Dental Materials最新文献

{"title":"Evaluation of a quadwave curing light compared to a dual-peak LED curing light","authors":"Soheil Ghaffari ,&nbsp;Anubhav Gulati ,&nbsp;Juliana Guarneri ,&nbsp;Richard Bengt Price","doi":"10.1016/j.dental.2025.02.005","DOIUrl":"10.1016/j.dental.2025.02.005","url":null,"abstract":"<div><h3>Objective</h3><div>To determine if the PinkWave (PW) light-curing unit (LCU) that emits red and infrared (IR) light as well as violet and blue light improves the depth of cure and degree of conversion (DC) of resin-based composites (RBCs).</div></div><div><h3>Methods</h3><div>The DC of RBCs at various distances was calculated from data collected at a rate of 13 Hz using attenuated total reflectance Fourier-transform infrared spectroscopy. To assess the contributions of the different wavelengths of light, optical filters were used to block the red and IR light from the PW. The depth of cure was also evaluated by photocuring RBC samples in both metal and plastic molds for 20 s at a 0 mm distance. The length of resin remaining was then measured and divided by 2. Starting from a baseline of 32 °C, the temperature rise during photocuring was measured in the plastic and metal rings reproducing the conditions used to measure the depth of cure and the DC respectively.</div></div><div><h3>Results</h3><div>In general, the PW produced greater depth of cure, however the use of metal molds greatly reduced this effect because the temperature increase was reduced. Increasing the distance by up to 4 mm from the light tip produced a significant increase in the DC for the RBCs photocured with the PW, but not for the G4. The wavelength of the blue peak (peaking at 473 nm) from the PW was longer compared to the control LCU (peaking at 448 nm). This 25 nm difference negatively affected the photocuring efficiency of some resins.</div></div><div><h3>Significance</h3><div>The internal optics and the additional red and IR wavelengths from the PW significantly increased the temperature in the RBCs and increased both depth of cure and the DC.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 5","pages":"Pages 503-512"},"PeriodicalIF":4.6,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530879","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 influence of pH on the adhesive performance of phosphoric ester monomers with zirconia","authors":"Aifang Han ,&nbsp;Noriko Hiraishi ,&nbsp;James Tsoi ,&nbsp;Jukka P. Matinlinna ,&nbsp;Junji Tagami ,&nbsp;Fumiaki Hayashi","doi":"10.1016/j.dental.2025.02.004","DOIUrl":"10.1016/j.dental.2025.02.004","url":null,"abstract":"<div><h3>Objective</h3><div>Functional phosphoric ester monomers containing primers have been widely used in dental adhesives. This study aims to analyze the atomic-level interaction between zirconia and phosphoric ester monomers under different pH conditions (acidic or neutral).</div></div><div><h3>Methods</h3><div>Solid-state ³¹P NMR spectroscopy was employed to investigate the binding interactions between two types of phosphoric ester monomers—glycerophosphate-dimethacrylate (GPDM) and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)—with zirconia under varying pH conditions. Contact angles were measured on the zirconia surfaces with and without the application of phosphoric ester monomers. Additionally, tensile bond strength (TBS) tests were conducted to determine the effects of different phosphoric ester monomer-containing primers under different pH conditions on zirconia.</div></div><div><h3>Results</h3><div>Solid-state ³¹P NMR spectroscopy revealed that both GPDM and MDP exhibited broadened peaks, positioned differently from their unreacted forms, indicating that the environment surrounding the phosphate groups in both GPDM and MDP changed upon adhesion to zirconia at the atomic level. Acidic MDP may form covalent bonds with zirconia through additional esterification on the zirconia surface. MDP-primed zirconia demonstrated a higher contact angle than GPDM-primed zirconia. The highest TBS was observed in the group of MDP reacted with zirconia under acidic conditions.</div></div><div><h3>Significance</h3><div>These findings suggest that phosphoric ester monomers, particularly MDP in acidic conditions, can chemically bind to zirconia, contributing to enhanced adhesion behavior.