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Novta E, Pantelić D, Blažić L, Tóth E, Cvejić Ž, Grujić D, Savić-Šević S, Lainović T. Impact of optical fiber-based photo-activation on dental composite polymerization. J Dent 2024; 145:104998. [PMID: 38636650 DOI: 10.1016/j.jdent.2024.104998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 04/04/2024] [Accepted: 04/16/2024] [Indexed: 04/20/2024] Open
Abstract
OBJECTIVES The study aimed to introduce a novel two-step optical fiber-based photo-activation of dental resin-based composites (RBCs) for reducing polymerization shrinkage stress (PSS). METHODS Proposed protocol design - in the first step, two flexible plastic optical fibers connected to a dental light curing unit (LCU), were used as light guides inserted into the filling to initiate low-irradiance polymerization from within; in the second step, fibers were extracted and remaining voids were filled with RBC, followed by conventional high-irradiance curing to finalize polymerization. Three bulk-fill RBCs were tested (Beautifil-Bulk Restorative, Filtek Bulk-fill Posterior, Tetric PowerFill) using tooth cavity models. Three non-invasive examination techniques were employed: Digital Holographic Interferometry, Infrared Thermography, and Raman spectroscopy for monitoring model deformation, RBC temperature change, and degree of conversion (DC), respectively. A control group (for each examined RBC) underwent conventional photo-activation. RESULTS The experimental protocol significantly reduced model deformation by 15 - 35 %, accompanied by an 18 - 54 % reduction in RBC temperature change, emphasizing the impact of thermal shrinkage on PSS. Real-time measurements of deformation and temperature provided indirect insights into reaction dynamics and illuminated potential mechanisms underlying PSS reduction. After a 24-hour dark-storage period, DC outcomes comparable to conventional curing were observed, affirming the clinical applicability of the method. CONCLUSIONS Protocol involving the use of two 1.5 mm fibers in the first step (300 mW/cm2 x 10 s), followed by a second conventional curing step (1000 mW/cm2 x 10 s), is recommended to achieve the desired PSS reduction, while maintaining adequate DC and ensuring efficient clinical application. CLINICAL SIGNIFICANCE Obtained PSS reduction offers promise in potentially improving the performance of composite restorations. Additionally, leveraging the flexibility of optical fibers improves light guide approach for restorations on posterior teeth. Meanwhile, implementation in clinical practice is easily achievable by coupling the fibers with commercial dental LCUs using the provided plastic adapter.
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Affiliation(s)
- Evgenije Novta
- University of Novi Sad, Faculty of Medicine, School of Dental Medicine, Hajduk Veljkova 12, Novi Sad, Serbia.
| | - Dejan Pantelić
- University of Belgrade, Institute of Physics, Pregrevica 118, Belgrade, Serbia
| | - Larisa Blažić
- University of Novi Sad, Faculty of Medicine, School of Dental Medicine, Hajduk Veljkova 12, Novi Sad, Serbia; Dental clinic of Vojvodina, Hajduk Veljkova 12, Novi Sad, Serbia
| | - Elvira Tóth
- University of Novi Sad, Faculty of Sciences, Department of Physics, Trg Dositeja Obradovića 3, Novi Sad, Serbia
| | - Željka Cvejić
- University of Novi Sad, Faculty of Sciences, Department of Physics, Trg Dositeja Obradovića 3, Novi Sad, Serbia
| | - Dušan Grujić
- University of Belgrade, Institute of Physics, Pregrevica 118, Belgrade, Serbia
| | | | - Tijana Lainović
- University of Novi Sad, Faculty of Medicine, School of Dental Medicine, Hajduk Veljkova 12, Novi Sad, Serbia
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Lee CH, Lee IB. Effect of translucency and absorbance of composite on temperature change during photopolymerization. Dent Mater J 2023; 42:894-900. [PMID: 37766575 DOI: 10.4012/dmj.2023-143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
This study investigated the effect of translucency and absorbance of conventional (FiltekTM-Z350-XT) and bulk-fill (Tetric®-N-Ceram) composites on temperature change during photopolymerization, using a non-contact infrared sensor. Three shades from each composite were selected to prepare disk-shaped specimens (n=3), which then photopolymerized with LED-light for 20 s. A second light exposure was performed on the photopolymerized specimens. The first peak temperature rise during composite photopolymerization (ΔTtotal), second peak temperature rise by the light (ΔTlight), and net peak temperature rise by composite curing heat (ΔTcomposite) were obtained from the temperature change vs. time curve. The changes in ΔTtotal and ΔTlight with varying the composite shade were greater than those in ΔTcomposite. The conventional composite showed higher ΔTtotal and ΔTlight than bulk-fill composite. ΔTtotal and ΔTlight increased as translucency parameter decreased, and absorbance increased. The potential risk for heat-induced pulpal damage should be considered when selecting a composite shade, especially for deep cavities.
