Dental Materials最新文献

{"title":"Is galvanic corrosion between implant abutments and roots a possible scenario? An experimental study under simulated healthy and inflammatory peri-implant conditions and F anions","authors":"Spiros Zinelis ,&nbsp;Georgios Polychronis ,&nbsp;Spiridon Silvestros ,&nbsp;Andreas Barbetseas ,&nbsp;Dimitris Karasoulos ,&nbsp;George Eliades","doi":"10.1016/j.dental.2024.11.009","DOIUrl":"10.1016/j.dental.2024.11.009","url":null,"abstract":"<div><h3>Purpose</h3><div>To assess the effect of healthy and inflammatory conditions and the presence of F anions on the galvanic coupling between the root surface and titanium abutments of commercially available titanium implants</div></div><div><h3>Materials and methods</h3><div>Eight pairs of three dental root-abutment couples (BEGO, MIS, NOBEL) were exposed to a neutral (pH=7.4) (HE) and an acidic (pH=4.0) (IN) phosphate buffer solution (PBS) simulating healthy and inflammatory conditions respectively. In order to simulate the presence of F anions, which is commonly used in toothpastes, 3.12 gr of NaF was added in both solutions simulating healthy conditions (HEF) and inflammatoy conditions (INF) with the presence of F anions respectively. The galvanic potential difference was recorded for 48 h and averaged. Physical appearance of abutment and roots were tested under a stereomicroscope. Scanning electron microscopy and X-ray energy dispersive spectroscopy (SEM/EDX) was used to characterize the materials under reseach and compare the surfaces before and after galvanic testing.</div></div><div><h3>Results</h3><div>All abutments are composed of Ti-6Al-4V alloy along with root of MIS system, while BEG and NOB are made of Ti according to the SEM/EDX analysis. No differences were identified in surface morphology before and after galvanic testing, while EDX analysis revealed only the presence of Na and F on the surface of MIS abutments after testing in INF conditions. All groups tested showed negligible potential difference and below the nominal threshold for triggering galvanic corrosion under HE, IN and HEF conditions. The same applies for BEG and MIS under INF conditions, while NOB presented an average potential difference value of −273 mV, which is above nominal thresshold for galvanic action. Only MIS abutment showed a color change from yellow to blue under INF conditions.</div></div><div><h3>Conclusions and clinical implications</h3><div>BEG and MIS implant systems are not prone to galvanic corrosion in all conditions tested. NOB was found vulnerable to galvanic corrosion under inflammatory peri-implant conditions in the presence of F anions. Galvanic reactions is a possible scenario even between Ti base implant components.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 203-211"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790633","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 TiF4-Dendrimer complex gel as an anti-demineralization agent for dentin: An in vitro study","authors":"Taraneh Estedlal ,&nbsp;Ladan Ranjbar Omrani ,&nbsp;Khosrou Abdi ,&nbsp;Niyousha Rafeie ,&nbsp;Zohreh Moradi","doi":"10.1016/j.dental.2024.11.007","DOIUrl":"10.1016/j.dental.2024.11.007","url":null,"abstract":"<div><h3>Objective</h3><div>The anti-caries effects of titanium tetrafluoride (TiF4) are well-documented, but its low pH challenges clinical application. This study evaluated PEG-citrate dendrimer as a carrier to enhance TiF4 stability and efficacy.</div></div><div><h3>Methods</h3><div>PEG-citrate dendrimer and TiF4-dendrimer gel were synthesized, and their structures confirmed using Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (1H NMR), and Liquid Chromatography–Mass Spectrometry (LC-MS). Thirty-six intact human teeth were prepared, randomly divided into three groups (n = 12) and subjected to pH cycling with the following treatments: titanium tetrafluoride (T), dendrimer (D), and dendrimer with TiF4 (TD). Vickers microhardness and Raman spectroscopy evaluated dentin demineralization. EDS analysis measured titanium and fluoride penetration into dentin in T and TD groups and mineral content (calcium and phosphorus) in all groups.</div></div><div><h3>Results</h3><div>The T group showed the highest microhardness loss (p &lt; 0.001), followed by D and TD groups. EDS analysis revealed no significant difference in titanium and fluoride content between the surface and subsurface in TD (p = 0.344), while T had more titanium on the surface (p &lt; 0.001). TD had higher subsurface calcium content compared to T (p = 0.008). Raman spectroscopy revealed significant changes in phosphate-to-amide and carbonate-to-amide ratios before and after pH cycling in all groups (p &lt; 0.001), with no statistical differences among the groups.