Journal of Functional Biomaterials

21 pages, 56304 KB

Open AccessArticle

Biomechanical Effects of Horizontal, Vertical, and Combined Misfits in Full-Arch Implant-Supported Titanium Frameworks: A Three-Dimensional Finite Element Analysis

by Hale Arikan Kalayci and Mustafa Baris Guncu

J. Funct. Biomater. 2026, 17(9), 478; https://doi.org/10.3390/jfb17090478 (registering DOI) - 19 Sep 2026

Abstract

This study evaluated the effects of misfit type, magnitude, and location on the stress distribution in full-arch screw-retained implant frameworks. A maxillary finite element model with four implants was analyzed under 16 scenarios, characterized by horizontal misfits of 10, 50, 100, and 200 [...] Read more.

This study evaluated the effects of misfit type, magnitude, and location on the stress distribution in full-arch screw-retained implant frameworks. A maxillary finite element model with four implants was analyzed under 16 scenarios, characterized by horizontal misfits of 10, 50, 100, and 200 µm; vertical misfits of 10 and 100 µm; and combined 10–10 and 100–100 µm misfits, each positioned anteriorly or posteriorly. Forced seating was simulated using prescribed displacement; no occlusal load or screw preload was applied. Von Mises stresses were evaluated in the framework, occlusal screws, and implants, and principal stresses were assessed in peri-implant bone. Framework stress increased with horizontal misfit magnitude. When the same numerical misfit value (10 or 100 µm) was applied at the same location under otherwise identical model conditions, vertical misfit produced higher framework stress than horizontal misfit, indicating a direction-dependent response associated with different seating deformation modes. The posterior 100–100 µm combined misfit produced the maximum framework (356 MPa), occlusal screw (193 MPa), and implant (250 MPa) stresses. In contrast, the maximum principal stress peaked at the posterior bone site with the anterior 200 µm horizontal misfit (V0 H200 A; 77 MPa), while the most negative minimum principal stress occurred at the posterior bone site with the posterior 200 µm horizontal misfit (V0 H200 P; −52 MPa). Among the tested scenarios, combined misfits yielded the highest framework and screw stresses, whereas implant and bone responses depended on the magnitude and location of the misfit. These findings indicate that the types, magnitudes, and locations of misfits should be considered during framework-fit assessments, with particular attention to combined misfits, before definitive seating. Full article

(This article belongs to the Section Dental Biomaterials)

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17 pages, 2370 KB

Open AccessArticle

Antimicrobial Effect of Fluoride-Generating Nonthermal Atmospheric Plasmas on In Vitro Triple-Species Oral Biofilms

by Anushri Warang, Linfeng Wu, Qingsong Yu, Liang Hong and Hongmin Sun

J. Funct. Biomater. 2026, 17(9), 477; https://doi.org/10.3390/jfb17090477 (registering DOI) - 19 Sep 2026

Abstract

This study investigates the feasibility of fluoride delivery via fluoride-generating nonthermal atmospheric plasma (FNTAP) and its antimicrobial effects on in vitro triple-species oral biofilms. FNTAPs were generated by adding 5 or 10 sccm (standard cubic centimeters per min) 1,1,1,2-tetrafluoroethane (TFE) to atmospheric argon [...] Read more.

This study investigates the feasibility of fluoride delivery via fluoride-generating nonthermal atmospheric plasma (FNTAP) and its antimicrobial effects on in vitro triple-species oral biofilms. FNTAPs were generated by adding 5 or 10 sccm (standard cubic centimeters per min) 1,1,1,2-tetrafluoroethane (TFE) to atmospheric argon (3000 sccm) nonthermal plasma (ArNTAP). Reactive plasma species were measured in plasma-treated phosphate-buffered saline (PBS). Twenty-four-hour biofilms were constructed from Streptococcus mutans, Streptococcus sanguinis, and Candida albicans for assessing the antimicrobial effects of FNTAPs via viability assays and colony-forming unit (CFU) assays. FNTAP treatments significantly increased the concentrations of F⁻ and NO₂⁻ in PBS compared to ArNTAP treatments (p < 0.01), and decreased the concentrations of H₂O₂ and NO₃⁻ in PBS (p < 0.001, p < 0.05). 5 sccm 2 min FNTAP treatment reduced biofilm viability by 94.12 ± 1.03% (p < 0.001), compared to a 69.32 ± 2.05% (p < 0.001) reduction with ArNTAP. CFU assays showed that FNTAPs were especially efficacious against C. albicans. 5 sccm 3 min FNTAP treatment reduced fungal log₁₀ CFUs by 4.28 ± 0.36 (p < 0.001). Fungal CFUs were below detectable levels for the 10 sccm 2 and 3 min groups, except for two data points in each group. In conclusion, FNTAP effectively produced measurable fluoride in PBS and significantly enhanced antimicrobial efficacy against triple-species biofilms, highlighting its potential as a multifunctional tool for caries control. Full article

(This article belongs to the Section Dental Biomaterials)

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15 pages, 2353 KB

Open AccessArticle

Morphological and Rheological Analysis of an Injectable Calcium Hydroxylapatite Dermal Filler with Lattice-Pore Surface Architecture

by Gi-Woong Hong, Yerin Park, Doo Yeoul Chang, Jeesoo Kook, Young Bin Lim, Ho Lee and Kyu-Ho Yi

J. Funct. Biomater. 2026, 17(9), 476; https://doi.org/10.3390/jfb17090476 (registering DOI) - 19 Sep 2026

Abstract

Background: Hydroxylapatite is a biocompatible calcium-phosphate ceramic used in regenerative biomaterials. Calcium hydroxylapatite (CaHA) fillers combine immediate mechanical support with subsequent extracellular matrix remodeling, and their material behavior depends on microsphere morphology, mineral composition, carrier interactions, and rheology. Objectives: To determine whether a [...] Read more.

