Dental Materials最新文献

Background: Bone tissue engineering requires bioinks that combine suitable rheological properties, printability, and biological activity. Leukocyte and platelet-rich fibrin (L-PRF) is a platelet concentrate providing a sustained release of bioactive molecules involved in angiogenesis and osteogenesis.

Objective: This study aimed to develop and characterize alginate/gelatin/hydroxyapatite (ALG5-GEL5-HAp10) composite bioinks supplemented with lyophilized L-PRF and to evaluate their rheological performance, cytotoxicity, and ability to promote dental pulp stem cell (DPSC) osteogenic differentiation.

Methods: Bioinks were rheologically characterized. Extrusion-based 3D printing produced scaffolds evaluated for cell viability (MTS assay). Growth factor release (PDGF-BB, EGF, VEGF-C, FGF-2, BMP2) from L-PRF-loaded scaffolds was quantified by Luminex for up to 21 days in conditioned medium. Osteogenic differentiation was analyzed by qRT-PCR of key genes (RUNX2, SP7/OSX, ALPL, COL1A1, OCN, OPN, OPG, RANKL, BMP2, TGFB2, VEGF).

Results: Inks exhibited shear-thinning and thixotropic recovery. L-PRF addition increased viscosity and storage modulus (G') while reducing extrusion pressure, improving printability without compromising scaffold fidelity. L-PRF-loaded scaffolds provided sustained growth factor release, with early peaks in PDGF-BB and EGF and detectable BMP2 up to day 7. Conditioned media enhanced DPSC proliferation, peaking at day 3, indicating functional activity of released biomolecules. Bioprinted scaffolds with L-PRF significantly upregulated osteogenic gene expression compared to 3D-printed scaffolds with post-DPSC seeding.

Conclusions: As a proof-of-concept, this study demonstrates that lyophilized L-PRF enhances the rheological, printability, and bioactive properties of ALG-GEL-HAp bioinks, supporting DPSC viability. Bioprinted scaffolds showed higher mRNA osteogenic gene expression. These findings support the potential of L-PRF-loaded bioprinted scaffolds for bone tissue regeneration applications, while highlighting the need for further mechanistic and in vivo validation.

Objectives: This study aimed to develop and assess a novel opaque liquid for high-translucency pre-colored zirconia (HT-Zr) that enhances shade masking while maintaining the frame original shade and optical performance.

Methods: Plate-shaped (8 × 8 × 1 mm) and crown-shaped A2-shaded HT-Zr specimens were prepared. Plates were assigned to seven groups: 3 opaque liquids with 2 numbers of applications conditions (single or triple) and one no-opaque control (n = 10 per group). Following application and sintering, light transmittance, penetration depth (PD), and penetration rate (PR) were evaluated. Color over different underlying substrates (white, A2, and metal) was measured; CIE L*a*b* and CIEDE2000 (ΔE₀₀) values were calculated using a transparent‑plate reference and interpreted using acceptability thresholds.

Results: The novel opaque liquid exhibited 13.94-21.28 % transmittance and the lowest PD (<0.32 mm) and PR (<16.75 %), with no change after sintering or multiple applications. Even after triple application, it still exhibited lower PD and PR values than the other groups. It maintained a near-neutral hue with stable a* and b* values and smaller L* shifts relative to conventional opaque liquids, thereby preserving lightness closer to the no‑opaque control. The novel opaque liquid also yielded the lowest Δ_E00 value across substrates and application frequencies; on metal, ΔE₀₀ (1.99) remained within the acceptability threshold, indicating effective masking with minimal clinically perceptible shade deviation. In contrast, conventional opaque liquids showed higher ΔE₀₀ values, increased penetration with multiple applications, and reduced b* values on dark substrates.

Significance: The novel opaque liquid effectively masks discolored or metallic substrates while preserving the intended shade and optical properties of HT-Zr, exhibiting controlled penetration and yielding clinically acceptable color differences. On white or tooth‑like substrates, additional masking may be unnecessary because all opaque liquids can induce perceptible shade shifts.