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 5","pages":"Pages 495-502"},"PeriodicalIF":4.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497756","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":"Bond strength of a 3-step total-etch bonding system to dentine – An improved approach","authors":"H. Hassan Elnadif,&nbsp;W. Palin,&nbsp;M.A. Hadis,&nbsp;B.W. Darvell","doi":"10.1016/j.dental.2025.02.007","DOIUrl":"10.1016/j.dental.2025.02.007","url":null,"abstract":"<div><h3>Background</h3><div>Generally, the bonding of one material to another is important for function, and especially in so-called ‘adhesive dentistry’. However, there are concerns about the clinical relevance and the discriminatory power of currently employed tests of bond strength.</div></div><div><h3>Objective</h3><div>Develop and validate a test protocol based on 4-point bending that may be used to examine the bonding of various dental materials to a range of substrates. The bonding of a resin-based composite (RBC) to dentine is taken as an example.</div></div><div><h3>Methods</h3><div>Slices of dentine ‘coupons’ (5.0 × 2.0 × ∼4–6 mm³) from extracted molars were prepared using a diamond saw under running water. Pairs of RBC bars (5.0 × 2.0 × ∼24 mm³) (Z250) were bonded symmetrically either side of a dentine coupon using all combinations of the following treatments: E: acid-etched (Scotchbond Universal Etchant), P: primer (Adper Scotchbond Multipurpose Adhesive); A: adhesive (Adper Scotchbond Multipurpose Primer) (all 3 M) as well as N: no treatment. Following retrieval from the mould, test pieces were immediately subjected to 4-point bending at 23 °C, cross-head speed 0.5 mm/min, until fracture. Three-way analysis of variance on log(flexural strength): etch × primer × adhesive, was applied. Scanning electron microscopy (SEM) was used to examine fracture surfaces and identify failure origins.</div></div><div><h3>Results</h3><div>Flexural strengths in MPa: N: 1.38 ± 0.56; P: 9.82 ± 0.89; A: 5.12 ± 0.73; E: 9.39 ± 1.78; E + P: 21.03 ± 2.63; E + A: 12.80 ± 1.53; P + A: 17.16 ± 3.03; E + P + A: 20.84 ± 3.93. The treatment main effects (all, p &lt; 10⁻¹²) were not additive, there being significant two-way (p &lt; 10⁻⁵) and three-way (p = 0.037) interactions. There was no significant difference between E + P + A and E + P (p = 0.86).</div></div><div><h3>Conclusion</h3><div>With good reproducibility (low scatter), discriminatory power (clear treatment effects), economy with regard to substrates, the method has the potential to be adaptable to many systems.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 5","pages":"Pages 483-494"},"PeriodicalIF":4.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447604","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":"Mapping water and monomer gradients in the adhesive/dentin interface with confocal micro-Raman imaging","authors":"Yong Wang,&nbsp;Xinglin Guo,&nbsp;Xiaomei Yao,&nbsp;Viviane Hass","doi":"10.1016/j.dental.2025.02.002","DOIUrl":"10.1016/j.dental.2025.02.002","url":null,"abstract":"<div><h3>Objectives</h3><div>Water in the adhesive/dentin (a/d) interface plays a crucial role in the quality of the hybrid layer (HL). This study aims to directly measure depth profiles of water content and adhesive monomers within the HL and explore the relationship between adhesive hydrophilicity and water content under wet bonding conditions using two model adhesives.</div></div><div><h3>Methods</h3><div>The occlusal one-third of the crown was removed from six unerupted human third molars. The exposed dentin surfaces were etched with 35 % phosphoric acid for 15 s, followed by the application of model adhesives with varying BisGMA/HEMA ratios (40/60 and 70/30) using the wet bonding technique. After light curing and 24 h of storage in water, the specimens were examined using a confocal Raman microscope under a 100x objective. Raman spectral imaging or mapping was performed at 1-micron intervals across the a/d interface in the Z direction. Reference spectra were obtained from model compounds, including type I collagen, BisGMA, HEMA, water, and the model adhesives, to generate calibration curves. These curves were then used to calculate the weight percentages of the components within the HL, which were subjected to statistical analysis (α = 0.05).