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Thanoon H, Silikas N, Watts DC. Effect of polymerisation protocols on water sorption, solubility and hygroscopic expansion of fast-cure bulk-fill composite. Dent Mater 2024:S0109-5641(24)00085-X. [PMID: 38734487 DOI: 10.1016/j.dental.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/30/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024]
Abstract
OBJECTIVE This study examines the effect of two light-curing protocols from a LED polywave light curing unit (LCU) on water sorption, solubility, and hygroscopic expansion of fast and conventional bulk-fill resin-based composites (RBCs) aged in distilled water for 120 d. METHODS Three bulk-fill RBCs materials were studied: Tetric PowerFill® (fast photo-polymerised composite) (TPF), Tetric EvoCeram bulk-fill (EVO), and GrandioSo x-tra bulk-fill (GSO) (conventional photo-polymerised composites). Specimens were prepared within a 3D-printed resin mold (8-mm diameter x 4-mm height) and light-cured from one side only with 2 modes of polywave LCU (Bluephase® PowerCure): 3 s mode and for 20 s in "Standard" mode. Water sorption and solubility were measured at fixed time intervals for 120 d of distilled water storage, then reconditioned to dry to measure desorption for 75 d, all at 37 ± 1 °C. Hygroscopic (volumetric) expansion was recorded at the same time intervals up to 120 d. Data were analysed through SPSS using Two-way ANOVA, One-way ANOVA, independent t-tests, and Tukey's post-hoc correction tests (p < 0.05). RESULTS TPF, when irradiated for 3 s demonstrated minimal water sorption (0.83%), solubility (1.01 μg/mm3), and least volumetric expansion (1.64%) compared to EVO and GSO. While EVO showed the highest water sorption (1.03%) and solubility (1.95 μg/mm3) at 3 s. GSO had the lowest sorption (0.67%) and (0.56%) in 3 s and 20 s protocols, respectively. Nevertheless, all the sorption and solubility data were within the ISO 4049 limits. SIGNIFICANCE For TPF, fast (3 s) polymerisation did not increase either water sorption or solubility, compared with 20 s irradiation. However, with the two comparative bulk-fill composites, fast cure increased water sorption by 15-25% and more than doubled solubility. These findings were consistent with the lesser volumetric expansions observed for Tetric PowerFill at both the fast and standard protocols, indicating its relative stability across polymerisation protocols.
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Affiliation(s)
- Halah Thanoon
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Department of Restorative Dentistry, College of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK
| | - David C Watts
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK; Photon Science Institute, University of Manchester, Manchester, UK.
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Alshabib A, Silikas N, Watts DC. Properties of model E-glass fiber composites with varying matrix monomer ratios. Dent Mater 2024; 40:441-450. [PMID: 38129191 DOI: 10.1016/j.dental.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE To evaluate properties of fiber-reinforced-composites (FRC) containing Bis-EMA/UDMA monomers but identical dispersed phase (60% wt BaSi glass power +10% wt E-glass fibre). METHODS A control (Group A), monomer mixture comprising 60% Bis-GMA, 30% TEGDMA, and 10% PMMA (typical FRC monomers) was used. The following monomer mass fractions were mixed: 50% bis-GMA plus 50% of different ratios of Bis-EMA+UDMA to produce consistent formulations (Groups B-E) of workable viscosities was also studied. Flexural strength (FS), fracture toughness (KIC), water sorption (SP), solubility (SL) and hygroscopic expansion (HE) were measured. FS and KIC specimens were stored for 1, 7 d, and 30 d in water at 37 °C. SP/SL specimens were water-immersed for 168d, weighed at intervals, then dried for 84 d at 37 °C. To analyze differences in FS, and KIC, a two-way ANOVA and Tukey post-hoc tests (α = 0.05) were conducted. For SP/SL, and HE, one-way ANOVA with subsequent Tukey post-hoc tests (α = 0.05) were utilized. RESULTS FS and KIC for groups A, D, E decreased progressively after 1 d. Groups B and C (highest amounts of Bis-EMA) did not decrease significantly. The modified matrix composites performed significantly better than the control group for SP and HE. The control group outperformed the experimental composites only for SL with up to 250% higher SL for group E (6.9 μg/mm) but still below the maximum permissible threshold of 7.5 μg/mm. SIGNIFICANCE EXPERIMENTAL: composites with highest amounts of Bis-EMA showed improved hydrolytic stability and overall enhancement in several clinically-relevant properties. This makes them potential candidates for alternative matrices to a semi-interpenetrating network in fiber-reinforced composites.
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Affiliation(s)
- Abdulrahman Alshabib
- Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK
| | - David C Watts
- Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK.
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Althaqafi KA, Satterthwaite J, AlShabib A, Silikas N. Synthesis and characterisation of microcapsules for self-healing dental resin composites. BMC Oral Health 2024; 24:109. [PMID: 38238688 PMCID: PMC10797747 DOI: 10.1186/s12903-023-03764-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 12/12/2023] [Indexed: 01/22/2024] Open
Abstract
AIM The purpose of this study was to i) synthesise TEGDMA-DHEPT microcapsules in a laboratory setting; ii) characterise the resultant microcapsules for quality measures. MATERIALS & METHODS Microcapsules were prepared by in situ polymerization of PUF shells. Microcapsules characterisation include size analysis, optical and SEM microscopy to measure the diameter and analyse the morphology of PUF microcapsules. FT-IR spectrometer evaluated microcapsules and benzyl peroxide catalyst polymerization independently. RESULT Average diameter of TEGDMA-DHEPT microcapsules was 120 ± 45 μm (n: 100). SEM imaging of the capsular shell revealed a smooth outer surface with deposits of PUF nanoparticles that facilitate resin matrix retention to the microcapsules upon composite fracture. FT-IR spectra showed that microcapsules crushed with BPO catalyst had degree of conversion reached to 60.3%. CONCLUSION TEGDMA-DHEPT microcapsules were synthesised according to the selected parameters. The synthesised microcapsules have a self-healing potential when embedded into dental resin composite as will be demonstrated in our future work.
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Affiliation(s)
- Khaled Abid Althaqafi
- Faculty of Dentistry, College of Dental Medicine, University of Umm Al Qura, Makkah, Kingdom of Saudi Arabia
| | - Julian Satterthwaite
- Division of Dentistry, School of Medical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Abdulrahman AlShabib
- Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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Elraggal A, Raheem IA, Holiel A, Alhotan A, Alshabib A, Silikas N, Watts DC, Alharbi N, Afifi RR. Bond Strength, Microleakage, Microgaps, and Marginal Adaptation of Self-adhesive Resin Composites to Tooth Substrates with and without Preconditioning with Universal Adhesives. J Adhes Dent 2024; 26:53-64. [PMID: 38329120 DOI: 10.3290/j.jad.b4949691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
PURPOSE This study investigated and compared the bond strengths, microleakage, microgaps, and marginal adaptation of self-adhesive resin composites (SAC) to dentin with or without universal adhesives. MATERIALS AND METHODS Dentin surfaces of 75 molars were prepared for shear and microtensile bond strength testing (SBS and µTBS). Silicon molds were used to build up direct restorations using the following materials to form 5 groups: 1. Surefil One; 2. Prime&Bond active Universal Adhesive + Surefil One; 3. Vertise Flow; 4. OptiBond Universal + Vertise Flow; 5. Scotchbond Universal + Filtek Z500 (control group). Bonded specimens were thermocycled 10,000x before being tested either for SBS or µTBS using a universal testing machine at a crosshead speed of 0.5 mm/min. Direct mesial and distal class-II cavities were created on 100 sound premolars, with the gingival margin of distal cavities placed below CEJ and restored according to the five groups. After thermocycling, microleakage scores were assessed following immersion of restored premolars in 2% methylene blue dye for 24 h, while marginal gaps and adaptation percentages were investigated on epoxy resin replicas under SEM at magnifications of 2000X and 200X, respectively. Results were statistically analyzed with parametric and non-parametric tests as applicable, with a level of significance set at α = 0.05. RESULTS Bond strengths, microleakage scores, microgaps, and percent marginal adaptation of Surefil One and Vertise Flow were significantly (p < 0.001) inferior to the control group. Dentin preconditioning with universal adhesives significantly increased the study parameter outcomes of Surefil One and Vertise Flow, yet they were still significantly below the performance of the control group. CONCLUSION Conventional resin composite outperformed the SAC whether applied solely or in conjunction with their corresponding universal adhesives.
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Liberato WF, Silikas N, Watts DC, Cavalcante LM, Schneider LFJ. Luting laminate veneers: Do resin-composites produce less polymerization stress than resin cements? Dent Mater 2023; 39:1190-1201. [PMID: 37858420 DOI: 10.1016/j.dental.2023.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 10/21/2023]
Abstract
OBJECTIVES Regular composites could produce less polymerization stress than resin cements when luting laminate veneers but there is no proper evidence to support this theory. The current study aimed to determine the degree of conversion, volumetric shrinkage, polymerization stress and the resultant elastic moduli of materials currently used for adhesive cementation and to determine possible correlations. METHODS The study considered (i) regular resin composites (Admira Fusion, Gradia, Grandioso, Palfique, Sirius Z, Viscalor and Z100) at room and pre-warmed (PW) at 69ºC, (ii) flowable composites (Sigma Flow and Grandioso Flow); (iii) solely light-activated cements (AllCem Veneer, Variolink Esthetic and RelyX Veneer); and (iv) one dual-activated resin cement (SpeedCEM). Degree of conversion (DC, n = 3) was accessed with FTIR 1 h after irradiation. Bonded-disk and Bioman II instruments were used to access polymerization shrinkage strain and shrinkage stress, respectively, for 60 min at 23 ± 1◦C (n = 3). The elastic modulus was determined by 3-point bending flexural test (n = 6). The results were submitted to analyse s of variance, Tukey's, and correlation tests. RESULTS For regular composites, the pre-warming did not affect DC, shrinkage and modulus but significantly increased the stress magnitude. Correlation tests indicated a significant relationship only between stress and polymerization shrinkage (r = 0.811343). SIGNIFICANCE Regular composites can produce less polymerization stress than resin cements when luting laminate veneers. Polymerization stress was dependent on the shrinkage magnitude, but not on the degree of conversion nor the elastic modulus.
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Affiliation(s)
- Walleska Feijó Liberato
- School of Dentistry, Federal Fluminense University, Niteroi, Rio de Janeiro, Brazil; Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom; Nucleus for Dental Biomaterials Research, Veiga de Almeida University, Rio de Janeiro, Brazil
| | - Nikolaos Silikas
- Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom
| | - David C Watts
- Biomaterials Research Group, School of Medical Sciences, Division of Dentistry, The University of Manchester, Manchester, United Kingdom
| | | | - Luis Felipe J Schneider
- School of Dentistry, Federal Fluminense University, Niteroi, Rio de Janeiro, Brazil; Nucleus for Dental Biomaterials Research, Veiga de Almeida University, Rio de Janeiro, Brazil.