</div></div><div><h3>Conclusion</h3><div>Using dendrimer as a carrier for TiF4 increased pH and enhanced TiF44 ability to limit dentin demineralization and microhardness loss.</div></div><div><h3>Clinical Relevance</h3><div>The application of the newly-developed TiF4-dendrimer gel might be an effective approach to prevent/ limit dentin demineralization and dentin caries.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 159-168"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778735","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":"Direct colour printing on zirconia using 222 nm UV-C photons","authors":"Xuedong Bai ,&nbsp;Mengxiao Xu ,&nbsp;Shixin Jin ,&nbsp;Edmond H.N. Pow ,&nbsp;Yanning Chen ,&nbsp;James K.H. Tsoi","doi":"10.1016/j.dental.2024.10.019","DOIUrl":"10.1016/j.dental.2024.10.019","url":null,"abstract":"<div><h3>Objectives</h3><div>To proof the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C through investigating the degree and durability of the colour changes, and testifying whether surface, mechanical and biological properties are influenced by the treatment.</div></div><div><h3>Methods</h3><div>222 nm UV-C light (Irradiance: 1.870 mW/cm²) was used to treat 3Y-TZP for durations from 15 min to 24 h. ΔE*, TP, crystalline structure, surface morphology, S_a, BFS and biological activities were investigated before and after irradiation. SPSS 28.0 was used for statistical analysis (α = 0.05).</div></div><div><h3>Results</h3><div>222 nm UV-C irradiation was capable to shade white 3Y-TZP into tooth colours. With the increase of ΔE*, TP decreased, such that the longer the irradiation time, the higher the ΔE* (logarithmic relationship) and lower the TP. Despite the induced optical changes being prone to fade, the process can be predicted by inversely proportional relationships between ΔE*, TP and the testing points. The treated surface exhibited enhanced hydrophilicity, while the recovery phenomenon was observed. Other properties were not altered by the treatment.</div></div><div><h3>Significance</h3><div>This is the seminal study demonstrating the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C. The new relationship between the colour centre and E_g of 3Y-TZP was established, whereas the induced optical changes were stabilised after a certain period and were highly predictable by controlling the irradiation periods. The irradiation was only correlated to the electron excitation and oxygen vacancies, and would not lead to any changes of other properties. A simple, safe and promising approach to achieve satisfactory colours on 3Y-TZP in clinical practice can be developed.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 101-112"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142563538","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":"Two-step sintering suppresses grain growth and improves flexural strength of dental zirconia","authors":"Chek Hai Lim ,&nbsp;Larissa M.M. Alves ,&nbsp;Sonaj Vardhaman ,&nbsp;Estevam A. Bonfante ,&nbsp;Do Kyung Kim ,&nbsp;Yu Zhang","doi":"10.1016/j.dental.2024.11.008","DOIUrl":"10.1016/j.dental.2024.11.008","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to elucidate the effect of various two-step sintering (TSS) protocols on the physical, mechanical, and optical properties of partially stabilized zirconia with different yttria dopant concentrations (Y-PSZ).</div></div><div><h3>Methods</h3><div>Disc-shaped specimens were obtained from most widely used commercial dental zirconia powders of various Y contents (Tosoh Corp.) by uniaxial pressing followed by cold-isostatic pressing. Densification was carried out using TSS protocols with varying temperatures for both sintering steps. Relative density (<em>ρ</em>_Rel), microstructure, and phase content were analyzed. Biaxial flexural strength (<em>σ</em>) and translucency parameter (<em>TP</em>) were evaluated.