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Affiliation(s)
- Chang-Ha Lee
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University
| | - In-Bog Lee
- Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University
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Ferreira MN, Neves Dos Santos M, Fernandes I, Marto CM, Laranjo M, Silva D, Serro AP, Carrilho E, Botelho MF, Azul AM, Delgado AH. Effect of varying functional monomers in experimental self-adhesive composites: polymerization kinetics, cell metabolism influence and sealing ability. Biomed Mater 2023; 18:065014. [PMID: 37738988 DOI: 10.1088/1748-605x/acfc8d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 09/22/2023] [Indexed: 09/24/2023]
Abstract
The aim was to evaluate the effects of adding different functional monomers to experimental self-adhesive composites (SACs) on polymerization kinetics, cell metabolic activity, and sealing ability. SACs were formulated using urethane dimethacrylate as the base monomer and triethylene glycol dimethacrylate. Additionally, 10 wt.% of distinct functional monomers were added - 10-methacryloyloxydecyl dihydrogen phosphate, glycerol phosphate dimethacrylate (GPDM), 2-hydroxyethyl methacrylate (HEMA) or hydroxyethyl acrylamide (HEAA). ATR-FTIR was used to determine real-time polymerization kinetics (20 min,n= 3). The final extrapolated conversion and polymerization rates were determined (DC,max;Rp,max). TheDC,maxvalues were employed to calculate volumetric shrinkage. The MTT assay was performed on MDPC-23 cells using disc extracts at different concentrations (n= 8). Class V cavities were prepared in 60 sound human molars, assigned to six groups (n= 10), depending on the composite used and aging type (T0 or TC, if thermocycled for 10 000 cycles). One-way ANOVA, two-way, andKruskal-Wallistests were employed to treat the data (ɑ= 0.05). Varying the functional monomers had a large impact on DC,max, as confirmed by one-way ANOVA (p<0.001). The highest was obtained for HEMA (64 ± 3%). The HEMA and HEAA formulations were found to be significantly more toxic at concentrations below 100%. For microleakage, having a functional monomer or not did not show any improvement, irrespective of margin or aging period (Mann-Whitney U,p> 0.05). Larger functional monomers MDP and GPDM affected polymerization properties. Conversely, their acidity did not seem to be detrimental to cell metabolic activity. Regarding sealing ability, it seems that the functional monomers did not bring an advantage to the composites. Varying the functional monomer in SACs had a clear impact on the polymerization kinetics as well as on their cytotoxic potential. However, it did not confer better microleakage and sealing. Claiming self-adhesiveness based only on functional monomers seems dubious.
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Affiliation(s)
- Marta Nunes Ferreira
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
| | - Marta Neves Dos Santos
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
| | - Inês Fernandes
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
| | - Carlos Miguel Marto
- Institute of Experimental Pathology, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Institute of Biophysics, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3000-354 Coimbra, Portugal
| | - Mafalda Laranjo
- Institute of Biophysics, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3000-354 Coimbra, Portugal
| | - Diana Silva
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
- Centro de Química Estrutural, Institute of Molecular Sciences and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Ana Paula Serro
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
- Centro de Química Estrutural, Institute of Molecular Sciences and Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Eunice Carrilho
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3000-354 Coimbra, Portugal
- Faculty of Medicine, Institute of Integrated Clinical Practice, University of Coimbra, 3004-531 Coimbra, Portugal
| | - Maria Filomena Botelho
- Institute of Biophysics, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Area of Environment, Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal
- Center for Innovative Biomedicine and Biotechnology (CIBB), University of Coimbra, 3000-548 Coimbra, Portugal
- Clinical Academic Center of Coimbra (CACC), 3000-354 Coimbra, Portugal
| | - Ana Mano Azul
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
| | - António Hs Delgado
- Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, 2829-511 Caparica, Almada, Portugal
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, NW3 2PF London, United Kingdom
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Alhussein A, Alsahafi R, Wang X, Mitwalli H, Filemban H, Hack GD, Oates TW, Sun J, Weir MD, Xu HHK. Novel Dental Low-Shrinkage-Stress Composite with Antibacterial Dimethylaminododecyl Methacrylate Monomer. J Funct Biomater 2023; 14:335. [PMID: 37504831 PMCID: PMC10381573 DOI: 10.3390/jfb14070335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/13/2023] [Accepted: 06/17/2023] [Indexed: 07/29/2023] Open
Abstract
OBJECTIVES Current dental resins exhibit polymerization shrinkage causing microleakage, which has the potential to cause recurrent caries. Our objectives were to create and characterize low-shrinkage-stress (LSS) composites with dimethylaminododecyl methacrylate (DMADDM) as an antibacterial agent to combat recurrent caries. METHODS Triethylene glycol divinylbenzyl ether and urethane dimethacrylate were used to reduce shrinkage stress. DMADDM was incorporated at different mass fractions (0%, 1.5%, 3%, and 5%). Flexural strength, elastic modulus, degree of conversion, polymerization stress, and antimicrobial activity were assessed. RESULTS The composite with 5% DMADDM demonstrated higher flexural strength than the commercial group (p < 0.05). The addition of DMADDM in BisGMA-TEGDMA resin and LSS resin achieved clinically acceptable degrees of conversion. However, LSS composites exhibited much lower polymerization shrinkage stress than BisGMA-TEGDMA composite groups (p < 0.05). The addition of 3% and 5% DMADDM showed a 6-log reduction in Streptococcus mutans (S. mutans) biofilm CFUs compared to commercial control (p < 0.001). Biofilm biomass and lactic acid were also substantially decreased via DMADDM (p < 0.05). CONCLUSIONS The novel LSS dental composite containing 3% DMADDM demonstrated potent antibacterial action against S. mutans biofilms and much lower polymerization shrinkage-stress, while maintaining excellent mechanical characteristics. The new composite is promising for dental applications to prevent secondary caries and increase restoration longevity.
