Dental Materials最新文献

{"title":"Effect of the anti-Alzheimer drug GSK-3β antagonist on numerical modeling of the energy dissipation through the resin-dentin interface","authors":"Manuel Toledano ,&nbsp;Enrique Fernández-Romero ,&nbsp;Estrella Osorio ,&nbsp;Fátima S. Aguilera ,&nbsp;Christopher D. Lynch ,&nbsp;María T. Osorio ,&nbsp;Raquel Toledano ,&nbsp;Raquel Osorio","doi":"10.1016/j.dental.2024.09.005","DOIUrl":"10.1016/j.dental.2024.09.005","url":null,"abstract":"<div><h3>Objectives</h3><div>The aim of this study was to determine the viscoelastic performance and energy dissipation of conditioned dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TDg) (TDg-NPs).</div></div><div><h3>Methods</h3><div>Dentin conditioned surfaces were infiltrated with NPs and TDg-NPs. Bonded interfaces were created, stored for 24 h and submitted to mechanical and thermal challenging. Resin-dentin interfaces were evaluated through nano-DMA/complex-loss-storage moduli-tan delta assessment and atomic force microscopy (AFM) analysis.</div></div><div><h3>Results</h3><div>Dentin infiltrated with NPs and load cycled attained the highest complex modulus at hybrid layer and bottom of hybrid layer. Intertubular dentin treated with undoped NPs showed higher complex modulus than peritubular dentin, after load cycling, provoking energy concentration and breakdown at the interface. After infiltrating with TDg-NPs, complex modulus was similar between peri-intertubular dentin and energy dissipated homogeneously. Tan delta at intertubular dentin was higher than at peritubular dentin, after using TDg-NPs and load cycling. This generated the widest bandwidth of the collagen fibrils and bridge-like mineral structures that, as sight of energy dissipation, fastened active dentin remodeling. TDg-NPs inducted scarce mineralization after thermo-cycling, but these bridging processes limited breakdown zones at the interface.</div></div><div><h3>Significance</h3><div>TDg-based NPs are then proposed for effective dentin remineralization and tubular seal, from a viscoelastic approach.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1909-1919"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142277750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Matrix metalloproteinases in dentin: Assessing their presence, activity, and inhibitors – a review of current trends","authors":"Lavanya Anumula ,&nbsp;Sindhu Ramesh ,&nbsp;Venkata Suneel Kumar Kolaparthi","doi":"10.1016/j.dental.2024.09.011","DOIUrl":"10.1016/j.dental.2024.09.011","url":null,"abstract":"<div><h3>Introduction</h3><div>Dentin integrity is a critical aspect of tooth structure, with matrix metalloproteinases (MMPs) playing a crucial role in dentinogenesis, caries formation, and dental bonding. It is crucial to accurately assess MMP activity to understand dentin pathophysiology and develop effective clinical strategies. Objectives: The study aimed to conduct a thorough review and comprehensive summary of diverse techniques employed in assessing MMPs in dentin. Data and sources: To conduct the research, electronic databases were systematically searched and manual citation searches were performed. A total of 621 articles were identified. After eliminating duplicates and irrelevant studies, 70 articles were included in the review. 25 articles with overlapping methodologies were also excluded. Study selection: The selection criteria were based on the relevance of the studies to MMPs and MMP inhibitors in dentin without regard to the study design. Only peer-reviewed articles published in English were included. The search was restricted to studies published until November 2022. Conclusion: The comprehensive analysis of various studies has yielded 37 techniques for evaluating MMPs and MMP inhibitors, which hold significant promise in creating diagnostic markers and devising targeted therapeutic interventions.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 2051-2073"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142378851","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":"Longevity of posterior direct versus indirect composite restorations: A systematic review and meta-analysis","authors":"Christian Tennert,&nbsp;Christina Maliakal,&nbsp;Lazàro Suarèz Machado,&nbsp;Thomas Jaeggi,&nbsp;Hendrik Meyer-Lueckel,&nbsp;Johannes Wierichs Richard","doi":"10.1016/j.dental.2024.07.033","DOIUrl":"10.1016/j.dental.2024.07.033","url":null,"abstract":"<div><h3>Objectives</h3><div>The goal of this systemic review and meta-analysis was to compare the longevity of direct and indirect composite restorations in posterior teeth.</div></div><div><h3>Data</h3><div>Randomized controlled trials (RCT) investigating direct and indirect composite restorations in permanent posterior teeth.