</div></div><div><h3>Results</h3><div>The TSS results were compared with optimized conventional sintering (CS) results from a previous study for the same Y-PSZ compositions. TSS 3Y-PSZ and 4Y-PSZ reached similar <em>ρ</em>_Rel to those of their CS counterparts, whereas 5Y-PSZ failed to achieve that regardless of TSS protocol. TSS yielded less cubic phase compared to CS, especially for 3Y-PSZ and for higher temperatures. TSS suppressed the grain growth throughout the temperature range investigated, promoting smaller grains than CS (p &lt; 0.05). The <em>TP</em> values for TSS Y-PSZ were lower than those of CS (p ≤ 0.0001), except for 3Y-PSZ. The <em>σ</em> values for TSS Y-PSZ were significantly higher than those of CS (p ≤ 0.0002).</div></div><div><h3>Significance</h3><div>TSS increased strength without significantly jeopardizing the optical properties of various Y-PSZ compositions relative to their CS counterparts. This alternative sintering method appears to be a promising technique for controlling grain growth while eliminating porosities in dental Y-PSZ ceramics, thus potentially enhancing the clinical longevity of zirconia restorations.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 194-202"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783569","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":"The evolution of adhesive dentistry: From etch-and-rinse to universal bonding systems","authors":"Lorenzo Breschi ,&nbsp;Tatjana Maravic ,&nbsp;Claudia Mazzitelli ,&nbsp;Uros Josic ,&nbsp;Edoardo Mancuso ,&nbsp;Milena Cadenaro ,&nbsp;Carmem S. Pfeifer ,&nbsp;Annalisa Mazzoni","doi":"10.1016/j.dental.2024.11.011","DOIUrl":"10.1016/j.dental.2024.11.011","url":null,"abstract":"<div><h3>Objectives</h3><div>This review aimed at presenting the mechanisms and pitfalls of adhesion to enamel and dentin, advances in the materials science and in the development of strategies to improve hybrid layer (HL) longevity.</div></div><div><h3>Methods</h3><div>Search of the literature was performed on PubMed, Scopus and Web of Science with keywords related to the structure of the dental substrate, HL degradation mechanisms and strategies to contrast them.</div></div><div><h3>Results</h3><div>Albeit the advances in the dental materials’ properties, HL degradation is still a relevant and current issue in adhesive dentistry. However, adhesive materials have become more resistant and less operator sensitive, and good adhesion is currently in the hands of every practitioner. Numerous novel strategies are being developed, able to improve the resistance of adhesive resins to degradation, their ability to infiltrate and chemically bond to dentin, to remove the unbound/residual water within the HL, reinforce the dentin collagen matrix, and inhibit endogenous metalloproteinases. Many of the strategies have turned to nature in search for powerful biomodifying compounds, and for the inspiration as to mimic naturally occurring regenerative processes.</div></div><div><h3>Significance</h3><div>Extensive knowledge on the structure of the dental substrate and the complexity of adhesion to dentin has led to the development of improved formulations of dental adhesives and numerous valid strategies to improve the strength and longevity of the HL. Nevertheless, for many of them the road from bench to chairside still seems long. We encourage practitioners to know their materials well and use the strategies readily available to them.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 141-158"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778739","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":"Bonding neat hydrophobic-rich resins to etched dentin: A proof of concept","authors":"Thiago Henrique Scarabello Stape ,&nbsp;Omar Abdelaziz Ismail ,&nbsp;Marcelo Capitanio ,&nbsp;Arzu Tezvergil-Mutluay","doi":"10.1016/j.dental.2024.10.018","DOIUrl":"10.1016/j.dental.2024.10.018","url":null,"abstract":"<div><h3>Objectives</h3><div>To examine whether the effectiveness of current dentin-priming approaches requiring solvated hydrophilic resins may be replicated by modifying the infiltration dynamics of neat methacrylate-based monomers into dry-etched dentin using dimethyl sulfoxide (DMSO) pretreatments. <em>Methods:</em> H₃PO₄-etched mid-coronal dentin surfaces from human molars were air-dried for 30 s and randomly pretreated with 50 %(v/v) ethanolic DMSO for 20 or 60 s. Untreated samples and an isolated wet-bonding group served as controls. Samples were bonded with a three-step etch-and-rinse adhesive or simply with the solvent-free hydrophobic-rich resin. Restored crown segments (n = 7/group) were stored in distilled water for 24 h and sectioned for microtensile bond strength testing. Resin-dentin beams (0.8 mm²) were