Pub Date : 2025-08-11DOI: 10.1016/j.dental.2025.08.005
Wuyuan Zhao , Jinxing Sun , Hao Ding , Sadia Manzoor , Hao Yu , Jiaming Bai , James K.H. Tsoi
<div><h3>Objectives</h3><div>To evaluate the feasibility of utilizing Digital Light Processing (DLP) 3D-printing technology to fabricate ultra-thin (0.1–0.7 mm) zirconia dental veneers.</div></div><div><h3>Materials and methods</h3><div>A high-load (80 wt%) 3Y-zirconia slurry (5 Pa·s at a shear rate of 30 s<sup>−1</sup>) was used to print zirconia green bodies with a custom-made DLP 3D-printer (405 nm UV light and X/Y plane resolution of 70 μm). Flexural strengths of green bodies and fully sintered zirconia printed in two orientations (0º and 90º) were evaluated using three-point bending (3PB) and biaxial flexural strength (BFS) tests, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the microstructure and crystalline phases of the sintered specimens. A commercial 3Y-zirconia (UPCERA MT) was used as a control for comparison with the best-performing DLP-printed specimens. XRD and SEM were used to assess low-temperature degradation (LTD) after artificial aging (autoclave, 5 hr). Transparency of the sintered DLP-printed and conventional zirconia at 0.5 mm and 1.0 mm thicknesses was measured using a desktop spectrophotometer (400–700 nm). Resin-zirconia bonding performance was evaluated via shear bond strength (SBS) testing and failure mode analysis. SBS was measured between a self-adhesive dual-curing resin cement and the surface of sintered zirconia specimens. The coefficient of thermal expansion (CTE) and Schwickerath three-point bending strength (τ<sub>b</sub>) were measured to evaluate porcelain-zirconia compatibility. Ultra-thin (0.1–0.7 mm) dental restorations were fabricated to demonstrate the practical potential application of this novel zirconia printing approach.</div></div><div><h3>Results</h3><div>The 3PB flexural strength of green bodies printed at 0º (21.35 ± 2.19 MPa) was significantly higher (p < 0.05) than at 90º (16.98 ± 1.68 MPa). The BFS of sintered zirconia printed at 0º (1040.33 ± 236.70 MPa) was also significantly higher (p < 0.05) than at 90º (685.91 ± 139.10 MPa). Sintered specimens printed at 0º exhibited an average grain size of 440 nm and a tetragonal phase. After artificial aging, the DLP-printed group exhibited superior resistance to LTD, with a lower monoclinic phase content (40.78 %) compared to the commercial zirconia group (72.51 %). DLP-printed zirconia exhibited lower transparency than commercial zirconia at both 0.5 mm (23.22 ± 1.55 % vs. 35.67 ± 0.14 %) and 1.0 mm (12.04 ± 1.45 % vs. 28.06 ± 0.25 %) thicknesses. Although the commercial zirconia group showed higher average SBS (10.77 ± 5.10 MPa), the difference was not statistically significant compared to the DLP-printed group (10.26 ± 5.91 MPa). Adhesive failure was the predominant failure mode in both groups. CTE of DLP-printed zirconia (10.56 ×10<sup>−6</sup>/ºC) was comparable to conventional zirconia (10.50 ×10<sup>−6</sup>/ºC). The τ<sub>b</sub> of DLP-printed zirconia (26.37 ± 2.37 MPa) was significan
{"title":"High-strength DLP-printed zirconia for ultra-thin dental veneers","authors":"Wuyuan Zhao , Jinxing Sun , Hao Ding , Sadia Manzoor , Hao Yu , Jiaming Bai , James K.H. Tsoi","doi":"10.1016/j.dental.2025.08.005","DOIUrl":"10.1016/j.dental.2025.08.005","url":null,"abstract":"<div><h3>Objectives</h3><div>To evaluate the feasibility of utilizing Digital Light Processing (DLP) 3D-printing technology to fabricate ultra-thin (0.1–0.7 mm) zirconia dental veneers.</div></div><div><h3>Materials and methods</h3><div>A high-load (80 wt%) 3Y-zirconia slurry (5 Pa·s at a shear rate of 30 s<sup>−1</sup>) was used to print zirconia green bodies with a custom-made DLP 3D-printer (405 nm UV light and X/Y plane resolution of 70 μm). Flexural strengths of green bodies and fully sintered zirconia printed in two orientations (0º and 90º) were evaluated using three-point bending (3PB) and biaxial flexural strength (BFS) tests, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the microstructure and crystalline phases of the sintered specimens. A commercial 3Y-zirconia (UPCERA MT) was used as a control for comparison with the best-performing DLP-printed specimens. XRD and SEM were used to assess low-temperature degradation (LTD) after artificial aging (autoclave, 5 hr). Transparency of the sintered DLP-printed and conventional zirconia at 0.5 mm and 1.0 mm thicknesses was measured using a desktop spectrophotometer (400–700 nm). Resin-zirconia bonding performance was evaluated via shear bond strength (SBS) testing and failure mode analysis. SBS was measured between a self-adhesive dual-curing resin cement and the surface of sintered zirconia specimens. The coefficient of thermal expansion (CTE) and Schwickerath three-point bending strength (τ<sub>b</sub>) were measured to evaluate porcelain-zirconia compatibility. Ultra-thin (0.1–0.7 mm) dental restorations were fabricated to demonstrate the practical potential application of this novel zirconia printing approach.