deviation of roughness values (S a ). Inferential analysis was performed using the ANOVA multiple comparison test followed by Tukey's post hoc test. Both tests used a 5% level of significance., Results: After air polishing, average roughness of group A, B and C were 0.036, 0.046 and 0.037 μm, respectively, with statistically significant differences between groups A and B (p < 0.05). No statistically significant differences were found between group A and group C, as well as between group B and C (p > 0.05). As for the morphology analysis, damages to the titanium surface were only observed in group B., Conclusions: The study indicates that air polishing with erythritol powder maintains titanium abutment integrity better than sodium bicarbonate, which increased surface roughness and caused damage. Erythritol is preferable for minimizing surface alterations and maintaining morphological stability., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: This study aimed to elucidate the effect of various two-step sintering (TSS) protocols on the physical, mechanical, and optical properties of partially stabilized zirconia with different yttria dopant concentrations (Y-PSZ)., Methods: Disc-shaped specimens were obtained from most widely used commercial dental zirconia powders of various Y contents (Tosoh Corp.) by uniaxial pressing followed by cold-isostatic pressing. Densification was carried out using TSS protocols with varying temperatures for both sintering steps. Relative density (ρ Rel ), microstructure, and phase content were analyzed. Biaxial flexural strength (σ) and translucency parameter (TP) were evaluated., Results: The TSS results were compared with optimized conventional sintering (CS) results from a previous study for the same Y-PSZ compositions. TSS 3Y-PSZ and 4Y-PSZ reached similar ρ Rel to those of their CS counterparts, whereas 5Y-PSZ failed to achieve that regardless of TSS protocol. TSS yielded less cubic phase compared to CS, especially for 3Y-PSZ and for higher temperatures. TSS suppressed the grain growth throughout the temperature range investigated, promoting smaller grains than CS (p < 0.05). The TP values for TSS Y-PSZ were lower than those of CS (p ≤ 0.0001), except for 3Y-PSZ. The σ values for TSS Y-PSZ were significantly higher than those of CS (p ≤ 0.0002)., Significance: TSS increased strength without significantly jeopardizing the optical properties of various Y-PSZ compositions relative to their CS counterparts. This alternative sintering method appears to be a promising technique for controlling grain growth while eliminating porosities in dental Y-PSZ ceramics, thus potentially enhancing the clinical longevity of zirconia restorations., Competing Interests: Declaration of Competing Interest All authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To compare the fatigue behavior and reliability of 5 pressed lithium disilicate ceramics and a 5 mol% yttria-stabilized zirconia (5Y-TZP) when 3 dynamic loading protocols were used., Methods: Bar-shaped specimens (30 × 4 × 3 mm) were fabricated from 5 pressed lithium disilicate ceramics (AMB, CEL, INI, IPS, and LIV) and a 5Y-TZP (ZR) (N = 324). Six specimens from each material were subjected to a static 4-point fracture load test, while the remaining specimens were subjected dynamic loading by increasing the starting load (30 % of the static fracture load) in every 5000 cycles by 50 N (loading protocol 1), in every 5000 cycles by 5 % (loading protocol 2) or in every 1000 cycles by 10 N (loading protocol 3) until fracture (n = 16). The fracture load, flexural strength, and number of cycles until failure were analyzed with 2-way analysis of variance and Scheffé tests. The survival rate was evaluated with Kaplan-Meier analysis and further compared with Mantel-Cox test, while the correlation between the fracture load and flexural strength was analyzed with Pearson's correlation test (α = 0.05). Fractographic analysis was also performed., Results: The interaction between the materials and the loading protocol affected the number of cycles until failure, while the material type affected fracture load and flexural strength values (P < 0.001). ZR had the highest and LIV mostly had lower fracture load and flexural strength (P ≤ 0.034). A positive correlation was found between the fracture load and flexural strength (r = 0.997, P < 0.001). For lithium disilicate ceramics, loading protocol 2 and for ZR, loading protocols 1 and 3 led to the highest number of cycles and survival rate (P ≤ 0.041). Regardless of the loading protocol, all lithium disilicate ceramics had a similar fragmentation pattern with single compression curls and 2-piece fractures were observed., Significance: Tested materials are suitable for adhesively luted monolithic single-unit prosthesis as they had mean flexural strength values higher than 100 MPa. Measuring the fracture load with loading protocol 3 can be considered time-efficient to evaluate the fatigue behavior of pressed lithium disilicate ceramics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Dental titanium implants and their surface modifications markedly improve implant biocompatibility. However, studies evaluating the mechanical biocompatibility of implants are scarce. In particular, the analysis of mechanical biocompatibility deficiencies leading to stress shield-induced bone resorption. Recently, we focused on using PEEK as a dental material. This study explored the hypothesis that PEEK implants improve the stress shielding of titanium. In this study, artificial bone surfaces were examined to measure strains on the artificial bone surface under compressive loading with the implants in place. Additionally, 3D image analysis of the fracture state inside the bone tissue was performed using micro-CT (µCT). This hypothesis was supported by µCT imaging analysis of bone tissue changes under stress, which revealed that PEEK implants transfer greater loads than titanium implants. µCT imaging and statistical analysis showed that bone porosity had little effect on stress shielding.

This study evaluated the effects of HEMA and 10-MDP in the bonding agent in a 2-step self-etch adhesive system, Clearfil SE Bond 2, on water sorption (W sp ) and elastic modulus (E) of the polymerized bonding agent. The microtensile bond strength (µTBS) to dentin was also evaluated initially and after 10,000 thermal cycles (TC10,000). Four bonding agents were tested: the original, H-free (excluding HEMA), M-free (excluding 10-MDP), and HM-free (excluding HEMA and 10-MDP). HEMA increased W sp and decreased E. Initial µTBS (TC0) was highest for the original and lowest for HM-free. After TC10,000, the original maintained the highest µTBS, indicating the importance of HEMA and 10-MDP. TC10,000 did not reduce µTBS for any groups. HEMA and 10-MDP compromised mechanical property and increased water sorption, suggesting these components could potentially compromise adhesive stability.

This study evaluated the influence of phosphoric acid and primer on enamel bonding performance using Panavia V5. Ground bovine enamels were assigned: using K-etchant syringe and Tooth Primer (CT), using K-etchant syringe (PA), using Tooth Primer (TP), neither K-etchant syringe nor Tooth Primer was used (NC). The micro-tensile bond strength values of CT and PA were significantly higher than TP. After thermal cycling, the values were higher in CT and PA. In the leakage test, line-shaped signal pattern at the adhesive interface was detected in NC, and the signal was partially detected in PA and TP. Observation of the adhesive interface after acid and base challenge confirmed tooth-like structures in groups except NC. Large spaces were observed between the enamel and cement in NC. Limited in this study, the lack of application of phosphoric acid or Tooth Primer may affect the enamel bonding performance.

This study investigates the moments generated when applying third-order bends to lingual brackets with different slot shapes and wires made of different materials. Three types of lingual brackets with different slot shapes: 0.018×0.018-inch square slot self-ligation bracket (AL-bracket); 0.018×0.025-inch slot self-ligation bracket (CL-bracket); 0.018×0.025-inch slot self-ligation bracket (ST-bracket). Wires of three different materials were measured. The torque value generated during torque application was measured using a torque gauge. The AL-bracket had a significantly larger torque moment than the CL- and ST-brackets at the same angles. The CL-bracket had the smallest torque moment of the three for the square wire; however, the CL-bracket revealed a larger torque moment than the ST-bracket for the rectangular wire. The torque moment of Ti-Ni wires was observed the smallest. In lingual orthodontic treatment, the results suggested the shape of the lingual bracket slot and the wire material should be considered when adjusting and applying third-order bends.