Background: Hydroxylapatite is a biocompatible calcium-phosphate ceramic used in regenerative biomaterials. Calcium hydroxylapatite (CaHA) fillers combine immediate mechanical support with subsequent extracellular matrix remodeling, and their material behavior depends on microsphere morphology, mineral composition, carrier interactions, and rheology. Objectives: To determine whether a CaHA formulation prepared using Lattice Pore Formation technology (Facetem) exhibits a distinct and internally consistent material profile across microsphere geometry, lattice-pore surface architecture, mineral composition, formulation-level sedimentation, and rheological behavior across dilution ratios, with selected morphology and sedimentation characteristics compared with Radiesse. Methods: Facetem (marketed in the Republic of Korea as DCLASSY) was evaluated as the test product, with Radiesse used as the comparator product. Microspheres were examined using field-emission scanning electron microscopy and laser-diffraction particle-size analysis. Surface morphology was assessed before and after 12 weeks of phosphate-buffered saline (PBS) incubation. Mineral composition was evaluated using X-ray diffraction and inductively coupled plasma optical emission spectroscopy. Extrusion continuity and sedimentation after saline dilution were evaluated, and rheological properties were measured across eight dilution ratios using saline, non-cross-linked hyaluronic acid, and semi-cross-linked hyaluronic acid. Results: Facetem had a mean particle diameter of 34.60 μm, with higher circularity (0.95 versus 0.88) and roundness (0.96 versus 0.85), a lower aspect ratio, and fewer particles below 20 μm (2.10% versus 14.50%) than Radiesse. Micrograin domains formed a lattice-pore surface that showed morphological changes after 12 weeks of PBS incubation while the spherical contour remained recognizable. Hydroxylapatite represented 99.09% of the mineral phase, with a Ca/P ratio of 1.67. Facetem extruded as a continuous strand and showed greater supernatant clarification after dilution. Storage modulus declined with dilution, and semi-cross-linked hyaluronic acid retained more elastic resistance than saline at equivalent ratios. Conclusions: Facetem demonstrated a consistent microsphere population, an organized lattice-pore surface, hydroxylapatite stoichiometry, and diluent-dependent rheology. The integrated analysis defines its physicochemical profile; the PBS findings should be interpreted as morphological stability under non-biological buffer conditions rather than in vivo degradation. Full article

(This article belongs to the Special Issue Material Innovations for Regenerative Medicine)

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14 pages, 734 KB

Open AccessArticle

Influence of Different Surface Modifications on the Reverse Torque Values of Abutment Screws: An In Vitro Study

by Merve Dede, Ozgun Yusuf Ozyilmaz, Ozge Doganay Ozyilmaz and Gamze Hanci Abay

J. Funct. Biomater. 2026, 17(9), 475; https://doi.org/10.3390/jfb17090475 (registering DOI) - 18 Sep 2026

Abstract

Evidence regarding tantalum nitride (TaN)-coated gold abutment screws is lacking, and studies on diamond-like carbon (DLC)-coated and anaerobic adhesive-coated abutment screws remain limited. This study evaluated the reverse torque values (RTVs) of abutment screws with different surface modifications. Sixty abutment screws from the [...] Read more.

Evidence regarding tantalum nitride (TaN)-coated gold abutment screws is lacking, and studies on diamond-like carbon (DLC)-coated and anaerobic adhesive-coated abutment screws remain limited. This study evaluated the reverse torque values (RTVs) of abutment screws with different surface modifications. Sixty abutment screws from the same implant system were divided into five groups (n = 12): gold, TaN-coated gold, titanium, DLC-coated titanium, and anaerobic adhesive-coated titanium. Abutments were tightened according to the manufacturer’s recommended torque. Specimens were then subjected to cyclic loading (50 N, 1 Hz, 480,000 cycles) in a dual-axis chewing simulator, after which RTVs were evaluated. ANOVA showed a significant difference only for the uncoated gold screw group (p < 0.05). The lowest RTVs were observed in the gold screws. Although the differences among the modified screw groups were not statistically significant, surface-treated screws demonstrated higher and more stable RTVs than their uncoated counterparts. TaN-, DLC-, and anaerobic adhesive-treated screws exhibited higher RTVs following cyclic loading, suggesting that these surface modifications may enhance screw stability and reduce the risk of abutment screw loosening. Full article

(This article belongs to the Special Issue Surface Analyses, Physicochemical and Mechanical Properties of Dental Biomaterials (2nd Edition))

21 pages, 6440 KB

Open AccessArticle

Concentration-Dependent Rheological Properties of Atelocollagen Are Associated with Fibroblast Mechanotransduction and Collagen Remodeling in Aged Skin

by Seyeon Oh, Gwahn Woo Cheon, Jae Ik Lee, Hyoung Moon Kim, Min Seung Kim, Soo Jeong Heo, Kuk Hui Son and Kyunghee Byun

J. Funct. Biomater. 2026, 17(9), 474; https://doi.org/10.3390/jfb17090474 (registering DOI) - 17 Sep 2026

Abstract

Injectable collagen biomaterials are used to modify the dermal extracellular matrix in aged skin; however, whether concentration-dependent rheological differences are associated with distinct fibroblast responses remain unclear. We compared 3% and 6% atelocollagen (AtCOL) and examined three mechanobiological programs: (i) integrin (ITG) α5β1–ERK–cyclin [...] Read more.

Injectable collagen biomaterials are used to modify the dermal extracellular matrix in aged skin; however, whether concentration-dependent rheological differences are associated with distinct fibroblast responses remain unclear. We compared 3% and 6% atelocollagen (AtCOL) and examined three mechanobiological programs: (i) integrin (ITG) α5β1–ERK–cyclin D1 signaling related to proliferation; (ii) ITGβ1–FAK–YAP signaling related to matrix synthesis; and (iii) ITGα11β1/Tensin-1–positive fibrillar adhesion related to collagen assembly. Under the tested oscillatory shear conditions, 6% AtCOL displayed higher storage modulus (G′), loss modulus (G″), and complex viscosity, together with a lower tan δ, than 3% AtCOL. In aged mouse skin, the 6% formulation was associated with greater increases in ITGα5, pERK1/2, cyclin D1, PCNA, pFAK, nuclear YAP, COL1A1, COL3A1, ITGα11β1/Tensin-1 co-expression signal, collagen type I/III ratio, collagen type I fiber bundle width, mature collagen content, dermal collagen density, and an instrument-derived skin elasticity index, while MMP1, MMP2, and MMP9 were reduced. In an H₂O₂-induced fibroblast senescence model, ITGβ1 knockdown attenuated AtCOL-associated proliferative, matrix-synthetic, and fibrillar-adhesion responses. Complementary ITGβ1 overexpression produced directionally concordant increases in ITGA11 expression, relative fibroblast proliferation, COL1A1, and COL3A1 and decreases in MMP1, MMP2, and MMP9. Collectively, these findings are consistent with a concentration-dependent, ITGβ1-centered mechanotransduction model linking fibroblast proliferation, matrix synthesis, and collagen assembly within a single AtCOL system. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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21 pages, 22745 KB