tested under tension until failure (0.5 mm/min) after 24 h or 2 years of storage in artificial saliva at 37 °C. Nanoleakage evaluation and hybrid layer characterization were performed by SEM. Bond strength data was examined by three-way ANOVA followed by Tukey and Dunnett’s test (α = 0.05). <em>Results:</em> Pretreatments significantly affected the ability of neat and solvated resins to bond to etched-dry dentin (<em>p</em> = 0.001). Ageing significantly lowered bond strengths depending on resin composition and DMSO-application times (<em>p</em> = 0.007). While hybridization of DMSO-treated dentin with the solvated resin produced no significant reductions in bond strengths after ageing (<em>p</em> &lt; 0.05) improving hybrid layer integrity, direct bonding of the neat hydrophobic-rich resin matched the long-term bonding performance of the “gold standard” wet-bonding protocol (<em>p</em> &gt; 0.05). <em>Significance</em>: Lowering dentin’s hydration state via DMSO-dry bonding allows direct coupling of neat methacrylate-based resins, which may contribute to developing new strategies to ultimately extend the durability of resin-dentin interfaces.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 113-121"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610822","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 preparation designs and CAD-CAM materials on step-stress fatigue survival of premolar partial coverage restorations: An in-vitro study with fractographic analysis","authors":"Dina M. Nasr ,&nbsp;Islam M Abdelraheem ,&nbsp;David C. Watts ,&nbsp;Nikolaos Silikas ,&nbsp;Marcia Borba ,&nbsp;Nada Alharbi ,&nbsp;Khaled Abid Althaqafi ,&nbsp;Alaaeldin Elraggal","doi":"10.1016/j.dental.2024.11.003","DOIUrl":"10.1016/j.dental.2024.11.003","url":null,"abstract":"<div><h3>Objectives</h3><div>The growing trend of minimally invasive approaches has encouraged the application of partial coverage designs in restorative dentistry. This study aimed to evaluate the cyclic fatigue performance of different CAD-CAM materials used in various partial coverage designs for premolar restorations.</div></div><div><h3>Methods</h3><div>A freshly extracted upper premolar was prepared using a high-speed handpiece to create mesio-occluso-distal (MOD) cavities with standardized dimensions. Three preparation designs were investigated: onlay, overlay, and vonlay. CAD software was used to create digital models of the restorations, which were milled into one of four CAD-CAM materials: Zr - zirconia polycrystals (4Y-PSZ); EX - lithium disilicate glass-ceramic; VS - zirconia-reinforced lithium silicate glass-ceramic; GB - nanohybrid composite. Partial coverage restorations were bonded to tooth replicas and subjected to step-stress cyclic fatigue testing using a chewing simulator device (n = 10). The number of cycles-to-failure and fatigue fracture resistance (N) were recorded and analysed with Kaplan-Meier survival statistics and Weibull analysis, respectively. Fracture surfaces were analysed using fractography.</div></div><div><h3>Results</h3><div>Zr exhibited significantly higher number of cycles-to-failure and greater characteristic fracture load (L₀) than the other materials, for onlay and overlay designs. For vonlay design, Zr, VS and EX had similar and greater number of cycles-to-failure than GB. When comparing different designs for the same material, Zr had lower number of cycles-to-failure for vonlay in comparison to onlay and overlay, while the other materials had similar values among the different designs. Weibull modulus was similar among experimental groups<strong>.</strong></div></div><div><h3>Significance</h3><div>The findings of this study emphasize the critical role of material selection and preparation design in optimizing the mechanical performance and clinical success of partial coverage restorations. 4Y-PSZ is recommended for high-stress areas due to its superior fatigue and fracture resistance. Overlay designs provide better fatigue resistance, making them more suitable for clinical scenarios requiring higher durability. Understanding the fatigue performance of different materials and designs aids in making informed decisions to enhance the longevity and success of partial coverage restorations in premolars.