</div></div><div><h3>Sources</h3><div>Three electronic databases (PubMed, CENTRAL (Cochrane) and Embase) were screened. No language or time restrictions were applied. Study selection, data extraction and quality assessment were done in duplicate. Risk of bias and level of evidence was graded using Risk of Bias 2.0 tool and Grade Profiler 3.6.</div></div><div><h3>Results</h3><div>A total of 3056 articles were found by electronic databases. Finally, five RCTs were selected. Overall, 627 restorations of which 323 were direct and 304 indirect composite restorations have been placed in 279 patients (age: 28–81 years). The highest annual failure rates (AFR) were found for indirect restorations ranging from 0 % to 15.5 %. Lower AFR were found for direct restorations ranging from 0 % to 5.4 %. The most frequent failures were found to be chipping and fracture of the restoration followed by caries. Meta-analysis revealed that the failure rate for direct restorations was significantly lower than for indirect restorations (Risk Ratio (RR) [95 %CI] = 0.61 [0.47; 0.79]; very low level of evidence). Furthermore, all studies showed a high risk of bias.</div></div><div><h3>Conclusion</h3><div>Direct and indirect composite restorations can be recommended for large class II cavities including cusp coverage in posterior teeth for single tooth restoration. Meta-analysis revealed significantly lower relative risk to fail for direct composite restorations than for indirect restorations but results are with high risk of basis.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages e95-e101"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141910986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of different viscosity and chemical composition of flowable composite resins: A 48-month split-mouth double-blind randomized clinical trial","authors":"Romina Ñaupari-Villasante ,&nbsp;Byron Carpio-Salvatierra ,&nbsp;André de Freitas ,&nbsp;Thalita de Paris Matos ,&nbsp;Alejandra Nuñez ,&nbsp;Chane Tarden ,&nbsp;Marcos Oliveira Barceleiro ,&nbsp;Alessadra Reis ,&nbsp;Alessandro Loguercio","doi":"10.1016/j.dental.2024.07.034","DOIUrl":"10.1016/j.dental.2024.07.034","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the clinical performance of two flowable composites based on methacrylate and one based on ormocer in treating non-carious cervical lesions (NCCLs) after 48-month evaluation in a split-mouth double-blind clinical study design.</div></div><div><h3>Methods</h3><div>A total of 183 restorations were performed on NCCLs using a universal adhesive system (Futurabond U, Voco GmbH) with selective enamel etching on 27 participants: two participants received twelve restorations each, three received nine restorations each, and 22 participants received six restorations each. Three different flowable composites were employed (n = 61): a low-viscosity methacrylate-based composite (GrandioSO Flow, LVM), a high-viscosity methacrylate-based composite (GrandioSO Heavy Flow, HVM), and an ormocer-based flowable composite (Admira Fusion Flow, ORM). All restorations were evaluated using FDI and USPHS criteria after 48 months. Statistical analysis was conducted using Kaplan-Meier Survival analysis and Kruskal-Wallis analysis of variance rank (α = 0.05).</div></div><div><h3>Results</h3><div>After 48 months, 17 restorations were lost: LVM 6, HVM 9, ORM 2. The retention rates (95 % confidence interval) were 89.4 % for LVM, 80.4 % for HVM, and 95.6 % for ORM, with a significant difference between HVM vs. LVM and HVM vs. ORM (p &lt; 0.05). Minor defects were observed in 30 restorations for marginal staining criteria (LVM 12, HVM 10, ORM 8) and in 71 restorations for marginal adaptation criteria (LVM 24, HVM 20, ORM 27) without significant difference between groups (p &gt; 0.05). No restorations showed postoperative sensitivity or recurrence of caries.</div></div><div><h3>Significance</h3><div>The increased viscosity of flowable composites could reduce the clinical longevity in NCCLs after 48 months. Ormocer-based and low-viscosity methacrylate-based flowable composites showed a successful clinical performance in NCCLs after 48 months.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1798-1807"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141987052","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":"Are we approaching the development of a novel calcium phosphate-based bioceramic dental material?","authors":"Letícia Florindo Pereira ,&nbsp;Lucas José de Azevedo-Silva ,&nbsp;Pedro Rodrigues Minim ,&nbsp;Paulo Noronha Lisboa-Filho ,&nbsp;Carlos Alberto Fortulan ,&nbsp;Jason Alan Griggs ,&nbsp;Brunna Mota Ferrairo ,&nbsp;Ana Flávia Sanches Borges","doi":"10.1016/j.dental.2024.07.019","DOIUrl":"10.1016/j.dental.2024.07.019","url":null,"abstract":"<div><h3>Objectives</h3><div>Develop a sustainable bovine hydroxyapatite dental ceramic with the addition of titanium dioxide (TiO₂) nanoparticles (5 % and 8 % by weight), analyzing the outcome of this addition to the microstructure, as well as its mechanical and chemical properties, in order to evaluate whether they satisfy the International Organization for Standardization (ISO) 6872:2015 for dental ceramics or not.