Open AccessArticle

Curcumin (Ferrocene)-Functionalized Polyurethane Composite Dressing Integrated with Dopamine-Grafted Sodium Alginate: Synergistic ROS Modulation and Durable Tissue Adhesion

by Jiacheng Yu, Chengming Wang, Xiue Ren, Huixia Wang, Yiqiang Huang and Changren Zhou

J. Funct. Biomater. 2026, 17(9), 473; https://doi.org/10.3390/jfb17090473 (registering DOI) - 17 Sep 2026

Abstract

Elevated levels of reactive oxygen species (ROS) and persistent inflammatory responses represent principal impediments to efficacious wound healing, particularly in mechanically dynamic or infected wound environments. Consequently, multifunctional hydrogel-based dressings capable of integrating coordinated antioxidant, anti-inflammatory, and antimicrobial activities with robust wet-tissue adhesion [...] Read more.

Elevated levels of reactive oxygen species (ROS) and persistent inflammatory responses represent principal impediments to efficacious wound healing, particularly in mechanically dynamic or infected wound environments. Consequently, multifunctional hydrogel-based dressings capable of integrating coordinated antioxidant, anti-inflammatory, and antimicrobial activities with robust wet-tissue adhesion are highly sought after, yet their development remains limited. Herein, we introduce a curcumin-functionalized polyurethane composite dressing (designated CPFSD), engineered through the incorporation of dopamine-grafted sodium alginate (SD) and ferrocene (Fc), which collectively confer synergistic ROS modulation alongside durable tissue adhesion. Mechanistically, curcumin provides intrinsic antioxidant and anti-inflammatory properties, while Fc facilitates reversible Fe²⁺/Fe³⁺ redox cycling, thereby augmenting ROS scavenging capacity; concurrently, catechol and hydroquinone moieties present on SD establish stable interfacial interactions with moist biological tissues. Comprehensive physicochemical characterization revealed that CPFSD effectively scavenged over 80% of both DPPH and hydroxyl (·OH) radicals, exhibited greater than 80% antibacterial efficacy against Escherichia coli and Staphylococcus aureus, and demonstrated markedly enhanced adhesive performance while preserving mechanical flexibility and cytocompatibility. In vitro assays further indicated that CPFSD significantly attenuated oxidative stress in L929 fibroblasts and RAW264.7 macrophages, accompanied by downregulation of pro-inflammatory cytokine expression. In a murine full-thickness excisional wound model, CPFSD facilitated accelerated epithelialization, angiogenesis, and wound contraction, achieving wound closure at day 11 without observable systemic toxicity. Collectively, these findings underscore that rational multicomponent design strategies can yield adhesion-capable wound dressings endowed with synergistic therapeutic functionalities suitable for addressing complex pathological wound conditions. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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24 pages, 3172 KB

Open AccessArticle

Descriptive Histological and Histomorphometrical Comparison of Four Xenogeneic and Synthetic Bone Blocks for Mandibular Onlay Augmentation in Rabbits

by Souichiro Honda, Daniele Botticelli, Erick Ricardo Silva, Samuel Porfirio Xavier, Giovanna Iezzi, Hitoshi Seo and Shunsuke Baba

J. Funct. Biomater. 2026, 17(9), 472; https://doi.org/10.3390/jfb17090472 - 17 Sep 2026

Abstract

Background: This exploratory study provided a primarily descriptive comparison of two xenogeneic and two synthetic blocks for mandibular onlay augmentation in rabbits. Methods: Twelve rabbits received bilateral block grafts, providing 24 sites allocated to Bio-Oss^® Block, SP-Block, ReproBone^® Block, or Alos [...] Read more.

Background: This exploratory study provided a primarily descriptive comparison of two xenogeneic and two synthetic blocks for mandibular onlay augmentation in rabbits. Methods: Twelve rabbits received bilateral block grafts, providing 24 sites allocated to Bio-Oss^® Block, SP-Block, ReproBone^® Block, or Alos Block (n = 6/material). After 10 weeks, undecalcified sections were evaluated within standardized inferior and superior regions. Newly formed bone was the primary outcome; secondary outcomes included residual graft, IBN-like tissue, soft-tissue components, and cross-sectional augmented area. Mixed-effects models accounted for clustering within animals. Results: No statistically significant difference in newly formed bone percentage was detected among biomaterials (p = 0.475). Residual graft differed significantly (p < 0.001) and was lower for all test materials than for Bio-Oss^® Block. ReproBone^® Block consistently exhibited IBN-like tissue (17.3 ± 2.9%). SP-Block showed more intra-compartment soft tissue than Bio-Oss^® Block. Alos Block had the smallest augmented area (12.9 ± 6.1 mm²; adjusted p = 0.001 versus Bio-Oss^® Block), and extra-compartment soft tissue was present in five of six sites. Conclusions: Although newly formed bone percentages did not differ significantly, the biomaterials displayed distinct profiles of scaffold persistence, incorporation, tissue organization, and cross-sectional augmented area at 10 weeks. These features should be considered together when evaluating block biomaterials for onlay augmentation. Full article

(This article belongs to the Special Issue Role of Dental Biomaterials in Promoting Oral Health (2nd Edition))

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17 pages, 1551 KB

Open AccessArticle

Perceptual Evaluation of 3D-Printed Typodont Teeth with Comparable Cutting Forces

by Alexander Jon Cresswell-Boyes, Aylin Baysan and Graham Roy Davis

J. Funct. Biomater. 2026, 17(9), 471; https://doi.org/10.3390/jfb17090471 - 17 Sep 2026

Abstract

Background: Pre-clinical training in endodontics relies heavily on typodont teeth to develop operative skills before patient care, but conventional polymer-based typodonts differ from human teeth in their cutting response, requiring greater force and producing an unrealistic cutting experience that often dissatisfies students. [...] Read more.