Adequate bone healing around the implant is critical to its clinical success. For decades, biomimetic composites with integrated osteogenic and anti-infective capacities have been a cornerstone of translational research targeting oral bone defect repair. Herein, we report the engineering of a novel composite: functional molecule-loaded, PEGylated polyglycerol sebacate (PEGS)-modified calcium phosphate cement (PCPC) composite. Specifically, calcium phosphate cement (CPC) was functionalized with PEGS, a hydrophilic elastomer, followed by the co-immobilization of berberine (BBR), a clinically approved anti-inflammatory agent, and recombinant human bone morphogenetic protein-2 (rhBMP-2), a potent osteogenic cytokine, to fabricate the PCPC composite.The optimized PCPC formulation-incorporating 250 μg of BBR and 2 μg of rhBMP-2 per gram of composite-exhibited superior cytocompatibility, robust mechanical performance, and desirable biodegradability. Notably, in vitro assays demonstrated that BBR incorporation exerted a synergistic effect with rhBMP-2, enhancing the osteogenic differentiation of MC3T3-E1 and inducing the polarization of anti-inflammatory M2 macrophages. In vivo evaluations further verified that BBR/rhBMP-2-loaded PCPC composites significantly accelerated mandibular bone regeneration and mitigated local inflammatory responses relative to unloaded PCPC controls. Collectively, this injectable, immunomodulatory, and osteoinductive PCPC composite emerges as a promising therapeutic platform for oral bone defect repair, providing novel insights into the rational design of next-generation dual-functional biomaterials.

Objectives: Organ-on-a-chip (OoC), as a highly biomimetic microphysiological system, is demonstrating significant potential in oral medicine research and clinical application. This review outlines the latest advances and specific applications of OoC in the field, with a focus on its value in emulating the complex oral microenvironment, facilitating the development of materials and drugs, and advancing personalized medicine. Furthermore, it discusses how emerging technologies such as artificial intelligence (AI) may contribute to the evolution of dentofacial OoCs.

Data and sources: A review of literature was conducted through online databases, including PubMed, Google Scholar, Embase, Scopus, and Web of Science.

Study selection: Studies were selected based on relevance, with a preference for research from the last 5 years.

Conclusions: This review concludes that the dentofacial tissues and their functions can be simulated via OoCs, including dentin, dental pulp, periodontal tissue, oral mucosa, and salivary glands. They hold significant value in modeling oral disease, evaluating oral restorative materials, studying head and neck tumor metastasis, and screening drugs. Furthermore, the integration with AI will enable intelligent acquisition and analysis of high-throughput, real-time dynamic data within the chips, assisting in their design and optimization, and promoting precise control of the microenvironment.

Objectives: To develop and investigate the physicomechanical properties of innovative conventional glass-ionomer and resin-modified glass-ionomer cements (CGIC and RMGIC) containing Succinic Anhydride-Modified Polyvinyl Alcohol (PVA-SA) polymer and bioactive compounds.

Methods: The new cements were formulated by adding 5 wt% bioactive glass (BAG), 5 % and10 wt% β-tricalcium phosphate (β-TCP) to the powder component of CGIC (Fuji IX) and RMGIC (Fuji II LC), along with 10 wt% PVA-SA in their liquid phase. Evaluations included Fourier-transform infrared spectroscopy (FT-IR), compressive strength and modulus (CS & CM), microhardness (MH), biaxial flexural strength (BFS), fluid uptake, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). The statistical analysis was determined using ANOVA followed by Bonferroni post-hoc tests.

Results: The PVA-SA-containing formulations displayed a more consistent FT-IR peak profile, suggesting effective interactions between components. The conventional GIC formulations exhibited increases of up to 11 %, 15 %, 21 %, and 23 % in the CS, CM, MH, and BFS, respectively. In contrast, the RMGIC showed enhancements of 16-27 % in these properties compared to their original cements (p < 0.05). The β-TCP-PVA-SA increased the hydration percentage of the CGIC to nearly 30 %, while it reached 120 % in the BAG-PVA-SA-containing cement. In contrast, the modified RMGIC exhibited a reduction of 20-60 %. A dense and smooth microstructure was observed in the PVA-SA-containing cements, along with irregularly shaped mineral-like deposits distributed across the surfaces of both GICs.

Significance: These novel GICs, with improved mechanical properties could enhance the clinical outcomes and restoration durability. Future clinical trials are required to investigate their practical applications in dentistry.