The aim was to compare different surface pretreatments on definitive resin crown materials manufactured additively or subtractively in terms of shear bond strength (SBS) values. Seven subgroups (n=10) were formed from additively manufactured VarseoSmile Crown Plus (VS) and subtractively manufactured Cerasmart270 blocks (CS) according to different surface pretreatments applied; sandblasting (subgroup SB), hydrofluoric acid (subgroup HF), Multi Primer (subgroup MP), subgroup SB-HF, subgroup SB-MP, subgroup SB-HF-MP, and control subgroup. A 3-mm-diameter composite was cemented onto each sample by self-adhesive resin cement. SBS values were measured and failure modes were analyzed after thermocycling. Data were analyzed with two-way ANOVA and Tukey HSD tests. The mean SBS value of VS was found significantly higher than CS (p<0.001). Subgroups SB-HF-MP, HF, SB-MP, and MP of VS exhibited the highest SBS values (p<0.001). The VS exhibited mostly cohesive failure, while CS exhibited mostly adhesive failure.

The material concept of resin cements capable of disintegrating due to near-infrared (NIR) radiation was verified. The cements were prepared by adding silicon carbide (SiC), which heats upon absorbing NIR rays, and thermally expandable particles (TEPs) to 4-META/MMA-TBB resin cement. The microtensile bond strength (µTBS) and cytocompatibility of the cements were evaluated. The resin cements with 5 mass% SiC and 20-40 mass% TEPs had significantly lower µTBS after NIR radiation than before NIR radiation, and their cytocompatibility was not decreased by SiC and TEPs additions. Furthermore, in vitro thermal damage tests were performed using the resin cement with 5 mass% SiC and 20 mass% TEPs, a typical composition. The results demonstrated conditions that significantly reduced µTBS and minimized thermal damage by NIR radiation. Although these data are only proof of concept, the possibility that dental devices bonded with these cements could be detached by NIR radiation was demonstrated.

Caries is a chronic oral disease causing a series of complications. This study aims to develop a material that could remineralize demineralized enamel and simultaneously exert antibacterial effects. A carboxymethyl chitosan (CMC)/amorphous calcium phosphate (ACP)/polyhexamethylene biguanide hydrochloride (PHMB) nanocomposite was synthesized for the first time, and its stability, remineralization ability, and antibacterial properties were investigated in this study. PHMB has excellent antibacterial properties, was used as an additive to stabilize ACP. The enamel surface covered with CMC/ACP/PHMB showed a uniform layer with a similar elemental ratio to that of natural hydroxyapatite and the ratio of crystal diffraction peaks was close to that of natural enamel. The mechanical properties, including hardness and elastic modulus, of the enamel in all experimental groups were restored. The antibacterial effect of 240 mg/L CMC/ACP/PHMB was comparable to that of 0.12% CMC/ACP/chlorhexidine. This study provides a theoretical and experimental basis for the development of novel dual-function anticaries agent.

This study aimed to evaluate ionic release, flexural strength and water absorption of UDMA resins containing 0-30 wt% surface pre-reacted glass-ionomer (S-PRG) filler fabricated by a DLP 3D printer. Release of Al, B, Na, Sr and F ions were measured by inductively coupled plasma (ICP) and an ion meter. Flexural strength test and water absorption measurements were performed according to the International Organization for Standardization (ISO) 4049 standard and ISO 1567 standard, respectively. Sr ions were released the most, followed by F, B, Na and Al ions. The highest flexural strength was recorded with the S-PRG filler amount 0 wt%, followed by the S-PRG filler amounts 30, 20 and 10 wt%. Water absorption after one week was below the 32 µg/mm 3 mark specified by ISO 1567. The release of ions was confirmed using UDMA-based photopolymerized resin containing S-PRG filler. Furthermore, the results suggest that this resin could be used for provisional restoration.