Background: Pre-clinical training in endodontics relies heavily on typodont teeth to develop operative skills before patient care, but conventional polymer-based typodonts differ from human teeth in their cutting response, requiring greater force and producing an unrealistic cutting experience that often dissatisfies students. Methods: This study evaluated four alternative 3D-printed typodont materials—15 wt.% carbonated hydroxyapatite, 15 wt.% Puraflake^® (glass flake filler), 15 wt.% zinc oxide, and a urethane/triethylene glycol dimethacrylate resin composite—based on their cutting force, post-cut surface roughness, and perceived cutting feel relative to extracted enamel, assessed via a five-point Likert scale questionnaire completed by 46 (n = 46) fourth- and fifth-year dental students. Results: No statistically significant differences in cutting force were detected between the four printed materials and extracted enamel, a finding confirmed using formal two one-sided equivalence testing (TOST); larger confirmatory studies would allow this equivalence to be established with greater statistical precision. Perception scores differed significantly between materials, and fifth-year students rated the dental resin composite significantly more favourably than fourth-year students, with only the composite effect surviving stringent Bonferroni correction across all four material comparisons, underscoring the reliability of this specific finding. Post-cut surface roughness showed a strong, statistically robust monotonic association with perception scores at the individual-respondent level (Page’s L trend test, n = 46, p < 0.001), suggesting that surface behaviour during material removal may contribute to perceived haptic similarity. Conclusions: Matching cutting force alone does not guarantee perceptual equivalence. Among the materials tested, the dental resin composite most closely approximated extracted-enamel surface roughness, received the most favourable and consistent perception scores, and is recommended as the preferred material for pre-clinical typodont fabrication where accessible. These 3D-printed typodonts offer a standardised, openly documented alternative to commercial typodonts for pre-clinical training, with digital models and manufacturing workflows openly available via an institutional platform (TactiTooth). Full article

(This article belongs to the Special Issue Biomaterials and 3D Printing in Dentistry: Research and Clinical Innovations)

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16 pages, 10356 KB

Open AccessArticle

Influence of Digital Workflows on Maxillary Complete Denture Base Fit Accuracy: A Prospective Clinical 3D Evaluation

by Helin Su Akyol-Kurtca, Deger Ongul and Bilge Gokcen-Rohlig

J. Funct. Biomater. 2026, 17(9), 470; https://doi.org/10.3390/jfb17090470 - 15 Sep 2026

Abstract

Background: This study investigated the fit accuracy of maxillary complete denture bases (CDBs) fabricated using conventional, fully digital, and two hybrid workflows. Methods: Thirteen edentulous patients each received four maxillary CDBs produced via conventional (C), fully digital (FD), hybrid early (HE), and hybrid [...] Read more.

Background: This study investigated the fit accuracy of maxillary complete denture bases (CDBs) fabricated using conventional, fully digital, and two hybrid workflows. Methods: Thirteen edentulous patients each received four maxillary CDBs produced via conventional (C), fully digital (FD), hybrid early (HE), and hybrid late (HL) workflows. Group C employed functional impressions and heat-polymerized polymethyl methacrylate (PMMA). Group FD utilized intraoral scanning (IOS), computer-aided design (CAD), and three-dimensional printing. The HE workflow combined digitally designed custom trays with conventional impressions, while the HL workflow digitized conventional master casts prior to digital fabrication. The master cast from the C workflow served as the reference. Deviations were calculated at 22 landmarks across six anatomical regions, with overall and regional analyses performed. Results: Group C exhibited the lowest deviation, followed by HE. HL and FD groups demonstrated significantly higher deviations (p < 0.001), with no significant difference between them. Regional variations were observed across most anatomical areas, except for the posterior palatal seal (p = 0.287). Conclusions: Clinical workflow significantly influences denture base fit accuracy. Conventional and hybrid early workflows provided more predictable adaptation, whereas hybrid late and fully digital workflows showed greater deviation, particularly in functional regions, potentially affecting clinical performance. Full article

(This article belongs to the Section Dental Biomaterials)

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36 pages, 3487 KB

Open AccessReview

Overcoming the Biomechanical Limitations of Titanium–Zirconia Dental Implants: Rationale for a Novel Ti-PEEK-Zr Tri-Layered Concept

by Marius Carnaru Vacaru, Corneliu Munteanu, Fabian Cezar Lupu, Grigorii Deleu, Ioana Ilinca Volocaru and Kamel Earar

J. Funct. Biomater. 2026, 17(9), 469; https://doi.org/10.3390/jfb17090469 - 14 Sep 2026

Abstract

Background: The clinical success of modern dental implants requires a balance between mechanical endurance and aesthetic integration. While titanium alloy (Ti-6Al-4V) provides a reliable load-bearing core, yttria-stabilized tetragonal zirconia (Y-TZP) is frequently preferred for the cervical collar to secure optimal peri-implant soft tissue [...] Read more.

