Dental Materials最新文献

{"title":"Fatigue behavior and estimated lifetime of implant/abutments of different diameters","authors":"Renan Brandenburg dos Santos ,&nbsp;Ulysses Lenz ,&nbsp;Jason Alan Griggs ,&nbsp;Alvaro Della Bona","doi":"10.1016/j.dental.2025.09.021","DOIUrl":"10.1016/j.dental.2025.09.021","url":null,"abstract":"<div><h3>Objectives</h3><div>Narrow-diameter (ND) implants may show distinct long-term mechanical behavior compared to standard-diameter (SD) implants when subjected to fatigue. This study evaluated the longevity of implant systems with different diameters by assessing structural damage and loosening after fatigue challenge.</div></div><div><h3>Methods</h3><div>This in vitro study used sixty internal conical connection implants/abutments that were divided into two groups (n = 30) based on their diameters (3.0mm-ND and 4.0mm-SD). The manufacturer recommended torque was achieved for each abutment using a digital torque wrench. In order to determine damage and permanent displacement of abutments, cone beam computed tomography (CBCT) scans were post-processed (software e-Vol DX). The boundary fatigue method was adapted to use 2 × 10⁶ cycles, with frequency of 2 Hz, and constant peak load of 80 N for the first experiment. Load was adjusted (17.8 %) according to the failure rate for the second and third experiments. In addition to the aforementioned CBCT scans, removal torque values were used to assess torque loss. The probability of failure over time and the Weibull modulus were calculated for each group.</div></div><div><h3>Results</h3><div>Loosening was observed in all ND specimens, regardless of the level of loading, and structural bending was observed in 6 abutments. In addition, 4 fractures occurred. No structural damage was observed for the SD specimens, and 6 of them did not suffer from loosening. The Weibull analysis showed a lower modulus (m) for SD (m=3.90; 95 %CI=2.75–5.54) than for ND (m=1.99; 95 %CI=1.50–2.64) resulting in lower probability of failure over time and slower decrease in removal torque for SD compared with ND specimens.</div></div><div><h3>Significance</h3><div>The shorter predicted lifetime and faster torque loss of narrow-diameter implant/abutment suggest for a more frequent clinical follow-up of this treatment option.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 177-184"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145205057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the integrity of titanium-oxide nanolayers of Ti6Al4V under chemo-mechanical stress","authors":"K. Shemtov-Yona ,&nbsp;Y. Miara ,&nbsp;D. Rittel","doi":"10.1016/j.dental.2025.10.014","DOIUrl":"10.1016/j.dental.2025.10.014","url":null,"abstract":"<div><div>Titanium-based biomaterials show a high success rate and excellent biocompatibility due to their properties, that can be partly attributed to the titanium’s ability to form a protective oxide layer. As such they are widely used, mostly Ti6Al4V, to manufacture dental implants and prosthetic devices. Unfortunately, implant failures can arise during implant use and are mainly due to peri-implant diseases involving bacterial infection and inflammatory stimuli. This study performs a systematic nano-structural evaluation of the contribution of inflammatory-simulating conditions (H₂O₂ and lactic acid), aside with room air and saline solution, combined with repeated mechanical loading, to the damage generated on the titanium surface and to the titanium oxide integrity. By using an array of high-resolution characterization techniques, such as ToF-SIMS and TEM, the synergy between mechanical loads and chemical reactions was unraveled.</div><div>In the more aggressive environments (<em>e.g.</em> lactic acid and H₂O₂), a clear increase in the titanium oxide’s thickness was observed compared to inert environments, such as air and saline. The effect of the mediums was more pronounced in the presence of loads. The TEM analysis observations revealed the porous and permeable nature of the oxide layer, affecting its neutrality and hence its biocompatibility.