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Machado-Santos L, Baroudi K, Silikas N, Tribst JPM, Coelho Sinhoreti MA, Brandt WC, Liporoni PCS. Physical analysis of an acrylic resin modified by metal and ceramic nanoparticles. Dent Med Probl 2023; 60:657-664. [PMID: 37966919 DOI: 10.17219/dmp/171844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 09/04/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND Nanoparticles (NPs) have gained significant attention in various fields due to their unique properties and potential applications. Polymethyl methacrylate (PMMA) is an acrylic resin widely used in dentistry and medicine. However, the effect of different types of NP fillers on the physical properties of PMMA-based resins has not been thoroughly explored in the literature. OBJECTIVES The present study aimed to evaluate the effects of 3 different types of NP fillers on the physical properties of an experimental PMMA-based resin as a function of the NP content and concentration. MATERIAL AND METHODS Ten groups (n = 10) were designed. The specimens were composed of an acrylic resin, silicon dioxide (SiO2), cerium dioxide (CeO2), and titanium dioxide (TiO2) at the following ratios (wt%): group 1 (G1) - control; group 2 (G2) - 0.5% SiO2; group 3 (G3) - 1% SiO2; group 4 (G4) - 3% SiO2; group 5 (G5) - 0.5% CeO2; group 6 (G6) - 1% CeO2; group 7 (G7) - 3% CeO2; group 8 (G8) - 0.5% TiO2; group 9 (G9) - 1% TiO2; and group 10 (G10) - 3% TiO2. Transmission electron microscopy (TEM) was used to assess the quality of NP dispersion. Thermal stability was assessed with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effects of the abovementioned NPs on the properties of the resin were evaluated using the Archimedes principle for density, the Vickers hardness (VH) test and the impact strength (IS) test. Data analysis employed the oneand two-way analysis of variance (ANOVA), followed by Duncan's post hoc test at a significance level of 0.05. RESULTS Transmission electron microscopy showed partial NP dispersion. All types of NPs enhanced the mechanical properties of the acrylic resin except for IS, which was similar to that of the control group. Among the types of NPs, irrespective of the weight percentage, CeO2 showed higher thermal stability and higher IS for 0.5 wt% and 1 wt% as compared to other groups, as well as the highest values of density at 0.5 wt%, 1 wt% and 3 wt%. Titanium oxide at 1 wt% presented a higher VH as compared to other groups. The fracture pattern was the same for all groups. CONCLUSIONS Incorporating the tested NPs into the acrylic resin resulted in enhanced physical properties, primarily attributed to a lower NP content.
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Affiliation(s)
| | - Kusai Baroudi
- Department of Restorative Dentistry, School of Dentistry, University of Taubaté, Brazil
- RAK College of Dental Sciences, RAK Medical and Health Sciences University, Ras Al Khaimah, UAE
| | - Nikolaos Silikas
- Department of Dentistry, School of Medical Sciences, University of Manchester, UK
| | - João Paulo Mendes Tribst
- Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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Alamoush RA, Salim NA, Elraggal A, Satterthwaite JD, Silikas N. The effect of water storage on nanoindentation creep of various CAD-CAM composite blocks. BMC Oral Health 2023; 23:543. [PMID: 37550631 PMCID: PMC10408048 DOI: 10.1186/s12903-023-03145-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 06/17/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND To study the effect of water storage (3 months) on the creep deformation of various CAD-CAM composite structures at the nanoscale and compare it to that at the macroscale. METHODS Seven CAD-CAM blocks were investigated: five resin-composite blocks (RCB), one polymer-infiltrated ceramic network (PICN) block, and one ceramic-filled polyetheretherketone (PEEK) block. Specimens of each material (n = 6) were separated into two groups (n = 3) according to their storage conditions (24 h dry storage at 23˚C and 3 months storage in 37˚C distilled water). Nano-indentation creep measurements were undertaken (creep depth measured in µm) using a nanoindenter (Nanovea) equipped with Berkovich three-sided pyramidal diamond tip. The machine was set for the chosen parameters: a load of 20 gf, a pause of 20 s, and the material type. Thirty indentations on 3 samples were made for each material for each test. Data were analysed using two-way ANOVA followed by one-way ANOVA and Bonferroni post hoc tests and independent t-test (< 0.05) for comparisons between the materials. RESULTS The nanoindentation creep depth after 24 h storage ranged from 0.09 to 0.33 μm and increased after 3 months storage in distilled water to between 0.28 and 3.46 μm. There was a statistically significant difference in nanoindentation creep behaviour between the two storage conditions for each investigated material (independent t-test) and between all materials (Bonferroni post hoc). There was a non-significant negative correlation between nanoindentation creep (µm) and filler weight% at 24 h dry storage but a significant correlation at 3 months of water storage. A further non-significant positive correlation between nanoindentation creep (µm) and bulk compressive creep (%) was found. CONCLUSION The PICN material showed superior dimensional stability in terms of nanoindentation creep depth in both storage conditions. Other composite blocks showed comparable performance at 24 h dry condition, but an increased nanoindentation creep upon water storage.
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Affiliation(s)
- Rasha A Alamoush
- Department of Fixed and Removable Prosthodontics, School of Dentistry, the University of Jordan, Amman, 11942, Jordan
| | - Nesreen A Salim
- Department of Fixed and Removable Prosthodontics, School of Dentistry, the University of Jordan, Amman, 11942, Jordan
| | - Alaaeldin Elraggal
- Operative Dentistry, Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt.
| | - Julian D Satterthwaite
- Division Dentistry, School of Medical Sciences, the University of Manchester, Manchester, UK
| | - Nikolaos Silikas
- Division Dentistry, School of Medical Sciences, the University of Manchester, Manchester, UK
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Liu S, Silikas N, Ei-Angbawi A. Analysis of the effectiveness of the fiber-reinforced composite lingual retainer: A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop 2022; 162:601-615.e2. [PMID: 36031511 DOI: 10.1016/j.ajodo.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Orthodontic fixed retainers are preferred as they depend less on patient compliance. Recently, researchers tried to use fiber-reinforced composite (FRC) to replace the multistranded stainless-steel wire (MSW) of the fixed retainers to enhance the mechanical properties and esthetics. This systematic review aimed to analyze the effectiveness of the FRC retainers. METHODS We searched the electronic databases (May 1, 2021), including Medline, the Cochrane Library, EMBASE, PubMed, Web of Science, and CINAHL. We applied no language or date restrictions in the searches of the databases. Only randomized controlled trials (RCTs) and prospective clinical controlled trials were included. The revised Cochrane risk of bias tool for randomized trials and risk of bias in nonrandomized studies of interventions were used to evaluate the risk of bias in RCTs and non-RCTs, respectively. The outcomes were pooled using Review Manager 5.4. The primary outcome of this review was teeth relapse, and the secondary outcomes were bonded retainer failure rate, adverse effect on oral health, and patient's satisfaction. RESULTS Eleven out of 99 studies, which included 873 participants, were used in this review, with the follow-up ranging from 6 months to 6 years. Ten studies compared the FRC retainers with MSW retainers, and 1 study compared FRC retainers with a different fiber material. Ten studies were RCT, and 1 was non-RCT. There was 0.39 less relapse with the FRC retainers than with MSW retainers (mean difference, -0.39; 95% confidence interval [CI], -0.41 to -0.37; P <0.00001). There was no statistically significant difference in the failure rate between the FRC and MSW with the whole retainer as an outcome unit risk ratio of 1.72 (95% CI, 0.57-5.14; P = 0.33) or with the teeth an as outcome unit risk ratio of 0.85 (95% CI, 0.47-1.52; P = 0.58). There was insufficient evidence to conduct the meta-analysis of the adverse effect on oral health and patient satisfaction. CONCLUSIONS Low-quality evidence is available to suggest that the effectiveness of the FRC is comparable to the MSW with no significant difference in the failure rate. However, we have very low certainty on these results. It is worth conducting future robust clinical studies to assess the effectiveness of FRC retainers with long follow-up.
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Affiliation(s)
- Shiyao Liu
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Ahmed Ei-Angbawi
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, United Kingdom.
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Agarwalla SV, Ellepola K, Sorokin V, Ihsan M, Silikas N, Neto AHC, Seneviratne CJ, Rosa V. Antimicrobial-free graphene nanocoating decreases fungal yeast-to-hyphal switching and maturation of cross-kingdom biofilms containing clinical and antibiotic-resistant bacteria. Biomater Biosyst 2022; 8:100069. [PMID: 36824379 PMCID: PMC9934433 DOI: 10.1016/j.bbiosy.2022.100069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 10/23/2022] [Accepted: 10/23/2022] [Indexed: 12/05/2022] Open
Abstract
Candida albicans and methicillin-resistant Staphylococcus aureus (MRSA) synergize in cross-kingdom biofilms to increase the risk of mortality and morbidity due to high resistance to immune and antimicrobial defenses. Biomedical devices and implants made with titanium are vulnerable to infections that may demand their surgical removal from the infected sites. Graphene nanocoating (GN) has promising anti-adhesive properties against C. albicans. Thus, we hypothesized that GN could prevent fungal yeast-to-hyphal switching and the development of cross-kingdom biofilms. Herein, titanium (Control) was coated with high-quality GN (coverage > 99%). Thereafter, mixed-species biofilms (C. albicans combined with S. aureus or MRSA) were allowed to develop on GN and Control. There were significant reductions in the number of viable cells, metabolic activity, and biofilm biomass on GN compared with the Control (CFU counting, XTT reduction, and crystal violet assays). Also, biofilms on GN were sparse and fragmented, whereas the Control presented several bacterial cells co-aggregating with intertwined hyphal elements (confocal and scanning electronic microscopy). Finally, GN did not induce hemolysis, an essential characteristic for blood-contacting biomaterials and devices. Thus, GN significantly inhibited the formation and maturation of deadly cross-kingdom biofilms, which can be advantageous to avoid infection and surgical removal of infected devices.
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Affiliation(s)
| | - Kassapa Ellepola
- Department of Oral Biology, College of Dentistry, University of Illinois Chicago, USA
| | - Vitaly Sorokin
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore,Department of Cardiac, Thoracic and Vascular Surgery, National University Hospital, National University Health System, Singapore
| | - Mario Ihsan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nikolaos Silikas
- Dentistry, The University of Manchester, Manchester, United Kingdom
| | - AH Castro Neto
- Centre for Advanced 2D Materials, National University of Singapore, Singapore
| | - Chaminda Jayampath Seneviratne
- School of Dentistry, The University of Queensland, Australia,Co-corresponding author at: School of Dentistry, The University of Queensland, 288 Herston Road, Cnr Bramston Terrace & Herston Road Herston QLD 4006, Australia.
| | - Vinicius Rosa
- Faculty of Dentistry, National University of Singapore, Singapore,Centre for Advanced 2D Materials, National University of Singapore, Singapore,ORCHIDS: Oral Care Health Innovations and Designs Singapore, National University of Singapore, Singapore,Corresponding author at: Faculty of Dentistry, National University of Singapore, 9 Lower Kent Ridge Road, 119085, Singapore.
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Elraggal A, Chen X, Silikas N. Effect of Sandblasting with Fluorapatite Glass-ceramic Powder and Chemical Primers/Adhesives on Shear Bond Strength of Indirect Repairing Composite to Zirconia. Oper Dent 2022; 47:574-584. [PMID: 36121727 DOI: 10.2341/21-108-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To investigate the effect of sandblasting with fluorapatite glass-ceramic (FGC) powder on zirconia surface roughness, crystallinity, and shear bond strength (SBS) of indirect repairing composite to zirconia using different primers/adhesives. METHODS Zirconia blocks were treated as follows: no treatment (control group), blasting with 30-μm silica-coated alumina (CoJet group), and blasting with FGC powder (FGC group). The surface topography, silica content, roughness, and crystallinity of treated zirconia surfaces were analyzed by a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), an optical profilometer, and X-ray diffraction (XRD), respectively. Four primers/adhesives (Monobond Plus, Calibra Silane, Futurabond M+, and Scotchbond Universal) were compared to bond precured resin composite to zirconia groups using Multilink Automix resin cement. Bonded specimens were thermocycled for 10,000 cycles and tested in SBS and the modes of failure were recorded. The effect of different surface treatments and primers/adhesives on SBS results were statistically analyzed using two-way ANOVA and Bonferroni post-hoc tests (α=0.05). RESULTS Both CoJet and FGC groups showed rough surfaces with a higher content of silica in FGC, but less monoclinic crystals, compared to the CoJet group. The highest mean SBS was found in the FGC group treated with Monobond Plus compared to CoJet and Control groups. Adhesive failure was predominant in control groups, while combined failure was found in the CoJet and FGC groups regardless of the primers/adhesives employed. CONCLUSION Sandblasting zirconia with FGC powder increased SBS of resin composite to zirconia with lower monoclinic phase transformation compared to CoJet sand. Monobond Plus reported the highest means of SBS values compared to other primers/adhesives.