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Affiliation(s)
- Abdullah Alhussein
- PhD Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia
| | - Rashed Alsahafi
- Department of Restorative Dental Sciences, Umm Al-Qura University, College of Dentistry, Makkah 24211, Saudi Arabia
| | - Xiaohong Wang
- American Dental Association Science and Research Institute, LLC., Gaithersburg, MD 20899, USA
| | - Heba Mitwalli
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hanan Filemban
- Department of Operative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Gary D Hack
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Thomas W Oates
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Jirun Sun
- The Forsyth Institute, Harvard School of Dental Medicine Affiliate, Cambridge, MA 02142, USA
| | - Michael D Weir
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Hockin H K Xu
- Biomaterials & Tissue Engineering Division, Department of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
- The Forsyth Institute, Harvard School of Dental Medicine Affiliate, Cambridge, MA 02142, USA
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Venturini AB, Dapieve KS, de Kok P, Pereira GKR, Valandro LF, Kleverlaan CJ. Effect of the region of the CAD/CAM block on the flexural strength and structural reliability of restorative materials. J Mech Behav Biomed Mater 2023; 138:105597. [PMID: 36459706 DOI: 10.1016/j.jmbbm.2022.105597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/20/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022]
Abstract
The aim of the study was to evaluate whether the region (internal or external) of the CAD/CAM block influences the mechanical performance of restorative materials. Blocks of different CAD/CAM materials (Composites: KAV - Katana Avencia; LULT - LULT Ultimate; Ceramics: ENAM - Vita Enamic; NICE - N!CE; EMP - IPS Empress CAD; VMII - Vita Mark II; EMAX - IPS e.max CAD) were selected, and direct resin composite blocks (APX - Clearfil AP-X; FSUP - Filtek Supreme) were built using the incremental technique on a mold from one of the CAD/CAM blocks. All blocks were sectioned into bar-shaped specimens (1 × 1 × 14 mm), which were separated into two groups according to the region of the block (inside or outside). 3-point bending tests were performed following ISO 6872:2015 and flexural strength data were analyzed using one-way ANOVA and Bonferroni post-hoc tests (p < 0.05). Weibull module and characteristic strength were also calculated. In general, the mean flexural strength values were not statistically different (p > 0.05) between the inside and outside regions of each material, except for LULT (inside > outside) and EMAX (outside > inside). Comparing the materials, a similar strength (only discrete variations) was observed for inside, outside or merged (inside and outside data assembled together) regions: EMAX > KAV = LULT > NICE = APX > EMP = ENAM = VMII ≥ FSUP (merged condition). Characteristic strength at 63.2% failure probability and at 5% failure probability generally corroborates such observations. There were no statistical differences for Weibull module data (inside, outside, or merged), except for KAV and NICE (outside > inside). Thus, the region from where the restoration is milled within the CAD/CAM block generally does not influence the mechanical performance hereof (flexural strength, failure probability, risk of premature failures, and mechanical reliability) of the material, except for LULT and EMAX.
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Affiliation(s)
- Andressa Borin Venturini
- Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Kiara Serafini Dapieve
- Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Paul de Kok
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands.
| | - Gabriel Kalil Rocha Pereira
- Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Cornelis Johannes Kleverlaan
- Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, Noord-Holland, the Netherlands.
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AlSahafi R, Wang X, Mitwalli H, Alhussein A, Balhaddad AA, Melo MAS, Oates TW, Sun J, Xu HK, Weir MD. Novel antibacterial low-shrinkage-stress resin-based cement. Dent Mater 2022; 38:1689-1702. [PMID: 36115699 DOI: 10.1016/j.dental.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE A low-shrinkage-stress resin-based cement with antibacterial properties could be beneficial to create a cement with lower stress at the tooth-restoration interface, which could help to enhance the longevity of the fixed dental restoration by reducing microleakage and recurrent caries. To date, there has been no report on the development of a low-shrinkage-stress and bio-interactive cement. Therefore, the objectives of this study were to develop a novel low-shrinkage-stress resin-based cement containing dimethylaminohexadecyl methacrylate (DMAHDM) and investigate the mechanical and antibacterial properties for the first time. METHODS The monomers urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE) were combined and denoted as UV resin. Three cements were fabricated: (1) UV+ 0%DMAHDM (experimental control); (2) UV+ 3%DMAHDM, (3) UV+ %5DMAHDM. RelyX Ultimate cement was used as commercial control. Mechanical properties and Streptococcus mutans (S. mutans) biofilms growth on cement were evaluated. RESULTS The novel bio-interactive cement demonstrated excellent antibacterial and mechanical properties. Compared to commercial and experimental controls, adding DMAHDM into the UV cement significantly reduced colony forming unit (CFU) counts by approximately 7 orders of magnitude, metabolic activities from 0.29 ± 0.03 A540/cm2 to 0.01 ± 0.01 A540/cm2, and lactic acid production from 22.3 ± 0.74 mmol/L to 1.2 ± 0.27 mmol/L (n = 6) (p < 0.05). The low-shrinkage-stress cement demonstrated a high degree of conversion of around 70 %, while reducing the shrinkage stress by approximately 60%, compared to a commercial control (p < 0.05). CONCLUSIONS The new antibacterial low-shrinkage-stress resin-based cement provides strong antibacterial action and maintains excellent mechanical properties with reduced polymerization shrinkage stress. CLINICAL SIGNIFICANCE A low-shrinkage-stress resin-based cement containing DMAHDM was developed with potent antibacterial effects and promising mechanical properties. This cement may potentially enhance the longevity of fixed dental restoration such as a dental crown, inlay, onlay, and veneers through its excellent mechanical properties, low shrinkage stress, and strong antibacterial properties.