Hydroxyapatite (HAp) nanocoatings on titanium alloys (e.g. Ti6Al4V) have been used for prosthetic orthopaedic implants in recent decades because of their osseointegration, bioactivity, and biocompatibility. HAp is brittle with low mechanical strength and poor adhesion to metallic surfaces, which limits its durability and bioactivity. Surface modification techniques have alleviated the imperfections in biomaterials by coating the substrate. Several methods for improving the characteristics of implants, such as physical vapour deposition, the thermal spray method, the sol-gel method, microarc oxidation, and electrochemical deposition methods, have been discussed in this review. These processes provide mechanical strength without sacrificing biocompatibility and may lead to the development of new ideas for future research. This review discusses various selective additives, including carbon allotropes, ceramic materials, metallic materials, and multiple materials, to enhance tribological characteristics, biocompatibility, wear resistance, and mechanical strength. This review focuses on the fabrication of nano-HAps as coatings using selective deposition methods with controlled deposition parameters, paying special attention to recent developments in bone tissue engineering. This report is organized in such a way that it may inspire further research on surface modifications during medical treatment. The present review may help prospective investigators understand the importance of surface modifications for obtaining excellent implantation performance., (© 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Polylactic acid (PLA) has garnered attention for use in interim dental restorations due to its biocompatibility, biodegradability, low cost, ease of fabrication, and moderate strength. However, its performance under intraoral conditions, particularly under heat and moisture, remains underexplored. This study evaluated the mechanical properties of PLA interim crowns compared with those of polymethylmethacrylate (PMMA) and bisphenol crowns under simulated intraoral conditions with thermocycling. Three CAD/CAM polymers-PMMA (milling), PLA (fused deposition), and bisphenol (stereolithography)-were tested for fracture resistance, hardness, and surface roughness. For fracture strength, 25 crowns from each group were cemented onto dies. The Shore D hardness and surface roughness were measured on round discs before and after 10,000 thermocycles (5°C/55°C). The surface topography was assessed via scanning electron microscopy. PMMA exhibited the highest fracture strength (2787.93 N), followed by bisphenol (2165.47 N) and PLA (2088.78 N), with no significant difference between the latter two. PMMA and bisphenol showed vertical fractures and cracks, whereas PLA showed crown tearing or die deformation. Bisphenol had the highest Shore D hardness, followed by PMMA and PLA, with no significant changes after thermocycling. The surface roughness (Ra) was lowest for bisphenol and similar between PMMA and PLA. The roughness (Rz) increased from bisphenol to PMMA to PLA. The roughness of the PMMA remained unchanged after thermocycling, whereas the Ra but not the Rz of the PLA increased. Bisphenol showed a significant increase in both Ra and Rz (p<0.0001). In conclusion, PLA interim crowns demonstrated mechanical properties comparable to those of conventional PMMA and bisphenol crowns after thermocycling., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2025 Doh et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Suture-associated surgical site infection (SSI) causes bacterial pathogens to colonize on the suture surface that are highly resistant to antibiotic treatment. Conventional suture materials used in surgical practice are causing complications such as infection and chronic inflammation. Surgical suture materials with antibacterial coatings are widely used in surgical practice. However, all the widely used antibacterial agents are not permanent (limited lasting) due to their instability and release depending on environmental conditions (pH or temperature, for example). Therefore, more long-lasting (low-dose) and effective antibacterial function materials are required. In the present work, we proposed a new material and method of antibacterial coating the surgical sutures based on the atomic layer deposition (ALD) technique to enhance its antibacterial activity for treatment of the SSI. We have proposed applying a vanadium-doped TiO 2 nanofilm (hybrid nanomaterial, TiVO x ) with 27.5 nm thickness to enhance the antibacterial property of surgical sutures using the ALD technique. We have illustrated that a base coating of Al 2 O 3 (seed layer) applied to the suture surface, which directly contacts the polypropylene (PP) suture, improves the adhesion of the deposited antibacterial material TiVO x . This provides a long-lasting antibacterial effect on the suture (a prolonged antibacterial effect of the coating material), i.e. increases the stability of the deposition (stable in water, air, in the human body, in different pH mediums, and at temperatures up to 70 °C). The sutures did not deteriorate after several wash cycles with sterilizing solvents. Also, the antibacterial agent (TiVO x ) is nontoxic. The concentration of vanadium in the film is below the toxicity limits due to the low diffusivity of vanadium and high adhesion with the base coating material (Al 2 O 3 ). Sutures coated with V-doped TiO 2 were characterized using scanning electron microscopy images, and elemental analysis was performed using energy dispersive spectroscopy Spectroscopy. The antibacterial activity of TiVO x coated sutures against two types of microorganisms, E. coli and Proteus vulgaris ( Pr. Vulgaris ) was compared to that of noncoated sutures. The quantitative assessment of antibacterial activity of suture materials with and without ALD nanocoating TiVO x against E. coli and Pr. Vulgaris has been performed. No growth of bacteria around the suture material with antibacterial TiVO x ALD nanocoating throughout the entire observation period of 48 and 72 h was observed. However, after 48 h, the concentration of bacteria of the E. Coli around the suture material without ALD TiVO x nanocoating on nutrient agar was 5.5 ± 0.3 Log CFU cm -3 , and after 72 h it was 8.0 ± 0.5 Log CFU cm -3 . For Pr. Vilgaris, after 48 h, the concentration of bacteria around the suture material without ALD TiVO x nanocoating on nutrient agar was 2.1 ± 0.1 Log CFU cm -3 , while after 72 h it was 4.5 ± 0.2 Log CFU cm -3 . ALD-coated TiVO x on the PP sutures inhibited approximately 100% of biofilm formation. Also, the inhibition zones in the disc diffusion assay revealed that all the ALD TiVO x coating inhibited (100%) the growth of E. coli and Pr. Vulgaris , notably compared to the uncoated suture samples., (© 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Objective: This study aims to examine color properties of repairs made with various composites on restorations produced through additive-manufactured resin composites (AM-RC) and zirconia (AM-Z) or subtractive manufacturing (SM) after coffee thermocycling (CTC)., Materials and Methods: Disk-shaped specimens (Ø10 × 2 mm; N = 120) were fabricated using six different material groups: additively manufactured resin composite (AM-RC) materials (Crowntec [C], NextDent [ND]), additively manufactured zirconia (AM-Z) materials (Lithoz [LI], INNI-Cera [IN]), and subtractively manufactured (SM) materials (CEREC Tessera [ALD], Vita Enamic [EN]). Subsequently, each group was further subdivided into two subgroups (n = 10) based on the type of repair using two different composites resins: Clearfil Majesty Posterior (CL) (n = 60) and Filtek Z350 (FZ) (n = 60). Specimens underwent thermal cycling (CTC), consisting of 10,000 cycles between 5 °C and 55 °C. Color measurements were performed both before and after thermal cycling for all materials. Color discrepancies (ΔE00) and relative translucency parameters (RTPs) were calculated. Statistical analyses were conducted at a significance level of α = 0.05., Results: A one-way ANOVA of ΔE00 values between CL and FZ revealed a significant difference (P = 0.007), with FZ exhibiting higher ΔE00 values. Significant differences in ΔE00 values were also observed among IN, C, and ND after CTC (P < 0.05). ALD demonstrated the lowest amount color change (P < 0.05). LI and EN colors showed no significant difference (P = 0.75). Following CTC, C, ND, and IN colors matched CL. In contrast, ALD, EN, and L colors exhibited significant differences (P ≤ 0.050). FZ showed a poor color match with all AM and SM materials. Furthermore, significant differences in RTP values were identified for all specimens (P < 0.001), with LI having the highest RTP and IN the lowest (P < 0.001)., Conclusion: The optical properties of composite and ceramic materials, as well as their stability over time, are crucial for their durability. ALD demonstrated the most consistent color stability. While the CL repair composites experienced some color changes, these changes remained within acceptable limits. Additionally, the LI (AM-Z) material exhibited the highest level of translucency., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Objectives: To investigate volumetric changes, in vivo biocompatibility, and systemic migration from eight commercial endodontic sealer materials in paste/paste, powder/liquid, and pre-mixed forms., Materials and Methods: The sealers AH Plus Bioceramic, AH Plus Jet, BioRoot RCS, MTApex, Bio-C Sealer, Bio-C Sealer Ion+, EndoSequence BC Sealer and NeoSEALER Flo were studied. After characterisation by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy and X-ray diffractometry (XRD), tubes were implanted in Wistar rats' alveolar bone and subcutaneous tissues. Micro-CT evaluated volumetric changes pre/post 30 days of implantation. Histological and immunohistochemistry analyses assessed biocompatibility. Kidney samples underwent spectrometry (ICP-MS) for tantalum, tungsten and zirconium. Statistical analysis determined normality and significance (udp < 0.05)., Results: Characterisation revealed calcium, silicon, and radiopacifiers in the materials. Volumetric changes showed greater alteration in subcutaneous tissues than alveolar bone; BioRoot RCS and MTApex (powder/liquid) were most stable. Histological analysis indicated intense inflammation for AH Plus Jet, moderate for others; IL-10 was marked positively for all materials. AH Plus Jet had an 18-fold higher tungsten and a 37-fold higher zirconium mass fraction in kidneys versus controls, while tantalum showed lower accumulation patterns., Conclusion: Root canal filling materials' responses varied by implantation site and form, demonstrating acceptable biocompatibility. Tantalum and zirconium oxide radiopacifiers appear systemically safe; tungsten-based radiopacifiers are unsuitable due to metal accumulation risks., Clinical Relevance: This study highlights the need for further in vivo studies on endodontic sealers' chemical, biological, and physical behaviors and their systemic migration., Competing Interests: Declarations. Ethical approval: This study was approved by the institutional ethics committee animal research of the Piracicaba Dental School (code CEUA 5888-1/2021 and 5889-1/2021). Consent to participate: This study did not involve humans. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: This study compared the torsional resistance, bending stiffness, and cyclic fatigue resistances of different heat-treated NiTi files for minimally invasive instrumentation., Methods: TruNatomy (TN) and EndoRoad (ER) file systems were compared with ProTaper Gold (PG). Torsional load, distortion angle, and bending stiffness were assessed using a custom device AEndoS, and toughness was calculated using the torsional data. Cyclic fatigue resistance was evaluated using another custom device (EndoC) with 45-degree curved canal in which file was rotated until fracture using dynamic pecking motion at 37 °C. One-way analysis of variance and Duncan's post-hoc comparison were conducted at a significance level of 95%. Scanning electron microscopy (SEM) analyzed fracture features and differential scanning calorimetry (DSC) analyzed phase transformation temperatures., Results: ER and TN showed significantly lower torsional strength than PG (p < 0.05). However, ER showed a significantly greater distortion angle and the highest toughness, followed by PG and TN (p < 0.05). Both ER and TN showed similar bending stiffness, which was lower bending stiffness than PG (p < 0.05). ER showed the highest cyclic fatigue resistance (p < 0.05). SEM revealed typical fracture features across all groups, with distinct milling grooves in PG and TN, not in ER. DSC indicated that PG and ER showed a peak of austenite (Ap) at temperatures higher than body temperature, 42 °C and 40 °C, respectively, while TN showed A p at 25 °C., Conclusion: Files for minimally invasive instrumentations typically exhibited high cyclic fatigue resistance but showed differences in the properties. The selection should depend on the root canal and tooth condition., Competing Interests: Declarations. Human ethics and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Threads coated with bioresponsive materials hold promise for innovative wearable diagnostics. However, most thread coatings reported so far cannot be easily customized for different analytes and frequently incorporate non-biodegradable components. Most optically active thread coatings rely on dyes, which often exhibit irreversible responses. In this work, we propose a biosensing coating for threads using curli fibers. Curli fibers are self-assembling fibers of the protein CsgA that can be genetically engineered to sense rapidly evolving diagnostic targets. We first established a simple electrostatic-mediated absorption protocol for coating anionic cotton threads with anionic curli fibers using an intervening cationic chitosan layer. We applied this protocol to two types of pH-sensing curli fibers, displaying either fluorescent pHuji or mCitrine proteins. This process ensures extensive curli coating over the entire thread surface using only water-based solvents. The resulting protein-coated threads are moderately hydrophobic, stretchable, and can monitor pH changes in real time through fluorescence. The coatings are also stable and functional on the surface for over 25 cycles of use, highlighting their potential for reusable practical applications. This straightforward and adaptable protocol can be extended to coat threads with diverse sensing and responsive capabilities for intelligent clothing.