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Affiliation(s)
- A Elraggal
- *Alaaeldin Elraggal, BSc, MSc, Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK; Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - X Chen
- Xiaohui Chen, BSc, MSc, PhD, Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
| | - N Silikas
- Nikolaos Silikas, BSc, MPhil, PhD, Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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Rodrigues NS, de Souza LC, Cunha DA, Souza NO, Silva P, Santiago SL, Loguercio AD, Silikas N, Saboia V. Postoperative Sensitivity of Composite Replacement of Amalgam Restoration: A Randomized Clinical Trial. Oper Dent 2022; 47:481-491. [PMID: 36098547 DOI: 10.2341/19-295-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2022] [Indexed: 11/23/2022]
Abstract
PURPOSE This randomized clinical trial aimed to evaluate the postoperative sensitivity of different resin composite/adhesive materials, placed either by an incremental or bulk-fill technique in posterior resin composite replacement of amalgam restorations. METHODS AND MATERIALS A total of 47 patients with good overall health and at least four class I or class II amalgam restorations to be replaced participated in this study. The characteristics of 188 cavities were registered and randomly restored using incremental (Z350XT, 3M) or bulk-fill (Filtek Bulk Fill, 3M; Sonic Fill, Kerr; and Opus Bulk Fill, FGM) technique. The postoperative sensitivity was assessed using a Visual Analog Scale (0-100) after 24 hours, 7 days, and 30 days. Pain scores were temporally analyzed using Friedman test followed by Dunn post hoc test (α=0.05). The frequency of tests was calculated according to the frequency and percentage of the McNemar test. RESULTS The restorative technique and the bulk-fill system used did not affect the postoperative sensitivity, except for Filtek Bulk Fill group, which presented less postoperative sensitivity after 24 hours (p=0.037). Regardless of the restorative material, the postoperative sensitivity decreased after 24 hours, and no differences were found after 7 and 30 days. CONCLUSIONS After 1 week, the filling technique and the bulk-fill system have no influence on the postoperative sensitivity.
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Affiliation(s)
- N S Rodrigues
- Nara Sousa Rodrigues, DDS, MS, PhD student, Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - L C de Souza
- Lidiane Costa de Souza, DDS, MS, PhD, Faculty of Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - D A Cunha
- Diana Araujo Cunha, DDS, MS, PhD student, Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - N O Souza
- Nayara de Oliveira Souza, DDS, MS student, Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - Pgb Silva
- Paulo Goberlanio Barros Silva, DDS, MS, PhD, professor, Graduate Program in Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil; and Department of Dentistry, Unichristus, Fortaleza, Ceará, Brazil
| | - S L Santiago
- Sérgio Lima Santiago, DDS, MS, PhD, professor, Department of Restorative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | - A D Loguercio
- Alessandro Dourado Loguercio, DDS, MS, PhD, professor, Department of Restorative Dentistry, State University of Ponta Grossa, Rua Carlos Cavalcanti
| | - N Silikas
- Nikolaos Silikas, DDS, MS, PhD, professor, Oral Biomaterials Sciences, School of Dentistry, University of Manchester, Manchester, UK
| | - Vpa Saboia
- *Vicente de Paulo Aragão Saboia, DDS, MS, PhD, professor, Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil
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12
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Velo MMDAC, Filho FGN, de Lima Nascimento TR, Obeid AT, Castellano LC, Costa RM, Brondino NCM, Fonseca MG, Silikas N, Mondelli RFL. Enhancing the mechanical properties and providing bioactive potential for graphene oxide/montmorillonite hybrid dental resin composites. Sci Rep 2022; 12:10259. [PMID: 35715426 PMCID: PMC9205868 DOI: 10.1038/s41598-022-13766-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/27/2022] [Indexed: 11/30/2022] Open
Abstract
This in vitro study synthetized hybrid composite nanoparticles of graphene oxide (GO) and montmorillonite MMt (GO-MMt) by ultrasound treatments. Samples were characterized by X-ray diffraction, FT-Raman, FTIR, TEM and SEM. The effect of their incorporation (0.3% and 0.5%) on the mechanical properties in a resin-based composite (RBC) and their bioactivity potential were evaluated. The specimens were characterized by evaluating their 3-point flexural strength (n = 6), modulus of elasticity (n = 6), degree of conversion (n = 6), microhardness (n = 6), contact angle (n = 3) and SEM analysis (n = 3). In vitro test in SBF were conducted in the RBCs modified by the hybrid. Overall, the synthetized hybrid composite demonstrated that GO was intercalated with MMt, showing a more stable compound. ANOVA and Tukey test showed that RBC + 0.3% GO-MMt demonstrated superior values of flexural strength, followed by RBC + 0.5% GO-MMt (p < 0.05) and both materials showed higher values of microhardness. All groups presented a contact angle below 90°, characterizing hydrophilic materials. RBCs modified by the hybrid showed Ca and P deposition after 14 days in SBF. In conclusion, RBCs composed by the hybrid showed promising results in terms of mechanical properties and bioactive potential, extending the application of GO in dental materials.
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Affiliation(s)
- Marilia Mattar de Amôedo Campos Velo
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Al. Dr Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil.
| | - Francisco Gilmário Nunes Filho
- Department of Chemistry, Research and Extension Center for Fuels and Materials Laboratory (NPELACOM), Federal University of Paraiba, João Pessoa, Paraíba, Brazil
| | - Tatiana Rita de Lima Nascimento
- Department of Chemistry, Research and Extension Center for Fuels and Materials Laboratory (NPELACOM), Federal University of Paraiba, João Pessoa, Paraíba, Brazil
| | - Alyssa Teixeira Obeid
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Al. Dr Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
| | - Lúcio Cançado Castellano
- Human Immunology Research and Education Group (GEPIH), UFPB Technical School of Health, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Reginaldo Mendonça Costa
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Al. Dr Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
| | | | - Maria Gardennia Fonseca
- Department of Chemistry, Research and Extension Center for Fuels and Materials Laboratory (NPELACOM), Federal University of Paraiba, João Pessoa, Paraíba, Brazil
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Rafael Francisco Lia Mondelli
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Al. Dr Octávio Pinheiro Brisolla, 9-75, Bauru, São Paulo, 17012-901, Brazil
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Alhotan A, Elraggal A, Yates J, Haider J, Jurado CA, Silikas N. Effect of Different Solutions on the Colour Stability of Nanoparticles or Fibre Reinforced PMMA. Polymers (Basel) 2022; 14:polym14081521. [PMID: 35458269 PMCID: PMC9028232 DOI: 10.3390/polym14081521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/01/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
This study aimed to evaluate the colour stability of polymethyl methacrylate (PMMA) denture base reinforced with ZrO2 nanoparticles, E-glass fibres, and TiO2 nanoparticles at various concentrations over 180-day storage in Steradent™ (STD) denture cleaner or coffee (CF). A total of 130 disc-shaped specimens were fabricated at various filler concentrations and divided into four main groups to measure the colour changes. Groups Z, T, and E consisted of PMMA reinforced with ZrO2 nanoparticles, TiO2 nanoparticles, or E-glass fibre, respectively, while Group C consisted of PMMA specimens without filler served as the control group (n = 10). The three reinforced groups were further subdivided according to the filler content (n = 10) added to the PMMA (1.5%, 3.0%, 5.0%, and 7.0% wt.%). Half of the specimens were stored in STD, while the other half was stored in CF for 180 days. A Minolta Chroma Meter was used to measure the colour changes (ΔE) at 7, 30, 90 and then 180 days. The results were assessed using two-way repeated-measures analysis of variance (RM-ANOVA) along with Bonferroni post hoc tests at a p ≤ 0.05 significance level. Significant different colour changes (ΔΕ) were observed between all tested groups and across different time points. TiO2-reinforced PMMA in coffee showed the lowest colour stability, while the E-glass fibre-reinforced PMMA in STD/CF showed the highest colour stability. Furthermore, coffee appeared to have the greatest impact on the CF change in comparison to the STD/CF. The results indicated that the filler type and concentration, type of solution, and length of storage all affected the colour stability of the tested specimens.
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Affiliation(s)
- Abdulaziz Alhotan
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 11454, Saudi Arabia
- Correspondence:
| | - Alaaeldin Elraggal
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria 21568, Egypt;
| | - Julian Yates
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Carlos Alberto Jurado
- Woody L. Hunt School of Dental Medicine, Texas Tech University Health Sciences Centre El Paso, 5001 El Paso Drive, El Paso, TX 79905, USA;
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
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Aldhafyan M, Silikas N, Watts DC. Influence of curing modes on monomer elution, sorption and solubility of dual-cure resin-cements. Dent Mater 2022; 38:978-988. [PMID: 35339295 DOI: 10.1016/j.dental.2022.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To explore the effect of two curing modes, for dual-cure resin cements, on their monomer elution, water sorption and solubility after 30 d water storage and 30 d dry reconditioning. METHODS Eight dual-cure resin-cements were investigated (Bifix SE, Nexus Third Generation, PANAVIA SA, PANAVIA V5, RelyX Ultimate Universal, RelyX Unicem 2, RelyX Universal and SpeedCEM Plus). Six disk-shaped specimens were made per curing mode: light-cure (LC) versus self-cure (SC) to measure amounts of eluted monomers after 30 d of water storage at 37 °C. Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC MS/MS) was performed to identify and quantify three eluted monomers (Bis-GMA, UDMA and TEGDMA). Water sorption/ solubility specimens were prepared according to ISO 4049. Specimens from each curing mode (LC/SC) were immersed separately in distilled water for 30 d and then reconditioned for 30 d; all at 37 °C. Mass change was measured at different time intervals. Data were analyzed via one-way ANOVA, Tukey post-hoc tests and independent sample t-tests (α = 0.05). RESULTS After 30 d of water storage, the three monomers Bis-GMA, UDMA and TEGDMA were detected in water. All monomers showed a variable extent of elution into water and were significantly higher (p < 0.0001) with SC compared to LC curing modes. BSE had the highest quantity of eluted monomers. After 30 d of water sorption (μg/mm3), all rein-cements showed significantly higher sorption (p < 0.05) of SC compared to LC curing modes except for PV5, RXU and CEM (p > 0.05). After 30 d of water solubility (μg/mm3), all resin-cements showed significantly higher solubility (p < 0.0001) of SC compared to LC curing mode. BSE had the highest water sorption and solubility. The total amounts of eluted monomers correlated positively with solubility: r2 = 0.95 for LC and r2 = 0.93 for SC. SIGNIFICANCE Whenever light access is possible, light curing remains beneficial to reduce the extent of resin degradation and related properties of dual-cure resin cements. BSE showed statistically the highest extent of eluted monomers, sorption and solubility.
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Affiliation(s)
- Mohammed Aldhafyan
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia
| | - Nikolaos Silikas
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK.
| | - David C Watts
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK.
