Pub Date : 2025-10-06DOI: 10.1016/j.dental.2025.09.014
Sivaranjani Gali , Akshay Arjun , Suhasini Gururaja
Background
An optimum combination of esthetics and mechanical properties is expected of all-ceramic restorations. Consequently, various pigmentation techniques of zirconia have been recommended to enhance the aesthetic results without compromising their long-term survival.
Methodology
Infiltrate solutions of ceria-yttria were prepared by mixing their precursors in various concentrations. Pre-sintered zirconia samples were soaked in the infiltrate solutions and sintered according to the manufacturer’s instructions. Phase analysis, microstructure using scanning electron microscopy, flexural strength, fatigue, CIE Lab, translucency parameter, surface roughness, and aging resistance of infiltrated zirconia were evaluated.
Results
Phase analysis confirmed the presence of the tetragonal phase of zirconia, and the microstructure revealed increased grain size. The flexural strength of infiltrated zirconia ranged from 248 MPa to 512 MPa, and the fatigue limit was lower than control zirconia with reduced surface roughness. The monoclinic content before and after aging was not detectable in the infiltrated samples. The CIE Lab values of the infiltrated samples showed a trend of decreasing lightness, accompanied by higher delta E values, with minimal change in translucency.
Conclusions
Ceria-yttria infiltrated zirconia exhibited reasonable flexural strength and fatigue performance, with improved aging resistance, and color suitable for anterior and low-stress-bearing monolithic restorations.
{"title":"Impact of ceria-yttria pigmentation on the mechanical performance and esthetics of zirconia dental restorations","authors":"Sivaranjani Gali , Akshay Arjun , Suhasini Gururaja","doi":"10.1016/j.dental.2025.09.014","DOIUrl":"10.1016/j.dental.2025.09.014","url":null,"abstract":"<div><h3>Background</h3><div>An optimum combination of esthetics and mechanical properties is expected of all-ceramic restorations. Consequently, various pigmentation techniques of zirconia have been recommended to enhance the aesthetic results without compromising their long-term survival<strong>.</strong></div></div><div><h3>Methodology</h3><div>Infiltrate solutions of ceria-yttria were prepared by mixing their precursors in various concentrations. Pre-sintered zirconia samples were soaked in the infiltrate solutions and sintered according to the manufacturer’s instructions. Phase analysis, microstructure using scanning electron microscopy, flexural strength, fatigue, CIE Lab, translucency parameter, surface roughness, and aging resistance of infiltrated zirconia were evaluated.</div></div><div><h3>Results</h3><div>Phase analysis confirmed the presence of the tetragonal phase of zirconia, and the microstructure revealed increased grain size. The flexural strength of infiltrated zirconia ranged from 248 MPa to 512 MPa, and the fatigue limit was lower than control zirconia with reduced surface roughness. The monoclinic content before and after aging was not detectable in the infiltrated samples. The CIE Lab values of the infiltrated samples showed a trend of decreasing lightness, accompanied by higher delta E values, with minimal change in translucency.</div></div><div><h3>Conclusions</h3><div>Ceria-yttria infiltrated zirconia exhibited reasonable flexural strength and fatigue performance, with improved aging resistance, and color suitable for anterior and low-stress-bearing monolithic restorations.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 145-156"},"PeriodicalIF":6.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145243349","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}
Pub Date : 2025-10-06DOI: 10.1016/j.dental.2025.09.020
Sachin Varma , Smrithi Chandran , Mangalampalli SR N. Kiran , Payel Bandyopadhyay
The viscoelastic creep behaviour and long-term stability of heat-cured poly(methyl methacrylate) (PMMA) denture bases under clinically relevant processing conditions remain poorly characterised, necessitating the optimisation of fabrication protocols. In this study, twelve PMMA specimens (Sets A–C; 4 specimens per set, 25 indents/specimen) were prepared by varying curing pressure (500–2000 psi), time (30–180 min), or temperature (80–140°C). Nanoindentation creep tests (20 mN peak load; 10 s load, 20 s hold, 10 s unload; 10 Hz) recorded depth–time data, which were fitted to a three-element Voigt model (R2 > 0.99) to extract instantaneous modulus (), delayed modulus (), and viscosity (μ). Statistical analyses (one-way ANOVA with Tukey HSD, α = 0.05) revealed that extending curing time from 30 to 180 nearly doubled (2.15 ± 0.12–4.26 ± 0.15 GPa; p < 0.001) and increased μ by 332 % (30 ± 3–129 ± 8 GPa·s; p < 0.001), with optimal properties at 120°C ( = 4.72 ± 0.10 GPa; μ = 133.6 ± 7 GPa·s). Ageing for 12 months induced significant stiffening in under-cured samples (Δ = +12 %; p < 0.05), but did not affect well-cured specimens. These results show that curing time and temperature critically govern PMMA’s short‑term creep resistance and ageing behaviour, and that a 120°C × 60 min protocol maximises mechanical stability and durability, offering predictive insight for tailoring denture fabrication, although the increased risk of pore formation at this temperature must be considered.