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 342-349"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145407642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrastructural and immunobiological responses of human periodontal ligament stem cells to novel tricalcium silicate sealers","authors":"Nuria Pérez-Guzmán ,&nbsp;Paula García-Rios ,&nbsp;Francisco J. Rodríguez-Lozano ,&nbsp;David García-Bernal ,&nbsp;Ali El Yahyaoui ,&nbsp;Sergio López-García","doi":"10.1016/j.dental.2025.10.011","DOIUrl":"10.1016/j.dental.2025.10.011","url":null,"abstract":"<div><h3>Objectives</h3><div>This study was conducted to examine the biocompatibility, regenerative potential, and immunomodulatory effects of three formulated calcium silicate-containing sealers (CSCS)—TotalFill BC Sealer (TFbc), NeoSEALER Flo (NS Flo), and NeoSEALER EZ Flo (NS EZ Flo)—on human periodontal ligament stem cells (hPDLSCs).</div></div><div><h3>Materials and Methods</h3><div>Third molars extracted from healthy patients (n = 15) were used to isolate hPDLSCs. Dilutions of 1:1, 1:2, and 1:4 were prepared, along with set sample discs of TFbc, NS Flo, and NS EZ Flo. The following assays were conducted: cell phenotyping, metabolic activity assessment (MTT assay), evaluation of cell attachment and morphology (scanning electron microscopy, SEM), cell migration analysis (wound-healing assay), cytoskeletal organization (phalloidin staining), proinflammatory cytokine release (IL-6 and IL-8, via ELISA), expression of differentiation markers (RT-qPCR), and assessment of cellular mineralization (Alizarin Red S staining). Statistical significance was set at p &lt; 0.05.</div></div><div><h3>Results</h3><div>The metabolic activity assay demonstrated that cell viability increased over time with the use of bioceramic sealers.These sealers also promoted remarkable cell confluence and a higher number of focal adhesion complexes, as evidenced by the phalloidin assay. Furthermore, they demonstrated enhanced cell adhesion and anti-inflammatory effects compared to the negative control group (untreated cells), with the latter effect being more pronounced in the case of TotalFill BC Sealer. NS Flo, followed by NS EZ Flo, were the bioceramic sealers that most significantly promoted mineralized nodule formation, comparable to the positive control (Osteodiff), thus contributing to osteogenic and cementogenic differentiation<strong>.</strong></div></div><div><h3>Conclusion</h3><div>This study demonstrates that all the bioceramic sealers investigated exhibit adequate cytocompatibility. NS Flo and NS EZ Flo demonstrate a strong ability to induce differentiation of hPDLSCs into osteogenic and cementogenic phenotypes. NS Flo significantly supports extracellular matrix mineralization. However, TFbc had a less substantial impact on these processes than the sealers. The effect was comparable during the first three days but decreased thereafter. In addition, the calcium silicate-containing sealers investigated exhibited relevant anti-inflammatory effects, offering potential therapeutic benefits in the field of regenerative endodontics.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 331-341"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145407651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro comparison of biological properties of CoCr, Ti-6Al-4V, and PEEK for removable partial denture","authors":"Karine Bertotti ,&nbsp;Nina Attik ,&nbsp;Angeline Poulon-Quintin ,&nbsp;Julia Mwenge-Wambel ,&nbsp;Christophe Sireix ,&nbsp;Christophe Jeannin ,&nbsp;Brigitte Grosgogeat","doi":"10.1016/j.dental.2025.10.001","DOIUrl":"10.1016/j.dental.2025.10.001","url":null,"abstract":"<div><h3>Statement of problem</h3><div>To address the limited biocompatibility of conventional removable dental prostheses (RDPs), new materials and manufacturing techniques are being actively investigated.</div></div><div><h3>Purpose</h3><div>This in vitro study aimed to evaluate and compare the biological response of human fibroblast (HGF) to cobalt-chrome (Co-Cr), titanium alloy (Ti), and polyetheretherketone (PEEK), fabricated via tree distinct methods: casting, selective laser melting (SLM) and machining.