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 122-133"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764958","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":"Fatigue behavior and reliability of pressed lithium disilicate ceramics compared to 5Y-TZP zirconia under different loading protocols","authors":"Ramona Buser ,&nbsp;Mustafa Borga Dönmez ,&nbsp;Moritz Hoffmann ,&nbsp;Rüdiger Hampe ,&nbsp;Bogna Stawarczyk","doi":"10.1016/j.dental.2024.11.005","DOIUrl":"10.1016/j.dental.2024.11.005","url":null,"abstract":"<div><h3>Objective</h3><div>To compare the fatigue behavior and reliability of 5 pressed lithium disilicate ceramics and a 5 mol% yttria-stabilized zirconia (5Y-TZP) when 3 dynamic loading protocols were used.</div></div><div><h3>Methods</h3><div>Bar-shaped specimens (30 × 4 × 3 mm) were fabricated from 5 pressed lithium disilicate ceramics (AMB, CEL, INI, IPS, and LIV) and a 5Y-TZP (ZR) (N = 324). Six specimens from each material were subjected to a static 4-point fracture load test, while the remaining specimens were subjected dynamic loading by increasing the starting load (30 % of the static fracture load) in every 5000 cycles by 50 N (loading protocol 1), in every 5000 cycles by 5 % (loading protocol 2) or in every 1000 cycles by 10 N (loading protocol 3) until fracture (n = 16). The fracture load, flexural strength, and number of cycles until failure were analyzed with 2-way analysis of variance and Scheffé tests. The survival rate was evaluated with Kaplan-Meier analysis and further compared with Mantel-Cox test, while the correlation between the fracture load and flexural strength was analyzed with Pearson’s correlation test (α = 0.05). Fractographic analysis was also performed.</div></div><div><h3>Results</h3><div>The interaction between the materials and the loading protocol affected the number of cycles until failure, while the material type affected fracture load and flexural strength values (<em>P</em> &lt; 0.001). ZR had the highest and LIV mostly had lower fracture load and flexural strength (<em>P</em> ≤ 0.034). A positive correlation was found between the fracture load and flexural strength (r = 0.997, <em>P</em> &lt; 0.001). For lithium disilicate ceramics, loading protocol 2 and for ZR, loading protocols 1 and 3 led to the highest number of cycles and survival rate (<em>P</em> ≤ 0.041). Regardless of the loading protocol, all lithium disilicate ceramics had a similar fragmentation pattern with single compression curls and 2-piece fractures were observed.</div></div><div><h3>Significance</h3><div>Tested materials are suitable for adhesively luted monolithic single-unit prosthesis as they had mean flexural strength values higher than 100 MPa. Measuring the fracture load with loading protocol 3 can be considered time-efficient to evaluate the fatigue behavior of pressed lithium disilicate ceramics.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 134-140"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764961","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":"The effect of photoinitiator systems on resin-based composite containing ZnO-nanoparticles","authors":"Abdulaziz Alayed ,&nbsp;Nikolaos Silikas ,&nbsp;David C. Watts","doi":"10.1016/j.dental.2024.12.002","DOIUrl":"10.1016/j.dental.2024.12.002","url":null,"abstract":"<div><h3>Objective</h3><div>Zinc oxide (ZnO) powder possesses antibacterial activity and although white in color, it can severely reduce the depth of cure (<strong>DoC</strong>) of resin-based composite (RBC). This study investigated the effect of unary and binary photoinitiator systems on the <strong>DoC</strong> and degree of conversion (<strong>DC</strong>) of formulated RBC containing ZnO-nanoparticles.</div></div><div><h3>Methods</h3><div>Fourteen RBCs (n = 3/group) were formulated consisting of 50 wt% mixture of monomers (Bis-GMA, TEGDMA, and UDMA) and 50 wt% fillers (inert barium glass powder and silica nanoparticles). ZnO-nanoparticles were added at 0 (control), 0.5, 1, 1.5 and 2 wt%. A unary initiator system consists of camphorquinone (CQ) 0.25, 0.5 and 1 wt% and ethyl 4-(dimethylamino)benzoate (EDMAB) 0.75 wt% or a binary initiator system consisting of diphenyliodonium hexafluorophosphate (DPI) 0.25, 0.5 and 1 wt%, CQ 0.25, 0.5 and 1 wt% and EDMAB 0.75 wt% were added to the monomer mixture. To measure the <strong>DoC</strong>, each specimen was prepared in a custom-made mold with a slot (16 x 8×2 mm) and a top cover plate, irradiated from one end (40 s), stored dry (37° C, 1 d) and measured at increasing depths using Vickers hardness (0.5 mm intervals). 1 mm thick specimens were prepared to measure <strong>DC</strong> continuously using FTIR, from zero up to 24 h post-irradiation.