</div></div><div><h3>Methods</h3><div>Disks were obtained through uniaxial followed by isostatic pressing from bovine hydroxyapatite powder and TiO₂ nanoparticles and sintered at 1300ºC for 2 h. Three experimental groups were developed (HA, HA+5 %TiO₂ and HA+8 %TiO₂) and subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), indentation fracture (IF), biaxial flexural strength (BFS) and chemical solubility test.</div></div><div><h3>Results</h3><div>XRD revealed, for HA group, the appearance of a peak corresponding to b-tricalcium phosphate (ß-TCP). For HA+ 5 %TiO₂ and HA+ 8 %TiO_2, the entire composition was converted into ß-TCP and calcium titanate (CaTiO₃). The SEM images showed a dense ceramic matrix and a uniform distribution of another phase in groups with TiO₂ nanoparticles. HA+ 5 %TiO₂ (1.40 ± 0.18 MPa.m^1/2) and HA+ 8 %TiO₂ (1.32 ± 0.18 MPa.m^1/2) showed significantly higher fracture toughness values than HA (0.67 ± 0.09 MPa.m^1/2). HA showed significantly higher characteristic stress (295.8 MPa) in comparison to groups with 5 % (235.1 MPa) and 8 % (214.4 MPa) TiO₂ nanoparticles. Differences were not observed between the Weibull modulus values. The solubility results indicated that all experimental ceramics were above the 2000 ug/cm² limit set by the ISO 6872:2015.</div></div><div><h3>Significance</h3><div>This study proposed the development and characterization of a new ceramic for dental prosthesis made from HA extracted from bovine bones, with the intention of reusing these solids waste and transforming them into a sustainable and low-cost material. Although the experimental calcium phosphate ceramic with additions of 5 % and 8 % of TiO₂ achieved desirable mechanical properties, the chemical solubility values were very high.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1843-1853"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142102789","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":"Development of antibacterial dual-cure dental resin composites via tetrapod-shaped zinc oxide incorporation","authors":"Hwalim Lee ,&nbsp;Yu-Jin Kim ,&nbsp;Ye-Jin Yang ,&nbsp;Jung-Hwan Lee ,&nbsp;Hae-Hyoung Lee","doi":"10.1016/j.dental.2024.07.021","DOIUrl":"10.1016/j.dental.2024.07.021","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to evaluate the effects of incorporating the 0–20 wt% tetrapod-shaped zinc oxide (tZnO) whiskers on the mechanical, antibacterial, and cytotoxic properties exhibited by experimental dual-cure resin composites.</div></div><div><h3>Methods</h3><div>Commercially obtained tZnO whiskers underwent surface modification using 3-methacryloxypropyltrimethoxysilane (γ-MPS). Subsequently, four groups of resin composites containing 0, 5, 10, and 20 wt% silanized tZnO along with barium borosilicate glass (BaBSG) fillers were fabricated while maintaining total filler loading at 60 wt%. Mechanical properties were examined utilizing specimens produced adhering to ISO 4049:2019 guidelines where applicable. Depth of cure was quantified immediately, while three-point flexural strength, flexural modulus, fracture toughness, Vickers hardness, compressive strength, and diametral tensile strength were assessed after 24 h of storage in 37 °C distilled water. Planktonic bacteria of <em>Streptococcus mutans</em> (<em>S</em>. <em>mutans</em>) were cultured and tested for antibacterial activity using disk diffusion and microbial anti-adhesion assays. Cytotoxicity was examined by preparing extracts from specimens in a cell culture medium and exposing stem cells from human exfoliated deciduous teeth (SHED) to serial dilutions of these extracts, then assessing cell viability and survival using CCK-8 assay and live/dead staining.</div></div><div><h3>Results</h3><div>Elevating tZnO loading yielded significant reductions in depth of cure, compressive (from 296.4 to 254.6 MPa), and diametral tensile strength (from 42.7 to 31.0 MPa), while flexural strength (91.3–94.1 MPa), flexural modulus (6.4–6.6 GPa), fracture toughness (0.96–1.04 MPa·m^0.5), and Vickers hardness (36.5–37.4 kgf·mm⁻²) remained the same. Composites integrating tZnO displayed markedly enhanced antibacterial activity against <em>S</em>. <em>mutans</em>, based on anti-adhesion tests and live/dead staining. No cytotoxicity was observed for SHED treated with extracts from resin composites possessing up to 20 wt% tZnO whiskers.