{"title":"Nanoindentation-derived viscoelastic creep and ageing stability of heat-cured PMMA denture bases using a three-element Voigt model","authors":"Sachin Varma , Smrithi Chandran , Mangalampalli SR N. Kiran , Payel Bandyopadhyay","doi":"10.1016/j.dental.2025.09.020","DOIUrl":"10.1016/j.dental.2025.09.020","url":null,"abstract":"<div><div>The viscoelastic creep behaviour and long-term stability of heat-cured poly(methyl methacrylate) (PMMA) denture bases under clinically relevant processing conditions remain poorly characterised, necessitating the optimisation of fabrication protocols. In this study, twelve PMMA specimens (Sets A–C; 4 specimens per set, 25 indents/specimen) were prepared by varying curing pressure (500–2000 psi), time (30–180 min), or temperature (80–140°C). Nanoindentation creep tests (20 mN peak load; 10 s load, 20 s hold, 10 s unload; 10 Hz) recorded depth–time data, which were fitted to a three-element Voigt model (R<sup>2</sup> > 0.99) to extract instantaneous modulus (<span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span>), delayed modulus (<span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mn>2</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span>), and viscosity (μ). Statistical analyses (one-way ANOVA with Tukey HSD, α = 0.05) revealed that extending curing time from 30 to 180 nearly doubled <span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span> (2.15 ± 0.12–4.26 ± 0.15 GPa; p < 0.001) and increased μ by 332 % (30 ± 3–129 ± 8 GPa·s; p < 0.001), with optimal properties at 120°C (<span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span> = 4.72 ± 0.10 GPa; μ = 133.6 ± 7 GPa·s). Ageing for 12 months induced significant stiffening in under-cured samples (Δ<span><math><msubsup><mrow><mi>E</mi></mrow><mrow><mn>1</mn></mrow><mrow><mi>e</mi></mrow></msubsup></math></span> = +12 %; p < 0.05), but did not affect well-cured specimens. These results show that curing time and temperature critically govern PMMA’s short‑term creep resistance and ageing behaviour, and that a 120°C × 60 min protocol maximises mechanical stability and durability, offering predictive insight for tailoring denture fabrication, although the increased risk of pore formation at this temperature must be considered.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 185-196"},"PeriodicalIF":6.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145243367","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}
Pub Date : 2025-10-01DOI: 10.1016/j.dental.2025.09.021
Renan Brandenburg dos Santos , Ulysses Lenz , Jason Alan Griggs , Alvaro Della Bona
Objectives
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.
Methods
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.
Results
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.
Significance
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.
{"title":"Fatigue behavior and estimated lifetime of implant/abutments of different diameters","authors":"Renan Brandenburg dos Santos , Ulysses Lenz , Jason Alan Griggs , 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 × 10<sup>6</sup> 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":"2025-10-01","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}
To evaluate the impact of simulated aging with food-simulating liquids (FSLs) on the Martens hardness, indentation depth, flexural strength, and reliability of lithium aluminosilicate glass-ceramics.
Methods
Sixty square plates (12 ×12 ×1.5 mm) were prepared from a machinable fully crystallized lithium aluminosilicate glass-ceramic (Cerec Tessera, CT), then randomly allotted to four FSL groups: artificial saliva (CT-AS), citric acid (CT-CA), ethanol (CT-ET), or heptane (CT-HP). Martens hardness (HM) and indentation depth (ID) data were obtained using a hardness tester. Biaxial flexural strength (σ) was determined using the ball-on-three-balls apparatus in a universal testing machine. Weibull analysis was used to determine the characteristic strength (σ0) and reliability (m̂U). Data for HM and σ were analysed by one-way ANOVA, Tukey’s HSD, and Pearson correlations (α = 0.05).
Results
FSL type had a significant effect on HM (p < 0.001, ηp2 = 0.889), ID (p < 0.001, ηp2 = 0.879), and σ (p < 0.001, ηp2 = 0.623). Minimal differences were observed between the effects of artificial saliva and heptane on HM (p = 0.914), whereas citric acid (p < 0.001) and ethanol (p = 0.001) showed significantly different effects. The highest σ0 and m̂U values were found in CT-AS (σ0 = 319.26 MPa, m̂U = 10.79), while the lowest were observed in CT-CA. A positive correlation was confirmed between HM and σ (p < 0.001, r = 0.731).
Significance
Fully crystallized machinable lithium aluminosilicates exhibited adequate hardness and flexural strength after accelerated aging in artificial saliva; conversely, prolonged exposure to acidic FSLs jeopardized their mechanical properties.