</div></div><div><h3>Results</h3><div>Increasing the concentrations of ZnO led to a significant reduction of <strong>DoC</strong> (p &lt; 0.05). But most of the binary initiator groups showed significantly higher <strong>DoC</strong> (p &lt; 0.05). Depth, at 80 % of max VHN, of unary initiator groups reduced from 6.8 mm (ZnO at 0 wt%) to 2.1 mm (ZnO at 2 wt%) and in binary initiator groups from 8.4 mm to 2.3 mm. Groups with lower photoinitiator concentrations (0.25 wt%) showed a significant increase in DoC compared with groups with higher concentrations (1 wt%) (p &lt; 0.05). <strong>DC</strong> after 24 h was independent of either ZnO concentration or the photoinitiator system (p &gt; 0.05). However, faster conversions were observed in binary initiator groups. The RP_max of binary groups ranged from 8.1 % to 10.1 %/s, and unary groups ranged from 5.2 % to 7.2 %/s.</div></div><div><h3>Significance</h3><div>The addition of DPI resulted in an overall increased curing depth, which was enhanced when lower concentrations of photoinitiators were used. Also, DPI resulted in faster conversions. This is desirable in designing antibacterial RBC containing ZnO.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 220-228"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142790608","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":"Preparation of dental resin composites with anti-bacterial adhesion against Streptococcus mutans using fluorinated and silicon containing dimethacrylates","authors":"Shengcan Zhang ,&nbsp;Xinlin He ,&nbsp;Fang Liu ,&nbsp;Xiangya Huang ,&nbsp;Sui Mai ,&nbsp;Jingwei He","doi":"10.1016/j.dental.2024.11.010","DOIUrl":"10.1016/j.dental.2024.11.010","url":null,"abstract":"<div><h3>Objective</h3><div>The purpose of this study was to enhance the anti-bacterial adhesion effect against Streptococcus mutans (<em>S. mutans</em>) of fluorinated dimethacrylate (DF MA) based dental resin composites (DRCs) by using silicone dimethacrylate (SMA-MEO).</div></div><div><h3>Method</h3><div>The SMA-MEO was added into mixture of DFMA and tricyclo (5.2.1.0) decanedimethanol diacrylate (SR833s) (DFMA/SR833s = 50 wt./50 wt.) with mass ratios of 10 wt% and 20 wt% to form resin matrix both with fluorinated and silicon containing dimethacrylates, and then DRCs named DS+ 10 %SMA-MEO and DS+ 20 %SMA-MEO were prepared by mixing the resin matrix with silaned BaAlSiO₂ filler particles at a mass ratio of 30 wt./70 wt. Double bond conversion, volumetric shrinkage and shrinkage stress, flexural strength and modulus, water sorption and solubility, contact angle and surface free energy, anti-bacterial adhesion effect against <em>Streptococcus mutans</em> (<em>S. mutans</em>), and cytotoxicity of prepared DRCs were investigated according to standard or referenced methods. Fluorinated dimethacrylate (DFMA) based DRC named DS and 2,2-bis[4-(2-hydroxy-3-methacryloy-loxypropyl)-phenyl]propane (Bis-GMA) based DRC named BT were used as controls.</div></div><div><h3>Results</h3><div>Adding SMA-MEO into DFMA based DRC could lead to higher double bond conversion (<em>p</em> &lt; 0.05), higher hydrophobicity (<em>p</em> &lt; 0.05), and lower surface free energy (<em>p</em> &lt; 0.05). Only DS+ 10 %SMA-MEO had better anti-bacterial adhesion effect against <em>S. mutans</em> than DS (<em>p</em> &lt; 0.05). The SMA-MEO had no influence on volumetric shrinkage, shrinkage stress, flexural modulus, water sorption and solubility of DRC (<em>p</em> &gt; 0.05), but could reduce flexural strength of dry DRC (<em>p</em> &lt; 0.05). After water immersion, SMA-MEO containing DRCs had comparable flexural strength as DS (<em>p</em> &gt; 0.05). Compared with BT, DS and SMA-MEO containing DRCs had better or comparable physicochemical properties, and lower amount of adherent <em>S. mutans</em>. All of DRCs had comparable cytotoxicity (<em>p</em> &gt; 0.05).</div></div><div><h3>Significance</h3><div>DRCs with both DFMA and SMA-MEO could have better anti-bacterial adhesion effect against <em>S. mutans</em> than DRC only with DFMA due to increased hydrophobicity and decreased Surface free energy, and the optimal mass fraction of SMA-MEO in DFMA based resin matrix was 10 wt%.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 2","pages":"Pages 169-178"},"PeriodicalIF":4.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764962","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}