</div></div><div><h3>Material and methods</h3><div>The surface chemical composition and the wettability of cast Co-Cr, SLM Co-Cr, SLM Ti, machined Ti, and PEEK were assessed. HGF were cultured in contact with material extracts, and all assays were conducted following this exposure. Ion release was assessed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), and pH measurement. Surface roughness was subsequently measured on each sample. Cell viability was assessed using the Live/Dead staining, while metabolic activity was evaluated using the Alamar Blue assay. Cell morphology was observed by scanning electron microscopy (SEM) and confocal microscopy, while inflammatory profile was assessed using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using one-way ANOVA and Tukey’s test (p &lt; 0.05 and 0.001).</div></div><div><h3>Results</h3><div>SLM Co-Cr exhibited higher Co and Cr surface content than cast Co-Cr, while SLM Ti showed a reduced titanium content and increased aluminum content relative to machined Ti. Among all tested materials, machined Ti demonstrated the highest surface wettability, evidenced by a significantly lower contact angle (p &lt; 0.001). HGF exposed to extracts of machined Ti and PEEK exhibited greater cell viability and metabolic activity, comparable to the control group. In contrast, cast Co-Cr was associated with significantly increased IL-6 secretion, although TNF-α and IL-10 levels remained stable across tested groups.</div></div><div><h3>Conclusions</h3><div>Machined titanium (Ti) and PEEK exhibited favorable in vitro biocompatibility, with high cell viability, enhanced cellular adhesion, and no significant cytotoxicity under our experimental conditions. These findings suggest that both materials may represent promising alternatives to CoCr alloys for the fabrication of removable partial dentures, although their clinical application requires further validation of their mechanical, physical, and long-term properties.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 259-269"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145317974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrospun antibacterial β-Ag(VO3)/PCL composite membranes for periodontal tissue regeneration","authors":"André F.P. Lopes ,&nbsp;Manuel F.R.P. Alves ,&nbsp;Inês Baptista ,&nbsp;Tânia Caetano ,&nbsp;Maria Helena F.V. Fernandes ,&nbsp;Sandra I. Vieira ,&nbsp;Samuel Guieu","doi":"10.1016/j.dental.2025.09.018","DOIUrl":"10.1016/j.dental.2025.09.018","url":null,"abstract":"<div><h3>Objective</h3><div>Periodontitis is a widespread and challenging oral disease, which often involves recurring infections that complicate treatment. This study explores a novel tissue engineering approach to address such an issue, involving the design of a nanofibers-based composite material containing silver, a natural antibacterial agent.</div></div><div><h3>Methods</h3><div>Pure β-Ag(VO₃) nanorods were synthesized via microwave irradiation and loaded into electrospun polycaprolactone (PCL) membranes. Integration was confirmed through FTIR, EDS, and XRD analyses and the release profile of Ag and V from the fibers was evaluated by ICP-OES. Biocompatibility towards mammalian cells recurred to resazurin metabolic, cell scoring and microscopy assays in cultured fibroblasts. Bioactivity against bacteria was evaluated in agar diffusion susceptibility tests using <em>E. coli</em> (Gram-negative) and <em>S. aureus</em> (Gram-positive).</div></div><div><h3>Results</h3><div>A PCL-based electrospun membrane, loaded with β-Ag(VO₃) nanorods, was successfully developed and characterized. Incorporation of the nanorods improved the nanofibers’ morphology, and the membranes showed a high cytocompatibility with fibroblasts. Importantly, a 0.5 % β-Ag(VO₃) concentration in the composite demonstrated antibacterial efficacy against Gram-negative and Gram-positive bacteria. This antibacterial effect is most likely due to a kill-on-contact mechanism rather than from the released of Ag ions, that was &lt; 1 ppm over the 24 h of exposure.</div></div><div><h3>Significance</h3><div>The ease of incorporating silver vanadates into polymeric membranes using the methodology here described, combined with the antibacterial effects and cytocompatibility presented by the composite membranes, suggests that these materials may represent a promising avenue for tackling recurring infections in the oral cavity and become valuable options in periodontitis treatment.