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15
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Alhotan A, Yates J, Zidan S, Haider J, Jurado CA, Silikas N. Behaviour of PMMA Resin Composites Incorporated with Nanoparticles or Fibre following Prolonged Water Storage. Nanomaterials (Basel) 2021; 11:nano11123453. [PMID: 34947803 PMCID: PMC8707186 DOI: 10.3390/nano11123453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/15/2021] [Indexed: 11/25/2022]
Abstract
When PMMA denture base acrylics are exposed to oral environments for prolonged periods, the denture base absorbs water, which has a negative influence on the denture material and the degree to which the denture base will be clinically effective. This study assessed the water sorption, desorption, and hygroscopic expansion processes within PMMA denture-base resins reinforced with nanoparticles or fibre in comparison to the non-reinforced PMMA. The surfaces of the fillers were modified using a silane coupling agent (y-MPS) before mixing with PMMA. Group C consisted of specimens of pure PMMA whereas groups Z, T, and E consisted of PMMA specimens reinforced with ZrO2, TiO2 nanoparticles, or E-glass fibre, respectively. The reinforced groups were subdivided into four subgroups according to the percentage filler added to the PMMA resin by weight (1.5%, 3.0%, 5.0%, or 7.0%). Five specimens in disc shape (25 ± 1 mm × 2.0 ± 0.2 mm) were tested for each group. To assess water sorption and hygroscopic expansion, specimens from each group were individually immersed in water at 37 ± 1 °C for 180 days. The samples were then desorbed for 28 days at 37 ± 1 °C, to measure solubility. Water sorption and solubility were calculated using an electronic balance in accordance with ISO Standard 20795-1, and hygroscopic expansion was measured using a laser micrometre. Statistical analysis was undertaken at a p ≤ 0.05 significance level using a one-way ANOVA followed by Tukey post-hoc tests. The results demonstrated that the values of sorption (Wsp), mass sorption (Ms%), and % expansion within the tested groups reached equilibrium within 180 days. A noticeable difference was observed in groups Z and E for (Wsp)/(Ms%) compared to the Group C, but this was not significant. However, the difference between Group C and Group T for these measurements was significant. Non-significant differences also existed between each respective reinforced group and the control group in terms of hygroscopic expansion % values. During the 28-day desorption period, there were no differences in the values of solubility (Wsl)/mass desorption (Md%) between Group C and each of the reinforced tested groups. The findings indicate that the inclusion of ZrO2 nanoparticles or E-glass fibres does not increase the water solubility/sorption of the PMMA. However, modifying the PMMA with TiO2 did significantly increase the water sorption level.
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Affiliation(s)
- Abdulaziz Alhotan
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 11454, Saudi Arabia
- Correspondence:
| | - Julian Yates
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
| | - Saleh Zidan
- Department of Dental Materials, Faculty of Dentistry, Sebha University, Sebha 18758, Libya;
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Carlos Alberto Jurado
- Woody L. Hunt School of Dental Medicine, Texas Tech University Health Sciences Centre El Paso, 5001 El Paso Drive, El Paso, TX 79905, USA;
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
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16
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Aldhafyan M, Silikas N, Watts DC. Influence of curing modes on conversion and shrinkage of dual-cure resin-cements. Dent Mater 2021; 38:194-203. [PMID: 34924201 DOI: 10.1016/j.dental.2021.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To explore the effect of curing modes of dual-cure resin cements on their degree of conversion (DC) and polymerization shrinkage (PS) over specific post-activation periods. METHODS Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE, and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation, and RelyX Ultimate Universal) dual-cure resin cements were studied. Four specimens (n = 4) were made per curing mode (light/self-cure) to measure either DC or PS. FTIR was utilized to measure real-time DC (%) over 24 h. The Bonded Disk method was used to measure shrinkage at 23 °C over 1 h. The data were analyzed using one-way ANOVA, Tukey post-hoc tests and independent/ paired sample t-tests (a = 0.05). RESULTS After 1 h post-activation, the DC of light-cured (LC) specimens ranged between 66.6% and 77.4%, whereas for self-cured (SC) specimens DC ranged between 44.4% and 73.2%. After 24 h, the DC of LC specimens ranged between 74.8% and 82.4% and between 62.7% and 81.7% for SC specimens. After 24 h, the DC of three cements (BSE, PV5, and RXU) were comparable between their curing modes (p > 0.05), whereas five cements (CEM, NX3, PSA, RXU2, RXL) had significantly lower DC for SC compared to LC specimens (p < 0.05). After 1 h post-activation, shrinkage ranged between 5.9% and 8.5% for LC and between 4.9% and 8.3% for SC specimens. Most cements were not significantly different between curing modes. However, light-cured PAS, RXL and RXU2 had significantly higher shrinkage (p < 0.05). After 1 h post-activation, a strong positive correlation existed between conversion and shrinkage (LC: r2 = 0.95 and SC: r2 = 0.93). SIGNIFICANCE Whenever light access is possible, light-curing of resin-cements remains beneficial to the overall efficacy of their conversion and thus all factors that depend on that. Conversion and shrinkage behavior are intrinsically important factors in clinical selection of resin-cement products.
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Affiliation(s)
- Mohammed Aldhafyan
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia
| | - Nikolaos Silikas
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK.
| | - David C Watts
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK.
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Aldhafyan M, Silikas N, Watts DC. Influence of curing modes on thermal stability, hardness development and network integrity of dual-cure resin cements. Dent Mater 2021; 37:1854-1864. [PMID: 34593244 DOI: 10.1016/j.dental.2021.09.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/20/2021] [Accepted: 09/20/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To explore the effect of different curing modes of conventional and self-adhesive dual-cure resin cements on their rates of thermal decomposition, hardness development and network integrity. METHODS Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation and RelyX Ultimate Universal) dual-cure resin cements were investigated. Thermal decomposition stages, initial onset temperatures, the maximum rate of mass-loss and the filler mass-fraction of each resin cement were analysed by thermogravimetric analysis (TGA). Surface hardness was measured at 1h post-cure and after 24h of dry storage at 37°C. The relative network integrities were estimated from reductions in hardness after 168h of water storage. Data were analysed via one-way ANOVA, Tukey post-hoc tests and paired/independent sample t-tests (a=0.05). RESULTS No difference was apparent between TGA data for self-cured and light-cured specimens. Numerical differentiation of mass-loss versus temperature showed either single or multiple peaks. For the set of 8 cements, the maximum rate of mass-loss (%/°C) correlated negatively with residual mass at 600°C. All dry-stored cements increased in hardness from 1 to 24h, ranging from 20.4% to 52.6% for light-cure mode and from 41.3% to 112.6% for self-cure. After 168h water storage, the hardness of cements decreased: by 18.5%-36.2% for light-cured and by 9.8%-17.9% for self-cured. Overall, surface hardness was greater for light-cured cements. The initial onset temperature (IOT) of thermal decomposition correlated negatively with the hardness decrease produced by water-storage: r2=0.77 for light-cure and r2=0.88 for self-cure. This provided the basis for a relative scale of composite network integrity, probably reflecting differences in cross-link density. SIGNIFICANCE Light-curing, where possible, remains beneficial to the hardness and related properties of dual-cure resin cements. Combination of TG analysis and solvent softening experiments give an indication of relative network integrity - between materials - and their relative cross-link densities.
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Affiliation(s)
- Mohammed Aldhafyan
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia
| | - Nikolaos Silikas
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK.
| | - David C Watts
- Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK.
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18
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Rosa V, Malhotra R, Agarwalla SV, Morin JLP, Luong-Van EK, Han YM, Chew RJJ, Seneviratne CJ, Silikas N, Tan KS, Nijhuis CA, Castro Neto AH. Graphene Nanocoating: High Quality and Stability upon Several Stressors. J Dent Res 2021; 100:1169-1177. [PMID: 34253090 DOI: 10.1177/00220345211024526] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Titanium implants present 2 major drawbacks-namely, the long time needed for osseointegration and the lack of inherent antimicrobial properties. Surface modifications and coatings to improve biomaterials can lose their integrity and biological potential when exposed to stressful microenvironments. Graphene nanocoating (GN) can be deposited onto actual-size dental and orthopedic implants. It has antiadhesive properties and can enhance bone formation in vivo. However, its ability to maintain structural integrity and quality when challenged by biologically relevant stresses remains largely unknown. GN was produced by chemical vapor deposition and transferred to titanium via a polymer-assisted transfer technique. GN has high inertness and did not increase expression of inflammatory markers by macrophages, even in the presence of lipopolysaccharides. It kept high coverage at the top tercile of tapered dental implant collars after installation and removal from bone substitute and pig maxilla. It also resisted microbiologically influenced corrosion, and it maintained very high coverage area and quality after prolonged exposure to biofilms and their removal by different techniques. Our findings show that GN is unresponsive to harsh and inflammatory environments and that it maintains a promising level of structural integrity on the top tercile of dental implant collars, which is the area highly affected by biofilms during the onset of implant diseases. Our findings open the avenues for the clinical studies required for the use of GN in the development of implants that have higher osteogenic potential and are less prone to implant diseases.
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Affiliation(s)
- V Rosa
- Faculty of Dentistry, National University of Singapore, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore
| | - R Malhotra
- Faculty of Dentistry, National University of Singapore, Singapore
| | - S V Agarwalla
- Faculty of Dentistry, National University of Singapore, Singapore
| | - J L P Morin
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore
| | - E K Luong-Van
- Faculty of Dentistry, National University of Singapore, Singapore
| | - Y M Han
- Department of Chemistry, National University of Singapore, Singapore
| | - R J J Chew
- Faculty of Dentistry, National University of Singapore, Singapore
| | | | - N Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - K S Tan
- Faculty of Dentistry, National University of Singapore, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore
| | - C A Nijhuis
- Department of Molecules and Materials, Faculty of Science and Technology, University of Twente, Enschede, Netherlands
| | - A H Castro Neto
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore
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Malhotra R, Han Y, Nijhuis CA, Silikas N, Castro Neto AH, Rosa V. Graphene nanocoating provides superb long-lasting corrosion protection to titanium alloy. Dent Mater 2021; 37:1553-1560. [PMID: 34420797 DOI: 10.1016/j.dental.2021.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 07/17/2021] [Accepted: 08/04/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The presence of metallic species around failed implants raises concerns about the stability of titanium alloy (Ti-6Al-4V). Graphene nanocoating on titanium alloy (GN) has promising anti-corrosion properties, but its long-term protective potential and structural stability remains unknown. The objective was to determine GN's anti-corrosion potential and stability over time. METHODS GN and uncoated titanium alloy (Control) were challenged with a highly acidic fluorinated corrosive medium (pH 2.0) for up to 240 days. The samples were periodically tested using potentiodynamic polarization curves, electrochemical impedance spectroscopy and inductively coupled plasma-atomic emission spectroscopy (elemental release). The integrity of samples was determined using Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and scanning electron microscopy. Statistical analyses were performed with one-sample t-test, paired t-test and one-way ANOVA with Tukey post-hoc test with a pre-set significance level of 5%. RESULTS There was negligible corrosion and elemental loss on GN. After 240 days of corrosion challenge, the corrosion rate and roughness increased by two and twelve times for the Control whereas remained unchanged for GN. The nanocoating presented remarkably high structural integrity and coverage area (>98%) at all time points tested. SIGNIFICANCE Graphene nanocoating protects titanium alloy from corrosion and dissolution over a long period while maintaining high structural integrity. This coating has promising potential for persistent protection of titanium and potentially other metallic alloys against corrosion.
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Affiliation(s)
- Ritika Malhotra
- Faculty of Dentistry, National University of Singapore, Singapore.
| | - Yingmei Han
- Department of Chemistry, National University of Singapore, Singapore.
| | - Christian A Nijhuis
- Department of Molecules and Materials, Faculty of Science and Technology, University of Twente, Netherlands.
| | - Nikolaos Silikas
- Dental Biomaterials, Dentistry, The University of Manchester, Manchester, United Kingdom.
| | - A H Castro Neto
- Centre for Advanced 2D Materials, National University of Singapore, Singapore.
| | - Vinicius Rosa
- Faculty of Dentistry, National University of Singapore, Singapore; Centre for Advanced 2D Materials, National University of Singapore, Singapore.