</div></div><div><h3>Results</h3><div>The 3PB flexural strength of green bodies printed at 0º (21.35 ± 2.19 MPa) was significantly higher (p < 0.05) than at 90º (16.98 ± 1.68 MPa). The BFS of sintered zirconia printed at 0º (1040.33 ± 236.70 MPa) was also significantly higher (p < 0.05) than at 90º (685.91 ± 139.10 MPa). Sintered specimens printed at 0º exhibited an average grain size of 440 nm and a tetragonal phase. After artificial aging, the DLP-printed group exhibited superior resistance to LTD, with a lower monoclinic phase content (40.78 %) compared to the commercial zirconia group (72.51 %). DLP-printed zirconia exhibited lower transparency than commercial zirconia at both 0.5 mm (23.22 ± 1.55 % vs. 35.67 ± 0.14 %) and 1.0 mm (12.04 ± 1.45 % vs. 28.06 ± 0.25 %) thicknesses. Although the commercial zirconia group showed higher average SBS (10.77 ± 5.10 MPa), the difference was not statistically significant compared to the DLP-printed group (10.26 ± 5.91 MPa). Adhesive failure was the predominant failure mode in both groups. CTE of DLP-printed zirconia (10.56 ×10<sup>−6</sup>/ºC) was comparable to conventional zirconia (10.50 ×10<sup>−6</sup>/ºC). The τ<sub>b</sub> of DLP-printed zirconia (26.37 ± 2.37 MPa) was significan","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1430-1441"},"PeriodicalIF":6.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833627","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 : 2025-08-11DOI: 10.1016/j.dental.2025.08.007
Morteza Mohammadi Ghayeghchi, Mohammad Atai, Azizollah Nodehi
Objective
To synthesize an addition-fragmentation chain transfer monomer (AFCTM) and evaluate its effects on the polymerization shrinkage, physical, and mechanical properties of experimental dental resin and composite.
Methods
The AFCTM was synthesized using an iodosulfonylation-dehydroiodination process and characterized by FTIR and ¹H NMR spectroscopy. The AFCTM was then incorporated into a dental matrix resin consisting of Bis-GMA, TEGDMA, and photo-initiator system. The degree of conversion (DC%) was measured using FTIR spectroscopy, and polymerization shrinkage kinetics were assessed using the bonded-disk technique. Shrinkage stress was measured with a universal testing machine equipped with a stress measurement device. DMTA analysis was used to determine dynamic mechanical properties. Flexural properties, were evaluated on the photo-polymerized composite samples.
Results
The incorporation of AFCTM into the dental resin system effectively reduced polymerization shrinkage stress. Higher AFCTM concentrations also led to reductions in maximum shrinkage strain and shrinkage strain rates. The incorporation of AFCTM up to 10 % had no statistically significant effect on the flexural properties. Water absorption and solubility increased at higher AFCTM concentrations.
Conclusion
AFCTM demonstrates promise as an additive for dental composites, effectively reducing polymerization shrinkage stress up to 74 %, while maintaining acceptable mechanical properties. Optimization of AFCTM concentration is essential to balance mechanical strength, water absorption, and shrinkage reduction, paving the way for improved dental composite formulations.
{"title":"Addition-fragmentation chain transfer monomer in dental resins: Synthesis, characterization, and properties","authors":"Morteza Mohammadi Ghayeghchi, Mohammad Atai, Azizollah Nodehi","doi":"10.1016/j.dental.2025.08.007","DOIUrl":"10.1016/j.dental.2025.08.007","url":null,"abstract":"<div><h3>Objective</h3><div>To synthesize an addition-fragmentation chain transfer monomer (AFCTM) and evaluate its effects on the polymerization shrinkage, physical, and mechanical properties of experimental dental resin and composite.</div></div><div><h3>Methods</h3><div>The AFCTM was synthesized using an iodosulfonylation-dehydroiodination process and characterized by FTIR and ¹H NMR spectroscopy. The AFCTM was then incorporated into a dental matrix resin consisting of Bis-GMA, TEGDMA, and photo-initiator system. The degree of conversion (DC%) was measured using FTIR spectroscopy, and polymerization shrinkage kinetics were assessed using the bonded-disk technique. Shrinkage stress was measured with a universal testing machine equipped with a stress measurement device. DMTA analysis was used to determine dynamic mechanical properties. Flexural properties, were evaluated on the photo-polymerized composite samples.</div></div><div><h3>Results</h3><div>The incorporation of AFCTM into the dental resin system effectively reduced polymerization shrinkage stress. Higher AFCTM concentrations also led to reductions in maximum shrinkage strain and shrinkage strain rates. The incorporation of AFCTM up to 10 % had no statistically significant effect on the flexural properties. Water absorption and solubility increased at higher AFCTM concentrations.</div></div><div><h3>Conclusion</h3><div>AFCTM demonstrates promise as an additive for dental composites, effectively reducing polymerization shrinkage stress up to 74 %, while maintaining acceptable mechanical properties. Optimization of AFCTM concentration is essential to balance mechanical strength, water absorption, and shrinkage reduction, paving the way for improved dental composite formulations.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1442-1453"},"PeriodicalIF":6.3,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833626","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 : 2025-08-09DOI: 10.1016/j.dental.2025.07.016
Ana Carolina da Silva , Juliana de Freitas Gouveia Silva , Tiago Moreira Bastos Campos , Gilmar Patrocínio Thim , Kartikeya Singh Jodha , Susana Maria Salazar Marocho , Renata Marques de Melo Marinho , Jason Alan Griggs
Objective
To evaluate the fatigue life of 5Y-PSZ crowns coated with antimicrobial glasses and the wear on the antagonist, comparing it to a commercial glaze.