</div></div><div><h3>Significance</h3><div>This study demonstrates that incorporating up to 20 wt% silanized tZnO in place of traditional barium glass particles appreciably enhances dual-cure resin composite antibacterial function against <em>S</em>. <em>mutans</em> without compromising mechanical properties.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1762-1772"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141905235","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":"Diversity of short-term DC outcomes in bulk-fill RBCs subjected to a 3 s high-irradiance protocol","authors":"Hamad Algamaiah ,&nbsp;Abdulrahman Alshabib ,&nbsp;Muadh Algomaiah ,&nbsp;Jiawei Yang ,&nbsp;David C. Watts","doi":"10.1016/j.dental.2024.08.008","DOIUrl":"10.1016/j.dental.2024.08.008","url":null,"abstract":"<div><h3>Objectives</h3><div>To determine the short-term (5 min) initial effects of a high-irradiance light-curing (LC) protocol on light transmission (LT%), radiant exposure (RE) and degree of conversion (DC%) of different bulk-fill resin-based composites (RBCs).</div></div><div><h3>Materials and methods</h3><div>Six bulk-fill composites with different viscosities were investigated: OBF (One Bulk Fill, 3 M), EB (Estelite bulkfill,Tokuyama), PFill, PFlow, ECeram and EFlow (PowerFill, Poweflow, Tetric EvoCeram bulkfill, Tetric Evoflow bulkfill, Ivoclar), subjected to different LC protocols: one ultra-high-intensity (3 W/cm² −3 s via PowerCure LCU) and two conventional (1.2 W/cm² −10 s and 20 s via PowerCure and Elipar S10 LCUs). Specimens (n = 5) were polymerized within their molds (ϕ5 mm <span><math><mo>×</mo></math></span> 4 mm depth) to determine LT% and RE at 4 mm using a MARC-LC spectrometer. For real-time DC% measurements by FTIR, similar molds were utilized. Data were analyzed by one-way ANOVA and Tukey <em>post-hoc</em> tests at 5 % significance.</div></div><div><h3>Results</h3><div>Regardless of the applied LC protocols, OBF and low-viscosity RBCs (EB, PFlow and EFlow) had the lowest and highest LT%, RE, DC% and RPmax, respectively. RE results of all RBCs were in the same sequence: Elipar-20 s &gt; PCure-10 s &gt; PCure-3 s. DC% of PFill and PFlow displayed no significant difference between the applied LC protocols (p &gt; 0.05). The polymerization kinetic in all materials was well described by an exponential sum function (r² varied between 0.85 and 0.98), showing a faster polymerization with the PCure-3 s protocol.</div></div><div><h3>Significance</h3><div>The measurement of LT% and DC% at 5 min gave an insight into the developing polymerization process. The initial response of these bulk-fill composite to a high-irradiation protocol varied depending on their composition and viscosity, being faster for low viscosity materials. Nevertheless, even though multiple resin composites are designed to be efficient during photopolymerization, care should be taken when selecting materials/curing protocol.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1872-1880"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142124337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of phosphoric acid etching and blasting with aluminum oxide on the enamel topography and adhesion of resin composite to intact or abraded enamel","authors":"Tainah Oliveira Rifane ,&nbsp;Ronaldo Hirata ,&nbsp;Vitaliano Gomes Araújo-Neto ,&nbsp;Thiago Ottoboni ,&nbsp;Victor Pinheiro Feitosa ,&nbsp;Marcelo Giannini","doi":"10.1016/j.dental.2024.08.003","DOIUrl":"10.1016/j.dental.2024.08.003","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the effects of the phosphoric acid (PA) etching, self-etching technique (SE) and blasting with Al₂O₃ particles (BL) on the bonding of a dental adhesive to intact (INT) or abraded (ABR) enamel.</div></div><div><h3>Methods</h3><div>Enamel surfaces were treated as follows: 1- ABR-PA: INT was abraded with SiC paper and etched with PA (20 s) before Clearfil Universal Bond Quick adhesive application; 2- ABR-SE: ABR was SiC and adhesive applied in SE mode; 3- INT-PA: INT was etched with PA and adhesive applied; 4- INT-SE: the adhesive (SE mode) was applied to INT; 5- INT-BL: INT was BL and the adhesive was applied (SE mode), and 6- INT-BA: INT was BL, etched with PA and adhesive applied (SE mode). The enamel surface treated was examined with scanning electron microscopy (SEM) (n = 3) and Al₂O₃ particles were characterized using SEM and EDX. The enamel bond strength was measured by microtensile test (24 h and 1 year) (n = 8) and the morphology of enamel-adhesive interfaces were analyzed by SEM (n = 3). Bond strength data were analyzed by two-way ANOVA and Tukey’s test (α = 0.05).</div></div><div><h3>Results</h3><div>Al₂O₃ particles had an irregular shape, their length varied (50–20 µm) and the perimeter mean was 38.8 µm. The enamel morphology significantly influenced the enamel bond strength. ABR-PA, INT-BL, and INT-BA provided greater and stable enamel-dentin interaction and bond strength.