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Alhotan A, Yates J, Zidan S, Haider J, Silikas N. Assessing Fracture Toughness and Impact Strength of PMMA Reinforced with Nano-Particles and Fibre as Advanced Denture Base Materials. Materials (Basel) 2021; 14:ma14154127. [PMID: 34361320 PMCID: PMC8348661 DOI: 10.3390/ma14154127] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
Statement of Problem: Polymethyl methacrylate (PMMA) denture resins commonly fracture as a result of the denture being dropped or when in use due to heavy occlusal forces. Purpose: To investigate the effects of E-glass fibre, ZrO2 and TiO2 nanoparticles at different concentrations on the fracture toughness and impact strength of PMMA denture base. Materials and Methods: To evaluate fracture toughness (dimensions: 40 × 8 × 4 mm3; n = 10/group) and impact strength (dimensions: 80 × 10 × 4 mm3; n = 12/group), 286 rectangular tested specimens were prepared and divided into four groups. Group C consisted of the PMMA specimens without any filler (control group), while the specimens in the remaining three groups varied according to the concentration of three filler materials by weight of PMMA resin: 1.5%, 3%, 5%, and 7%. Three-point bending and Charpy impact tests were conducted to measure the fracture toughness and impact strength respectively. Scanning Electron Microscope (SEM) was utilised to examine the fractured surfaces of the specimens after the fracture toughness test. One-way analysis of variance (ANOVA) followed by Tukey post-hoc tests were employed to analyse the results at a p ≤ 0.05 significance level. Results: Fracture toughness of groups with 1.5 and 3 wt.% ZrO2, 1.5 wt.% TiO2, and all E-glass fibre concentrations were significantly higher (p < 0.05) than the control group. The samples reinforced with 3 wt.% ZrO2 exhibited the highest fracture toughness. Those reinforced with a 3 wt.%, 5 wt.%, and 7 wt.% of E-glass fibres had a significantly (p < 0.05) higher impact strength than the specimens in the control group. The heat-cured PMMA modified with either ZrO2 or TiO2 nanoparticles did not exhibit a statistically significant difference in impact strength (p > 0.05) in comparison to the control group. Conclusions: 1.5 wt.%, 3 wt.% of ZrO2; 1.5 wt.% ratios of TiO2; and 1.5 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% of E-glass fibre can effectively enhance the fracture toughness of PMMA. The inclusion of E-glass fibres does significantly improve impact strength, while ZrO2 or TiO2 nanoparticles did not.
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Affiliation(s)
- Abdulaziz Alhotan
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh 11454, Saudi Arabia
- Correspondence:
| | - Julian Yates
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
| | - Saleh Zidan
- Department of Dental Materials, Faculty of Dentistry, Sebha University, Sebha 18758, Libya;
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (J.Y.); (J.H.); (N.S.)
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Zidan S, Silikas N, Al-Nasrawi S, Haider J, Alshabib A, Alshame A, Yates J. Chemical Characterisation of Silanised Zirconia Nanoparticles and Their Effects on the Properties of PMMA-Zirconia Nanocomposites. Materials (Basel) 2021; 14:ma14123212. [PMID: 34200948 PMCID: PMC8230683 DOI: 10.3390/ma14123212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/21/2022]
Abstract
Objectives: The objective of this study was to investigate the mechanical properties of high-impact (HI) heat-cured acrylic resin (PMMA) reinforced with silane-treated zirconia nanoparticles. Methods: Forty-five PMMA specimens reinforced with zirconia were fabricated and divided into three groups: Pure HI PMMA (control group), PMMA reinforced with 3 wt.% of non-silanised zirconia nanoparticles and PMMA reinforced with 3 wt.% of silanised zirconia nanoparticles. Silanised and non-silanised zirconia nanoparticles were analysed with Fourier Transform Infrared (FTIR) Spectroscopy. For measuring the flexural modulus and strength, a Zwick universal tester was used, and for surface hardness, a Vickers hardness tester were used. Furthermore, raw materials and fractured surfaces were analysed using Scanning Electron Microscopy (SEM). A one-way ANOVA test followed by a post-hoc Bonferroni test was employed to analyse the data. Results: The results showed that the mean values for flexural strength (83.5 ± 6.2 MPa) and surface hardness (20.1 ± 2.3 kg/mm2) of the group containing 3 wt.% treated zirconia increased significantly (p < 0.05) in comparison to the specimens in the group containing non-treated zirconia (59.9 ± 7.1 MPa; 15.0 ± 0.2 kg/mm2) and the control group (72.4 ± 8.6 MPa; 17.1 ± 0.9 kg/mm2). However, the group with silanised zirconia showed an increase in flexural modulus (2313 ± 161 MPa) but was not significantly different (p > 0.05) from the non-silanised group (2207 ± 252 MPa) and the control group (1971 ± 235 MPa). Conclusion: Silane-treated zirconia nano-filler improves the surface hardness and flexural strength of HI PMMA-zirconia nanocomposites, giving a potentially longer service life of the denture base.
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Affiliation(s)
- Saleh Zidan
- Department of Dental Materials, Faculty of Dentistry, Sebha University, Sebha 18758, Libya
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.H.); (J.Y.)
- Correspondence:
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.H.); (J.Y.)
| | - Suhad Al-Nasrawi
- Department of Restorative Dentistry, Faculty of Dentistry, University of Kufa, Najaf 54001, Iraq;
| | - Julfikar Haider
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.H.); (J.Y.)
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Abdulrahman Alshabib
- Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh 11362, Saudi Arabia;
| | - Alshame Alshame
- Department of Oral Surgery, Faculty of Dentistry, Sebha University, Sebha 18758, Libya;
| | - Julian Yates
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.H.); (J.Y.)
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Algamaiah H, Silikas N, Watts DC. Polymerization shrinkage and shrinkage stress development in ultra-rapid photo-polymerized bulk fill resin composites. Dent Mater 2021; 37:559-567. [DOI: 10.1016/j.dental.2021.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 12/20/2022]
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Abstract
The objective of this study was to determine the long-term water sorption, solubility and hygroscopic expansion of resin composites with and without incorporated short fibers. Three resin composites incorporating fibers were examined: everX Posterior (EVX), NovoPro Universal (NPU) and NovoPro Flow (NPF). Four Particulate filled composites were used as controls: Filtek bulk Fill (FBF), Filtek one bulkfill (FBO), Filtek Supreme XTE (XTE), and Filtek Supreme Flow (XTEF). For sorption and solubility measurements, specimens were immersed in water for140 days, weighed at intervals, then dried for a further 42 days at 37±1°C. Laser micrometer measured diametral expansion. XTEF exhibited the highest sorption. The solubility range was between -1.4 to 4.1 μg/mm; XTEF had the highest solubility, with EVX demonstrating negative solubility. Hygroscopic expansion ranged between 1.4% for hydroxyapatite fiber reinforced composite (NPU) and 2.2% for E-glass fiber reinforced composite (EVX). A nano-fiber containing composite (NPU) had the most favorable outcomes compared to a range of composites.
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Affiliation(s)
- Abdulrahman Alshabib
- Dentistry, School of Medical Sciences, University of Manchester.,Department of Restorative Dentistry, College of Dentistry, King Saud University
| | - Hamad Algamaiah
- Dentistry, School of Medical Sciences, University of Manchester.,Department of Restorative Dentistry, College of Dentistry, King Saud University
| | | | - David C Watts
- Dentistry, School of Medical Sciences, University of Manchester.,Photon Science Institute, University of Manchester
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Elraggal A, Silikas N. Effect of Air-Abraded Versus Laser-Fused Fluorapatite Glass-Ceramics on Shear Bond Strength of Repair Materials to Zirconia. Materials (Basel) 2021; 14:ma14061468. [PMID: 33802778 PMCID: PMC8002453 DOI: 10.3390/ma14061468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 11/16/2022]
Abstract
Zirconia repair could be a feasible alternative option to total replacement in fractured zirconia-based restorations. Maximising the bond strength by enriching zirconia with fluorapatite glass-ceramics (FGC) powder has been addressed and compared to other surface treatments. Besides resin composite, other repair materials have been proposed and compared. Zirconia blocks received different surface treatments (A-sandblasting with tribochemical silica-coated alumina (CoJet). B-sandblasting with FGC powder (FGC), C-fluorapatite glass-ceramic coat+ neodymium-doped yttrium aluminum garnet laser irradiation (FGC + Nd: YAG), and D-no surface treatment). The surface roughness, topography, and crystallinity were investigated by a profilometer, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses, respectively. For each surface treatment, three repair materials (feldspathic porcelain, lithium disilicate, and resin composite) were bonded to zirconia with 10, Methacryloyloxydecyl dihydrogen phosphate (MDP)-Monobond Plus/ Multilink Automix. Bonded specimens were thermocycled for 10,000 cycles and tested for shear bond strength (SBS) at a speed of 1 mm/min, followed by the analysis of the mode of failure. FGC + Nd: YAG laser group reported the highest surface roughness and monoclinic content compared to CoJet, FGC, and control groups. The highest mean SBS was found in FGC-blasted zirconia, followed by FGC + Nd: YAG laser and CoJet treated groups. However, the lowest SBS was found in control groups regardless of the repair material. Sandblasting zirconia with FGC powder increased SBS of resin to zirconia with lower monoclinic phase transformation compared to FGC + Nd: YAG or CoJet groups.
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Affiliation(s)
- Alaaeldin Elraggal
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK;
- Conservative Dentistry Department, Faculty of Dentistry, Alexandria University, Alexandria 21568, Egypt
- Correspondence: ; Tel.: +20-1145096263
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, UK;
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Rosa V, Ho D, Sabino-Silva R, Siqueira WL, Silikas N. Fighting viruses with materials science: Prospects for antivirus surfaces, drug delivery systems and artificial intelligence. Dent Mater 2021; 37:496-507. [PMID: 33441249 PMCID: PMC7834288 DOI: 10.1016/j.dental.2020.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/30/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Viruses on environmental surfaces, in saliva and other body fluids represent risk of contamination for general population and healthcare professionals. The development of vaccines and medicines is costly and time consuming. Thus, the development of novel materials and technologies to decrease viral availability, viability, infectivity, and to improve therapeutic outcomes can positively impact the prevention and treatment of viral diseases. METHODS Herein, we discuss (a) interaction mechanisms between viruses and materials, (b) novel strategies to develop materials with antiviral properties and oral antiviral delivery systems, and (c) the potential of artificial intelligence to design and optimize preventive measures and therapeutic regimen. RESULTS The mechanisms of viral adsorption on surfaces are well characterized but no major breakthrough has become clinically available. Materials with fine-tuned physical and chemical properties have the potential to compromise viral availability and stability. Emerging strategies using oral antiviral delivery systems and artificial intelligence can decrease infectivity and improve antiviral therapies. SIGNIFICANCE Emerging viral infections are concerning due to risk of mortality, as well as psychological and economic impacts. Materials science emerges for the development of novel materials and technologies to diminish viral availability, infectivity, and to enable enhanced preventive and therapeutic strategies, for the safety and well-being of humankind.
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Affiliation(s)
- Vinicius Rosa
- Faculty of Dentistry, National University of Singapore, Singapore; Craniofacial Research and Innovation Center, National University of Singapore, Singapore.
| | - Dean Ho
- The N.1 Institute for Health (N.1), Institute for Digital Medicine (WisDM), Department of Biomedical Engineering, and Department of Pharmacology, National University of Singapore, Singapore.
| | - Robinson Sabino-Silva
- Department of Physiology, Institute of Biomedical Sciences, Federal University of Uberlandia, Brazil.
| | | | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, United Kingdom.