{"title":"The effect of food-simulating liquids on the mechanical properties of lithium aluminosilicate glass-ceramics","authors":"Hanan Al-Johani , Ashraf Al-Amoudi , Adolfo Di Fiore , Yu Zhang","doi":"10.1016/j.dental.2025.09.015","DOIUrl":"10.1016/j.dental.2025.09.015","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the impact of simulated aging with food-simulating liquids (FSLs) on the Martens hardness, indentation depth, flexural strength, and reliability of lithium aluminosilicate glass-ceramics.</div></div><div><h3>Methods</h3><div>Sixty square plates (12 ×12 ×1.5 mm) were prepared from a machinable fully crystallized lithium aluminosilicate glass-ceramic (Cerec Tessera, CT), then randomly allotted to four FSL groups: artificial saliva (CT-AS), citric acid (CT-CA), ethanol (CT-ET), or heptane (CT-HP). Martens hardness (HM) and indentation depth (ID) data were obtained using a hardness tester. Biaxial flexural strength (σ) was determined using the ball-on-three-balls apparatus in a universal testing machine. Weibull analysis was used to determine the characteristic strength (σ<sub>0</sub>) and reliability (m̂<sub>U</sub>). Data for HM and σ were analysed by one-way ANOVA, Tukey’s HSD, and Pearson correlations (α = 0.05).</div></div><div><h3>Results</h3><div>FSL type had a significant effect on HM (<em>p</em> < 0.001, η<sub>p</sub><sup>2</sup> = 0.889), ID (<em>p</em> < 0.001, η<sub>p</sub><sup>2</sup> = 0.879), and σ (<em>p</em> < 0.001, η<sub>p</sub><sup>2</sup> = 0.623). Minimal differences were observed between the effects of artificial saliva and heptane on HM (<em>p</em> = 0.914), whereas citric acid (<em>p</em> < 0.001) and ethanol (<em>p</em> = 0.001) showed significantly different effects. The highest σ<sub>0</sub> and m̂<sub>U</sub> values were found in CT-AS (σ<sub>0</sub> = 319.26 MPa, m̂<sub>U</sub> = 10.79), while the lowest were observed in CT-CA. A positive correlation was confirmed between HM and σ (<em>p</em> < 0.001, r = 0.731).</div></div><div><h3>Significance</h3><div>Fully crystallized machinable lithium aluminosilicates exhibited adequate hardness and flexural strength after accelerated aging in artificial saliva; conversely, prolonged exposure to acidic FSLs jeopardized their mechanical properties.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 138-144"},"PeriodicalIF":6.3,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184472","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}
Pub Date : 2025-09-27DOI: 10.1016/j.dental.2025.09.019
Yue Zhu , Chenyuan Zhu , Jian Sun
Objectives
To evaluate the optical properties of additively manufactured zirconia monoliths and substrates for porcelain veneering and make a comparison with computer numerical control (CNC) milled zirconia.
Methods
Stereolithography (SLA), digital light processing (DLP) and CNC milling technology were used to fabricate monolithic zirconia specimens with different thickness (Φ14.0 ×0.5/1.0 mm, n = 5). A2 feldspathic veneering ceramic (1.0 mm) was sintered to zirconia substrates (Φ14.0 ×0.5 mm) to prepare bilayered specimens (Φ14.0 ×1.5 mm, n = 5). Monolithic specimens underwent thermocycling between 5 ℃ and 55 ℃ up to 50000 cycles. A spectrophotometer was used to conduct color measurements before thermocycling and at every 10000 cycles. Translucency parameter (TP) of all specimens and color difference (ΔE) between bilayered specimens and A2 veneering ceramic were calculated. Data were analyzed by ANOVA and Tukey’s post hoc tests (α=0.05).
Results
The ANOVA revealed that material, thickness and thermocycles had significant influence on translucency(P＜0.001). Before and at each cycling interval, the TP of monolithic zirconia with different thickness ranking from highest to least were: CNC＞DLP＞SLA (P＜0.05). TP changed significantly at 30000 cycles for 0.5 mm-thickness SLA zirconia (P = 0.035), at 50000 cycles for 0.5 mm-thickness DLP zirconia (P = 0.036), 1.0mm-thickness SLA zirconia (P = 0.036) and 1.0 mm-thickness DLP zirconia (P = 0.017). ΔE between A2 veneer and SLA or DLP bilayered zirconia exceeded acceptability threshold (AT＞1.8).
Significance
SLA and DLP monolithic zirconia had inferior translucency and color stability compared to CNC zirconia. A2 veneered bilayered SLA and DLP zirconia had a clinically unacceptable color difference with A2 shade.