Background: The clinical success of modern dental implants requires a balance between mechanical endurance and aesthetic integration. While titanium alloy (Ti-6Al-4V) provides a reliable load-bearing core, yttria-stabilized tetragonal zirconia (Y-TZP) is frequently preferred for the cervical collar to secure optimal peri-implant soft tissue responses. Yet, fusing these materials directly creates a structural challenge, an abrupt stiffness gradient. This discontinuity promotes localized tensile stresses within the brittle ceramic component, elevating the risk of subcritical crack initiation under oblique masticatory loads. Methods: To address this challenge, we conducted a narrative review to establish the rationale for a novel Ti-PEEK-Zr tri-layered concept. This approach integrates materials science and dental biomechanics to provide a theoretical framework prior to experimental testing. Results: The synthesized data supports the integration of polyetheretherketone (PEEK) as an intermediate compliant layer. Rather than serving as an intermediate stiffness layer, PEEK operates as a viscoelastic buffer. This functional transition zone dampens oblique forces, redistributing localized stress away from the fragile rigid–rigid junction and shielding the Y-TZP collar. The modular tri-layered configuration offers a theoretically sound mechanical hypothesis, though its clinical feasibility depends on rigorous validation that must encompass not only biomechanical performance but also biological compatibility, resistance to bacterial colonization, and long-term stability under the challenging conditions of the oral environment. The practical advantages, including manufacturability, surgical handling, and cost-effectiveness, remain to be demonstrated through future experimental and numerical studies. Conclusions: The Ti-PEEK-Zr multi-material concept is a biomechanical hypothesis. By functionally isolating the roles of each material, this paradigm addresses several limitations of traditional hybrid implants, providing the basis for future finite element analyses. Full article

(This article belongs to the Special Issue Advanced Metallic Biomaterials: Characterization, Optimization and Biomedical Applications)

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19 pages, 16304 KB

Open AccessArticle

Physicochemical Properties of Pineapple Stem Fiber/Gellan Gum Biocomposite Films as a Potential Platform for Buccal Drug Delivery

by Tuty Fareyhynn Mohammed Fitri, Azlin Fazlina Osman, Eid Alosime, Sinar Arzuria Adnan and Nur Hidayah Ahmad Zaidi

J. Funct. Biomater. 2026, 17(9), 468; https://doi.org/10.3390/jfb17090468 - 12 Sep 2026

Abstract

The physicochemical properties of buccal films are vital for evaluating their suitability for mucosal applications. By focusing on these properties, researchers can enhance the mechanical functionality and mucoadhesion of the films. This study aimed to overcome the mechanical limitations of neat gellan gum [...] Read more.

The physicochemical properties of buccal films are vital for evaluating their suitability for mucosal applications. By focusing on these properties, researchers can enhance the mechanical functionality and mucoadhesion of the films. This study aimed to overcome the mechanical limitations of neat gellan gum and to produce biocomposite films with enhanced physicochemical properties and mucoadhesive properties for potential use in buccal drug delivery. Biocomposite films composed of gellan gum (GG) and pineapple stem fiber (PSF), with glycerine as a plasticizer, were prepared using the solvent casting method to develop a formulation suitable for this application. Fourier transform infrared (FTIR) spectroscopy, pH and thickness measurements, tensile test, folding endurance, swelling index, scanning electron microscope (SEM), mucoadhesion test and X-ray diffraction (XRD) analysis were conducted to determine the optimal PSF content in the GG-based biocomposite film formulation. The results indicated that the optimal formulation, GG/3PSF, was achieved with the incorporation of 3 wt% PSF relative to the GG mass. Specifically, the GG/3PSF biocomposite film exhibited a tensile strength of 17.10 ± 0.4 MPa (a 50% increase compared to neat GG), an elongation at break of 46.0 ± 2.5%, a tensile toughness of 41 ± 2.0 MPa, and an ex vivo mucoadhesive residence time of at 7.76 ± 0.51 h for GG/3PSF (compared to 3.90 ± 0.24 h for neat GG). Additionally, it maintained a moderate and optimal swelling index of 115.31 ± 2.3% after 60 min of hydration, which prevents structural instability associated with excessive swelling (such as 161.81 ± 4.7% observed in GG/7PSF), while possessing acceptable thickness (0.09 ± 0.005 mm) and neutral pH (7.0 ± 0.05). The developed buccal film is environmentally friendly due to the utilization of pineapple stem fiber, an agricultural by-product that can reduce material costs compared with synthetic fillers and shows considerable potential as a biocomposite film for buccal drug delivery applications. Full article

(This article belongs to the Special Issue Natural Biomaterials as Drug Delivery Platforms)

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13 pages, 3885 KB

Open AccessArticle

Effect of Smear Layer Deproteinization on Gingival Marginal Sealing of Self-Adhesive Flowable Composites: A Micro-CT Study

by Fulya Aydin, Burcu Öztürk, Gülbike Demirel, Özgür Irmak, Arda Buyuksungur, İsmail Hakki Baltacioğlu, Özgür Karstarli and Kaan Orhan

J. Funct. Biomater. 2026, 17(9), 467; https://doi.org/10.3390/jfb17090467 - 12 Sep 2026

Abstract

Self-adhesive flowable resin composites have been developed to simplify restorative procedures by eliminating separate adhesive application; however, their gingival sealing to dentin remains a concern. This study assessed the gingival marginal sealing of resin composites by measuring silver nitrate solution (AgNO₃) [...] Read more.

Self-adhesive flowable resin composites have been developed to simplify restorative procedures by eliminating separate adhesive application; however, their gingival sealing to dentin remains a concern. This study assessed the gingival marginal sealing of resin composites by measuring silver nitrate solution (AgNO₃) penetration using micro-computed tomography (µCT). Materials and Methods: Seventy-five human third molars with 150 standardized cavities were allocated into 15 experimental groups based on three surface pretreatments (no pretreatment, sodium hypochlorite solution [NaOCl], and a hypochlorous acid-containing aqueous solution [HCS]) and five restorative materials: three self-adhesive flowable composites (Fusio Self-Adhesive, Vertise Flow, and Nova Compo SF) and two conventional composites (Clearfil Majesty Posterior and Clearfil Majesty Flow). Following thermal cycling, microleakage was quantified by measuring silver nitrate penetration along the gingival floor of the restorations using µCT and statistically analyzed. Results: HCS significantly reduced silver nitrate penetration in all self-adhesive composites (p < 0.05), while NaOCl significantly reduced silver nitrate penetration only in the 10-MDP-containing Nova Compo SF (p < 0.05). Conventional composites bonded with a self-etch adhesive exhibited significantly lower microleakage than self-adhesive materials (p < 0.05). Conclusions: HCS improved the gingival marginal sealing of self-adhesive flowable composites to dentin, whereas the effect of NaOCl was material-dependent. Conventional resin composites used with a self-etch adhesive demonstrated superior gingival marginal sealing compared with self-adhesive flowable composites. Full article