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Affiliation(s)
- Rashed AlSahafi
- PhD Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Sciences, Umm Al-Qura University, College of Dentistry, Makkah 24211, Saudi Arabia
| | - Xiaohong Wang
- American Dental Association Science and Research Institute, LLC., Gaithersburg, MD 20899, USA
| | - Heba Mitwalli
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia
| | - Abdullah Alhussein
- PhD Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia
| | - Abdulrahman A Balhaddad
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, P.O.Box 1982, Dammam 31441, Saudi Arabia
| | - Mary Anne S Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Biomaterials & Tissue Engineering Division, Dept. of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Thomas W Oates
- Biomaterials & Tissue Engineering Division, Dept. of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Jirun Sun
- The Forsyth Institute, Harvard School of Dental Medicine Affiliate, Cambridge, MA 02142, USA.
| | - H K Xu
- Biomaterials & Tissue Engineering Division, Dept. of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Michael D Weir
- Biomaterials & Tissue Engineering Division, Dept. of Advanced Oral Sciences and Therapeutics, University Maryland School of Dentistry, Baltimore, MD 21201, USA.
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Li W, Wang K, Wang Z, Li B. Optimal resin monomer ratios for light-cured dental resins. Heliyon 2022; 8:e10554. [PMID: 36119854 PMCID: PMC9475325 DOI: 10.1016/j.heliyon.2022.e10554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/07/2022] [Accepted: 09/01/2022] [Indexed: 12/01/2022] Open
Abstract
Monomer ratios play a crucial role on the performances of dental resins, the optimal monomer ratios for dental resins are determined by combining the degree of conversion (DC), rate of polymerization (Rp), and mechanical properties, based on commonly-used Bis-GMA (bisphenol A-glycidyl methacrylate), UDMA (urethane dimethacrylate), and TEGDMA (triethyleneglycol dimethacrylate) resins. The DC and mechanical properties of the dental resins are examined by NIR (Near Infrared Ray) spectroscopy and nanoindentation tests, respectively. The results indicate that the Rp increases while the DC decreases with the loading content of Bis-GMA or UDMA in dental resins (i.e., Bis-GMA/TEGDMA and UDMA/TEGDMA). Meanwhile, both elastic modulus and hardness also present a tendency to increase. Various different monomers maybe create a strong polymer matrix in proper proportions, comprehensively comparing the performances of dental resins in different monomer ratios, the cured resins containing Bis-GMA (15–35 wt%), UDMA (37–60 wt%) and TEGDMA (20–35 wt%) show better material properties. The present study offers a quantitative analysis for Bis-GMA/UDMA/TEGDMA dental resins as well as provides guidance for the research of dental resins.
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Affiliation(s)
- Weideng Li
- School of Materials Science and Engineering, Research Center for Materials Genome Engineering, Wuhan University of Technology, Wuhan 430070, China
| | - Kun Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Zhengzhi Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Bei Li
- School of Materials Science and Engineering, Research Center for Materials Genome Engineering, Wuhan University of Technology, Wuhan 430070, China.,State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430073, China
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8
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Albeshir EG, Alsahafi R, Albluwi R, Balhaddad AA, Mitwalli H, Oates TW, Hack GD, Sun J, Weir MD, Xu HHK. Low-Shrinkage Resin Matrices in Restorative Dentistry-Narrative Review. MATERIALS (BASEL, SWITZERLAND) 2022; 15:2951. [PMID: 35454643 PMCID: PMC9029384 DOI: 10.3390/ma15082951] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 02/06/2023]
Abstract
Dimethacrylate-based resin composites restorations have become widely-used intraoral materials in daily dental practice. The increasing use of composites has greatly enhanced modern preventive and conservative dentistry. They have many superior features, especially esthetic properties, bondability, and elimination of mercury and galvanic currents. However, polymeric materials are highly susceptible to polymerization shrinkage and stresses that lead to microleakage, biofilm formation, secondary caries, and restoration loss. Several techniques have been investigated to minimize the side effects of these shrinkage stresses. The primary approach is through fabrications and modification of the resin matrices. Therefore, this review article focuses on the methods for testing the shrinkage, as well as formulations of resinous matrices available to reduce polymerization shrinkage and its associated stress. Furthermore, this article reviews recent cutting-edge developments on bioactive low-shrinkage-stress nanocomposites to effectively inhibit the growth and activities of cariogenic pathogens and enhance the remineralization process.