</div></div><div><h3>Significance</h3><div>The enamel morphology significantly influenced the enamel bond strength. Using the adhesive in etch-and-rinse mode, enamel must be abraded before etching and must be Al₂O₃-blasted when used in SE mode.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages e102-e111"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141999057","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":"Fatigue lifetime of reduced-diameter implants placed in different bone models","authors":"Pedro Henrique Wentz Tretto ,&nbsp;Jason Alan Griggs ,&nbsp;Kartikeya Singh Jodha ,&nbsp;Yuanyuan Duan ,&nbsp;Susana María Salazar Marocho ,&nbsp;Alvaro Della Bona","doi":"10.1016/j.dental.2024.09.003","DOIUrl":"10.1016/j.dental.2024.09.003","url":null,"abstract":"<div><h3>Objectives</h3><div>This study assessed the fatigue lifetime of reduced-diameter implants placed in either bovine rib or polymer-based bone model.</div></div><div><h3>Methods</h3><div>Bovine ribs were classified according to the criteria proposed by Lekholm and Zarb and were analyzed for bone fraction. Fourteen dental implants (3.25 mm in diameter × 15 mm in length) were placed in bovine ribs used as a bone model. They were subjected to resonance frequency analysis. Stainless steel loading hemisphere caps were bonded on the abutments position at 30-degree angle and with a moment arm of 11 mm. Accelerated life testing using the step-stress method was conducted at 2 Hz with a stress ratio of 0.1 until fracture on a servo-hydraulic load frames machine (MTS). Results were compared with those of a previous study wherein implants were placed in a polymer-based bone model. Fatigue lifetime statistics (characteristic lifetime and Weibull modulus) of physical specimens were estimated in a reliability analysis software (ALTA PRO). Fractured specimens were examined under an electron scanning microscope to determine the failure mode.</div></div><div><h3>Result</h3><div>The implants exhibited high stability quotient values (75.07 ± 3.81). Implants placed in bovine ribs showed better data dispersion and longer fatigue lifetime than those placed in polymer-based bone models, with no significant difference between groups. All fractures occurred in the implant body near the bone level and were indicative of fatigue fractures.</div></div><div><h3>Significance</h3><div>Bovine ribs appear to be a more suitable material for accelerated life testing than the polymer-based material because of better data dispersion.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 1920-1926"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142277762","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":"Synthesis and characterization of the dental adhesive monomer 10-MDP","authors":"Paula Roberta Perondi Furtado,&nbsp;Rafael Minski Savanhago,&nbsp;Nataly Castro,&nbsp;Rogerio Aparecido Gariani,&nbsp;Marcia Margarete Meier","doi":"10.1016/j.dental.2024.09.009","DOIUrl":"10.1016/j.dental.2024.09.009","url":null,"abstract":"<div><div>Many studies have demonstrated the excellent performance of 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate) as a functional monomer for dental adhesive materials and as a primer for ceramic surfaces. Although adhesive performance is affected by the purity level of 10-MDP, this parameter is rarely described, and possible byproducts have been suggested in the literature, but have not been identified to date. The present study aims to present an accessible 10-MDP synthesis strategy with easily handled reagents and address the characterization challenges, especially in identifying byproducts. 10-MDP was synthesized from 10-hydroxydecyl methacrylate and phosphorus pentoxide in acetone. The final product was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR) and mass spectrometry MALDITOF/TOF. The main chemical groups associated with 10-MDP were identified by ¹H, ³¹P, and ¹³C NMR analyses. Only mass spectrometry analyses (MALDITOF/TOF) could identify the presence of dimers as byproducts. Its proposed chemical structure indicates that the dimers were formed by the reaction between the phosphate ester groups and others formed by the reaction of the methacrylic group of 10-MDP molecules. Careful adjustment of the synthesis conditions to reduce the formation of these byproducts is also described. The results indicate that the characterization of 10-MDP batches as raw materials is an important task because, depending on the byproduct present, its ability to polymerize or acid etching capacity may be compromised.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"40 11","pages":"Pages 2000-2007"},"PeriodicalIF":4.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142338153","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}