Methods
Forty-five crowns of 5Y-PSZ zirconia were divided into: commercial glaze (G); boron-doped soda-lime glass (BSL), and boron-doped soda-lime glass with silver (BSLAg). Step-stress accelerated life testing was conducted at 2 Hz with a stress ratio of 0.1 on a custom servo-hydraulic load frame. The characteristic lifetime and Weibull modulus were estimated using the ALTAPRO software. Energy-Dispersive Spectroscopy (EDS), surface roughness (SR, Sa, and Sz) for the coated crowns and the pistons, fractography, and piston wear analysis were conducted. Crown's SR and piston wear were analyzed by two-way ANOVA, and Tukey's method (α=0.05). Piston's SR was examined by Linear Mixed Model (LMM) (α=0.05).
Results
EDS identified zirconium in the composition of the radiopaque structures on both experimental glass coating surfaces. Crowns coated by BSL showed the lowest Sz values after all the different fatigue profiles. After the fatigue test, the SR (Sa and Sz) of the piston for all groups was similarly higher than before. No significant difference could be detected between the groups after the fatigue lifetime analysis. Fractures originated at the glass surface for all groups. The pistons in contact with the G group crowns presented greater volume wear for the mild fatigue profile.
Significance
5Y-PSZ zirconia crowns coated by BSL and BSLAg maintained the fatigue performance and significantly reduced wear on the piston/antagonist compared to the commercial glaze group. These coatings show potential for clinical applications in ceramic restorations, particularly in environments prone to biofilm accumulation.
{"title":"Ultra-translucent zirconia crowns with antimicrobial glass coatings: fatigue life and antagonist wear analysis","authors":"Ana Carolina da Silva , Juliana de Freitas Gouveia Silva , Tiago Moreira Bastos Campos , Gilmar Patrocínio Thim , Kartikeya Singh Jodha , Susana Maria Salazar Marocho , Renata Marques de Melo Marinho , Jason Alan Griggs","doi":"10.1016/j.dental.2025.07.016","DOIUrl":"10.1016/j.dental.2025.07.016","url":null,"abstract":"<div><h3>Objective</h3><div>To evaluate the fatigue life of 5Y-PSZ crowns coated with antimicrobial glasses and the wear on the antagonist, comparing it to a commercial glaze.</div></div><div><h3>Methods</h3><div>Forty-five crowns of 5Y-PSZ zirconia were divided into: commercial glaze (G); boron-doped soda-lime glass (BSL), and boron-doped soda-lime glass with silver (BSLAg). Step-stress accelerated life testing was conducted at 2 Hz with a stress ratio of 0.1 on a custom servo-hydraulic load frame. The characteristic lifetime and Weibull modulus were estimated using the ALTAPRO software. Energy-Dispersive Spectroscopy (EDS), surface roughness (SR, Sa, and Sz) for the coated crowns and the pistons, fractography, and piston wear analysis were conducted. Crown's SR and piston wear were analyzed by two-way ANOVA, and Tukey's method (α=0.05). Piston's SR was examined by Linear Mixed Model (LMM) (α=0.05).</div></div><div><h3>Results</h3><div>EDS identified zirconium in the composition of the radiopaque structures on both experimental glass coating surfaces. Crowns coated by BSL showed the lowest Sz values after all the different fatigue profiles. After the fatigue test, the SR (Sa and Sz) of the piston for all groups was similarly higher than before. No significant difference could be detected between the groups after the fatigue lifetime analysis. Fractures originated at the glass surface for all groups. The pistons in contact with the G group crowns presented greater volume wear for the mild fatigue profile.</div></div><div><h3>Significance</h3><div>5Y-PSZ zirconia crowns coated by BSL and BSLAg maintained the fatigue performance and significantly reduced wear on the piston/antagonist compared to the commercial glaze group. These coatings show potential for clinical applications in ceramic restorations, particularly in environments prone to biofilm accumulation.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1376-1387"},"PeriodicalIF":6.3,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144815425","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 : 2025-08-08DOI: 10.1016/j.dental.2025.07.022
Daranee Tantbirojn , Jared Quave , Anne E. Hill , Clint S. Conner , Antheunis Versluis
Objectives
Polymerization shrinkage in restored teeth is implicated in restoration longevity. This study explored how development of shrinkage and elastic modulus of resin-based composites interact and discussed the level of residual stress they create.