目的：评价增材制造的氧化锆整体体和陶瓷贴面衬底的光学性能，并与计算机数控（CNC）铣削氧化锆进行比较。方法：采用立体光刻（SLA）、数字光处理（DLP）和数控铣削技术制备不同厚度（Φ14.0 ×0.5/1.0 mm, n = 5）的氧化锆单片试样。将A2长石贴面陶瓷（1.0 mm）与氧化锆衬底（Φ14.0 ×0.5 mm）烧结，制备双层试样（Φ14.0 ×1.5 mm, n = 5）。整体试样在5℃至55℃之间进行热循环，循环次数达50000次。在热循环前和每10000次循环时使用分光光度计进行颜色测量。计算了所有试件的半透明参数（TP）和双层试件与A2贴面陶瓷的色差（ΔE）。数据分析采用方差分析和Tukey事后检验（α=0.05）。结果：方差分析显示，材料、厚度和热循环对半透明性有显著影响（P<0.001）。各循环间隔前和循环间隔时，不同厚度单片氧化锆的TP从高到低依次为：CNC>DLP>SLA （P<0.05）。0.5 mm-厚度的SLA氧化锆（P = 0.035）在30000次循环时，0.5 mm-厚度的DLP氧化锆（P = 0.036），1.0mm-厚度的SLA氧化锆（P = 0.036）和1.0mm-厚度的DLP氧化锆（P = 0.017）在50000次循环时，TP变化显著。A2贴面与SLA或DLP双层氧化锆之间的ΔE超过可接受阈值（AT>1.8）。意义：与CNC氧化锆相比，SLA和DLP单片氧化锆的透明度和颜色稳定性较差。A2贴面双层SLA和DLP氧化锆与A2色度存在临床不可接受的色差。
{"title":"Optical properties of vat photopolymerization additively manufactured zirconia monoliths and substrates for porcelain veneering: A pilot study","authors":"Yue Zhu , Chenyuan Zhu , Jian Sun","doi":"10.1016/j.dental.2025.09.019","DOIUrl":"10.1016/j.dental.2025.09.019","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the optical properties of additively manufactured zirconia monoliths and substrates for porcelain veneering and make a comparison with computer numerical control (CNC) milled zirconia.</div></div><div><h3>Methods</h3><div>Stereolithography (SLA), digital light processing (DLP) and CNC milling technology were used to fabricate monolithic zirconia specimens with different thickness (Φ14.0 ×0.5/1.0 mm, n = 5). A2 feldspathic veneering ceramic (1.0 mm) was sintered to zirconia substrates (Φ14.0 ×0.5 mm) to prepare bilayered specimens (Φ14.0 ×1.5 mm, n = 5). Monolithic specimens underwent thermocycling between 5 ℃ and 55 ℃ up to 50000 cycles. A spectrophotometer was used to conduct color measurements before thermocycling and at every 10000 cycles. Translucency parameter (TP) of all specimens and color difference (ΔE) between bilayered specimens and A2 veneering ceramic were calculated. Data were analyzed by ANOVA and Tukey’s post hoc tests (α=0.05).</div></div><div><h3>Results</h3><div>The ANOVA revealed that material, thickness and thermocycles had significant influence on translucency(<em>P</em>＜0.001). Before and at each cycling interval, the TP of monolithic zirconia with different thickness ranking from highest to least were: CNC＞DLP＞SLA (<em>P</em>＜0.05). TP changed significantly at 30000 cycles for 0.5 mm-thickness SLA zirconia (<em>P</em> = 0.035), at 50000 cycles for 0.5 mm-thickness DLP zirconia (<em>P</em> = 0.036), 1.0mm-thickness SLA zirconia (<em>P</em> = 0.036) and 1.0 mm-thickness DLP zirconia (<em>P</em> = 0.017). ΔE between A2 veneer and SLA or DLP bilayered zirconia exceeded acceptability threshold (AT＞1.8).</div></div><div><h3>Significance</h3><div>SLA and DLP monolithic zirconia had inferior translucency and color stability compared to CNC zirconia. A2 veneered bilayered SLA and DLP zirconia had a clinically unacceptable color difference with A2 shade.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 2","pages":"Pages 169-176"},"PeriodicalIF":6.3,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184347","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}
Pub Date : 2025-09-26DOI: 10.1016/j.dental.2025.09.017
Zhao Li , Ying Kong , Qun Zhang , Jing Han , Kezheng Chen , Baojin Ma
Traditional guided bone regeneration (GBR) membranes face challenges in balancing mechanical strength, bioactivity, and osteoconductivity for effective periodontal bone regeneration. While collagen-based GBR membranes dominate clinical use, the weak mechanical properties and lack of osteoinductive capacity limit regeneration efficacy. Here, we presented a gas diffusion-mediated single-sided mineralization strategy to fabricate silk fibroin (SF)-based GBR membranes with dual barrier/osteoinductive functions. SF was dissolved in formic acid with Ca2 + and, optionally, other bioactive metal ions (BMIs, such as Sr2+, Cu2+, or Mg2+), and a colloid was formed after the evaporation of formic acid. Followed by gradient mineralization under CO2/NH3 atmosphere and β-sheet induction via ethanol treatment, SF-Ca/X (X refers to other BMIs) membranes were prepared. Mineralized SF membranes featured a dense, mineral-free side for mechanical support and barrier, and an osteoinductive side by releasing BMIs. Interestingly, the calcium phosphate layer formed on the mineralized side, and the phase of CaCO3 changed from calcite to vaterite, which helps phosphate mineralization. In vitro results demonstrated that the SF-Ca/Sr membrane enhanced osteogenic differentiation by upregulating BMP2/SMAD1 expression. In a rat mandibular defect model, the SF-Ca/Sr membrane significantly promotes new bone regeneration and collagen formation. Overall, this gas diffusion-mediated single-sided gradient mineralization approach integrates barrier properties with localized bioactivity, allowing for the required barrier/osteoinduction functions in the GBR process in one membrane.