Biofilm formation on medical devices has become a worldwide issue arising from its resistance to bactericidal agents and presenting challenges to eradicating biofouling adhesion, especially in biological fluids. Metal-phenolic networks have been demonstrated as a versatile and efficient strategy to prevent biofilm formation by endowing medical devices with prolonged antifouling and antibacterial activities in a one-step surface modification. In this study, we report a simple and environmentally friendly method using coordination chemistry between copper ions (Cu 2+ ) and dopamine-containing copolymer to fabricate metal-phenolic network-based coatings. The phenolic groups also imparted the adhesion of glycopolymer-containing dopamine residues to inorganic and organic substrates, resulting in dual antifouling and bactericidal surfaces. 2-gluconamidoethyl methacrylamide monomer (GAEMA) was first copolymerized with dopamine methacrylamide (DMA) using a free-radical polymerization process. The resulting copolymer (GAEMA-DMA), denoted as GADMA, was then mixed with copper ions in a one-step process to form the GADMA-Cu coating. The GADMA-Cu coating was hydrophilic and significantly reduced the water contact angle (WCA) and adsorption of bovine serum albumin protein even after incubation in a bovine serum albumin solution for 30 h. Moreover, the coating exhibited strong antibacterial activity against Escherichia coli and Staphylococcus aureus and was biocompatible with 99% cell viability toward normal human fibroblast (HDFa) cells. Thus, our coating shows great potential for application in medical devices.

Glucose-dependent insulin delivery systems have been recognized as a promising approach for controlling blood sugar levels in individuals with diabetes mellitus (DM). Recently, titanium dioxide nanoparticles have garnered huge attention in scientific research for their small size and effective drug delivery capabilities. In this study, we developed alizarin (AL)-capped phenylboronic acid (PBA)-functionalized titanium dioxide nanoparticles (TiO 2 ) for glucose-sensitive insulin delivery (TiO 2 -PBA-INS-AL) aiming to manage both blood sugar levels and its associated organ pathology in DM. The synthesized nanoparticles demonstrated favorable loading capacity as well as high insulin encapsulation efficiency. Initial studies demonstrated glucose-responsive insulin release from TiO 2 -PBA-INS-AL in a cell-free environment upon exposure to different glucose concentrations. Notably, in vitro experiments revealed that insulin release from TiO 2 -PBA-INS-AL was more effective in muscle cells (primary glucose storage cells) compared to lung cells when subjected to different glucose concentrations (5.5-25 mM), indicating a glucose-sensitive intracellular insulin delivery mechanism. Furthermore, treatment with TiO 2 -PBA-INS-AL significantly enhanced GLUT4 translocation and glucose utilization in muscle cells treated with sodium palmitate (PA, 0.75 mM), compared to treatments with TiO 2 or insulin alone. In diabetic animal models, a single oral dose of TiO 2 -PBA-INS-AL maintained normoglycemia for up to 12 h, indicating a significant improvement over subcutaneous or oral insulin treatment. Oral administration of TiO 2 -PBA-INS-AL also increased insulin bioavailability in both serum and muscle tissue compared to other administration methods. Besides, TiO 2 -PBA-INS-AL treatment showed no toxicity against both in vitro and in vivo models. Taken together, this nanocarrier-based drug delivery system mimics the natural regulation of insulin secretion in a noninvasive manner, enhancing patient adherence, reducing the risk of hyperglycemia, and improving diabetes management.

Hybridization of carbon nanotubes (CNTs) and manganese dioxide (MnO 2 ) integrates the biocompatibility and outstanding electrocatalytic activity of MnO 2 with the exceptional conductivity of CNTs, thus providing a superior synergistic sensing platform for the detection of biomolecules. However, the existing methods for synthesizing MnO 2 /CNT hybrids are complex and inefficient, resulting in low yields and limited surface functionalities. Hence, in this study, we present a low-cost and ultrafast solid-phase synthesis of the MnO 2 /CNT hybrid using a facile microwave technique to detect a crucial biomolecule bilirubin. The successful synthesis of the MnO 2 /CNT hybrid is confirmed through characteristic Raman and X-ray diffraction peaks, while morphology is analyzed by imaging techniques such as FESEM and HRTEM. The MnO 2 /CNT/nickel foam (NF) sensor is thereafter used for the electrochemical detection of bilirubin. The sensor demonstrates a wide linear detection range from 10 nM to 1 mM, with a sensitivity of 6.87 mA nM -1 cm -2 toward bilirubin, as determined through the differential pulse voltammetry technique. The lower limit of detection is noted at 3.3 nM (=3.3 S / m ). Furthermore, the as-fabricated sensor showcases high selectivity against the interfering species. Real-time analysis conducted in simulated blood serum using the standard addition method reveals an outstanding recovery percentage of approximately 98%. The conductive MnO 2 /CNT hybrid interacts robustly with bilirubin, aided by the porous NF substrate for stability, catalytic activity, and rapid electron transfer, enabling sensitive bilirubin detection. The work provides an ultrafast, low-cost, and high-yield solid-phase microwave synthesis of MnO 2 /CNT hybrid material and broadens its application in the detection of biological specimens for clinical diagnosis and biomedical research.

In 2023, around 850 million people globally were affected by chronic kidney disease, which leads to the retention of uremic toxins and excess fluid in the blood. This study examines the adsorption of these toxins to poly(ethylene oxide) (PEO) films, known for their low-fouling properties. The gold surfaces were treated with 5 mM end-thiolated methoxy-terminated PEO ( m -PEO) and analyzed using dynamic contact angle measurements, X-ray photoelectron spectroscopy, and spectroscopic ellipsometry to confirm the PEO film's presence and determine chain density. The adsorption of 25 different uremic toxins to m -PEO films was evaluated by using liquid chromatography-mass spectrometry (LC/MS), focusing on their binding affinity and adsorption dynamics. Results showed the effective modification of surfaces with m -PEO, with a notable change in contact angles and chain density (∼0.5 and 0.8 chains/nm 2 ). Interestingly, pyruvic acid showed significant adsorption, whereas other toxins, such as hippuric acid, creatinine, and xanthosine had minimal interactions with the film. This indicates that the adsorption of these toxins is not primarily concentration driven and is rather dependent on the chemical structure of each toxin. These findings provide important insights for designing low-fouling coatings for biomedical devices.