Methods
Residual stress was assessed by cuspal flexure of typodont premolars with 3 × 3 mm mesio-occlusal-distal preparations. The teeth were restored with one of three bulk-fill flowable composites (everX Flow Short-fiber Reinforced, GC; Filtek Bulk Fill, 3 M; or SDR Flow+ Bulk Fill, Dentsply Sirona) placed in one bulk increment. Tooth surfaces were scanned before (‘baseline’) and after restoration (15 min and 24hrs). Cuspal flexure was determined by comparing scans of restored teeth with their baseline. Bond integrity was verified with dye. Post-gel shrinkage was measured using a strain gauge, and elastic modulus at 15 min and 24hrs using four-point bending. Sample size was 10. Results were analyzed with ANOVA statistics (α=0.05).
Results
Cuspal flexure differed significantly among composites (p = 0.001) but not between 15 min and 24hrs (p = 0.889). The fiber-reinforced composite caused significantly higher cuspal flexure compared to the conventional flowables (17μm versus 7μm) despite its lower post-gel shrinkage (0.53 versus 0.74 and 0.58 vol%). The elastic modulus of the fiber-reinforced composite was significantly higher at 15 min than the other composites (8 GPa versus 2 GPa), and increased significantly at 24hrs (12 GPa versus 8 GPa).
Significance
High elastic modulus development rate eliminated benefits associated with low post-gel shrinkage. Cuspal flexure and therefore residual shrinkage stress was largely determined by the early elastic modulus, when composite was still shrinking, not the mature (final) elastic modulus value.
目的：修复牙的聚合收缩与修复寿命有关。本研究探讨了树脂基复合材料的收缩率和弹性模量的发展如何相互作用，并讨论了它们产生的残余应力水平。方法：采用3 × 3 mm的中牙合远端制剂，通过牙尖屈曲来评估残余应力。采用三种可流动填充复合材料中的一种修复牙齿(everX Flow Short-fiber Reinforced， GC；Filtek散装填料，3 M；或SDR流量+散装填充，Dentsply Sirona)放置在一个散装增量中。在修复前（“基线”）和修复后（15 min和24小时）扫描牙齿表面。牙尖屈曲是通过比较修复牙齿的扫描结果和基线来确定的。用染料验证了键的完整性。凝胶后收缩率采用应变计测量，弹性模量在15 min和24小时采用四点弯曲。样本量为10。结果采用方差分析（α=0.05）。结果：复合材料的尖屈曲有显著差异（p = 0.001），但在15 min和24h之间无显著差异（p = 0.889）。尽管纤维增强复合材料的凝胶后收缩率较低（0.53 vs 0.74和0.58 vol%），但与传统流动材料相比（17μm vs 7μm），其尖端挠度明显更高。纤维增强复合材料的弹性模量在15 min时显著高于其他复合材料（8 GPa vs 2 GPa），在24h时显著增加（12 GPa vs 8 GPa）。意义：高弹性模量发展速率消除了低凝胶后收缩相关的益处。尖端弯曲和残余收缩应力很大程度上取决于复合材料仍在收缩时的早期弹性模量，而不是成熟（最终）弹性模量。
{"title":"Shrinkage stress is determined by the elastic modulus during shrinkage, not the final elastic modulus","authors":"Daranee Tantbirojn , Jared Quave , Anne E. Hill , Clint S. Conner , Antheunis Versluis","doi":"10.1016/j.dental.2025.07.022","DOIUrl":"10.1016/j.dental.2025.07.022","url":null,"abstract":"<div><h3>Objectives</h3><div>Polymerization shrinkage in restored teeth is implicated in restoration longevity. This study explored how development of shrinkage and elastic modulus of resin-based composites interact and discussed the level of residual stress they create.</div></div><div><h3>Methods</h3><div>Residual stress was assessed by cuspal flexure of typodont premolars with 3 × 3 mm mesio-occlusal-distal preparations. The teeth were restored with one of three bulk-fill flowable composites (everX Flow Short-fiber Reinforced, GC; Filtek Bulk Fill, 3 M; or SDR Flow+ Bulk Fill, Dentsply Sirona) placed in one bulk increment. Tooth surfaces were scanned before (‘baseline’) and after restoration (15 min and 24hrs). Cuspal flexure was determined by comparing scans of restored teeth with their baseline. Bond integrity was verified with dye. Post-gel shrinkage was measured using a strain gauge, and elastic modulus at 15 min and 24hrs using four-point bending. Sample size was 10. Results were analyzed with ANOVA statistics (α=0.05).</div></div><div><h3>Results</h3><div>Cuspal flexure differed significantly among composites (p = 0.001) but not between 15 min and 24hrs (p = 0.889). The fiber-reinforced composite caused significantly higher cuspal flexure compared to the conventional flowables (17<em>μ</em>m versus 7<em>μ</em>m) despite its lower post-gel shrinkage (0.53 versus 0.74 and 0.58 vol%). The elastic modulus of the fiber-reinforced composite was significantly higher at 15 min than the other composites (8 GPa versus 2 GPa), and increased significantly at 24hrs (12 GPa versus 8 GPa).</div></div><div><h3>Significance</h3><div>High elastic modulus development rate eliminated benefits associated with low post-gel shrinkage. Cuspal flexure and therefore residual shrinkage stress was largely determined by the early elastic modulus, when composite was still shrinking, not the mature (final) elastic modulus value.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1388-1394"},"PeriodicalIF":6.3,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803082","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 : 2025-08-08DOI: 10.1016/j.dental.2025.07.018
Akimasa Tsujimoto , J.C. Thomas , Daniel Caplan
Objectives
The longevity of resin-based composite (RBC) restorations is influenced by many factors, and it is difficult to assess all of them in small data sets. This study uses a large data set from a university and its dental clinics to assess many potentially predictive factors of restoration survival.