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Affiliation(s)
- Ebtehal G. Albeshir
- Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; (E.G.A.); (R.A.)
- Department of Restorative Dentistry, King Abdul-Aziz Medical City, Ministiry of National Guard—Health Affairs, Riyadh 11426, Saudi Arabia;
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia
- King Abdullah International Medical Research Center, Ministiry of National Guard—Health Affairs, Riyadh 11426, Saudi Arabia
| | - Rashed Alsahafi
- Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; (E.G.A.); (R.A.)
- Department of Restorative Dental Sciences, College of Dentistry, Umm Al-Qura University, Makkah 24381, Saudi Arabia
| | - Reem Albluwi
- Department of Restorative Dentistry, King Abdul-Aziz Medical City, Ministiry of National Guard—Health Affairs, Riyadh 11426, Saudi Arabia;
- King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia
- King Abdullah International Medical Research Center, Ministiry of National Guard—Health Affairs, Riyadh 11426, Saudi Arabia
| | - Abdulrahman A. Balhaddad
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman bin Faisal University, Dammam 31441, Saudi Arabia;
| | - Heba Mitwalli
- Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Thomas W. Oates
- Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (T.W.O.); (G.D.H.)
| | - Gary D. Hack
- Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (T.W.O.); (G.D.H.)
| | - Jirun Sun
- The Forsyth Institute, A Harvard School of Dental Medicine Affiliate, 245 First Street, Cambridge, MA 02142, USA
| | - Michael D. Weir
- Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (T.W.O.); (G.D.H.)
| | - Hockin H. K. Xu
- Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; (T.W.O.); (G.D.H.)
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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9
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Rocha MG, Oliveira DCRSD, de Menezes LR, Roulet JF, Sinhoreti MAC, Correr AB. The use of an elastomeric methacrylate monomer (Exothane 24) to reduce the polymerization shrinkage stress and improve the two-body wear resistance of bulk fill composites. Dent Mater 2021; 38:e43-e57. [PMID: 34953625 DOI: 10.1016/j.dental.2021.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVES Characterize the chemical structure of an elastomeric monomer (Exothane 24) and evaluate the degree of conversion (DC), polymerization shrinkage stress (PSS), rate of polymerization (Rp), flexural strength (FStrenght), flexural modulus (FModulus), Vickers hardness (VHardness) and two-body wear resistance of dental bulk fill composites (BFCs) containing Exothane 24. METHODS The Exothane 24 was characterized using mass spectroscopy, elemental analysis, 13C- and 1H NMR. BFCs were formulated containing Exothane 24 (E10, E25, and E50). Similar BFCs containing regular UDMA (U10, U25, and U50), commercial conventional, and BFCs were used as control groups. ATR-FTIR spectroscopy was used to measure DC and the Rp of the composites. The PSS was measured using the universal testing machine method. Specimen bars were used to assess the FStrenght, FModulus, and VHardness. RBCs were submitted to a two-body wear test using a chewing simulator machine; the rate and volumetric wear loss were evaluated using an optical scanner. Data were analyzed statistically with α = 0.05 and β = 0.2. RESULTS Exothane 24 is a urethane isophorone tetramethyl methacrylate monomer with polymerization stress-relieving properties. No differences were found in the DC up to 4 mm in depth for E25. All BFCs had similar FStrenght, except for E50. E25 had the lowest volumetric wear loss and wear rate. E25 had approximately 30% lower PSS and slower Rp than commercial BFCs with similar wear resistance to conventional commercial composites. SIGNIFICANCE The Exothane 24 reduced the PSS and increased the wear resistance of BFCs; however, the formulation is important to optimize the properties of the BFCs.
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Affiliation(s)
- Mateus Garcia Rocha
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA.
| | | | - Livia Rodrigues de Menezes
- Institute of Macromolecules Professor Eloisa Mano, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jean-François Roulet
- Center for Dental Biomaterials, Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL, USA
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10
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Par M, Prskalo K, Tauböck TT, Skenderovic H, Attin T, Tarle Z. Polymerization kinetics of experimental resin composites functionalized with conventional (45S5) and a customized low-sodium fluoride-containing bioactive glass. Sci Rep 2021; 11:21225. [PMID: 34707213 PMCID: PMC8551297 DOI: 10.1038/s41598-021-00774-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/18/2021] [Indexed: 12/18/2022] Open
Abstract
This study aimed to investigate polymerization kinetics and curing light transmittance of two series of experimental dental resin composites filled with 0–40 wt% of either 45S5 bioactive glass (BG) or a customized low-Na F-containing BG. Polymerization kinetics in 0.1-mm and 2-mm thick layers were investigated through real-time degree of conversion measurements using a Fourier transform infrared (FTIR) spectrometer. FTIR spectra were continuously collected at a rate of 2 s−1 during light-curing (1340 mW/cm2). Light transmittance through 2-mm thick composite specimens was measured using a UV–Vis spectrometer at a rate of 20 s−1. Unlike BG 45S5, which led to a dose-dependent reduction in the rate and extent of polymerization, the customized low-Na F-containing BG showed a negligible influence on polymerization. The reduction in light transmittance of experimental composites due to the addition of the low-Na F-containing BG did not translate into impaired polymerization kinetics. Additionally, the comparison of polymerization kinetics between 0.1-mm and 2-mm thick layers revealed that polymerization inhibition identified for BG 45S5 was not mediated by an impaired light transmittance, indicating a direct effect of BG 45S5 on polymerization reaction. A customized low-Na F-containing BG showed favourable behaviour for being used as a functional filler in light-curing dental resin composites.