</div></div><div><h3>Results</h3><div>Raman imaging shows that the HL is not a uniform structure, exhibiting gradients in both adhesive penetration and dentin demineralization. However, water content consistently remains higher in the HL compared to both the adhesive and underlying dentin. The water content in the HL formed by the model adhesives varies between approximately 9 % and 24 %, depending on location. This water content is strongly influenced by the hydrophobicity of the adhesives, with greater water accumulation at the bottom of the HL when a more hydrophobic adhesive (BisGMA/HEMA = 70/30) is used.</div></div><div><h3>Significance</h3><div>For the first time, the distribution of water, collagen, and adhesive within the HL has been quantified using confocal Raman microscopy combined with z-mapping. This technique allows for direct, nondestructive detection of the HL’s interfacial structure and composition.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 4","pages":"Pages 473-481"},"PeriodicalIF":4.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143447567","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":"Influence of surface treatment before glazing on wear and flexural strength of translucent zirconia","authors":"Manon Wenger ,&nbsp;Nicola U. Zitzmann ,&nbsp;Nadja Rohr","doi":"10.1016/j.dental.2025.02.006","DOIUrl":"10.1016/j.dental.2025.02.006","url":null,"abstract":"<div><h3>Objectives</h3><div>To determine whether the surface treatment of translucent zirconia prior to glazing affects wear and flexural strength.</div></div><div><h3>Methods</h3><div>Translucent zirconia disks were either left as-sintered, polished, or sandblasted. Half of the specimens within these three groups were glazed. Human enamel and dentin substrates were prepared as control. The wear volume and depth, as well as surface roughness parameters, were obtained after chewing simulation (n = 8 per group). Biaxial flexural strength of zirconia specimens was measured and fractures were analyzed. Statistics was performed with multifactorial ANOVAs (α = 0.05).</div></div><div><h3>Results</h3><div>The overall wear volume was significantly higher on glazed surfaces (0.020 ± 0.007 mm³) compared to non-glazed zirconia (0.001 ± 0.001 mm³; p &lt; 0.001). No significant difference in wear volume was found among different surface treatments (<em>p</em> = 0.368). Nevertheless, wear volume significantly increased when rough antagonists were used for zirconia and tooth substrates (both <em>p</em> &lt; 0.001). The lowest wear volume was measured on polished zirconia (&lt; 0.001 ± &lt; 0.001 mm³) and highest on dentin (2.327 ± 1.686 mm³). The flexural strength was significantly higher for polished zirconia surfaces (652 ± 135 MPa) than for all other groups (<em>p</em> &lt; 0.001).</div></div><div><h3>Significance</h3><div>Lowest wear and highest flexural strength of a translucent zirconia restoration can be expected when the surface is polished. When applying glaze, the prior surface treatment does not affect wear. Applied to clinical situations, perfect surface polishing after occlusion adjustments is recommended to prevent increased wear of the antagonist.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 4","pages":"Pages 464-472"},"PeriodicalIF":4.6,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143432092","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":"Screening dental implant design parameters for effect on the fatigue limit of reduced-diameter implants","authors":"Megha Satpathy ,&nbsp;Matthew Loeb ,&nbsp;Rose M. Jose ,&nbsp;Matthew J. Sinclair ,&nbsp;Yuanyuan Duan ,&nbsp;Susana M. Salazar Marocho ,&nbsp;Michael D. Roach ,&nbsp;Jason A. Griggs","doi":"10.1016/j.dental.2025.02.001","DOIUrl":"10.1016/j.dental.2025.02.001","url":null,"abstract":"<div><h3>Objectives</h3><div>This study screened the design parameters of a reduced-diameter implant to determine which parameters have the most significant effect on the implant fatigue limit.