Methods
This retrospective cohort study used de-identified data from electronic dental records of patients attending records the University of Iowa and its dental clinics. Multivariable Cox proportional hazards models were generated to determine which variables influenced the longevity of the restorations, and model selection via best subset selection on Bayesian Information Criterion (BIC) was used to select the best model.
Results
The number of surfaces covered by the restoration showed a very strong influence, with more surfaces leading to reduced longevity (HR 2.49 (CI 1.97–3.15), p < 0.001 for 4 surfaces), but the inclusion of a proximal surface did not have a significant influence. The presence of an eating disorder (HR 1.72 (CI 1.15–2.56), p = 0.008), dry mouth (HR 1.20 (1.02–1.43), p = 0.033), or dental fear (HR 1.39 (CI 1.14–1.69), p = 0.001) also had a negative effect on restoration longevity, but bruxism/clenching did not. The type of filler used in the RBC, conventional or supra-nano spherical, also affected restoration longevity, with greater longevity for supra-nano spherical filler (HR 0.61 (CI 0.45–0.82), p = 0.001).
Conclusions
Type of provider showed no impact on restoration longevity in this study, and only a very limited number of patient factors were significant. Differences in the type of filler and the number of surfaces covered by the restoration did have a significant effect on restoration longevity.
目的：树脂基复合材料（RBC）修复体的寿命受许多因素的影响，很难在小数据集中对所有因素进行评估。本研究使用来自一所大学及其牙科诊所的大量数据集来评估许多潜在的预测修复生存的因素。方法：本回顾性队列研究使用来自爱荷华大学及其牙科诊所就诊患者电子牙科记录的去识别数据。建立多变量Cox比例风险模型，确定影响修复体寿命的变量，并通过贝叶斯信息准则（BIC）的最佳子集选择来选择最佳模型。结果：修复体覆盖的表面数量对修复体寿命的影响非常大，表面越多，寿命越短(HR 2.49 (CI 1.97-3.15)， p 结论：在本研究中，提供者类型对修复体寿命没有影响，只有非常有限的患者因素具有显著性。填充物类型和修复体覆盖表面数量的差异确实对修复寿命有显著影响。
{"title":"Factors influencing the longevity of resin-based composite restorations","authors":"Akimasa Tsujimoto , J.C. Thomas , Daniel Caplan","doi":"10.1016/j.dental.2025.07.018","DOIUrl":"10.1016/j.dental.2025.07.018","url":null,"abstract":"<div><h3>Objectives</h3><div>The longevity of resin-based composite (RBC) restorations is influenced by many factors, and it is difficult to assess all of them in small data sets. This study uses a large data set from a university and its dental clinics to assess many potentially predictive factors of restoration survival.</div></div><div><h3>Methods</h3><div>This retrospective cohort study used de-identified data from electronic dental records of patients attending records the University of Iowa and its dental clinics. Multivariable Cox proportional hazards models were generated to determine which variables influenced the longevity of the restorations, and model selection via best subset selection on Bayesian Information Criterion (BIC) was used to select the best model.</div></div><div><h3>Results</h3><div>The number of surfaces covered by the restoration showed a very strong influence, with more surfaces leading to reduced longevity (HR 2.49 (CI 1.97–3.15), p < 0.001 for 4 surfaces), but the inclusion of a proximal surface did not have a significant influence. The presence of an eating disorder (HR 1.72 (CI 1.15–2.56), p = 0.008), dry mouth (HR 1.20 (1.02–1.43), p = 0.033), or dental fear (HR 1.39 (CI 1.14–1.69), p = 0.001) also had a negative effect on restoration longevity, but bruxism/clenching did not. The type of filler used in the RBC, conventional or supra-nano spherical, also affected restoration longevity, with greater longevity for supra-nano spherical filler (HR 0.61 (CI 0.45–0.82), p = 0.001).</div></div><div><h3>Conclusions</h3><div>Type of provider showed no impact on restoration longevity in this study, and only a very limited number of patient factors were significant. Differences in the type of filler and the number of surfaces covered by the restoration did have a significant effect on restoration longevity.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1395-1401"},"PeriodicalIF":6.3,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144811491","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 : 2025-08-08DOI: 10.1016/j.dental.2025.07.021
Yuyang Gan , Yuan Yuan , Yanning Gong , Quan Fang , Guangjun Liu , Yuqian Li , Denson Cao , Daniel C.N. Chan , Jianying Feng
Objectives
This study evaluates the feasibility and safety of a laser-induced reversible adhesive (LIRA) by assessing intrapulpal temperature changes (ITC), shear bond strength (SBS) following laser irradiation, and optimal adhesive removal methods.