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AlAli M, Silikas N, Satterthwaite J. The Effects of Toothbrush Wear on the Surface Roughness and Gloss of Resin Composites with Various Types of Matrices. Dent J (Basel) 2021; 9:dj9010008. [PMID: 33445457 PMCID: PMC7827053 DOI: 10.3390/dj9010008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 01/31/2023] Open
Abstract
Objective: To evaluate and compare the surface roughness and gloss of a DMA-free composite and Bis-GMA-free composite with a DMA-based composite before and after toothbrushing simulation. Materials and Methods: Fifteen dimensionally standardised composite specimens of three nano-hybrid resin composites (Tetric EvoCeram, Admira Fusion, and Venus Diamond) were used. Five specimens from each composite were polished and then subjected to a toothbrushing simulator. Surface roughness (Ra) and gloss were measured before toothbrushing and after 5000, 10,000, 15,000, and 20,000 toothbrushing cycles. The data was analysed using 5 × 3 ANOVA to assess surface roughness and gloss values and pairwise comparisons in the form of Tukey post hoc tests were performed to interpret main effects. Results: For all tested materials, surface roughness increased, and gloss decreased after toothbrushing abrasion. Surface roughness (Ra) values ranged from 0.14 to 0.22 μm at baseline and increased to between 0.41 and 0.49 μm after 20,000 toothbrushing cycles. Gloss values ranged between 31.9 and 50.6 GU at baseline and between 5.1 and 19.5 GU after 20,000 toothbrushing cycles. The lowest initial Ra value was detected in Venus Diamond and the highest initial gloss value was detected in Tetric EvoCeram. Conclusions: Simulated toothbrushing abrasion led to an increase in surface roughness and a decrease in gloss for all tested materials. Venus Diamond had the smoothest surface and Tetric EvoCeram had the glossiest surface after polishing and following 20,000 cycles of toothbrushing abrasion. Admira Fusion demonstrated the roughest surface and had the lowest gloss values before and after toothbrushing abrasion.
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Affiliation(s)
- Murtadha AlAli
- Prosthodontic Department, Alahsa Dental Centre, Ministry of Health, Alahsa 39182, Saudi Arabia
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.S.)
- Correspondence: ; Tel.: +966-506989262
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.S.)
| | - Julian Satterthwaite
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.S.)
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Agarwalla SV, Ellepola K, Silikas N, Castro Neto AH, Seneviratne CJ, Rosa V. Persistent inhibition of Candida albicans biofilm and hyphae growth on titanium by graphene nanocoating. Dent Mater 2020; 37:370-377. [PMID: 33358443 DOI: 10.1016/j.dental.2020.11.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/30/2020] [Accepted: 11/26/2020] [Indexed: 01/01/2023]
Abstract
OBJECTIVES Candida albicanscolonizes biomaterial surfaces and are highly resistant to therapeutics. Graphene nanocoating on titanium compromises initial biofilm formation. However, its sustained antibiofilm potential is unknown. The objective of this study was to investigate the potential of graphene nanocoating to decrease long-term fungal biofilm development and hyphae growth on titanium. METHODS Graphene nanocoating was deposited twice (TiGD) or five times (TiGV) on grade 4 titanium with vacuum assisted technique and characterized with Raman spectroscopy and atomic force microscope. The biofilm formation and hyphae growth of C. albicans was monitored for seven days by CFU, XTT, confocal, mean cell density and scanning electronic microscopy (SEM). Uncoated titanium was the Control. All tests had three independent biological samples and were performed in independent triplicates. Data was analyzed with one- or two-way ANOVA and Tukey's HSD (α = 0.05). RESULTS Both TiGD and TiGV presented less biofilms at all times points compared with Control. The confocal and SEM images revealed few adhered cells on graphene coated samples, absence of hyphae and no features of a mature biofilm architecture. The increase in number of layers of graphene nanocoating did not improve its antibiofilm potential. SIGNIFICANCE The graphene nanocoating exerted a long-term persistent inhibitory effect on the biofilm formation on titanium. The fewer cells that were able to attach on graphene coated titanium were scattered and unable to form a mature biofilm with hyphae elements. The findings open opportunities to prevent microbial attachment and proliferation on implantable materials without the use of antibiotics.
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Affiliation(s)
| | - Kassapa Ellepola
- Louisiana State University Health Sciences Center, School of Dentistry, USA
| | - Nikolaos Silikas
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - A H Castro Neto
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore
| | - Chaminda Jayampath Seneviratne
- National Dental Centre Singapore, SingHealth, Duke NUS Medical School, 05, Hospital Avenue, National Dental Centre Singapor, Singapore.
| | - Vinicius Rosa
- Faculty of Dentistry, National University of Singapore, 9 Lower Kent Ridge Road, Singapore; Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore; NUS Craniofacial Research and Innovation Center, National University of Singapore, Singapore.
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Zidan S, Silikas N, Haider J, Alhotan A, Jahantigh J, Yates J. Assessing Tensile Bond Strength Between Denture Teeth and Nano-Zirconia Impregnated PMMA Denture Base. Int J Nanomedicine 2020; 15:9611-9625. [PMID: 33293810 PMCID: PMC7718964 DOI: 10.2147/ijn.s273541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/10/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose This study evaluated tensile bond strength (TBS) between anterior acrylic teeth and denture bases made of high-impact heat-cured acrylic resin (HI PMMA) impregnated with zirconia nanoparticles. Materials and Methods A total of 30 specimens (each specimen containing a set of six upper anterior teeth) were fabricated from HI PMMA denture base acrylic resin reinforced with different weight concentrations of zirconia nanoparticles: 0% (control), 1.5%, 3%, 5%, 7% and 10%. TBS was tested according to a British standard (BS EN ISO 22112: 2017). A one-way analysis of variance (ANOVA) was employed with a Tukey post-hoc test. Results TBS values between the anterior teeth (central and lateral incisors and canine) and HI-PMMA denture base groups containing 7 wt.% (261.5 ± 66.0 N, 172.5 ± 57.4 N and 271.9 ± 86.3 N) and 10 wt.% (332.1 ± 122.9 N, 165.4 ± 48.7 N and 301.6 ± 73.2 N) zirconia were significantly lower compared to the control group (645.4 ± 84.8 N, 306.1 ± 81.6 N and 496.7 ± 179.1 N) and the other nanocomposite groups. However, TBS values for HI PMMA with 1.5 wt.% (534.4 ± 115.3 N, 304.7 ± 86.4 N, 514.0 ± 143.2 N), 3 wt.% (685.7 ± 159.6 N, 281.1 ± 78.3 N, 462.6 ± 122.1 N) and 5 wt.% (514.5 ± 134.3 N, 229.8 ± 67.3 N, 387.2 ± 99.4 N) zirconia showed slightly lower values than that of the control group but these were not significant. Failure modes between the teeth and denture base nanocomposites were predominantly cohesive fractures, which were clinically acceptable according to the Standard. Conclusion The addition of zirconia nanoparticles to HI PMMA denture base at high concentration (7 wt.% and 10 wt. %) significantly (p<0.05) reduced the bonding strength for all types of anterior teeth compared to the control group.
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Affiliation(s)
- Saleh Zidan
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.,Department of Dental Materials, Faculty of Dentistry, Sebha University, Sebha, Libya
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Julfikar Haider
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK
| | - Abdulaziz Alhotan
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Javad Jahantigh
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK
| | - Julian Yates
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK
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Algamaiah H, Silikas N, Watts DC. Conversion kinetics of rapid photo-polymerized resin composites. Dent Mater 2020; 36:1266-1274. [DOI: 10.1016/j.dental.2020.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
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Zidan S, Silikas N, Haider J, Yates J. Long-Term Sorption and Solubility of Zirconia-Impregnated PMMA Nanocomposite in Water and Artificial Saliva. Materials (Basel) 2020; 13:ma13173732. [PMID: 32847026 PMCID: PMC7503455 DOI: 10.3390/ma13173732] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 11/30/2022]
Abstract
Exposure of denture base acrylic resins to the oral environment and storage media for extended periods of time results in sorption of saliva or water, leading to a reduction in physical properties and thus clinical service life. The purpose of this in vitro study was to assess the sorption and solubility of high-impact heat-polymerised denture base acrylic resin (HI PMMA) impregnated with zirconia nanoparticles after being stored for 180 days in distilled water (DW) and artificial saliva (AS). The specimens were divided into six groups for each storage medium, according to the concentration of zirconia nanoparticles (0, 1.5, 3.0, 5.0, 7.0, and 10.0 wt.%). Data were statistically analysed for sorption and solubility using one-way and two-way ANOVA statistical tests. Sorption in DW and AS for all groups containing zirconia showed sorption values lower than the control group at 90 days, though not significantly different (p > 0.05) compared to the control group. For both the DW and AS groups, the lowest solubility value was measured in the group containing 3 wt.% zirconia, however, there was no significant difference compared to the control group except when observing 10 wt.% zirconia in AS, which showed a significantly higher solubility (p < 0.05). High-impact PMMA, impregnated with low concentrations of ZrO2, showed the lowest sorption and solubility in both media, but was not significantly different compared to pure HI PMMA.
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Affiliation(s)
- Saleh Zidan
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.Y.)
- Department of Dental Materials, Faculty of Dentistry, Sebha University, Sebha, Libya
- Correspondence: or ; Tel.: +44-79-3309-6536
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.Y.)
| | - Julfikar Haider
- Department of Engineering, Manchester Metropolitan University, Manchester M1 5GD, UK;
| | - Julian Yates
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK; (N.S.); (J.Y.)
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Yang J, Silikas N, Watts DC. Pre-heating time and exposure duration: Effects on post-irradiation properties of a thermo-viscous resin-composite. Dent Mater 2020; 36:787-793. [DOI: 10.1016/j.dental.2020.03.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 10/24/2022]
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Althaqafi KA, Satterthwaite J, Silikas N. A review and current state of autonomic self-healing microcapsules-based dental resin composites. Dent Mater 2020; 36:329-342. [DOI: 10.1016/j.dental.2019.12.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 11/30/2022]
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Dimitriadi M, Zinelis S, Zafiropoulou M, Silikas N, Eliades G. Self-Etch Silane Primer: Reactivity and Bonding with a Lithium Disilicate Ceramic. Materials (Basel) 2020; 13:ma13030641. [PMID: 32023979 PMCID: PMC7040894 DOI: 10.3390/ma13030641] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 01/26/2020] [Accepted: 01/30/2020] [Indexed: 11/18/2022]
Abstract
The aim of the study was to evaluate the stability, reactivity, and bond strength with a lithium disilicate ceramic of a self-etch silane primer (Monobond Etch and Prime/MEP). The stability was evaluated by 1H-,31P-NMR spectroscopy (before/after aging), and the reactivity by micro MIR-FTIR spectroscopy on Ge surfaces (0, 1, 24 h) using a prehydrolyzed silane primer (Calibra Silane Coupling Agent/CLB), as a control. The effect of MEP vs. 5% HF-etching on ceramic roughness was assessed by optical profilometry. The shear bond strength (SBS) of a resin composite bonded to polished ceramic surfaces treated with MEP, HF without silane (HF+NS), HF+CLB, and HF+MEP (n = 20) was evaluated after storage in water (A: 37 °C/1 week, B: 5000×/5–55 °C and C: 100 °C/24 h). Aging did not affect the silanol groups of MEP, but only the phosphate co-monomer. Silanols were reactive forming siloxanes, but exhibited lower consumption rate than CLB. HF-etching induced significantly higher values than MEP, in all the roughness parameters tested (Sa, Sz, Sdr, Sc, Sv), with the greatest differences found in Sdr and Sv. For SBS, MEP was inferior to all treatments/storage conditions, except of HF+NS in A, where the values were similar. However, on a HF-etched substrate, MEP provided highest strength and reliability.
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Affiliation(s)
- Maria Dimitriadi
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.D.); (S.Z.); (M.Z.)
| | - Spiros Zinelis
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.D.); (S.Z.); (M.Z.)
| | - Maria Zafiropoulou
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.D.); (S.Z.); (M.Z.)
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M15 6FH, UK;
| | - George Eliades
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece; (M.D.); (S.Z.); (M.Z.)