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 197-206"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of delayed post-polymerization on physical, chemical, and biological properties of a 3D printing interim resin","authors":"Yukyung Choi ,&nbsp;Patricia Comeau ,&nbsp;Bum-Soon Lim ,&nbsp;Adriana P. Manso ,&nbsp;Shin Hye Chung","doi":"10.1016/j.dental.2025.10.005","DOIUrl":"10.1016/j.dental.2025.10.005","url":null,"abstract":"<div><h3>Objectives</h3><div>This study evaluated the effects of delayed post-polymerization on color, degree of conversion (DC), flexural strength (FS), and cellular response of a 3D-printed dental interim resin.</div></div><div><h3>Methods</h3><div>Specimens were divided into six groups based on delays of 0 h, 2 h, 4 h, 6 h, 8 h, and 10 h before post-polymerization. Color was characterized using a spectrophotometer (n = 10), DC (n = 10) with FTIR-ATR, and FS (n = 10) with a universal testing machine. Cellular response (n = 30) was assessed through cell viability and pro-inflammatory gene expression of the gingival fibroblast cell line (L929) and human monocytic cell line (THP-1).</div></div><div><h3>Results</h3><div>Delayed post-polymerization significantly affected color (L* and b*; both P &lt; 0.001,) and color difference (P = 0.016). L* values at 6 h, 8 h, and 10 h significantly decreased compared to 0 h (P &lt; 0.001), while b* values showed a significant decrease in all groups. (P &lt; 0.001). No significant difference was found in a* (P = 0.417) or translucency (P = 0.394). DC significantly decreased at 8 h and 10 h (P &lt; 0.05). There was no significant difference in FS. Cytotoxicity and pro-inflammatory gene expression (IL-6 and TNF-α) were not significantly affected by time delays.</div></div><div><h3>Significance</h3><div>Within the limitations of this study, a delay of up to 6 h before post-polymerization did not compromise FS, FM, cell viability, or pro-inflammatory gene expression. However, notable changes in DC and color suggest that the appearance and polymerization characteristics may be adversely affected, while mechanical and biological properties remained stable.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 240-246"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145385538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-step vs. two-step deposition of CaF2 nanoparticles: From the perspective of confined water release and bonding effectiveness improvement","authors":"Jiajia Xu ,&nbsp;Yanji Lu ,&nbsp;Kai Zhang,&nbsp;Qiaojie Luo,&nbsp;Xiaodong Li","doi":"10.1016/j.dental.2025.10.006","DOIUrl":"10.1016/j.dental.2025.10.006","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Objective&lt;/h3&gt;&lt;div&gt;To compare the bonding efficacy of one-step versus two-step calcium fluoride (CaF₂) nanoparticle deposition and to elucidate the underlying mechanisms. The null hypotheses tested are as follows: 1) Nanoparticles deposited via the one-step strategy are less uniformly distributed than those deposited via the two-step strategy; 2) The one-step strategy does not release more confined water compared to the two-step strategy; 3) The one-step strategy is inferior to the two-step strategy in enhancing dentin bonding durability.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Methods&lt;/h3&gt;&lt;div&gt;A stable amorphous calcium fluoride (ACF) precursor solution was prepared by mixing 10 mM CaCl₂ and 10 mM NaF in 20 mM HEPES buffer for 20 s, enabling one-step CaF₂ nanoparticle deposition through the mineralization-regulating function of non-collagenous proteins acting as pseudonuclei. The two-step strategy consisted of sequentially applying 0.1 M CaCl₂ and 0.2 M NaF, each for 20 s. Neutralization of matrix negative charges, reduced hydration capacity, and confined water release were assessed via cationic dye adsorption, zeta potential, water contact angle, ATR-FTIR spectroscopy, and thermogravimetric analysis. Interface characteristics were evaluated using SEM, TEM, and XPS. Bonding effectiveness was determined by adhesive infiltration depth, micro-tensile bonding strength (μTBS), and nanoleakage expression, both initially and after aging.