Methods
Thirty premolars were used to measure ITC under laser powers of 1 W, 2 W, and 3 W until the temperature exceeded the 5.6 ℃ threshold. For SBS testing, one hundred and twenty premolars were divided into twelve groups based on bracket type (metal/ceramic) and laser treatment (untreated, 1 W-4 s, 2 W-4 s, 1 W-8 s, 2 W-8 s, and 3 W-4 s). Adhesive remnant index (ARI) was recorded. Additionally, one hundred thirty-five premolars were assigned to nine groups based on laser power (1 W, 2 W, 3 W) and adhesive removal methods (ultrasonic scaler, tungsten carbide bur, diamond bur) for surface roughness and removal time assessment. Statistical analysis was performed using ANOVA, t-tests, and the Kruskal-Wallis test (α=0.05). Furthermore, the debonding resin-enamel interface and enamel surface morphology were observed by scanning electron microscopy (SEM).
Results
The time to exceed the temperature threshold decreased with increasing laser power. The 1 W-8 s and 2 W-8 s groups showed the lowest SBS (p < 0.05). Ultrasonic scaler removal exhibited significantly lower enamel roughness (p < 0.05), while removal time showed no significant difference at 2 W laser power (p > 0.05).
Significance
LIRA may provide a potentially safer and more efficient strategy for orthodontic bracket bonding, achieving efficient debonding while minimizing enamel damage and ensuring pulp safety.
{"title":"Feasibility and safety of a novel laser-induced adhesive for orthodontic debonding","authors":"Yuyang Gan , Yuan Yuan , Yanning Gong , Quan Fang , Guangjun Liu , Yuqian Li , Denson Cao , Daniel C.N. Chan , Jianying Feng","doi":"10.1016/j.dental.2025.07.021","DOIUrl":"10.1016/j.dental.2025.07.021","url":null,"abstract":"<div><h3>Objectives</h3><div>This study evaluates the feasibility and safety of a laser-induced reversible adhesive (LIRA) by assessing intrapulpal temperature changes (ITC), shear bond strength (SBS) following laser irradiation, and optimal adhesive removal methods.</div></div><div><h3>Methods</h3><div>Thirty premolars were used to measure ITC under laser powers of 1 W, 2 W, and 3 W until the temperature exceeded the 5.6 ℃ threshold. For SBS testing, one hundred and twenty premolars were divided into twelve groups based on bracket type (metal/ceramic) and laser treatment (untreated, 1 W-4 s, 2 W-4 s, 1 W-8 s, 2 W-8 s, and 3 W-4 s). Adhesive remnant index (ARI) was recorded. Additionally, one hundred thirty-five premolars were assigned to nine groups based on laser power (1 W, 2 W, 3 W) and adhesive removal methods (ultrasonic scaler, tungsten carbide bur, diamond bur) for surface roughness and removal time assessment. Statistical analysis was performed using ANOVA, t-tests, and the Kruskal-Wallis test (α=0.05). Furthermore, the debonding resin-enamel interface and enamel surface morphology were observed by scanning electron microscopy (SEM).</div></div><div><h3>Results</h3><div>The time to exceed the temperature threshold decreased with increasing laser power. The 1 W-8 s and 2 W-8 s groups showed the lowest SBS (<em>p</em> < 0.05). Ultrasonic scaler removal exhibited significantly lower enamel roughness (<em>p</em> < 0.05), while removal time showed no significant difference at 2 W laser power (<em>p</em> > 0.05).</div></div><div><h3>Significance</h3><div>LIRA may provide a potentially safer and more efficient strategy for orthodontic bracket bonding, achieving efficient debonding while minimizing enamel damage and ensuring pulp safety.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1402-1410"},"PeriodicalIF":6.3,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803081","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 : 2025-08-05DOI: 10.1016/j.dental.2025.07.015
Helena Reis de Souza Schacher , Maiara Monteiro Oliveira , Renata Medina-Silva , Luciane Macedo de Menezes
Objectives
Considering the pathogenic potential of some bacteria and yeast species in oral cavity this study aimed to analyze the capability of Streptococcus mutans and Candida albicans in artificial saliva (AS) to form biofilm on clear aligners.
Methods
Clear aligners fragments (Invisalign™) were subjected to a 7-day biofilm formation experiment in AS and tryptic soy broth (TSB) with S. mutans or C. albicans pre-inoculated. TSB and AS cultures were evaluated for microbial growth and biofilm formation with crystal violet assay. Quantitative data were statistically compared using the Mann-Whitney test and the Pearson correlation. Also, fragments were qualitatively processed using scanning electron microscopy (SEM) images.