Objectives: To evaluate the effect of dual cure activator (DCA) on the bond strength of universal adhesives to bleached enamel and to analyze changes in surface morphology and elemental composition.

Methods: Bovine enamel specimens (n = 198) were divided into bleached and unbleached groups. DCA (Clearfil DC Activator) was applied to etched enamel surfaces before application of three universal adhesives: Clearfil Universal Bond Quick (UBQ), Optibond Universal (OBU), and Palfique Universal Bond (PUB). Shear bond strength (SBS) was measured after 24-hour water storage. Surface morphology and elemental composition were analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). Statistical analysis was performed using one-way ANOVA with Dunnett's T3 post hoc test (α=0.05).

Results: PUB demonstrated the lowest bond strength to unbleached enamel but showed significant improvement with DCA application (p < 0.001). Bleaching significantly reduced SBS across all adhesive groups (p < 0.001), with UBQ showing the least reduction. DCA application significantly increased SBS to bleached enamel for OBU (p < 0.001) and PUB (p < 0.001) but had no significant effect on UBQ (p = 0.72). SEM/EDS analysis revealed morphological alterations after bleaching and confirmed successful DCA incorporation through sulfur detection.

Significance: Bleaching significantly compromised the bond strength of universal adhesives to enamel in etch-and-rinse mode. The application of DCA can enhance the bonding performance of bleached enamel, particularly with specific adhesives. These findings underscore DCA as a viable clinical strategy for immediate post-bleaching restorative procedures in certain scenarios.

Objective: This study aimed to develop patient-specific biodegradable mandibular implants composed of polycaprolactone (PCL) reinforced with 30 wt% β-tricalcium phosphate (β-TCP) using fused deposition modeling (FDM), and to evaluate how gradient lattice structural designs influence early postoperative mechanical stability and degradation behavior in critical-sized mandibular defects, thereby establishing practical design criteria for reliable reconstruction.

Methods: Gradient lattice architectures were designed by finite element-based topology optimization, assigning dense lattices (P06, ∼1000 μm pores) to high-stress regions and larger pores (P08, ∼1500 μm) to low-stress zones. Two implant spans were investigated: RI-2, with an arc length approximately twice the average bone width, and RI-3, with an arc length about three times the bone width. Mechanical properties were characterized by tensile and four-point bending tests, and a dual-mode platform applied hydrolytic degradation and cyclic loading (20-200 N, 1 Hz) to replicate early postoperative oral conditions.

Results: The PCL/β-TCP composite showed an elastic modulus of 450 ± 20 MPa and cell viability of average 84.5 %. Four-point bending revealed that the RI-2 design achieved a proof load of 83.8 ± 5.3 N and bending strength of 1466 ± 92 N·mm, 2.35-fold higher than RI-3. Under dual hydrolysis-loading, all RI-2 implants maintained structural integrity for one month, whereas RI-3 failed after 14.4 ± 1.2 days. Micro-CT confirmed greater dimensional stability of P06 versus P08 lattices.

Significance: This work demonstrates that high-content PCL/β-TCP composites can be reliably 3D printed into stress-adaptive mandibular implants, and establishes quantitative design thresholds for balancing early mechanical support with degradation in oral and maxillofacial reconstruction.

Objective: This study evaluated the in vitro cytotoxicity, oxidative stress, and inflammatory responses of three 3D printed dental resins compared with CAD-CAM zirconia, CAD-CAM composite blocks, and direct resin composites, using human gingival fibroblasts.

Materials and methods: Eight materials were tested: three 3D printed resins (SC, CC, TQ), three direct resin composites (TE, EP, VP), one CAD-CAM resin composite block (CS), and one CAD-CAM zirconia block (ZR). Specimens were prepared according to manufacturers' protocols, polished and sterilized. Material characterization included SEM surface analysis and degree of conversion (DC). Biological assessments included metabolic activity (AlamarBlue™), viability (Live/Dead™), morphology (DAPI/phalloidin), intracellular ROS levels (OxiSelect™), and IL-6 secretion (ELISA), evaluated under direct and indirect contact conditions.