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;Our results demonstrate that the one-step strategy produces smaller, more homogeneous nanoparticles that penetrate collagen fibrils more effectively. We thus reject the null hypothesis 1. Compared to the unmodified demineralized dentin matrix (DDM), the DDM obtained with the two-step approach exhibits reduced interfacial water, which further reduced by the one-step strategy. The null hypothesis 2 is thus rejected. Compared to the conventional wet-bonding control (AW), bonding performed on these optimized DDM leads to enhanced adhesive infiltration. Both one-step (ACF) and two-step strategies (CW) improve the immediate bonding strength (43.00 ± 4.15 MPa and 36.81 ± 3.32 vs. 31.57 ± 2.02 MPa). after 12 months of storage in water at 37 °C, bonding strength of the AW group significantly decreased to 26.92 ± 2.35 MPa (p &lt; 0.05), whereas the CW group decreased to 30.20 ± 4.66 MPa (p &lt; 0.05) and the ACF group maintained a high level (39.22 ± 5.12 MPa, p &gt; 0.05).&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Significance&lt;/h3&gt;&lt;div&gt;This novel one-step dentin bonding strategy effectively addresses the challenge of dentin bonding durability. By simultaneously reduced electronegativity, lower hydration capacity, decreased confined water, enhanced mechanical properties, and reinforcement at the basal level, adhesive infiltration was improved, clinical procedure was simplified, and bond durability was sustained provided. The one-step dentin bonding strategy offers a clinically practical, time-efficient, and superior alternat","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 227-239"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of crown–core material combinations on cervical surface strain and of crown type on antagonist enamel wear in a simulated deciduous tooth model","authors":"Yuika Yamanaka ,&nbsp;Kanae Wada ,&nbsp;Shinya Oishi ,&nbsp;Daiki Kondo ,&nbsp;Yujeong Shin ,&nbsp;Kaori Kohi ,&nbsp;Misaki Hamashima ,&nbsp;Asuna Sugimoto ,&nbsp;Atsushi Oishi ,&nbsp;Wataru Komada ,&nbsp;Tsutomu Iwamoto","doi":"10.1016/j.dental.2025.10.004","DOIUrl":"10.1016/j.dental.2025.10.004","url":null,"abstract":"<div><h3>Objective</h3><div>This study evaluated the effects of different core–crown material combinations on cervical surface strain at the crown and root and the influence of crown type on antagonist enamel wear.</div></div><div><h3>Methods</h3><div>Three pediatric crown types, zirconia (ZC), stainless steel crowns (SC), and CAD-CAM composite (CA) were tested with two core materials: resin-modified glass ionomer cement (RG) and flowable composite resin (CR). Six groups (n = 8) were prepared for each crown–core combination. Strain gauges were attached to four locations (buccal and palatal sides of both the crown and root in the cervical region) and subjected to loading to measure the surface strain. Additionally, each crown was opposed by deciduous enamel in the impact-sliding wear test, where RG was used as the core material. All data were statistically analyzed.</div></div><div><h3>Results</h3><div>All combinations resulted in significantly higher strains in the cervical region of the palatal root. There, the ZC/RG combination produced the lowest root strain (−228.28; IQR = 85.69; <em>p</em> = 0.009); however, ZC also exhibited significantly greater wear depth on the opposing enamel (226.68 ± 45.58 μm; <em>p</em> = 0.002). In contrast, CA exhibited minimal wear depth on the opposing enamel (8.97 ± 3.77 μm; <em>p</em> &lt; 0.001).</div></div><div><h3>Significance</h3><div>Although ZC/RG minimized cervical strain, its high antagonist wear suggests limited suitability when preservation of the opposing dentition is a priority, such as in pediatric patients. Therefore, the CA/RG combination, which offers moderate strain and minimal wear, may be a more clinically suitable choice.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 219-226"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145306517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eco-friendly reinforcement of dental composites with poly(methyl methacrylate) and hydroxyapatite synthesized from eggshell waste","authors":"Amine Yerou ,&nbsp;Bel Abbes Bachir bouiadjra ,&nbsp;Omar Khatir ,&nbsp;Mohamed Mokhtar Bouziane ,&nbsp;Mohamed Elmeguenni ,&nbsp;Mahmoud Khedr ,&nbsp;Antti Järvenpää","doi":"10.1016/j.dental.2025.10.002","DOIUrl":"10.1016/j.dental.2025.10.002","url":null,"abstract":"<div><h3>Objectives</h3><div>Hydroxyapatite (HAp), owing to its chemical similarity to enamel and bone, can enhance the bioactivity, biocompatibility, and antibacterial performance of poly(methyl methacrylate) (PMMA). This study aimed to develop and characterize a sustainable dental biocomposite by reinforcing PMMA with HAp synthesized from eggshell waste, with the objective of improving its mechanical and thermal performance while maintaining biocompatibility.