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Affiliation(s)
- Matej Par
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia.
| | - Katica Prskalo
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia
| | - Tobias T Tauböck
- Department of Conservative and Preventive Dentistry, Centre for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich, Switzerland
| | | | - Thomas Attin
- Department of Conservative and Preventive Dentistry, Centre for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich, Switzerland
| | - Zrinka Tarle
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia
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11
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Palagummi SV, Hong T, Jiang L, Chiang MYM. Thermal shrinkage reveals the feasibility of pulse-delay photocuring technique. Dent Mater 2021; 37:1772-1782. [PMID: 34607708 DOI: 10.1016/j.dental.2021.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/12/2021] [Accepted: 09/13/2021] [Indexed: 02/08/2023]
Abstract
OBJECTIVES To resolve the feasibility of the pulse-delay photocuring technique as a clinical strategy for reducing the detrimental polymerization stress induced in dental composites during the photocuring process. METHODS Model dental composites with high and low-filler contents were cured with the pulse-delay photocuring technique using different combinations of photocuring variables (irradiance, exposure time, and delay time). Irradiance used ranged from 0.1W/cm2 to 4W/cm2. The exposure time of the first pulse varied from 0.2s to 27.2s and the delay times ranged from 10s to 120s. The radiant exposure was varied from 4J/cm2 to 20J/cm2. A cantilever-beam based instrument (NIST Standards Reference Instrument 6005) was used to implement the photocuring technique for the measurement of the polymerization properties (the degree of monomer conversion, polymerization stress induced due to shrinkage, and temperature change due to the reaction exotherm and curing light absorbance) simultaneously in real-time. These properties were compared with those obtained using the conventional photocuring technique (i.e., using a constant irradiance for a fixed exposure time, a uniform exposure). RESULTS There exists a minimum radiant exposure, such that a reduction in the polymerization stress can be achieved without sacrificing the degree of monomer conversion by using the pulse-delay over the conventional photocuring technique. More specifically, stress reductions of up to 19% and 32% was observed with the pulse-delay when compared with the conventional photocuring technique at an irradiance of 0.5W/cm2 and 4W/cm2, respectively. The reduction occurred when the exposure time of the first pulse was greater than, but closer to, the gelation time (i.e., lower than the vitrification time) of the composite, regardless of the delay time used. Lower thermal shrinkage (contraction) during the post-curing time, rather than the stress relaxation during the delay time or lower degree of monomer conversion as claimed in the literature, is the cause of the reduction in the polymerization stress. SIGNIFICANCE The study clarifies a long-standing confusion and controversy on the applicability of the pulse-delay photocuring technique for reducing the polymerization stress and promotes its potential clinical success for dental restorative composites.
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Affiliation(s)
- Sri Vikram Palagummi
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Taeseung Hong
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, USA; Department of Materials Science and Engineering, Pukyong National University, Busan, Republic of Korea
| | - Li Jiang
- Department of General Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
| | - Martin Y M Chiang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
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12
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Filemban H, Bhadila G, Wang X, Melo MAS, Oates TW, Weir MD, Sun J, Xu HH. Novel low-shrinkage-stress bioactive nanocomposite with anti-biofilm and remineralization capabilities to inhibit caries. J Dent Sci 2021; 17:811-821. [PMID: 35756812 PMCID: PMC9201927 DOI: 10.1016/j.jds.2021.09.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/23/2021] [Indexed: 11/19/2022] Open
Abstract
Background/purpose A common reason for dental composite restoration failure is recurrent caries at the margins. Our objectives were to: (1) develop a novel low-shrinkage-stress, antibacterial and remineralizing resin composite; (2) evaluate the effects of dimethylaminohexadecyl methacrylate (DMAHDM) on mechanical properties, biofilm inhibition, calcium (Ca) and phosphate (P) ion release, degree of conversion, and shrinkage stress on the new low-shrinkage-stress resin composite for the first time. Material and methods The resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE) with high resistance to salivary hydrolytic degradation. Composites were made with 0%–8% of DMAHDM for antibacterial activity, and 20% of nanoparticles of amorphous calcium phosphate (NACP) for remineralization. Mechanical properties and Streptococcus mutans biofilm growth on composites were assessed. Ca and P ion releases, degree of conversion and shrinkage stress were evaluated. Results Adding 2–5% DMAHDM and 20% NACP into the low-shrinkage-stress composite did not compromise the mechanical properties (p > 0.05). The incorporation of DMAHDM greatly reduced S. mutans biofilm colony-forming units by 2–5 log and lactic acid production by 7 folds, compared to a commercial composite (p < 0.05). Adding 5% DMAHDM did not compromise the Ca and P ion release. The low-shrinkage-stress composite maintained a high degree of conversion of approximately 70%, while reducing the shrinkage stress by 37%, compared to a commercial control (p < 0.05). Conclusion The bioactive low-shrinkage-stress composite reduced the polymerization shrinkage stress, without compromising other properties. Increasing the DMAHDM content increased the antibacterial effect in a dose-dependent manner.