Results
TSB induced the growth of S. mutans more effectively when compared to AS. Both media induced significant growth of C. albicans compared to biofilm, with TSB being significantly higher than AS. However, for both microorganisms, biofilm formation in AS and TSB did not show differences, indicating they may not depend on nutrients to adhere on clear aligners. SEM images showed bacteria and yeast cells adhering to the appliance’s inner surfaces for both media.
Significance
Aligners cover tooth enamel and gingival tissues for a long time and can interfere with oral microbiota and human health. Recognizing the real capacity of bacteria and yeast species to adhere to the surface of new aligners is important for raising awareness among professionals and patients.
{"title":"In vitro Streptococcus mutans and Candida albicans adhesion on clear orthodontic aligners exposed to artificial saliva","authors":"Helena Reis de Souza Schacher , Maiara Monteiro Oliveira , Renata Medina-Silva , Luciane Macedo de Menezes","doi":"10.1016/j.dental.2025.07.015","DOIUrl":"10.1016/j.dental.2025.07.015","url":null,"abstract":"<div><h3>Objectives</h3><div>Considering the pathogenic potential of some bacteria and yeast species in oral cavity this study aimed to analyze the capability of <em>Streptococcus mutans</em> and <em>Candida albicans</em> in artificial saliva (AS) to form biofilm on clear aligners.</div></div><div><h3>Methods</h3><div>Clear aligners fragments (Invisalign™) were subjected to a 7-day biofilm formation experiment in AS and tryptic soy broth (TSB) with <em>S. mutans</em> or <em>C. albicans</em> pre-inoculated. TSB and AS cultures were evaluated for microbial growth and biofilm formation with crystal violet assay. Quantitative data were statistically compared using the Mann-Whitney test and the Pearson correlation. Also, fragments were qualitatively processed using scanning electron microscopy (SEM) images.</div></div><div><h3>Results</h3><div>TSB induced the growth of <em>S. mutans</em> more effectively when compared to AS. Both media induced significant growth of <em>C. albicans</em> compared to biofilm, with TSB being significantly higher than AS. However, for both microorganisms, biofilm formation in AS and TSB did not show differences, indicating they may not depend on nutrients to adhere on clear aligners. SEM images showed bacteria and yeast cells adhering to the appliance’s inner surfaces for both media.</div></div><div><h3>Significance</h3><div>Aligners cover tooth enamel and gingival tissues for a long time and can interfere with oral microbiota and human health. Recognizing the real capacity of bacteria and yeast species to adhere to the surface of new aligners is important for raising awareness among professionals and patients.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 10","pages":"Pages 1332-1338"},"PeriodicalIF":6.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144768178","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 : 2025-08-05DOI: 10.1016/j.dental.2025.07.017
Muqi Jiang , Yasheng Sun , Zhixiang Nie , William M. Palin , Lihua Qian , Jukka P. Matinlinna , Li Hu , Zhen Zhang
Objectives
Surface treatments of titanium dental implants can improve osseointegration and reduce the incidence of peri-implantitis. This study provides a new approach for surface modification by utilizing the principle of cavitation(CAV), which can generate high temperature and pressure with micro-jets acting on the surface.
Methods
Titanium surfaces were treated by CAV, and compared with a control group (sandblasted, large grit, and acid-etched, SLA). The microscopic morphology and roughness of the titanium surfaces, as well as their effect on osteoblast and macrophage biocompatibility were measured.
Results
Characteristic CAV pits were formed on the surface following CAV treatment, and roughness was significantly increased compared to the SLA surface (p < 0.05). The CAV treatment not only promoted adhesion, proliferation, and osteogenic differentiation of osteoblasts more effectively than SLA, but also facilitated the polarization of macrophages towards an anti-inflammatory phenotype.
Conclusions
An innovative titanium implant surface treatment that utilises the CAV effect has been developed and demonstrates superior biocompatibility and ability to promote osteogenesis and immunomodulation compared with conventional surface treatment methods.
Significance
The CAV titanium surface treatment offers distinct advantages over SLA surface treatment, including superior osteogenic and immunomodulatory potential, along with a simpler and more environmentally friendly manufacturing process. These benefits establish CAV as a promising new strategy for enhancing titanium implant surfaces.