As the core component of microbial fuel cells, the conductivity and biocompatibility of anode are hard to achieve simultaneously but significantly influence the power generation performance and the overall cost of microbial fuel cells. Stainless steel felt has a low price and high conductivity, making it a potential anode for the large-scale application of microbial fuel cells. However, its poor biocompatibility limits its application. This study provides a one-step binder-free modification method of a stainless steel felt anode with reduced graphene oxide to retain the high conductivity while greatly improving biocompatibility. The maximum power density achieved by reduced graphene oxide modified stainless steel felt was 951.89 mW/m 2 , 5.49 and 1.91 times higher than the unmodified stainless steel felt anode and reduced graphene oxide coated stainless steel felt by Nafion, respectively. The robust reduced graphene oxide modification markedly improved the biocompatibility by forming a uniform biofilm and utilizing the high conductivity of reduced graphene oxide to enhance the charge transfer rate. It led to 92.7 and 37.9% decreases in charge transfer resistance of reduced graphene oxide modified stainless steel felt compared to the unmodified one and the anode modified with reduced graphene oxide by Nafion, respectively. The excellent performance and green synthesis method of the anode validated its potential as a high-performance anode material for scaled-up microbial fuel cell applications.

Background: This study aimed to develop ion-releasing and antibacterial resin-based dental sealants comprising 3 to 6 wt% monocalcium phosphate monohydrate (MCPM, M), 3 to 6 wt% bioactive glass (BAG, B), and 3 to 6 wt% polylysine (PLS, P). The physical properties, mechanical performance, cytotoxicity, and inhibition of S. mutans biofilm by these materials were subsequently evaluated., Methods: Five experimental dental sealants were formulated as follows: F1 (M6B6P6), F2 (M6B6P3), F3 (M3B3P6), F4 (M3B3P3), and F5 (M0B0P0, serving as the control). ClinproXT (CP, 3 M, Saint Paul, MN, USA) was used for commercial comparison. The degree of monomer conversion (DC) was determined using attenuated total reflectance-Fourier transform infrared spectroscopy (n = 5). The biaxial flexural strength (n = 6) and Vickers surface microhardness (n = 5) of the materials were evaluated after a 24-hour immersion in water. The element release over 4 weeks was measured using inductively coupled plasma-optical emission spectrometry (ICP-OES) (n = 3). The cell viability of mouse fibrosarcoma cells exposed to the extract was assessed via an MTT assay (n = 3). Additionally, the inhibition of S. mutans biofilm was tested (n = 3). Statistical analysis was conducted using one-way ANOVA and the Tukey HSD test., Results: The lowest DC among experimental sealants was obtained from F1 (66 ± 4%), which was significantly higher than CP (54 ± 2%, p < 0.001). The lowest biaxial flexural strength was obtained from F3 (131 ± 47 MPa). This was comparable to that of CP (140 ± 58 MPa, p = 0.992). The lowest surface microhardness among experimental materials was detected with F2 (19 ± 2 Vickers hardness number), which was higher than that of CP (12 ± 1 Vickers hardness number, p = 0.003). Furthermore, high cell viability of > 90% after exposure to extracts from the experimental materials was detected, which was similar to that observed with CP. Additionally, the experimental materials exhibited higher Ca and P release compared to CP and showed a potential trend for reducing S. mutans biofilm formation. Increasing additive concentrations exhibited minimal effects on material properties, except for enhanced elemental release and a slight reduction in BFM with higher PLS content., Conclusion: The experimental sealants provided sufficient physical and mechanical strength and maintained cell viability and bacterial inhibition with higher elemental release than the commercial product., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: Anne Young has a patent on the use of MCPM in dental composites licensed to a dental company (Davis Schottlander and Davis Ltd., Letchworth Garden City, UK). The other authors declare no conflicts of interest., (© 2025. The Author(s).)

Objective: This in vitro study aimed to investigate the effect of five polishing systems on the surface roughness (SR) and color change (CC) of novel bulk-fill composite resins., Methods: Fifty composite resin samples were prepared for each of the five groups: Stark Bulk Fill, SDR Plus, SonicFill 3, Charisma Bulk Flow One, and Filtek Z250. Each group of composite resins was further subdivided into five subgroups based on the polishing method applied: OptraGloss (OG), OptraGloss combined with Diapolisher paste (OG D ), OptiDisc (OD), OptiDisc combined with Diapolisher paste (OD D ), and Occlubrush (OCC) (n = 10). Surface roughness was measured using a profilometer following the polishing procedures, while surface morphology was assessed through atomic force microscopy and scanning electron microscopy. Subsequently, the samples were divided into two further subgroups for aging in distilled water and coffee (n = 5). The initial color parameters and those measured after 7 days were recorded to evaluate color change. Statistical analysis was performed using two-way ANOVA, followed by Tukey's post-hoc tests (α = 0.05)., Results: SR significantly varied based on the composite resin and polishing system (p < 0.001). OCC polishing yielded the smoothest surface for STARK and SDR composites, while Charisma exhibited the lowest roughness in the OD D group (p < 0.05). OG D group consistently produced lower SR across multiple composites compared to the OG group (p < 0.001). Significant color changes (ΔE 00 ) were found, with SonicFill and Filtek showing the greatest color stability when polished with OG D and OCC. For all polishing systems, except OD D , the SDR composite showed the greatest CC in coffee storage (p < 0.003)., Conclusion: This study demonstrated that both the polishing technique and composite resin type significantly influenced SR. SR was notably affected by the interaction between the polishing method and resin type, with the OCC system consistently producing the lowest SR values. Additionally, Charisma exhibited surface properties similar to Filtek. Variations in color change were also observed based on both the polishing method and resin type, highlighting the critical role these factors play in determining the color stability of restorative materials., Competing Interests: Declarations. Ethics approval and consent to participate: This study received approval from the Cukurova University Faculty of Medicine Clinical Research Ethics Committee (approval no: 2022/126.30). The samples used were composite resin materials and no humans were involved. Consent for publication: Not applicable. Clinical trial number: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Although implants have undergone a remarkable development over the past decades, modern implants still show complications that make the improvement of materials necessary. The presented study investigates the load-bearing capacity of an experimental dental implant made of a niobium alloy (Nb1Zr) compared to identical implants made of Ti6Al4V using chewing simulation for artificial aging. Eight implants each with an experimental design were manufactured from Nb1Zr and Ti6Al4V. A standardized abutment made of Ti6Al4V was fabricated for each implant and screwed into the implant with a screw made of the same material. A shape-identical crown for an upper first molar was fabricated for all implants using the CAD/CAM technique. All specimens were artificially aged using chewing simulation for 1 × 10 6 cycles and thermocycling between 5 °C and 55 °C for 4 × 10 3 cycles. After that, all specimens were loaded until failure. This was followed by a 3D analysis of the deformation of the samples. 100% of the samples survived the artificial aging. The Nb1Zr samples failed at 2595 ± 1069 N. In the Ti6Al4V group, failure occurred at 2958 ± 1058 N. The first deformations occurred in both groups from a load of at least 1114 N. The 3D analysis revealed deformations of 0.08 mm in the implant shoulder area of the Nb1Zr implants and of 0.04 mm in the Ti6Al4V implants. This difference was significant (p = 0.016). The investigated Nb1Zr alloy appears to be suitable for implants. The measured load-bearing capacity is significantly higher than the expected intraoral masticatory forces., Competing Interests: Compliance with ethical standards. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s).)