{"title":"Gas diffusion-mediated single-sided in situ gradient mineralized silk fibroin membrane for enhanced guided bone regeneration","authors":"Zhao Li , Ying Kong , Qun Zhang , Jing Han , Kezheng Chen , Baojin Ma","doi":"10.1016/j.dental.2025.09.017","DOIUrl":"10.1016/j.dental.2025.09.017","url":null,"abstract":"<div><div>Traditional guided bone regeneration (GBR) membranes face challenges in balancing mechanical strength, bioactivity, and osteoconductivity for effective periodontal bone regeneration. While collagen-based GBR membranes dominate clinical use, the weak mechanical properties and lack of osteoinductive capacity limit regeneration efficacy. Here, we presented a gas diffusion-mediated single-sided mineralization strategy to fabricate silk fibroin (SF)-based GBR membranes with dual barrier/osteoinductive functions. SF was dissolved in formic acid with Ca<sup>2 +</sup> and, optionally, other bioactive metal ions (BMIs, such as Sr<sup>2+</sup>, Cu<sup>2+</sup>, or Mg<sup>2+</sup>), and a colloid was formed after the evaporation of formic acid. Followed by gradient mineralization under CO<sub>2</sub>/NH<sub>3</sub> atmosphere and β-sheet induction via ethanol treatment, SF-Ca/X (X refers to other BMIs) membranes were prepared. Mineralized SF membranes featured a dense, mineral-free side for mechanical support and barrier, and an osteoinductive side by releasing BMIs. Interestingly, the calcium phosphate layer formed on the mineralized side, and the phase of CaCO<sub>3</sub> changed from calcite to vaterite, which helps phosphate mineralization. In vitro results demonstrated that the SF-Ca/Sr membrane enhanced osteogenic differentiation by upregulating BMP2/SMAD1 expression. In a rat mandibular defect model, the SF-Ca/Sr membrane significantly promotes new bone regeneration and collagen formation. Overall, this gas diffusion-mediated single-sided gradient mineralization approach integrates barrier properties with localized bioactivity, allowing for the required barrier/osteoinduction functions in the GBR process in one membrane.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 157-167"},"PeriodicalIF":6.3,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145181737","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}
Machine learning (ML) predictive models promise to handle complex data and deliver accurate predictions in the medical field. The aim of this study was to develop ML predictive models for posterior dental restorations failures in both primary and permanent teeth.
Methods
Data from two clinical datasets were used in this study, encompassing a Randomized Controlled Trial (RCT) for permanent teeth (CaCIA Trial) and a corresponding RCT for primary teeth (CARDEC 3). Models were developed using five different algorithms—Decision Tree, Random Forest, XGBoost, CatBoost and Neural Network—ensuring thorough cross-validation and calibration for predictive reliability. Clinical variables related to patients and teeth were considered as predictors. Model performances were assessed using accuracy, precision, recall, F1-score and ROC AUC, alongside SHAP plots for interpretability.
Results
In the primary teeth dataset, all models demonstrated acceptable performance with AUC values around 0.67–0.75 and a balanced trade-off between precision and recall. In contrast, the models applied to permanent teeth yielded less predictive ability, with AUC values ranging from 0.53 to 0.62.
Conclusion
Our results highlight how ML approaches effectively process intricate, multi-dimensional data related to restoration longevity, successfully integrating variables across patient characteristics, tooth properties, and diagnostic assessments within a unified analytical framework. Though promising as analytical tools, clinical implementation requires further validation with expanded, heterogeneous datasets to improve robustness and accuracy.
Clinical significance
Machine-learning models that predict the risk of posterior restoration failure—using routinely collected patient, tooth, and diagnostic data—may help dentists tailor recall intervals, prioritize preventive or reparative care, and allocate chair time more efficiently.