- Correspondence:
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Ashy LM, Marghalani H, Silikas N. In Vitro Evaluation of Marginal and Internal Adaptations of Ceramic Inlay Restorations Associated with Immediate vs Delayed Dentin Sealing Techniques. INT J PROSTHODONT 2019; 33:48-55. [PMID: 31860913 DOI: 10.11607/ijp.6372] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To investigate the marginal and internal adaptations of ceramic inlay restorations placed with immediate dentin sealing (IDS) vs delayed dentin sealing (DDS) procedures. MATERIALS AND METHODS Mesial and distal Class II cavities were prepared in 12 extracted molar teeth, which were randomly allocated into six groups of 2 teeth each. Lava Ultimate inlays were fabricated and luted to the cavities using All-Bond universal adhesive system and eCEMENT dual-curing resin cement following IDS/immediate cementation (control groups 1 and 2), IDS/delayed cementation (groups 3 and 4), or DDS/delayed cementation (groups 5 and 6) protocols. Teeth in groups 2, 4, and 6 were subjected to thermocycling of 500 cycles between 5°C and 55°C after inlay cementation. Following staining with silver nitrate solution, the marginal and internal gap volumes were determined using microcomputed tomography images. Statistical analyses were conducted using independent t test and one-way analysis of variance followed by Tukey post hoc test (P < .05). RESULTS Marginal gap volume for DDS (1.856 ± 0.323 mm3) was significantly higher than that of IDS immediately after inlay cementation (0.891 ± 0.281 mm3) (P = .025). Following thermocycling, the internal gap volume for DDS (0.838 ± 0.248 mm3) was significantly higher than that for IDS (0.098 ± 0.066 mm3) (P = .000), but the marginal gap volume of DDS (1.964 ± 0.956 mm3) was not significantly different from that of IDS (1.426 ± 0.725 mm3) (P = .622). CONCLUSION Luted ceramic inlays have a superior marginal adaptation right after cementation and a superior internal adaptation after thermocycling when using the IDS technique compared to the DDS technique. However, marginal adaptation after thermocycling was not significantly different between the two techniques.
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Wagstaffe M, Hussain H, Taylor M, Murphy M, Silikas N, Thomas AG. Interaction of a tripeptide with titania surfaces: RGD adsorption on rutile TiO 2(110) and model dental implant surfaces. Mater Sci Eng C Mater Biol Appl 2019; 105:110030. [PMID: 31546374 DOI: 10.1016/j.msec.2019.110030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/01/2019] [Accepted: 07/28/2019] [Indexed: 01/04/2023]
Abstract
The adsorption of peptides on metal oxides is an area of significant interest, both fundamentally and in a number of technologically important areas. These range from the integration of biomaterials in the body, to denaturation of protein therapeutics and the use of biomolecules and bioinspired materials in synthesis and stabilization of novel nanomaterials. Here we present a study of the tripeptide arginylglycylaspartic acid (RGD) on the surfaces of vacuum-prepared single crystalline TiO2(110), pyrocatechol-capped TiO2(110), and model SLA and SLActive dental implant samples. X-ray Photoelectron Spectroscopy and Scanning Tunneling Microscopy show that the RGD adsorption mode on the single crystal is consistent with bonding through the deprotonated carboxylate groups of the peptide to surface Ti atoms of the substrate. Despite the increased hydrophobicity of the pyrocatechol-capped TiO2(110) surface RGD adsorption from solution increases following this surface treatment. RGD adsorption on SLA and SLActive surfaces shows that the SLActive surface has a greater uptake of RGD. The RGD uptake on the pyrocatechol capped single crystal and the model implant surfaces suggest that the ease with which surface contaminant hydrocarbons are removed from the surface has a greater influence on peptide adsorption than hydrophobicity/hydrophilicity of the surface.
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Affiliation(s)
- Michael Wagstaffe
- School of Physics and Astronomy, The University of Manchester, Oxford, Road, M13 9PL, UK
| | - Hadeel Hussain
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Mark Taylor
- Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK
| | - Matthew Murphy
- School of Materials, The University of Manchester, Manchester M13 9PL, UK
| | - Nikolaos Silikas
- School of Dentistry, The University of Manchester, Manchester M13 9PL, UK
| | - Andrew G Thomas
- School of Materials, The University of Manchester, Manchester M13 9PL, UK; The Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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Velo MMAC, Nascimento TRL, Scotti CK, Bombonatti JFS, Furuse AY, Silva VD, Simões TA, Medeiros ES, Blaker JJ, Silikas N, Mondelli RFL. Improved mechanical performance of self-adhesive resin cement filled with hybrid nanofibers-embedded with niobium pentoxide. Dent Mater 2019; 35:e272-e285. [PMID: 31519351 DOI: 10.1016/j.dental.2019.08.102] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/25/2019] [Accepted: 08/20/2019] [Indexed: 10/26/2022]
Abstract
OBJECTIVES In this study hybrid nanofibers embedded with niobium pentoxide (Nb2O5) were synthesized, incorporated in self-adhesive resin cement, and their influence on physical-properties was evaluated. METHODS Poly(D,L-lactide), PDLLA cotton-wool-like nanofibers with and without silica-based sol-gel precursors were formulated and spun into submicron fibers via solution blow spinning, a rapid fiber forming technology. The morphology, chemical composition and thermal properties of the spun fibers were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC), respectively. Produced fibers were combined with a self-adhesive resin cement (RelyX U200, 3M ESPE) in four formulations: (1) U200 resin cement (control); (2) U200+1wt.% PDLLA fibers; (3) U200+1wt.% Nb2O5-filled PDLLA composite fibers and (4) U200+1wt.% Nb2O5/SiO2-filled PDLLA inorganic-organic hybrid fibers. Physical properties were assessed in flexure by 3-point bending (n=10), Knoop microhardness (n=5) and degree of conversion (n=3). Data were analyzed with One-way ANOVA and Tukey's HSD (α=5%). RESULTS Composite fibers formed of PDLLA-Nb2O5 exhibited an average diameter of ∼250nm, and hybrid PDLLA+Nb2O5/SiO2 fibers were slightly larger, ∼300nm in diameter. There were significant differences among formulations for hardness and flexural strength (p<0.05). Degree of conversion of resin cement was not affected for all groups, except for Group 4 (p<0.05). SIGNIFICANCE Hybrid reinforcement nanofibers are promising as fillers for dental materials. The self-adhesive resin cement with PDLLA+Nb2O5 and PDLLA+Nb2O5/SiO2 presented superior mechanical performance than the control group.
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Affiliation(s)
- Marilia M A C Velo
- Bauru School of Dentistry, University of São Paulo-USP, Bauru, SP, Brazil.
| | - Tatiana R L Nascimento
- Materials and Biosystems Laboratory (LAMAB), Department of Materials Engineering (DEMat), Federal University of Paraíba (UFPB), João Pessoa, Brazil; Bio-Active Materials Group, Department of Materials, MSS Tower, The University of Manchester, Manchester, M13 9PL, UK
| | - Cassiana K Scotti
- Bauru School of Dentistry, University of São Paulo-USP, Bauru, SP, Brazil
| | | | - Adilson Y Furuse
- Bauru School of Dentistry, University of São Paulo-USP, Bauru, SP, Brazil
| | - Vinícius D Silva
- Materials and Biosystems Laboratory (LAMAB), Department of Materials Engineering (DEMat), Federal University of Paraíba (UFPB), João Pessoa, Brazil
| | - Thiago A Simões
- Materials and Biosystems Laboratory (LAMAB), Department of Materials Engineering (DEMat), Federal University of Paraíba (UFPB), João Pessoa, Brazil
| | - Eliton S Medeiros
- Materials and Biosystems Laboratory (LAMAB), Department of Materials Engineering (DEMat), Federal University of Paraíba (UFPB), João Pessoa, Brazil
| | - Jonny J Blaker
- Bio-Active Materials Group, Department of Materials, MSS Tower, The University of Manchester, Manchester, M13 9PL, UK
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, The University of Manchester, Manchester M13 9PL, UK
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Zidan S, Silikas N, Alhotan A, Haider J, Yates J. Investigating the Mechanical Properties of ZrO 2-Impregnated PMMA Nanocomposite for Denture-Based Applications. Materials (Basel) 2019; 12:ma12081344. [PMID: 31027157 PMCID: PMC6515448 DOI: 10.3390/ma12081344] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/18/2019] [Accepted: 04/20/2019] [Indexed: 12/16/2022]
Abstract
Acrylic resin PMMA (poly-methyl methacrylate) is used in the manufacture of denture bases but its mechanical properties can be deficient in this role. This study investigated the mechanical properties (flexural strength, fracture toughness, impact strength, and hardness) and fracture behavior of a commercial, high impact (HI), heat-cured denture base acrylic resin impregnated with different concentrations of yttria-stabilized zirconia (ZrO2) nanoparticles. Six groups were prepared having different wt% concentrations of ZrO2 nanoparticles: 0% (control), 1.5%, 3%, 5%, 7%, and 10%, respectively. Flexural strength and flexural modulus were measured using a three-point bending test and surface hardness was evaluated using the Vickers hardness test. Fracture toughness and impact strength were evaluated using a single edge bending test and Charpy impact instrument. The fractured surfaces of impact test specimens were also observed using a scanning electron microscope (SEM). Statistical analyses were conducted on the data obtained from the experiments. The mean flexural strength of ZrO2/PMMA nanocomposites (84 ± 6 MPa) at 3 wt% zirconia was significantly greater than that of the control group (72 ± 9 MPa) (p < 0.05). The mean flexural modulus was also significantly improved with different concentrations of zirconia when compared to the control group, with 5 wt% zirconia demonstrating the largest (23%) improvement. The mean fracture toughness increased in the group containing 5 wt% zirconia compared to the control group, but it was not significant. However, the median impact strength for all groups containing zirconia generally decreased when compared to the control group. Vickers hardness (HV) values significantly increased with an increase in ZrO2 content, with the highest values obtained at 10 wt%, at 0 day (22.9 HV0.05) in dry conditions when compared to the values obtained after immersing the specimens for seven days (18.4 HV0.05) and 45 days (16.3 HV0.05) in distilled water. Incorporation of ZrO2 nanoparticles into high impact PMMA resin significantly improved flexural strength, flexural modulus, fracture toughness and surface hardness, with an optimum concentration of 3–5 wt% zirconia. However, the impact strength of the nanocomposites decreased, apart from the 5 wt% zirconia group.
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Affiliation(s)
- Saleh Zidan
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.
| | - Abdulaziz Alhotan
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.
| | - Julfikar Haider
- School of Engineering, Manchester Metropolitan University, Manchester M1 5GD UK.
| | - Julian Yates
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.
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Alrahlah A, Khan R, Alotaibi K, Almutawa Z, Fouad H, Elsharawy M, Silikas N. Simultaneous Evaluation of Creep Deformation and Recovery of Bulk-Fill Dental Composites Immersed in Food-Simulating Liquids. Materials (Basel) 2018; 11:ma11071180. [PMID: 29996519 PMCID: PMC6073768 DOI: 10.3390/ma11071180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 11/16/2022]
Abstract
The aim of this study is to compare the creep/recovery behavior of bulk-fill dental composites after storage in various food simulating organic solvents. For this purpose, five different resin-composites (four bulk-fills and one conventional) were used. A total of 20 rectangular specimens (14 mm × 3 mm × 0.7 mm) were prepared by filling the resin-composites in Teflon mold. All of the specimens for each material (n = 5) were divided into four groups namely dry (control), distilled water (DW), artificial saliva, and absolute ethanol. The specimens were subjected to three-point bending creep test during immersion directly. A constant load of 2 N was used for each specimen with loading and unloading time 2 h each. RESULTS SF2 and XF showed a lower creep strain % after immersion, ranging from 0.44 (dry) to 0.75 (saliva) and 0.43 (dry) to 0.80 (ethanol), respectively. TNC BF depicts the maximum creep strain % ranging from 1.24% (dry) to 2.87% (ethanol) followed by FBF ranging from 1.17 (dry) to 2.59 (ethanol). However, the conventional material (GR) showed lower creep strain after immersion ranging from 0.28 to 0.54. Moreover, SF2 resulted in the highest creep recovery in all of the composites groups, as well as conventional material. The other composite groups showed lower creep recovery as compared to the conventional material (GR). The creep strain % for all the bulk-fill composites materials were increased during immersion in the liquids. However, for the conventional material, the creep deformation is decreased after immersion. SF2 showed the highest percentage of creep recovery among the bulk-fill composites, followed by XF.