Bone cement is commonly utilized to secure prosthetic joints in the body because of its robust fixation, stability, biocompatibility, and immediate load-bearing capability. However, issues such as loosening, leakage, and insufficient bioactivity can lead to its failure. Therefore, improving its mechanical, physical, and biological properties is crucial for enhancing its efficiency. This study examines the impact of incorporating four different nanomaterials-Titanium Dioxide (TiO 2 ), Magnesium Oxide (MgO), Calcium Phosphate (Ca 3 (PO 4 ) 2 ), and Alumina Oxide (Al 2 O 3 )-into bone cement on its mechanical, physical, and biological properties. TiO 2 and Al 2 O 3 nanoparticles are selected to enhance the compression strength of bone cement, thereby preventing loosening. Magnesium Oxide (MgO) and Ca 3 (PO 4 ) 2 nanoparticles are chosen to improve cell adhesion and reducing the risk of cement leakage. Five specimens were prepared: the first with 100% pure bone cement powder, the second with 98% pure bone cement powder and modified with 2% MgO and TiO2, and the remaining three with 95% pure bone cement powder and modified with 5% varying ratios of MgO, TiO 2 , Ca 3 (PO 4 ) 2 , and Al 2 O 3 . Compression, tensile, hardness, and bending strengths were assessed to determine improvements in mechanical properties. Setting temperature, porosity, and degradation were measured to evaluate physical properties. Cell adhesion and toxicity tests were conducted to examine the surface structure and biological properties. The results demonstrated that the modified specimens increased compression strength by 8.14%, tensile strength by 3.4%, and bending strength by 4.96%. Porosity, degradation, and setting temperature in modified specimens increased by 3.24%, 0.64%, and 5.17% respectively pure bone cement values. Cell adhesion in modified bone cement specimens showed normal attachment when scanned with FE-SEM. All of the tested modified specimens showed no toxicity, except for specimens with 2% Al 2 O 3 that showed 25% toxicity which could be averted by employing antibiotics., Competing Interests: Compliance with ethical standards. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s).)

3D-printed customized titanium alloy (Ti6Al4V, TC4) as load-bearing prostheses and implants, such as intervertebral cages, have been widely used in clinical practice. Native biological inertia and inadequate bone in-growth of porous titanium alloy scaffolds hampered their clinical application efficiency and then extended the healing period. To improve the osseointegration capacity of 3D-printed intervertebral cages, sandblasting was selected to execute their surface treatment. On the one hand, sandblasting treatment can efficiently eliminate incomplete unmelted powder that adheres to struts in intervertebral cages during the manufacture of 3D printing, resulting in high surface area and low surface flatness induced by the rough surface could favor osseointegration. On the other hand, sandblasting can also induce ultrafine grains and nanograins in the near-surface layer that are conductive to mechanical strength enhancement. This can be verified by both microhardness and residual compressive stress reaching peak values (404.2 HV, 539.1 MPa) in the transverse section of its near-surface layer along the depth from the surface. This is attributed to the fact that more grain boundaries can impede dislocation movement. Sandblasting surfaces in intervertebral cages could favor osseointegration and in-growth, providing a foundation for sandblasting treatment of 3D-printed intervertebral cages in clinical applications., (© 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Background: This study aims to compare design, phase transformation behavior, and torsional resistance of the ProGlider (PG) and ProTaper ultimate slider (PUS) and to compare the performance of two files in the glide-path preparation of a double-curved artificial canal., Methods: Scanning electron microscopy, micro-computed tomography, and differential scanning calorimetry were used to characterize the samples. A torsional resistance test was performed to obtain ultimate strength and distortion angle. Simulated glide-path preparation was conducted with a double-curved resin canal, and both PG and PUS were operated on by 300 and 400 rpms. Maximum screw-in force, torque generated during canal shaping, number of pecking strokes to reach the apex were compared between groups. After canal shaping centering ratio and alteration of files were assessed. Statistical analyses were performed using the Mann-Whitney U test, and the Kruskal-Wallis test with Bonferroni correction. A p value less than 0.05 was considered significant., Results: While the PG had a square cross-section, the PUS had variable square and rhomboid cross-sections and alternating cutting-edge. PG and PUS have austenitic transformation starting and finishing temperatures of 24-25℃, and 57-59℃, respectively. Ultimate strength of PUS are superior to that of PG, whereas the distortion angle of PG is greater than that of PUS (p < 0.05). The maximum screw-in force and clockwise torque generated during glide-path preparation were highest in the PUS group rotated at 300 rpm (p < 0.05). Shaping with the PG at 300 rpm and shaping with the PUS at 400 rpm exhibited comparable maximum screw-in forces. There were no significant differences in the number of pecking strokes to reach the apex and centering ability among groups shaped with PG and PUS at both rotation speeds. PG shaped at 400 rpm demonstrated severe alteration on its surface, while PUS shaped at 300 and 400 rpms exhibited comparable surface alterations., Conclusions: PG has a constant square cross-section, while PUS has a variable cross-section and alternating cutting-edge. Using PUS at recommended speed of 400 rpm ensures safe use with minimal screw-in force and surface alteration. At recommended speeds, both PG and PUS perform comparably and are safe for double-curved canals., Competing Interests: Declarations. Ethic approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Purpose: The purpose of this study is to compare the shear bond strength of ultraviolet (UV)-polymerized resin to 3D-printed denture materials, both with and without post-polymerization. Moreover, the effects of surface treatment and thermocycling on shear bond strength after post-polymerization were investigated., Methods: Cylindrical 3D-printed denture bases and teeth specimens were prepared. The specimens are subjected to two tests. For Test 1, the specimens were bonded without any surface treatment or thermal stress for comparison with and without post-polymerization. In Test 2, specimens underwent five surface treatments: untreated (CON), ethyl acetate (EA), airborne particle abrasion (APA) with 50 μm (50-APA) and 110 μm alumina (110-APA), and tribochemical silica coating (TSC). A UV-polymerized resin was used for bonding. Half of the Test 2 specimens were thermocycled for 10,000 cycles. Shear bond strength was measured and analyzed using Kruskal-Wallis and Steel-Dwass tests (n = 8)., Results: In Test 1, post-polymerization significantly reduced shear bond strength of both 3D-printed denture materials (P < 0.05). No notable difference was observed between the denture teeth and the bases (P > 0.05). In Test 2, before thermocycling, the CON and EA groups exhibited low bond strengths, while the 50-APA, 110-APA, and TSC groups exhibited higher bond strengths. Thermocycling did not reduce bond strength in the latter groups, but significantly reduced bond strength in the EA group (P < 0.001)., Conclusions: Post-polymerization can significantly reduce the shear bond strength of 3D-printed denture materials. Surface treatments, particularly APA and TSC, maintained bond strength even after thermocycling.