(This article belongs to the Section Dental Biomaterials)

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18 pages, 6494 KB

Open AccessArticle

A Type I Aggregation-Induced Emission Photosensitizer Enables Peroxide-Free Photodynamic Tooth Whitening While Preserving Enamel Integrity

by Kaiqi Peng, Jingheng Liang, Yiyi Huang, Yixue Li, Feng-Shou Liu and Yan Zhou

J. Funct. Biomater. 2026, 17(9), 466; https://doi.org/10.3390/jfb17090466 - 10 Sep 2026

Abstract

Conventional hydrogen peroxide (HP) tooth whitening treatments frequently induce structural deterioration of enamel, necessitating the development of biocompatible and highly efficient alternatives. This in vitro study investigated the application of a novel functional biomaterial, the Type I aggregation-induced emission (AIE) photosensitizer CPTQ, for [...] Read more.

Conventional hydrogen peroxide (HP) tooth whitening treatments frequently induce structural deterioration of enamel, necessitating the development of biocompatible and highly efficient alternatives. This in vitro study investigated the application of a novel functional biomaterial, the Type I aggregation-induced emission (AIE) photosensitizer CPTQ, for peroxide-free photodynamic tooth whitening. Under white-light irradiation (25 mW/cm²), CPTQ (12.5 μM) demonstrated rapid degradation of representative chromogenic molecules (crystal violet, malachite green, and rhodamine B). Extracted human teeth stained with both model pigments and complex beverage mixtures (coffee, tea, and fruit juices) were allocated into four treatment groups: negative control (NC), CPTQ, 7.5% HP, and 30% HP (n = 6 per group). Colorimetric parameters (ΔE₀₀, Δa*, Δb*, and ΔL*) and enamel-related endpoints—including surface morphology, roughness, mineral composition (Ca/P), and microhardness—were evaluated over 6 h and analyzed using one-way ANOVA. For pigment-stained teeth, the photodynamic whitening efficiency of CPTQ was comparable to that of 30% HP (ΔE₀₀, p > 0.05) during the 6 h treatment period. At 1.5 h, the ΔE₀₀ value in the CPTQ group (23.35 ± 2.32) was significantly greater than those in the NC group (15.70 ± 1.78, p < 0.05) and the 7.5% HP group (15.02 ± 1.63, p < 0.05). For beverage-stained teeth, the whitening efficiency (ΔE₀₀) of CPTQ was significantly greater than that of the control group at 1.5 h (6.22 ± 2.09 vs. 1.82 ± 0.56, p < 0.01) and was significantly greater than that of 7.5% HP at 4.5 h (10.94 ± 2.82 vs. 7.56 ± 1.78, p < 0.05). Crucially, unlike the change observed after 30% HP treatments, CPTQ treatment resulted in no statistically significant differences from NC in preserved enamel surface integrity, including morphology assessed by SEM, surface roughness (R_a and S_a, both p > 0.05), mineral composition (Ca and P, both p > 0.05), and microhardness (ΔH_V, p > 0.05). Mechanistic investigations using reactive oxygen species (ROS) scavengers (TBA and DABCO) suggested that hydroxyl radicals generated via the Type I photodynamic pathway are the primary drivers of pigment degradation, reducing ΔE₀₀ from 12.56 to 1.09 upon •OH inhibition. CPTQ achieved measurable in vitro whitening through a predominantly Type I ROS-mediated mechanism while causing limited changes in the evaluated enamel surface endpoints. Full article

(This article belongs to the Section Dental Biomaterials)

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13 pages, 13824 KB

Open AccessArticle

Shear Bond Strength of TheraCal PT and Calcium Silicate-Based Cement to a Flowable Composite Resin According to Bonding Strategy

by Soram Oh

J. Funct. Biomater. 2026, 17(9), 465; https://doi.org/10.3390/jfb17090465 - 10 Sep 2026

Abstract

This study aimed to evaluate the micro-shear bond strength (μSBS) of TheraCal PT (TP), Endocem MTA Premixed Heavy (EC), One-Fil Putty (OF), and BC Universal RRM (RM) bonded to a flowable composite resin using two universal adhesives (G-Premio Bond or Prime & Bond [...] Read more.

This study aimed to evaluate the micro-shear bond strength (μSBS) of TheraCal PT (TP), Endocem MTA Premixed Heavy (EC), One-Fil Putty (OF), and BC Universal RRM (RM) bonded to a flowable composite resin using two universal adhesives (G-Premio Bond or Prime & Bond Universal) in two etching modes (etch-and-rinse or self-etch). Disc-shaped specimens (n = 60 per pulp capping material) were allowed to set for 72 h and then divided into four groups according to the adhesive and etching mode used. The μSBS was measured using a universal testing machine. Data were analyzed with three-way ANOVA and post hoc tests for the pulp capping material. Failure modes were determined. Spectra were recorded before and after adhesive application using attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy. Three-way ANOVA revealed that the effects of the adhesive (p = 0.002), etching mode (p < 0.001), and pulp capping material (p < 0.001) on the μSBS were significant. The interaction between the adhesive and etching mode, as well as the interaction between the adhesive and pulp capping material, was significant (p < 0.001). TP exhibited higher μSBS values than EC, OF, and RM. TP failed in mixed, cohesive, and adhesive modes, whereas EC, OF, and RM failed mostly cohesively within the material. ATR-FTIR spectroscopy confirmed the functional monomer peaks on the material surfaces after adhesive application. Full article

(This article belongs to the Special Issue Biomaterials in Dentistry: Current Status and Advances)

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20 pages, 20255 KB

Open AccessArticle

Biocompatible Germanium-Enriched Nanocomposite Coatings on Titanium Designed Toward Preventing Early Inflammation and Promoting Osteogenic Differentiation

by Miloš Lazarević, Evelina Herendija, Milica Jakšić Karišik, Marijana R. Pantović Pavlović, Miroslav M. Pavlović, Katarina R. Pantović Spajić and Nenad L. Ignjatović

J. Funct. Biomater. 2026, 17(9), 464; https://doi.org/10.3390/jfb17090464 - 10 Sep 2026

Abstract

The study seeks to develop a multifunctional germanium-enriched nanocomposite coating on titanium and to evaluate its ability to modulate early inflammatory responses while promoting osteogenic differentiation in a dental pulp stem cell (DPSC)-based regenerative model. A multifunctional Ti/Coating composed of nanohydroxyapatite (nHAp) particles, [...] Read more.