{"title":"Predicting restoration failures in primary and permanent teeth – A machine learning approach","authors":"Vitor Henrique Digmayer Romero , Eduardo Trota Chaves , Shankeeth Vinayahalingam , Helena Silveira Schuch , Xiongjie Chen , Yunpeng Li , Falk Schwendicke , Mariana Minatel Braga , Daniela Prócida Raggio , Cácia Signori , Raiza Dias Freitas , Fausto Medeiros Mendes , Marie-Charlotte Huysmans , Maximiliano Sérgio Cenci","doi":"10.1016/j.dental.2025.09.009","DOIUrl":"10.1016/j.dental.2025.09.009","url":null,"abstract":"<div><h3>Objective</h3><div>Machine learning (ML) predictive models promise to handle complex data and deliver accurate predictions in the medical field. The aim of this study was to develop ML predictive models for posterior dental restorations failures in both primary and permanent teeth.</div></div><div><h3>Methods</h3><div>Data from two clinical datasets were used in this study, encompassing a Randomized Controlled Trial (RCT) for permanent teeth (CaCIA Trial) and a corresponding RCT for primary teeth (CARDEC 3). Models were developed using five different algorithms—Decision Tree, Random Forest, XGBoost, CatBoost and Neural Network—ensuring thorough cross-validation and calibration for predictive reliability. Clinical variables related to patients and teeth were considered as predictors. Model performances were assessed using accuracy, precision, recall, F1-score and ROC AUC, alongside SHAP plots for interpretability.</div></div><div><h3>Results</h3><div>In the primary teeth dataset, all models demonstrated acceptable performance with AUC values around 0.67–0.75 and a balanced trade-off between precision and recall. In contrast, the models applied to permanent teeth yielded less predictive ability, with AUC values ranging from 0.53 to 0.62.</div></div><div><h3>Conclusion</h3><div>Our results highlight how ML approaches effectively process intricate, multi-dimensional data related to restoration longevity, successfully integrating variables across patient characteristics, tooth properties, and diagnostic assessments within a unified analytical framework. Though promising as analytical tools, clinical implementation requires further validation with expanded, heterogeneous datasets to improve robustness and accuracy.</div></div><div><h3>Clinical significance</h3><div>Machine-learning models that predict the risk of posterior restoration failure—using routinely collected patient, tooth, and diagnostic data—may help dentists tailor recall intervals, prioritize preventive or reparative care, and allocate chair time more efficiently.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 100-108"},"PeriodicalIF":6.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145172130","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}
Pub Date : 2025-09-25DOI: 10.1016/j.dental.2025.09.016
Yinying Chen , Xinyu Yang , Suqin Zhang , Hanjiao Wang , Haifeng Xie , Chen Chen
Objective
Dentin bionic remineralization is an effective strategy for enhancing the stability of the resin-dentin bonding interface. Conventional biomimetic mineralization methods still face limitations such as restricted applicability and low mineralization efficiency. Citrate, present at high levels in biological mineralized tissues, plays a significant role in biomineralization. This study prepared polyacrylic acid/citrate/amorphous calcium phosphate complexes (PAA-Cit-ACP) and investigated its ability to promote biomimetic mineralization and improve the stability of the resin-dentin bonding interface.
Methods
Four types of PAA-Cit-ACP complexes, each doped with different contents of citrate (PAA-Cit-ACP-0.5, PAA-Cit-ACP-1, PAA-Cit-ACP-2, and PAA-Cit-ACP-5), were synthesized and characterized. Molecular dynamics simulation was used to clarify the mechanism behind the formation of the PAA-Cit-ACP complexes. Single-layer recombinant collagen fibers and demineralized dentin slices were constructed as mineralization models to validate the mineralization potential of PAA-Cit-ACP. Nanoleakage and in situ zymography were used to evaluate the effect of PAA-Cit-ACP on the durability of resin dentin bonding.
Results
Each group of PAA-Cit-ACP manifested as negatively charged, amorphous spherical nanoparticles with good biocompatibility. After treatment with PAA-Cit-ACP, both single-layer recombinant collagen fibers and demineralized dentin slices demonstrated rapid mineralization, and the resin-dentin bonding interface showed reduced nanoleakage and MMP activity, with PAA-Cit-ACP-1 and PAA-Cit-ACP-2 showing better effectiveness.
Significance
These findings suggest that PAA-Cit-ACP promotes rapid biomimetic remineralization, protecting exposed demineralized collagen fibrils from water- and MMPs-induced degradation, and improving the stability of the hybrid layer.