Objectives: To compare the impact of intaglio surface treatments - airborne particle abrasion and hydrofluoric acid (HF) etching - of feldspar ceramic (FEL) crowns on the fracture load (FL) and to investigate the effects of abutment materials and artificial aging. The aim was to assess whether etching could be replaced by an alternative surface roughening method., Materials and Methods: FEL crowns had their intaglio surfaces either abraded (25 µm Al 2 O 3 , 0.1 MPa), etched (HF, 60 s), or untreated and then bonded to CoCrMo- and polymer-abutments. FL was measured for non-aged and aged (1.2 million mastication cycles) specimens. Data were analyzed using, Weibull modulus, two-/one-way ANOVA with Tukey HSD-post-hoc-test, t-tests, and TOST equivalence (p < 0.05)., Results: For crowns bonded to CoCrMo abutments, aging affected the FL and Weibull modulus, but pretreatment methods did not. For initial specimens, airborne abraded and etched crowns were equivalent within a 400N bound, however, for aged specimens, equivalence was inconclusive. For crowns bonded to polymer-abutments, pretreatment and aging influenced the FL. Etching decreased the initial FL by over 420N compared to airborne abraded and untreated specimens. After aging, untreated crowns' FL decreased by 528N, while airborne abraded and etched specimens showed no aging effect., Conclusions: Airborne particle abrasion of FEL crowns' intaglio surfaces did not negatively impact FL and was comparable to etched crowns. Conclusions regarding pretreatment methods and aging differed between CoCrMo- and polymer-abutments., Clinical Relevance: Airborne particle abrasion may be an alternative procedure for the intaglio surface treatment of FEL crowns prior bonding., Competing Interests: Declarations. Conflicts of interest: The authors declare that there are no conflicts of interest related to this publication. Ethical approval: This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent: For this type of study, formal consent was not required., (© 2025. The Author(s).)

Background: Home bleaching is a promising option for addressing discolored teeth conservatively. However, its impact on the physical and mechanical properties of indirect restorations remains unknown. This study provides comparative insights into the material responses to aesthetic treatments by assessing the effects of home bleaching agents on two hybrid ceramics: VITA ENAMIC ® and Grandio Blocs. The focus is on evaluating color stability and biaxial flexural strength., Methods: 60 discs (12 × 1 mm) were prepared from hybrid ceramics. Specimens were divided into two groups according to type of hybrid ceramic (30 specimens in each group); group A: VITA ENAMIC ® , group B: Grandio Blocs. Each group was further subdivided into 3 subgroups according to the concentration of home bleaching agents used (10 specimens in each subgroup); subgroup C: unbleached control group, subgroup C10%: carbamide peroxide 10% bleaching agent, and subgroup C35%: carbamide peroxide 35% bleaching agent. Samples of subgroup C10% were bleached with Home Bleaching Opalescence PF (10%) for 8 h per day for 14 days, as directed by the manufacturer. Samples of subgroup C35% were bleached using WHITEsmile Carbamide Peroxide (35%), following the manufacturer's directions for 30 min every day for 14 days. Color change (ΔE) was assessed using of the CIE L*a*b* system. Then, the biaxial flexural strength test was done. The data were analyzed using two-way ANOVA tests and Weibull analysis., Results: VITA ENAMIC samples exhibited significantly higher color change than Grandio Blocs (p < 0.001), while Grandio Blocs showed significantly higher biaxial flexural strength (p < 0.001). The concentration of the bleaching agent had no significant effect on color change (p = 0.086). However, regardless of its concentration, bleaching significantly reduced biaxial flexural strength in both materials (p < 0.001). Weibull analysis showed that Grandio Blocs had higher characteristic strength, while VITA ENAMIC demonstrated more reliable failure behavior., Conclusions: Compared to Grandio Blocs, VITA ENAMIC ® exhibited a greater color change with both 10% and 35% carbamide peroxide home bleaching agents. Additionally, both concentrations of carbamide peroxide reduced the biaxial flexural strength of hybrid ceramics. These findings can guide clinicians in selecting hybrid ceramics based on clinical demands for aesthetics and durability. VITA ENAMIC ® offers greater structural reliability and predictability for aesthetic restorations, while Grandio Blocs provide superior durability and stress resistance for high-stress clinical applications., Competing Interests: Declarations. Ethics approval and consent to participate: Ethics committee approval: FDAsu-RecEMo22311 (Research ethics committee of Faculty of Dentistry Ain Shams University) was obtained. Consent of publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Objectives: To address the high surface roughness and poor optical properties of three-dimensional (3D) printed orthodontic clear retainers, an alternative post-processing protocol was investigated with the goal of achieving improved surface, optical, and mechanical properties while preserving dimensional accuracy., Materials and Methods: Samples were prepared from two biocompatible methacrylate-based 3D-printing resins (Formlabs Dental LT Clear V2, NextDent OrthoFlex) and one thermoplastic material (Duran). For the 3D-printed resins, one group was post-processed by rinsing in isopropyl alcohol, while another group was centrifuged before post-curing in glycerine. Three different testing conditions were used: dry, wet (24-h water immersion), and aged (thermocycling for 10,000 cycles). Surface characteristics were evaluated qualitatively and quantitatively. Optical properties were assessed for transparency and colour stability, while mechanical properties were elicited from tensile and microhardness tests. Water sorption and solubility were calculated. Samples mounted on a dental model were scanned by micro-computed tomography to measure thickness and gap width., Results: 3D-printed samples post-processed by centrifugation showed significantly decreased surface roughness and improved visible light transmission, colour stability, tensile strength, and hardness. The centrifuged samples showed significantly increased thickness, while designing an offset equal to this thickness improved the adaptation., Conclusions: Post-processing by centrifugation produces surface coating that enhances the surface and optical properties of the 3D-printed orthodontic retainers, while curing in an oxygen-free environment improves their mechanical properties. Design modifications may be necessary for this protocol to ensure proper adaptation to the dentition., Clinical Relevance: Proper design and post-processing protocols are necessary to achieve the desired properties of orthodontic clear retainers., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. This was an in vitro experimental study which did not involve any human subjects. Consent for publication: Not applicable. This research did not utilize any individual person’s data. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Statement of Problem: The use of additive manufacturing Ti-6Al-4V (AM Ti64) in removable partial denture (RPD) frameworks has become increasingly prevalent in clinical practice. However, the elastic and fatigue properties of AM Ti64 clasps are not well understood., Purpose: The purpose of this in vitro study was to investigate the elastic and fatigue properties of AM Ti64 clasps by comparing them with milled Ti64 (Milled TC4) clasps., Material and Methods: Dumbbell specimens of AM Ti64 and Milled TC4 were prepared for tensile tests following the International Organization for Standardization (ISO) 22674 standard (n=6). Raw (R) and mechanically polished (P) clasp-shaped specimens were prepared for elastic and fatigue tests and divided into 4 groups: AM Ti64R, AM Ti64P, Milled TC4R, and Milled TC4P. The clasp intaglio surface roughness was measured before testing (n=10). The elastic deformation limit (EDL) of the clasp was determined through incremental displacement loading (n=10). Fatigue tests were conducted on 160 clasps (40 specimens per group) at displacements from 0.30 mm to 1.00 mm for 10 5 cycles (n=5 per displacement). The fracture surfaces of failed clasps were observed using a scanning electron microscope (SEM), and the microstructures were analyzed using optical microscopy. Statistical analyses were conducted using t tests and Kruskal-Wallis tests (α=.05)., Results: AM Ti64 exhibited higher 0.2% offset yield strength and ultimate tensile strength than Milled TC4 (P<.001), with no significant difference in percentage elongation (P=.298) or elastic modulus (P=.151). No significant differences in intaglio surface roughness were found between AM Ti64 and Milled TC4 clasps in both the raw (P=.306) and polished (P>.999) groups. AM Ti64 clasps demonstrated greater EDL values than Milled TC4 clasps in both the raw and polished groups (P<.001). The fatigue life of AM Ti64 clasps was significantly shorter than that of Milled TC4 clasps (P<.001), with no significant difference between the raw and polished groups in both AM Ti64 (P=.611) and Milled TC4 clasps (P>.999). SEM observation revealed fatigue cracks originating from surface defects in AM Ti64 clasps. Microstructural analysis showed lamellar α phase dominance in AM Ti64, while Milled TC4 exhibited primarily equiaxed α phase., Conclusions: The AM Ti64 clasp showed better elasticity but inferior fatigue performance compared with Milled TC4 clasps. Mechanical polishing did not significantly affect the elasticity or fatigue properties of the titanium clasp., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the effects of 1 versus 2 glaze firings on the color and mechanical properties of an extrinsically characterized lithium disilicate ceramic after thermal cycling, brushing, or both., Materials and Methods: Eighty specimens were divided into 2 groups: 1 glaze firing (GL1) and 2 glaze firings (GL2). Each group was subdivided into 4 groups (n = 10), according to the experimental conditions: thermal-cycling, brushing, thermal-cycling + brushing, and immersion in distilled water (control). Color variation, surface roughness, and Vickers microhardness were analyzed before each designated experiment and after the simulated periods of 2.5, 5, and 10 years. Three-way mixed ANOVA was used for all outcomes, followed by 1-way ANOVA, repeated measures 1-way ANOVA, Bonferroni post hoc test, and t-test to check for statistical differences (α = 0.05)., Results: Thermal cycling generated greater color changes in the GL1 group at 2.5 and 5 years (p < 0.001; p = 0.013). Brushing generated color changes in GL1 at 5 years (p = 0.003) and in GL2 at 10 years (p = 0.017). Regarding surface roughness, the GL1 group suffered alterations in thermal cycling + brushing at 5 years. In the control group, the GL1 group exhibited higher roughness values than GL2 (p < 0.05). Most of the groups experienced an increase in microhardness at 2.5 years (p < 0.05). In the GL1 group, thermal-cycling increased the microhardness at 5 years (p = 0.006); at 5 and 10 years, the GL1 group had a higher microhardness than the GL2 in thermal-cycling + brushing (p < 0.05)., Conclusion: Ceramics with 1 glaze firing showed greater color, roughness, and microhardness changes compared to those submitted to 2 firings., (© 2023 by the American College of Prosthodontists.)