The study seeks to develop a multifunctional germanium-enriched nanocomposite coating on titanium and to evaluate its ability to modulate early inflammatory responses while promoting osteogenic differentiation in a dental pulp stem cell (DPSC)-based regenerative model. A multifunctional Ti/Coating composed of nanohydroxyapatite (nHAp) particles, chitosan-oligolactate (ChOL), and germanium (Ge) was developed using a combined anodizing/anaphoretic electrodeposition approach. The Ti/Coating system exhibited good biocompatibility, as confirmed by microscopy, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, with cell viability consistently exceeding 90% and moderate LDH release across all time points. Annexin V/PI assay demonstrated a predominance of viable cells (>94%), while intracellular ROS analysis indicated moderate oxidative activity. Gene expression analysis revealed significant downregulation of pro-inflammatory markers (TNF-α, IL-1β, IL-6, COX-2, and MAPK), suggesting attenuation of inflammatory signalling. Flow cytometry further demonstrated reduced CD120b (TNFR2) expression, while intracellular TNF-α levels remained unchanged, indicating selective modulation at the receptor level. In addition, the Ti/Coating promoted osteogenic differentiation, as evidenced by enhanced mineralization, and upregulation of osteogenic genes (ALP, RUNX2, BMP2). Full article

(This article belongs to the Section Dental Biomaterials)

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20 pages, 321 KB

Open AccessArticle

Prosthetic Retention Mode and Peri-Implant Marginal Bone Level at a Minimum Five-Year Follow-Up After Maxillary Sinus Floor Elevation: A Retrospective Clustered Cohort Study

by Cristian Niky Cumpătă, Călin Rareș Roman, Mihaela Jana Ţuculină, Ioana Smaranda Cumpătă, Alexandru Burcea, Cristina Maria Munteanu, Mădălina Anca Moldovan, Adrian Camen, Sebastian Petrescu and Paolo Di Francesco

J. Funct. Biomater. 2026, 17(9), 463; https://doi.org/10.3390/jfb17090463 - 9 Sep 2026

Abstract

Background/Objectives: Evidence comparing cement- and screw-retained implant-supported restorations remains heterogeneous, particularly in augmented posterior maxillae. This study evaluated the association between definitive retention mode and peri-implant marginal bone level at a minimum 5-year follow-up after maxillary sinus floor elevation. Methods: This retrospective clustered [...] Read more.

Background/Objectives: Evidence comparing cement- and screw-retained implant-supported restorations remains heterogeneous, particularly in augmented posterior maxillae. This study evaluated the association between definitive retention mode and peri-implant marginal bone level at a minimum 5-year follow-up after maxillary sinus floor elevation. Methods: This retrospective clustered cohort included 248 patients and 528 bone-level implants; radiographic measurements were available for 522 implants from 247 patients. Marginal bone level was assessed by CBCT immediately after implant placement and at least 60 months later. The primary adjusted analysis used generalized estimating equations with patient-level clustering and robust standard errors. Results: Mean marginal bone level at final follow-up was 0.133 mm for cement-retained and 0.105 mm for screw-retained restorations; the unadjusted difference was not statistically significant (Mann–Whitney U = 31,366; p = 0.064). In the primary GEE model, which excluded provisional retention because of its strong collinearity with definitive retention, definitive screw retention was not associated with marginal bone level at follow-up (B = −0.0028 mm; 95% CI: −0.0165–0.0108; p = 0.684). The time × definitive retention interaction was also not significant (B = −0.0069 mm; 95% CI: −0.0187–0.0049; p = 0.249). Conclusions: Definitive retention mode was not significantly associated with marginal bone level in the primary adjusted analysis, and longitudinal marginal bone change did not differ significantly between retention strategies. Sensitivity analyses indicated that estimates were influenced by the strong collinearity between provisional and definitive retention. These observational findings do not demonstrate superiority or equivalence of either retention strategy. Full article

(This article belongs to the Special Issue State of the Art: Biomaterials and Oral Implantology)

17 pages, 6419 KB

Open AccessArticle

Multimodal Evaluation of Surface Topography and Color Stability in Pediatric Restorative Materials Exposed to Antihistamine Syrups

by Oğuzhan Çağlayan, Nihal Şehkar Oktay, Hüseyin Yüce, Pınar Yılmaz Atalı and Başak Durmuş

J. Funct. Biomater. 2026, 17(9), 462; https://doi.org/10.3390/jfb17090462 - 8 Sep 2026

Abstract

Background/Aim: Restorative materials in pediatric dentistry are frequently exposed to acidic oral liquid medications, which may alter their surface properties and color. This in vitro study compared the surface roughness, three-dimensional topography, and color stability (ΔE₀₀) of a glass hybrid restorative [...] Read more.