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Affiliation(s)
- Hanan Filemban
- Ph.D. Program in Dental Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, USA
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, USA
- Department of Operative Dentistry, King AbdulAziz University, Jeddah, Saudi Arabia
| | - Ghalia Bhadila
- Department of Pediatric Dentistry, King AbdulAziz University, Jeddah, Saudi Arabia
- Corresponding author.
| | - Xiaohong Wang
- American Dental Association Science and Research Institute, LLC., Gaithersburg, USA
| | - Mary Ann S. Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, USA
| | - Thomas W. Oates
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, USA
| | - Michael D. Weir
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, USA
- Corresponding author. Biomaterials & Tissue Engineering Division. Department of Advanced Oral Sciences and Therapeutics, University of Maryland Dental School, Baltimore, 21201, MD, USA.
| | - Jirun Sun
- The Forsyth Institute, Harvard School of Dental Medicine Affiliate, Cambridge, USA
- Corresponding author. The Forsyth Institute, Harvard School of Dental Medicine Affiliate, 245 First Street, Cambridge, 02142, MA, USA.
| | - Hockin H.K. Xu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, USA
- Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, USA
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, USA
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13
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Taylor R, Fuentealba R, Brackett WW, Roberts HW. 24 hour polymerization shrinkage of resin composite core materials. J ESTHET RESTOR DENT 2021; 33:775-785. [PMID: 34060198 DOI: 10.1111/jerd.12788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/20/2021] [Accepted: 05/06/2021] [Indexed: 12/01/2022]
Abstract
PURPOSE The study's purpose was to evaluate the 24-hour polymerization shrinkage of resin composite core materials. MATERIAL AND METHODS Eleven resin composite core material samples (n = 12) were evaluated using a non-contact imaging device with measurements obtained over 24 h. Shrinkage values were determined corresponding to proposed times involved with CAD/CAM same-day treatment and at 24 h. Shrinkage data was statistically compared using Friedman/Dunn's test for intragroup analysis and Kruskal Wallis/Dunn's test for intergroup analysis, all at a 95% level of confidence (α = 0.05). RESULTS Mean results identified a wide volumetric shrinkage range with considerable similarity overlap. Inconsistent shrinkage behavior was evident and all materials reached maximum values before 24 h. No significant difference was observed during proposed digital same day all ceramic crown procedures, but some differences were noted at 24 h. CONCLUSIONS Under this study's conditions results were material specific, at times inconsistent, with wide variation. Shrinkage consistently increased for all products and it is not known if the continued shrinkage magnitude may compromise the stability and fit of all-ceramic crowns at 24 h.
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Affiliation(s)
- Robert Taylor
- Division of Comprehensive Care, University of Kentucky College of Dentistry, Lexington, Kentucky, USA
| | - Rodrigo Fuentealba
- Division of Prosthodontics, University of Kentucky College of Dentistry, Lexington, Kentucky, USA
| | - William W Brackett
- Operative Dentistry and Fixed Prosthodontics, Department of Restorative Sciences, Dental College of Georgia, Augusta, Georgia, USA
| | - Howard W Roberts
- Director of Graduate Studies, University of Kentucky College of Dentistry, Lexington, Kentucky, USA.,Comprehensive Dentistry, Uniformed Services University of the Health Sciences Postgraduate Dental School, Bethesda, Maryland, USA
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14
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Raju R, Rajan G, Farrar P, Prusty BG. Dimensional stability of short fibre reinforced flowable dental composites. Sci Rep 2021; 11:4697. [PMID: 33633198 PMCID: PMC7907147 DOI: 10.1038/s41598-021-83947-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 02/08/2021] [Indexed: 11/24/2022] Open
Abstract
Fibre-reinforced dental composites are proven to have superior mechanical properties in comparison with micro/nano/hybrid filled composites. However, the addition of small quantities of short glass fibres could affect the dimensional stability of the restoration both during initial stages as well as through the life of the restoration. This in-vitro study aims at evaluating the physical properties of short S-Glass reinforced flowable dental composites. Two S-Glass short fibre-particulate reinforced (5 wt% of aspect ratios 50 and 70) and one particulate only reinforced flowable dental composites were prepared with UDMA-TEGDMA based dental monomer systems. Samples were photopolymersied for 60 s and stored in distilled water at 37 °C for 24 h before testing. Depth of cure (through-thickness microhardness), volumetric shrinkage (Archimedes technique), polymerisation stress (cantilever based tensometer), curing exotherm (thermocouple), water sorption and solubility (ISO 4049) and thermal expansion coefficient (dilatometer) were determined. The test results were statistically analysed using one-way ANOVA (p < 0.05). Depth of cure increased by 41%, volumetric shrinkage increased by 8.3%, shrinkage stress increased by 37.6%, exotherm increased by 20.2%, and thermal expansion reduced by 6.4% while water sorption and solubility had a negligible effect with the inclusion of short glass fibres. The study demonstrates that within the same organic resin system and quantity, a small replacement of fillers with short fibres could significantly affect the dimensional stability of the composite system. In conjunction with mechanical properties, this study could help clinicians to gain confidence in fibre reinforced dental composite restorative system.