To evaluate the microstructural characterization, mechanical properties and antimicrobial activity of acrylic resins incorporated with different concentrations of reduced graphene oxide (rGO). Specimens were made of self-cured and heat-cured acrylic resins for the control group and concentrations of 0.5%, 1%, and 3%. The microstructural characterization was evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDS). For mechanical testing, flexural strength, and Knoop hardness tests were performed. Microbiological evaluations were performed by colony forming units (CFU) analysis, tetrazolium salt reduction (XTT), and SEM images. The modified acrylic resins showed increased mechanical properties at low concentrations (p < 0.05) and with reduced S. mutans (p < 0.05). Reduced graphene oxide interfered with the mechanical performance and microbiological properties of acrylic resins depending on the concentration of rGO, and type of polymerization and microorganism evaluated. The incorporation of graphene compounds into acrylic resins is an alternative to improve the antimicrobial efficacy and performance of the material., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no conflict of interest. Ethical approval: This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent: For this type of study, formal consent is not required., (© 2024. The Author(s), under exclusive licence to The Society of The Nippon Dental University.)

Statement of Problem: Evaluating the effect of low-temperature degradation (LTD) on multilayered zirconia blocks is important for the long-term life of zirconia restorations., Purpose: The purpose of this in vitro study was to analyze the changes in color, translucency, and hardness of a single layer of multilayered zirconia after an LTD treatment., Material and Methods: Ninety multilayered 10×10×1.0-mm zirconia specimens (3M Lava Esthetic) were designed using Auto CAD 2006 (Autodesk) and divided into 6 groups (n=15) based on LTD (no treatment, LTD treatment) and the inherent layer type (incisal, transition, and body). The hardness of each specimen was measured using a microVickers hardness tester. The CIELab color coordinates were measured using a spectrophotometer, and the data were used to calculate the color difference and translucency (TP). Data were analyzed using 2-way ANOVA and the Scheffé test (α=.05)., Results: LTD treatment did not alter the hardness of multilayered zirconia (P=.572). A significant difference was found in the hardness between the layers of multilayered zirconia (P<.001). LTD treatment did not alter the b∗ or L∗ values (P=.773, P=.701) but did change the a∗ values (P<.001). On LTD treatment, the a∗ value was found to decrease. The L∗, a∗, and b∗ values differed based on the respective layer within the material (P<.001). As layers progress from the incisal to the body, the L∗ value decreased and the a∗ and b∗ values increased. In all groups, the color difference values were highest in the following order: the incisal and transition layers < the transition and body layers < the incisal and body layers. On LTD treatment, the color difference between the layers decreased. The LTD treatment did not affect the TP value (P=.208), but the TP value for each layer showed a significant difference (P<.001)., Conclusions: LTD treatment did not affect the optical properties or hardness of the multilayered zirconia. The hardness of the multilayered zirconia increased from the incisal to the body layer. In multilayered zirconia, the brightness decreased from the incisal to the body layer, and red and yellow color changes were observed. The TP of multilayered zirconia increased from the incisal to the body layer., (Copyright © 2023 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the surface roughness, optical properties, and microhardness of additively or subtractively manufactured CAD-CAM materials after simulated brushing and coffee thermal cycling., Material and Methods: Two additively manufactured resins (Crowntec, CT and VarseoSmile Crown Plus, VS) and 3 subtractively manufactured materials (a reinforced composite (Brilliant Crios, BC), a polymer-infiltrated ceramic network (Enamic, VE), and a feldspathic ceramic (Mark II, VM)) were used to fabricate disk-shaped specimens (Ø10×1-mm) (n = 10). Surface roughness, Vickers microhardness, and color coordinates were measured after polishing, while surface roughness was also measured before polishing. Specimens were then subjected to 25000 cycles of brushing and 10000 cycles of coffee thermal cycling, and measurements were repeated after each time interval. Color difference (ΔE 00 ) and relative translucency parameter (RTP) were calculated. Robust analysis of variance test was used to evaluate surface roughness, ΔE 00 , and RTP data, while generalized linear model analysis was used for microhardness data (α = 0.05)., Results: Material type and time interval interaction affected tested parameters (p ≤ 0.002). In addition, material type affected all parameters (p < 0.001) other than surface roughness (p = 0.051), and time interval affected surface roughness and microhardness values (p < 0.001). Tested materials mostly had their highest surface roughness before polishing (p ≤ 0.026); however, there was no clear trend regarding the roughness of materials within different time intervals along with ΔE00 and RTP values within materials or time intervals. VS and CT had the lowest microhardness regardless of the time interval, while the remaining materials were listed as VM, VE, and BC in decreasing order (p < 0.001). Coffee thermal cycling only reduced the microhardness of VM (p < 0.001)., Conclusions: Tested additively manufactured resins can be considered more susceptible to simulated brushing and coffee thermal cycling than the other materials, given the fact that their surface roughness and ΔE00 values were higher than previously reported acceptability thresholds and because they had the lowest microhardness after all procedures were complete., (© 2023 The Authors. Journal of Prosthodontics published by Wiley Periodicals LLC on behalf of American College of Prosthodontists.)