{"title":"Polyacrylic acid/citrate/amorphous calcium phosphate complex for dentin remineralization and bond durability","authors":"Yinying Chen , Xinyu Yang , Suqin Zhang , Hanjiao Wang , Haifeng Xie , Chen Chen","doi":"10.1016/j.dental.2025.09.016","DOIUrl":"10.1016/j.dental.2025.09.016","url":null,"abstract":"<div><h3>Objective</h3><div>Dentin bionic remineralization is an effective strategy for enhancing the stability of the resin-dentin bonding interface. Conventional biomimetic mineralization methods still face limitations such as restricted applicability and low mineralization efficiency. Citrate, present at high levels in biological mineralized tissues, plays a significant role in biomineralization. This study prepared polyacrylic acid/citrate/amorphous calcium phosphate complexes (PAA-Cit-ACP) and investigated its ability to promote biomimetic mineralization and improve the stability of the resin-dentin bonding interface.</div></div><div><h3>Methods</h3><div>Four types of PAA-Cit-ACP complexes, each doped with different contents of citrate (PAA-Cit-ACP-0.5, PAA-Cit-ACP-1, PAA-Cit-ACP-2, and PAA-Cit-ACP-5), were synthesized and characterized. Molecular dynamics simulation was used to clarify the mechanism behind the formation of the PAA-Cit-ACP complexes. Single-layer recombinant collagen fibers and demineralized dentin slices were constructed as mineralization models to validate the mineralization potential of PAA-Cit-ACP. Nanoleakage and in situ zymography were used to evaluate the effect of PAA-Cit-ACP on the durability of resin dentin bonding.</div></div><div><h3>Results</h3><div>Each group of PAA-Cit-ACP manifested as negatively charged, amorphous spherical nanoparticles with good biocompatibility. After treatment with PAA-Cit-ACP, both single-layer recombinant collagen fibers and demineralized dentin slices demonstrated rapid mineralization, and the resin-dentin bonding interface showed reduced nanoleakage and MMP activity, with PAA-Cit-ACP-1 and PAA-Cit-ACP-2 showing better effectiveness.</div></div><div><h3>Significance</h3><div>These findings suggest that PAA-Cit-ACP promotes rapid biomimetic remineralization, protecting exposed demineralized collagen fibrils from water- and MMPs-induced degradation, and improving the stability of the hybrid layer.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 126-137"},"PeriodicalIF":6.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145172080","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}
Pub Date : 2025-09-25DOI: 10.1016/j.dental.2025.09.013
Surendrasingh Y. Sonaye , Karim Elhattab , Luci R. Duncan , Sai R. Dharmavarapu , Vasudev Vivekanand Nayak , Erfan Noorbakhsh Noshahri , Nishitraj C. Sherigar , Josiah S. Owusu-Danquah , Lukasz Witek , Marco C. Bottino , Prabaha Sikder
Objectives
This study aims to explore the application of Fused Deposition Modeling (FDM) as a 3D printing technique for developing endosseous Polyetheretherketone (PEEK) dental implants. Specifically, the primary aim of the study is to systematically investigate the effects of key FDM processing parameters, including thermal conditions, print speed, layer height, build orientation, and post-processing heat treatments, on the mechanical and thermal properties of PEEK implants. By conducting an in-depth analysis, this study aims to establish optimized processing guidelines for the reliable manufacturing of high-performance, clinically viable PEEK dental implants.
Methods
PEEK dental implants were fabricated using FDM with variations in thermal conditions (nozzle, bedplate, and chamber temperatures), print speed, layer height, build orientation, and post-print heat treatments. Mechanical testing (compression and fatigue), detailed thermal characterization using Differential Scanning Calorimetry (DSC), and fractographic analysis were performed. Finite Element Analysis (FEA) was also conducted to understand the implant's load-bearing performance.
Results
Nozzle temperature dictates implant resolution, while chamber temperature is a key determinant of implant crystallinity. Interestingly, for PEEK dental implants, all the FDM thermal processing conditions play a crucial role in influencing the part's thermal properties. Moreover, print speed plays an essential role in developing dimensionally accurate high-strength implants. Notably, the fractographic analysis of the failed implants revealed interesting multimodal fracture behavior specific to 3D-printed threaded implants. FEA demonstrates that the implants tend to buckle under load and break at the implant-abutment interface, consistent with experimental results. Furthermore, fatigue testing reveals that PEEK implants, fabricated at a specific build orientation with respect to the bedplate, suffice the Food and Drug Administration durability requirements.
Significance
These findings underscore the clinical potential of FDM-developed PEEK as a customizable, lightweight, and durable alternative to conventional metallic implants, paving the way for next-generation patient-specific lightweight dental implant solutions.
{"title":"Influence of fused deposition modeling parameters on the mechanical and thermal properties of 3D-printed PEEK dental endosseous implants","authors":"Surendrasingh Y. Sonaye , Karim Elhattab , Luci R. Duncan , Sai R. Dharmavarapu , Vasudev Vivekanand Nayak , Erfan Noorbakhsh Noshahri , Nishitraj C. Sherigar , Josiah S. Owusu-Danquah , Lukasz Witek , Marco C. Bottino , Prabaha Sikder","doi":"10.1016/j.dental.2025.09.013","DOIUrl":"10.1016/j.dental.2025.09.013","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aims to explore the application of Fused Deposition Modeling (FDM) as a 3D printing technique for developing endosseous Polyetheretherketone (PEEK) dental implants. Specifically, the primary aim of the study is to systematically investigate the effects of key FDM processing parameters, including thermal conditions, print speed, layer height, build orientation, and post-processing heat treatments, on the mechanical and thermal properties of PEEK implants. By conducting an in-depth analysis, this study aims to establish optimized processing guidelines for the reliable manufacturing of high-performance, clinically viable PEEK dental implants.</div></div><div><h3>Methods</h3><div>PEEK dental implants were fabricated using FDM with variations in thermal conditions (nozzle, bedplate, and chamber temperatures), print speed, layer height, build orientation, and post-print heat treatments. Mechanical testing (compression and fatigue), detailed thermal characterization using Differential Scanning Calorimetry (DSC), and fractographic analysis were performed. Finite Element Analysis (FEA) was also conducted to understand the implant's load-bearing performance.</div></div><div><h3>Results</h3><div>Nozzle temperature dictates implant resolution, while chamber temperature is a key determinant of implant crystallinity. Interestingly, for PEEK dental implants, all the FDM thermal processing conditions play a crucial role in influencing the part's thermal properties. Moreover, print speed plays an essential role in developing dimensionally accurate high-strength implants. Notably, the fractographic analysis of the failed implants revealed interesting multimodal fracture behavior specific to 3D-printed threaded implants. FEA demonstrates that the implants tend to buckle under load and break at the implant-abutment interface, consistent with experimental results. Furthermore, fatigue testing reveals that PEEK implants, fabricated at a specific build orientation with respect to the bedplate, suffice the Food and Drug Administration durability requirements.</div></div><div><h3>Significance</h3><div>These findings underscore the clinical potential of FDM-developed PEEK as a customizable, lightweight, and durable alternative to conventional metallic implants, paving the way for next-generation patient-specific lightweight dental implant solutions.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 109-125"},"PeriodicalIF":6.3,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145172149","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}
Pub Date : 2025-09-24DOI: 10.1016/j.dental.2025.09.012
Anastasiia Grymak , Alexander Hui Xiang Yang , Kai Chun Li , Sunyoung Ma
Objectives
This study aimed to develop and validate a machine learning-based predictive model for forecasting wear loss in additively manufactured (AM) dental resin materials using Long Short-Term Memory (LSTM) recurrent neural networks.