Results: SEM revealed that all 3D printed resins exhibited a micro-hybrid structure and higher DC values (83 %-93 %) than direct resin composites (45 %-60 %). Two 3D printed resins (SC, TQ), the composite block (CS), and zirconia (ZR) demonstrated excellent cytocompatibility, while one 3D printed resin (CC) displayed reduced responses in indirect assays. ROS levels were significantly higher in all printed resins than in ZR or CS, whereas IL-6 remained moderate compared to the TE direct resin composite, which exhibited the most significant proinflammatory response. ZR displayed the most stable biological profile across all assays.

Significance: Within the study limits, 3D printed resins showed acceptable cytocompatibility and better performance than direct resin composites, though associated with high oxidative stress. These findings underline the importance of combining cytotoxicity and inflammatory markers when assessing the biological safety of dental materials.

Objectives: Vital pulp therapy is an effective approach for prolonging tooth lifespan; however, none of the currently available pulp capping materials exhibit anti-inflammatory properties. This study evaluated the anti-inflammatory activity and reparative dentin-forming capacity of smart bioactive glasses (BGs) designed to sequentially release lithium and strontium ions as novel pulp capping materials.

Methods: Lithium- and strontium-releasing phosphate BGs (Li/Sr-BGs) were prepared by mixing lithium-containing BG with four BGs exhibiting different strontium release profiles. Ion release from Li/Sr-BGs was measured over 100 days. The effects of Li/Sr-BGs on odontoblastic differentiation were examined using human dental pulp stem cells (DPSCs) and lipopolysaccharide-stimulated inflamed DPSCs (IF-DPSCs). Anti-inflammatory effects were evaluated in IF-DPSCs, and the in vivo efficacy of Li/Sr-BGs as direct pulp capping materials was assessed using a rat pulpitis model.

Results: Li/Sr-BGs exhibited stepwise ion release characterized by rapid lithium release followed by sustained strontium release. Li/Sr-BGs promoted odontoblastic differentiation of DPSCs and IF-DPSCs in accordance with the amount of strontium released. Furthermore, all Li/Sr-BGs restored the proliferative capacity of IF-DPSCs and suppressed inflammatory marker expression. In the rat pulpitis model, Li/Sr-BG treatment prevented pulp necrosis on day 3 and promoted reparative dentin formation by day 28.

Significance: Li/Sr-BGs demonstrated sequential therapeutic effects on dental pulp tissue, first suppressing inflammation and subsequently enhancing odontoblastic differentiation. These findings suggest that smart Li/Sr-BGs are promising next-generation direct pulp capping materials for vital pulp therapy.

Objective: Silane coupling agents are routinely used to improve adhesion of inorganic particles to the polymer matrix in resin composites. In resorbable resin composites for bone surgery, the silanization of bioactive glass fillers enhances mechanical properties before leaching begins. This study aimed to characterize the physicochemical and biological effects of silanization on bioactive glass S53P4 (BG) using three γ-MPS concentrations (3-(methacryloyloxy)propyltrimethoxysilane).

Methods: The starting solution for silanization consisted of 95 % ethanol (pH 4.5, adjusted with acetic acid). Different γ-MPS concentrations (1, 1.5 and 2 %) were obtained by diluting γ-MPS in the starting solution and used to treat micro-sized BG particles. Physicochemical characterizations were performed using ATR-FTIR and SEM. Particles were dissolved in cell culture medium for 7 days and during the dissolution period, the pH change of medium was continuously measured, and quantity of released Si ions was measured at the end. Biocompatibility of γ-MPS treated BG particles was assessed using MC3T3-E1 pre-osteoblastic cells.

Results: During dissolution, the pH varied slightly between the γ-MPS treated and untreated BG, although at the end point of the dissolution period no differences were observed in Si ion release (∼55 mg/L for all groups). No differences were observed in in vitro biomineralization of BG surfaces after γ-MPS treatment. Furthermore, γ-MPS treatment of BG did not influence viability of pre-osteoblastic cells (p > 0.05).

Significance: Silanization of BG particles with γ-MPS allowed in vitro biomineralization, indicating bioactivity. Biological in vitro tests with pre-osteoblastic cells showed good cell viability in both γ-MPS treated and untreated BG groups.