Background/Aim: Restorative materials in pediatric dentistry are frequently exposed to acidic oral liquid medications, which may alter their surface properties and color. This in vitro study compared the surface roughness, three-dimensional topography, and color stability (ΔE₀₀) of a glass hybrid restorative system (GH), a polyacid-modified composite resin (PMC), and a nanohybrid bulk-fill resin composite (NHC) following a standardized repeated-exposure protocol to two pediatric antihistamine syrups: ketotifen (Zaditen^®) and cetirizine (Zyrtec^®). Materials and Methods: Disc-shaped specimens were randomly allocated to three immersion subgroups per material (Zaditen^®, Zyrtec^®, distilled water). After baseline measurements (t0), specimens underwent 5000 thermal cycles (t1), then immersion in the assigned solution for 5 min, twice daily, for 6 days (t2). Ra and ΔE₀₀ were evaluated quantitatively; surface degradation was further characterized descriptively using 3D optical profilometry and SEM. Data were analyzed using a three-way mixed-design ANOVA (Time × Material × Solution). Results: Antihistamine syrup exposure was associated with significant changes in surface topography and color stability (p < 0.001), with large-to-moderate effect sizes for time and its interactions. GH showed the highest Ra and largest color change, but much of this occurred after thermocycling, before syrup exposure. NHC and PMC generally showed smaller changes than GH. 3D profilometry and SEM revealed material-specific morphologies, interpreted descriptively rather than as confirmed degradation mechanisms. Conclusion: Standardized repeated exposure to ketotifen and cetirizine syrups was associated with material-dependent changes in surface topography and color stability, with GH showing the greatest change and NHC/PMC comparatively greater stability; clinical extrapolation requires further study. Full article

(This article belongs to the Special Issue Bioactive Dental Restorative Composite Materials)

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20 pages, 18378 KB

Open AccessArticle

Effect of Alginate Coatings on Hydroxyapatite/β-Tricalcium Phosphate Scaffold Behavior

by Michela Piccinini, Maria Laura Belladonna, Chiara Suvieri, Sara Meoni, Daniela Lanari, Silvia Caponi, Francesco Bonacci, Maurizio Ricci, Alessandro Di Michele and Valeria Ambrogi

J. Funct. Biomater. 2026, 17(9), 461; https://doi.org/10.3390/jfb17090461 - 8 Sep 2026

Abstract

Chronic oral and maxillofacial diseases are frequently associated with progressive alveolar bone loss, leading to impaired structural integrity of the jaw and increased risk of implant failure, microbial colonization, and microfracture formation. Ceramic scaffolds such as those made of hydroxyapatite (HA) and β-tricalcium [...] Read more.

Chronic oral and maxillofacial diseases are frequently associated with progressive alveolar bone loss, leading to impaired structural integrity of the jaw and increased risk of implant failure, microbial colonization, and microfracture formation. Ceramic scaffolds such as those made of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have attracted considerable attention because of their controlled resorption properties and the promotion of rapid new vital bone formation. The aim of this research is to enhance the performance of scaffolds composed of HA and β-TCP used for guided bone tissue regeneration in oral surgery. HA/β-TCP scaffolds were loaded with simvastatin (SIMV) and coated with multiple layers of alginate (ALG). The proposed strategy was designed to achieve a local and prolonged drug release while simultaneously improving mechanical properties. The scaffolds were characterized in terms of porosity, water absorption, in vitro degradation, in vitro bioactivity, and SIMV release. In addition, microscale mechanical properties were evaluated using Brillouin microscopy before and after the coating process. Cytocompatibility was further evaluated by using murine macrophages as an in vitro cellular model. The results demonstrated that ALG coatings significantly modulated SIMV release, promoting a delayed drug release. Moreover, ALG deposition improved the micromechanical properties of the scaffolds, conferring a dual structure analogous to those of bone tissue. These findings indicate that ALG-coated SIMV-loaded HA/β-TCP scaffolds represent a promising multifunctional platform for the medical field. Full article

(This article belongs to the Special Issue Biomaterials Applied in Dental Sciences (2nd Edition))

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18 pages, 5063 KB

Open AccessArticle

Long-Term In Vivo Biological Performance of PLLA–b–PEG/HA Filler

by Shujiang Zhang, Tong He, Shuhan Wang, Lixin Yuan, Hongjiang Liu, Ruizhi Li, Kun Zhang, Shiwei Wang and Chen Lai

J. Funct. Biomater. 2026, 17(9), 460; https://doi.org/10.3390/jfb17090460 - 8 Sep 2026

Abstract

Objective: This study aimed to evaluate the long-term degradation behavior, biostimulatory effects, and biocompatibility of a novel poly-L-lactic acid-block-polyethylene glycol/hyaluronic acid (PLLA–b–PEG/HA) composite filler for soft tissue augmentation. Methods: PLLA–b–PEG/HA microsphere properties were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform [...] Read more.

Objective: This study aimed to evaluate the long-term degradation behavior, biostimulatory effects, and biocompatibility of a novel poly-L-lactic acid-block-polyethylene glycol/hyaluronic acid (PLLA–b–PEG/HA) composite filler for soft tissue augmentation. Methods: PLLA–b–PEG/HA microsphere properties were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), thermogravimetry (TG) and differential scanning calorimetry (DSC). A 104-week in vivo rabbit model was established to systematically observe filler degradation and tissue responses. Ultrasound monitoring, histological staining, ELISA and RT-PCR were performed to assess volumetric changes, inflammatory reactions and collagen synthesis-related signaling. Results: Physicochemical property tests demonstrated that PLLA–b–PEG retains the fundamental physicochemical properties of pristine PLLA while exhibiting enhanced hydrophilicity. B-ultrasound demonstrated a presented uniform in vivo distribution without displacement or diffusion over time, confirming steady and predictable degradation. SEM verified progressive morphological degradation and porous evolution of the microspheres. The filler induced a mild, balanced inflammatory microenvironment with early expression of both pro-inflammatory (IL-12, TNF-α) and anti-inflammatory (IL-4) cytokines, which resolved gradually over time. Sustained TGF-β upregulation persisted throughout the 104-week observation period, driving continuous neocollagenesis and prominent neoelastogenesis, thereby achieving favorable and long-term tissue remodeling with excellent biocompatibility. Conclusions: The PLLA–b–PEG/HA composite filler exhibits controllable degradation properties and homeostatic regulatory effects, along with outstanding long-term biosafety and tissue integration capacity. As an ideal biostimulatory filler for soft tissue augmentation, it can effectively facilitate the regeneration of high-quality functional extracellular matrix rich in collagen fibers and elastic fibers, and holds promising clinical prospects for natural and long-lasting soft tissue filling applications. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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Journal of Functional Biomaterials

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