{"title":"Cavitation erosion: An efficient method for promoting osteogenesis and immunomodulation of titanium surface","authors":"Muqi Jiang , Yasheng Sun , Zhixiang Nie , William M. Palin , Lihua Qian , Jukka P. Matinlinna , Li Hu , Zhen Zhang","doi":"10.1016/j.dental.2025.07.017","DOIUrl":"10.1016/j.dental.2025.07.017","url":null,"abstract":"<div><h3>Objectives</h3><div>Surface treatments of titanium dental implants can improve osseointegration and reduce the incidence of peri-implantitis. This study provides a new approach for surface modification by utilizing the principle of cavitation(CAV), which can generate high temperature and pressure with micro-jets acting on the surface.</div></div><div><h3>Methods</h3><div>Titanium surfaces were treated by CAV, and compared with a control group (sandblasted, large grit, and acid-etched, SLA). The microscopic morphology and roughness of the titanium surfaces, as well as their effect on osteoblast and macrophage biocompatibility were measured.</div></div><div><h3>Results</h3><div>Characteristic CAV pits were formed on the surface following CAV treatment, and roughness was significantly increased compared to the SLA surface (p < 0.05). The CAV treatment not only promoted adhesion, proliferation, and osteogenic differentiation of osteoblasts more effectively than SLA, but also facilitated the polarization of macrophages towards an anti-inflammatory phenotype.</div></div><div><h3>Conclusions</h3><div>An innovative titanium implant surface treatment that utilises the CAV effect has been developed and demonstrates superior biocompatibility and ability to promote osteogenesis and immunomodulation compared with conventional surface treatment methods.</div></div><div><h3>Significance</h3><div>The CAV titanium surface treatment offers distinct advantages over SLA surface treatment, including superior osteogenic and immunomodulatory potential, along with a simpler and more environmentally friendly manufacturing process. These benefits establish CAV as a promising new strategy for enhancing titanium implant surfaces.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1350-1360"},"PeriodicalIF":6.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144787868","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 : 2025-08-05DOI: 10.1016/j.dental.2025.07.020
Yan Wang , Li Liu , Liyuan Zhou , Huan Cheng , Yifan Li , Anni Wu , Senjeet Sreekissoon , Xiao Chen , Peng Gao , Lei Lu , Zhennan Deng , Jinsong Liu
Postoperative infection significantly increases the risk of failure in titanium (Ti) dental implants. While the local application of antimicrobial agents can effectively mitigate these infections. Electrospinning has gained considerable attention for its ability to produce high-performance nanofibers suitable for localized drug release. Nevertheless, challenges such as weak interfacial bond with Ti surface limits its application as a surface coating strategy. In this study, we developed a novel electrospun coating composed of a plant polyphenol, epigallocatechin gallate (EGCG)-modified polycaprolactone (PCL) and gelatin (Gel), which enhanced its adhesion to the Ti surface through phenol-amine chemistry. This innovative approach significantly enhanced the interfacial bond strength between the nanofibers and the Ti surface, thereby improving the wear resistance of the coating. Additionally, the incorporation of rifampicin (Rif), a broad-spectrum antibiotic, into the EGCG-modified electrospun coating (Ti/NFs-0.5 %EG@Rif) enabled sustained Rif release over 28 days, providing potential long-term antibacterial activity. Both in vitro and in vivo studies demonstrated that the Ti/NFs-0.5 %EG@Rif coating exhibited significantly enhanced antibacterial and anti-inflammatory efficacy, along with excellent biocompatibility. In conclusion, the EGCG-modified electrospun coating represented a promising and cost-effective strategy for enhancing the functionality of Ti implants, with the potential to improve clinical outcomes in dental applications.
{"title":"Enhanced antibacterial activity of plant polyphenol-modified robust polycaprolactone/gelatin electrospun coating on titanium implant","authors":"Yan Wang , Li Liu , Liyuan Zhou , Huan Cheng , Yifan Li , Anni Wu , Senjeet Sreekissoon , Xiao Chen , Peng Gao , Lei Lu , Zhennan Deng , Jinsong Liu","doi":"10.1016/j.dental.2025.07.020","DOIUrl":"10.1016/j.dental.2025.07.020","url":null,"abstract":"<div><div>Postoperative infection significantly increases the risk of failure in titanium (Ti) dental implants. While the local application of antimicrobial agents can effectively mitigate these infections. Electrospinning has gained considerable attention for its ability to produce high-performance nanofibers suitable for localized drug release. Nevertheless, challenges such as weak interfacial bond with Ti surface limits its application as a surface coating strategy. In this study, we developed a novel electrospun coating composed of a plant polyphenol, epigallocatechin gallate (EGCG)-modified polycaprolactone (PCL) and gelatin (Gel), which enhanced its adhesion to the Ti surface through phenol-amine chemistry. This innovative approach significantly enhanced the interfacial bond strength between the nanofibers and the Ti surface, thereby improving the wear resistance of the coating. Additionally, the incorporation of rifampicin (Rif), a broad-spectrum antibiotic, into the EGCG-modified electrospun coating (Ti/NFs-0.5 %EG@Rif) enabled sustained Rif release over 28 days, providing potential long-term antibacterial activity. Both <em>in vitro</em> and <em>in vivo</em> studies demonstrated that the Ti/NFs-0.5 %EG@Rif coating exhibited significantly enhanced antibacterial and anti-inflammatory efficacy, along with excellent biocompatibility. In conclusion, the EGCG-modified electrospun coating represented a promising and cost-effective strategy for enhancing the functionality of Ti implants, with the potential to improve clinical outcomes in dental applications.</div></div>","PeriodicalId":298,"journal":{"name":"Dental Materials","volume":"41 11","pages":"Pages 1361-1375"},"PeriodicalIF":6.3,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144787869","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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