</div></div><div><h3>Methods</h3><div>HAp was synthesized from eggshells via wet chemical precipitation followed by calcination. The resulting powder was incorporated into PMMA at 10, 20, and 30 wt% fractions. Composites were evaluated using Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM). Mechanical properties were assessed under tensile and compressive loading.</div></div><div><h3>Results</h3><div>The synthesized HAp exhibited high purity and crystallinity. The composite containing 10 wt% HAp demonstrated the most balanced performance, with higher glass transition temperature, enhanced thermal stability, and improved tensile and compressive strength compared to pure PMMA. SEM analysis confirmed more homogeneous dispersion at low filler concentrations, while higher loadings (20–30 wt%) led to agglomeration and reduced performance.</div><div><strong>Significance:</strong></div><div>Clinically, the optimized composite (10 wt% HAp) offers enhanced strength, durability, and thermal stability while maintaining biocompatibility, making it promising for dental prostheses, denture bases, and repair resins. This eco-friendly approach valorizes eggshell waste into a functional bioactive filler, supporting the advancement of sustainable dentistry.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 207-218"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crown margin design and the marginal strength of multilayered zirconia: A step towards clinical relevance using the hoop-strength approach","authors":"U. Lohbauer ,&nbsp;J. Mayer ,&nbsp;L. Schwamberger ,&nbsp;R. Belli ,&nbsp;S. Wartzack","doi":"10.1016/j.dental.2025.10.007","DOIUrl":"10.1016/j.dental.2025.10.007","url":null,"abstract":"<div><h3>Objectives</h3><div>A demand for clinically relevant assessment of materials has been claimed mandatory for better understanding clinical design issues over pure material behavior. Here we focus on a strength test on dome-like half-spheres which serves to simulate the marginal fracture type in single crowns. On the example of a multilayer chairside zirconia material, we aimed to investigate the influence of cervical margin design on crown strength, thereby correlating numeric stress analysis with experimental strength testing assisted by fractographic post-processing.</div></div><div><h3>Materials and methods</h3><div>Ninety dome-like half-spheres were CAD/CAM manufactured in a chairside milling unit (PrimeMill, DentsplySirona) using a 4/5Y-PSZ zirconia multilayer chairside block (e.max ZirCAD MT Multi; Ivoclar). Three design variations were designed to simulate a clinical “shoulder”, “chamfer”, and “taper” preparation. A tapered (7°) hardened steel load piston was used to uniaxially load the domes to fracture by inducing radial hoop stress onto the margins. Fractographic post-processing was performed to confirm the fracture mode at cervical margins. Finite element modelling served to analyze the maximum principal stress (σ_MPS). Weibull statistics were applied on the σ_MPS data.</div></div><div><h3>Results</h3><div>Characteristic fracture forces were 744.3 N for shoulder, 651.1 N for chamfer, and 551.2 N for tapered margin designs. Fracture forces translated into characteristic strength and Weibull moduli of σ_MPS = 1588.8 MPa (m = 9.2), σ_MPS = 1616.5 MPa (m = 11.1), and σ_MPS = 1468.8 MPa (m = 7.6). Fracture initiation was confirmed in the region of dome margins.</div></div><div><h3>Significance</h3><div>The margin design had a significant influence on fracture strength, as a significant drop of σ_MPS at fracture was observed for the taper design. Fractography proved the potential of the test setup to trigger marginal fractures.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 247-258"},"PeriodicalIF":6.3,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145312060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}