</div></div><div><h3>Methods</h3><div>A dental implant assembly, which included an implant body (Biomet 3i), an abutment (GingiHue®), and an abutment screw (Gold-Tite Square screw) was scanned using micro-computed tomography (SkyScan 1172) and was measured using Mimics (Materialise) and an optical microscope (VHX-1000, Keyence). Sixteen design parameters were measured, and the values of the commercial design were taken as reference level for each design parameter. Values up to 20 % lower and 20 % higher than the reference were explored using a Taguchi orthogonal array (DOE++, Reliasoft), which varies more than one design parameter at a time to efficiently explore all main effects and lower order interactions across few implant designs. Solid models of these 27 implant designs and the reference design were constructed using SOLIDWORKS (Dassault Systèmes). Each solid model was loaded according to ISO 14801. fe-safe (Dassault Systèmes) was used to estimate the fatigue limits. ANOVA statistical test in DOE++ was used to screen the design parameters.</div></div><div><h3>Results</h3><div>Interaction between the coronal and apical tapers of the implant body had a significant effect on the fatigue limit (p ≤ 0.05), where fatigue limit was low for designs with a constant taper. Conversely, the combination of high degree of apical taper and low degree of coronal taper lead to the highest fatigue limit.</div></div><div><h3>Significance</h3><div>Using a Taguchi orthogonal array proved to be an efficient strategy for screening implant design parameters for effect on fatigue limit. The modified implant designed by manipulating the most influential parameters is predicted to have much greater fatigue limit compared to the commercially available design.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 4","pages":"Pages 444-450"},"PeriodicalIF":4.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424737","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 and characterization of 3D-printed denture base resin composites having self-healing potential","authors":"Mariam Raza Syed ,&nbsp;Sultan Aati ,&nbsp;Gavin Flematti ,&nbsp;Jukka P. Matinlinna ,&nbsp;Amr Fawzy","doi":"10.1016/j.dental.2025.02.003","DOIUrl":"10.1016/j.dental.2025.02.003","url":null,"abstract":"<div><h3>Objective</h3><div>This study aims to develop and characterize 3D-printed denture resin composites containing self-healing polyurea formaldehyde (PUF) microcapsules (TEGDMA as the core healing agent) for arresting microcracks formation and enhancing the mechanical durability of 3D-printed dentures.</div></div><div><h3>Methods</h3><div>The PUF microcapsules containing TEGDMA as core material were synthesized in oil-in-water emulsion and characterized for size, surface morphology and thermal stability. 3D-printed denture base resin with 0, 5, 15, and 25 wt% content of the synthesized PUF were printed and evaluated by degree of conversion, surface morphology, topography, surface hardness, flexural strength, fracture toughness, self-healing efficiency, and fluorescent microscopic visualization of the microcracks’ self-healing event through the in-situ release of rhodamine B labelled healing agent from ruptured PUF microcapsules inside the resin matrices.</div></div><div><h3>Results</h3><div>As compared to the control, a slight decrease was observed in the degree of conversion, surface hardness and flexural strength of the 3D-printed denture base composite modified with the PUF microcapsules. Results demonstrated that an increase in the microcapsule content significantly (<em>p</em> ≤ 0.05) enhances the fracture toughness and self-healing efficiency. The HPLC results analysis of the experimental groups demonstrated a controlled release profile of healing agent over time with the maximum release on day 7. The microscopic visualization findings demonstrated the successful encapsulation and intentional triggered release of the rhodamine B. labelled healing agent in the crack plane.</div></div><div><h3>Significance</h3><div>The 3D-printed denture base resin composites modified with the PUF microcapsules showed a significant potential for microcrack self-healing and enhanced fracture toughness based on the content (wt%) of microcapsules.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 4","pages":"Pages 451-463"},"PeriodicalIF":4.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424736","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":"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":"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}