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Affiliation(s)
- Ali Alrahlah
- Restorative Dental Sciences Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
- Engineer Abdullah Bugshan research chair for Dental and Oral Rehabilitation, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
| | - Rawaiz Khan
- Engineer Abdullah Bugshan research chair for Dental and Oral Rehabilitation, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
| | - Khalid Alotaibi
- Dental intern, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
| | - Ziad Almutawa
- Dental intern, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
| | - H Fouad
- Applied Medical Science Department, Community College, King Saud University, Riyadh 11545, Saudi Arabia.
- Department of Biomedical Engineering, Faculty of Engineering, Helwan University, Helwan 11792, Egypt.
| | - Mohamed Elsharawy
- Dental Biomaterials Research Chair, King Saud University, Riyadh 11433, Saudi Arabia.
| | - Nikolaos Silikas
- Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, UK.
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Solheiro L, Moura K, Rifane T, Silvestre F, Moreira M, Souza M, Zanotto E, Silikas N, Feitosa V. Bioactive glasses may interfere on dentin adhesion of experimental composites. Dent Mater 2018. [DOI: 10.1016/j.dental.2018.08.239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Velo M, Scotti C, Nascimento T, Mondelli R, Silva V, Simões T, Medeiros E, Blaker J, Silikas N. Performance of self-adhesive resin-cement by cotton-wool-like nanofibers-embedded with niobium. Dent Mater 2018. [DOI: 10.1016/j.dental.2018.08.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ferracane J, Hilton T, Stansbury J, Watts D, Silikas N, Ilie N, Heintze S, Cadenaro M, Hickel R. Academy of Dental Materials guidance—Resin composites: Part II—Technique sensitivity (handling, polymerization, dimensional changes). Dent Mater 2017; 33:1171-1191. [DOI: 10.1016/j.dental.2017.08.188] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 11/30/2022]
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Ilie N, Hilton TJ, Heintze SD, Hickel R, Watts DC, Silikas N, Stansbury JW, Cadenaro M, Ferracane JL. Academy of Dental Materials guidance-Resin composites: Part I-Mechanical properties. Dent Mater 2017; 33:880-894. [PMID: 28577893 DOI: 10.1016/j.dental.2017.04.013] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The objective of this project, which was initiated from the Academy of Dental Materials, was to review and critically appraise methods to determine fracture, deformation and wear resistance of dental resin composites, in an attempt to provide guidance for investigators endeavoring to study these properties for these materials. METHODS Test methods have been ranked in the priority of the specific property being tested, as well as of the specific test methods for evaluating that property. Focus was placed on the tests that are considered to be of the highest priority in terms of being the most useful, applicable, supported by the literature, and which show a correlation with clinical findings. Others are mentioned briefly for the purpose of being inclusive. When a standard test method exists, including those used in other fields, these have been identified in the beginning of each section. Also, some examples from the resin composite literature are included for each test method. RESULTS The properties for evaluating resin composites were ranked in the priority of measurement as following: (1) Strength, Elastic Modulus, Fracture toughness, Fatigue, Indentation Hardness, Wear-abrasion (third body) and Wear-attrition (contact/two body), (2) Toughness, Edge strength (chipping) and (3) Wear determined by toothbrush. SIGNIFICANCE The following guidance is meant to aid the researcher in choosing the proper method to assess key properties of dental resin composites with regard to their fracture, deformation and wear resistance.
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Affiliation(s)
- N Ilie
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany.
| | - T J Hilton
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - S D Heintze
- Ivoclar Vivadent AG, Research & Development, Schaan, Liechtenstein
| | - R Hickel
- Department of Operative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - D C Watts
- Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, UK; Photon Science Institute, University of Manchester, Manchester, UK
| | - N Silikas
- Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, UK
| | - J W Stansbury
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, CO, USA; Department of Chemical and Biological Engineering, University of Colorado at Boulder, Boulder, CO, USA
| | - M Cadenaro
- Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - J L Ferracane
- Division of Biomaterials & Biomechanics, Oregon Health & Science University, Portland, OR, USA
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Murphy M, Walczak M, Thomas A, Silikas N, Berner S, Lindsay R. Toward optimizing dental implant performance: Surface characterization of Ti and TiZr implant materials. Dent Mater 2017; 33:43-53. [DOI: 10.1016/j.dental.2016.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/29/2016] [Accepted: 10/09/2016] [Indexed: 01/05/2023]
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Papadogiannis D, Iliadi A, Bradley TG, Silikas N, Eliades G, Eliades T. Viscoelastic properties of orthodontic adhesives used for lingual fixed retainer bonding. Dent Mater 2016; 33:e22-e27. [PMID: 27769593 DOI: 10.1016/j.dental.2016.09.041] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/14/2016] [Accepted: 09/27/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the viscoelastic properties of two experimental BPA-free and one BisGMA-based orthodontic resin composite adhesives for bonding fixed retainers. METHODS A commercially available BisGMA-based (TXA: Transbond LR) and two bisphenol A-free experimental adhesives (EXA and EXB) were included in the study. The viscoelastic behavior of the adhesives was evaluated under static and dynamic conditions at dry and wet states and at various temperatures (21, 37, 50°C). The parameters determined were shear modulus (G), Young's modulus (E) under static testing and storage modulus (G1), loss tangent (tanδ) and dynamic viscosity (n*) under dynamic testing. Statistical analysis was performed by 2-way ANOVA and Bonferroni post-hoc tests (α=0.05). RESULTS For static testing, a significant difference was found within material and storage condition variables and a significant interaction between the two independent variables (p<0.001 for G and E). EXA demonstrated the highest G and E values at 21°C/dry group. Dry specimens showed the highest G and E values, but with no significant difference from 21°C/wet specimens, except EXA in G. Wet storage at higher temperatures (37°C and 50°C) adversely affected all the materials to a degree ranging from 40 to 60% (p<0.001). For dynamic testing, a significant difference was also found in material and testing condition groups, with a significant interaction between the two independent variables (p<0.001 for G1 and n*, p<0.01 for tanδ). Reduction in G1, and n* values, and increase in tanδ values were encountered at increased water temperatures. SIGNIFICANCE The apparent detrimental effect of high temperature on the reduction of properties of adhesives may contribute to the loss of stiffness of the fixed retainer configuration under ordinary clinical conditions with unfavorable effects on tooth position and stability of the orthodontic treatment result.
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Affiliation(s)
- D Papadogiannis
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece
| | - A Iliadi
- Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, Greece
| | - T G Bradley
- Section of Orthodontics, Developmental Sciences, School of Dentistry, Marquette University, Milwaukee, WI, USA
| | - N Silikas
- Dental Biomaterials Science, School of Dentistry, The University of Manchester, Manchester, UK
| | - G Eliades
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Greece
| | - T Eliades
- Clinic of Orthodontics and Paediatric Dentistry, School of Dental Medicine, University of Zurich, Zurich, Switzerland.
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Arpa C, Ceballos L, Watts D, Silikas N. 3-D hygroscopic expansion of resin-composites. Dent Mater 2016. [DOI: 10.1016/j.dental.2016.08.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bacchi A, Feitosa VP, da Silva Fonseca ASQ, Cavalcante LMA, Silikas N, Schneider LFJ. Shrinkage, stress, and modulus of dimethacrylate, ormocer, and silorane composites. J Conserv Dent 2015; 18:384-8. [PMID: 26430302 PMCID: PMC4578183 DOI: 10.4103/0972-0707.164051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Purpose: to evaluate the shrinkage, polymerization stress, elastic and bulk modulus resulting from composites formulated by siloranes, 2nd generation ormocers, and dimethacrylates. Materials and Methods: The bonded disc method was used to evaluate volumetric shrinkage. The polymerization stress was evaluated by mean of the Bioman. Cylindrical specimens (5 mm thickness and 6 mm diameter) were submitted to gradual loading. Young's and bulk modulus were obtained from the slope of the stress/strain curve. Data were analyzed using one-way analysis of variance and Tukey's test (5%). Results: Grandio and ormocer showed significant higher elastic and bulk modulus. Silorane presented significant lowest bulk modulus and maximum shrinkage. Ormocer and silorane presented lower values for the maximum rate of shrinkage. Extra-low shrinkage (ELS) composite presented the greatest maximum shrinkage. The higher maximum rate of shrinkage was attained by Grandio and ELS, statistically similar from each other. The silorane showed lower values of maximum stress and maximum rate of stress. The higher values of maximum stress were presented by ELS and Grandio, statistical similar between them. Grandio showed the significantly greatest maximum rate of stress. Conclusion: Silorane showed to promote lower shrinkage/stress among the composites, with the lowest elastic modulus. Ormocer showed lower shrinkage/stress than methacrylates despite of its high modulus.
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Affiliation(s)
- Atais Bacchi
- Department of Prosthetic Dentistry, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, RS, Brazil
| | - Victor Pinheiro Feitosa
- Department of Restorative Dentistry, School of Dentistry, Federal University of Ceará, Fortaleza, Ceará, Brazil
| | | | | | - Nikolaos Silikas
- Biomaterials Science Research Group, School of Dentistry, University of Manchester, Manchester, United Kingdom
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Al-Haddad A, Satterthwaite J, Silikas N. Influence of fibre-reinforcement on light-transmittance and microhardness of bulk-fill resin-composites. Dent Mater 2015. [DOI: 10.1016/j.dental.2015.08.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Al-Ahdal K, Silikas N, Watts D. Effects of composition and temperature on rheology of model resin-composites. Dent Mater 2014. [DOI: 10.1016/j.dental.2014.08.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Alrahlah A, Silikas N, Watts DC. Post-cure depth of cure of bulk fill dental resin-composites. Dent Mater 2013; 30:149-54. [PMID: 24268044 DOI: 10.1016/j.dental.2013.10.011] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/31/2013] [Accepted: 10/31/2013] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To determine the post-cure depth of cure of bulk fill resin composites through using Vickers hardness profiles (VHN). METHODS Five bulk fill composite materials were examined: Tetric EvoCeram(®) Bulk Fill, X-tra base, Venus(®) Bulk Fill, Filtek™ Bulk Fill, SonicFill™. Three specimens of each material type were prepared in stainless steel molds which contained a slot of dimensions (15 mm × 4 mm × 2 mm), and a top plate. The molds were irradiated from one end. All specimens were stored at 37°C for 24h, before measurement. The Vickers hardness was measured as a function of depth of material, at 0.3mm intervals. Data were analysed by one-way ANOVA using Tukey post hoc tests (α=0.05). RESULTS The maximum VHN ranged from 37.8 to 77.4, whilst the VHN at 80% of max.VHN ranged from 30.4 to 61.9. The depth corresponding to 80% of max.VHN, ranged from 4.14 to 5.03 mm. One-way ANOVA showed statistically significant differences between materials for all parameters tested. SonicFill exhibited the highest VHN (p<0.001) while Venus Bulk Fill the lowest (p≤0.001). SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure (5.03 and 4.47 mm, respectively) and was significant's different from X-tra base, Venus Bulk Fill and Filtek Bulk Fill (p≤0.016). Linear regression confirmed a positive regression between max.VHN and filler loading (r(2)=0.94). SIGNIFICANCE Bulk fill resin composites can be cured to an acceptable post-cure depth, according to the manufacturers' claims. SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure among the composites examined.
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Affiliation(s)
- A Alrahlah
- Biomaterials Research Group, School of Dentistry, University of Manchester, Manchester M13 9PL, UK; Department of Restorative Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
| | - N Silikas
- Biomaterials Research Group, School of Dentistry, University of Manchester, Manchester M13 9PL, UK
| | - D C Watts
- Biomaterials Research Group, School of Dentistry, University of Manchester, Manchester M13 9PL, UK; Photon Science Institute, University of Manchester, Manchester M13 9PL, UK
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