Materials and Methods
Wear data were collected from three wear testing methods: Ball-on-Disc (BoD), Block-on-Ring (BoR), and Reciprocation (Recip), using three different AM resin materials under varying loads (49 N, 70 N) and surface treatments (polished, glazed). The LSTM model was trained on standardized time-series wear data using both Leave-One-Material-Out (LOMO) and Leave-One-Group-Out (LOGO) cross-validation strategies. Prediction windows were assessed at 10 %, 20 %, and 30 % of total wear sequences, simulating early-stage prediction of long-term wear progression. Model performance was evaluated using RMSE (Root-Mean-Square Error), MSE (Mean-Square Error), and MAE (Mean-Average Error).
Results
The autoregressive LSTM forecasting approach accurately predicted wear progression across all testing methods, with prediction accuracies ranging between 82 % and 97 % depending on method and dataset, the models explaining approximately 82–97 % of the wear variability (depending on method and dataset). Predictions initiated at 10 % showed high cross-validation accuracy, while test set generalization improved when prediction started at 30 %. Optimal model performance was achieved using a 50-point input window and step size. The model demonstrated robustness in handling the inherent variability of experimental wear data across multiple AM materials and test conditions.
Significance
This study demonstrates the feasibility of applying LSTM models for early and accurate prediction of wear progression in AM dental materials, offering potential for reducing physical testing duration and enhancing data-driven material evaluation frameworks for clinical applications.
{"title":"LSTM-based prediction of wear in 3D-printed restorative materials under various methods","authors":"Anastasiia Grymak , Alexander Hui Xiang Yang , Kai Chun Li , Sunyoung Ma","doi":"10.1016/j.dental.2025.09.012","DOIUrl":"10.1016/j.dental.2025.09.012","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to develop and validate a machine learning-based predictive model for forecasting wear loss in additively manufactured (AM) dental resin materials using Long Short-Term Memory (LSTM) recurrent neural networks.</div></div><div><h3>Materials and Methods</h3><div>Wear data were collected from three wear testing methods: Ball-on-Disc (BoD), Block-on-Ring (BoR), and Reciprocation (Recip), using three different AM resin materials under varying loads (49 N, 70 N) and surface treatments (polished, glazed). The LSTM model was trained on standardized time-series wear data using both Leave-One-Material-Out (LOMO) and Leave-One-Group-Out (LOGO) cross-validation strategies. Prediction windows were assessed at 10 %, 20 %, and 30 % of total wear sequences, simulating early-stage prediction of long-term wear progression. Model performance was evaluated using RMSE (Root-Mean-Square Error), MSE (Mean-Square Error), and MAE (Mean-Average Error).</div></div><div><h3>Results</h3><div>The autoregressive LSTM forecasting approach accurately predicted wear progression across all testing methods, with prediction accuracies ranging between 82 % and 97 % depending on method and dataset, the models explaining approximately 82–97 % of the wear variability (depending on method and dataset). Predictions initiated at 10 % showed high cross-validation accuracy, while test set generalization improved when prediction started at 30 %. Optimal model performance was achieved using a 50-point input window and step size. The model demonstrated robustness in handling the inherent variability of experimental wear data across multiple AM materials and test conditions.</div></div><div><h3>Significance</h3><div>This study demonstrates the feasibility of applying LSTM models for early and accurate prediction of wear progression in AM dental materials, offering potential for reducing physical testing duration and enhancing data-driven material evaluation frameworks for clinical applications.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"42 1","pages":"Pages 91-99"},"PeriodicalIF":6.3,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145147137","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}
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