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Affiliation(s)
- Raju Raju
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ginu Rajan
- School of Electrical, Computer & Telecommunications Engineering, University of Wollongong, Wollongong, NSW, 2522, Australia. .,ARC Centre for Automated Manufacture of Advanced Composites, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Paul Farrar
- SDI Limited, Melbourne, VIC, 3153, Australia
| | - B Gangadhara Prusty
- ARC Centre for Automated Manufacture of Advanced Composites, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
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15
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Bhadila G, Wang X, Weir MD, Melo MAS, Martinho F, Fay GG, Oates TW, Sun J, Xu HHK. Low-shrinkage-stress nanocomposite: An insight into shrinkage stress, antibacterial, and ion release properties. J Biomed Mater Res B Appl Biomater 2021; 109:1124-1134. [PMID: 33386668 DOI: 10.1002/jbm.b.34775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 10/17/2020] [Accepted: 11/28/2020] [Indexed: 02/05/2023]
Abstract
The aims are: (a) To develop the first low-shrinkage-stress nanocomposite with antibacterial and remineralization capabilities through the incorporation of dimethylaminododecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP); (b) to investigate the effects of the new composite on biofilm inhibition, mechanical properties, shrinkage stress, and calcium (Ca) and phosphate (P) ion releases. The low-shrinkage-stress resin consisted of urethane dimethacrylate and triethylene glycol divinylbenzyl ether. Composite was formulated with 3% DMAHDM and 20% NACP. Mechanical properties, shrinkage stress, and degree of conversion were evaluated. Streptococcus mutans biofilm growth on composites was assessed. Ca and P ion releases were measured. The shrinkage stress of the low-shrinkage-stress composite containing 3% DMAHDM and 20% NACP was 36% lower than that of traditional composite control (p < 0.05), with similar degrees of conversion of 73.9%. The new composite decreased the biofilm colony-forming unit by 4 log orders and substantially reduced biofilm lactic acid production compared to control composite (p < 0.05). Incorporating DMAHDM to the low-shrinkage-stress composite did not adversely affect the Ca and P ion release. A novel bioactive nanocomposite was developed with low shrinkage stress, strong antibiofilm activity, and high levels of ion release for remineralization, without undermining the mechanical properties and degree of conversion.
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Affiliation(s)
- Ghalia Bhadila
- Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, Maryland, USA.,Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA.,Department of Pediatric Dentistry, King AbdulAziz University, Jeddah, Saudi Arabia
| | - Xiaohong Wang
- Volpe Research Center, American Dental Association Foundation, Frederick, Maryland, USA
| | - Michael D Weir
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Mary Ann S Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Frederico Martinho
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Guadalupe Garcia Fay
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Thomas W Oates
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA
| | - Jirun Sun
- Volpe Research Center, American Dental Association Foundation, Frederick, Maryland, USA
| | - Hockin H K Xu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland, USA.,Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, Maryland, USA.,Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
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16
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Mechanical manifestation of the C-factor in relation to photopolymerization of dental resin composites. Dent Mater 2020; 36:1108-1114. [DOI: 10.1016/j.dental.2020.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 11/20/2022]
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17
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Bhadila G, Wang X, Zhou W, Menon D, Melo MAS, Montaner S, Oates TW, Weir MD, Sun J, Xu HHK. Novel low-shrinkage-stress nanocomposite with remineralization and antibacterial abilities to protect marginal enamel under biofilm. J Dent 2020; 99:103406. [PMID: 32526346 DOI: 10.1016/j.jdent.2020.103406] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/25/2020] [Accepted: 06/03/2020] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES Polymerization shrinkage stress may lead to marginal damage, microleakage and failure of composite restorations. The objectives of this study were to : (1) develop a novel nanocomposite with low-shrinkage-stress, antibacterial and remineralization properties to reduce marginal enamel demineralization under biofilms; (2) evaluate the mechanical properties of the composite and calcium (Ca) and phosphate (P) ion release; and (3) investigate the cytotoxicity of the new low-shrinkage-stress monomer in vitro. METHODS The low-shrinkage-stress resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE), and 3 % dimethylaminohexadecyl methacrylate (DMAHDM) and 20 % calcium phosphate nanoparticles (NACP) were added. Mechanical properties, polymerization shrinkage stress, and degree of conversion were evaluated. The growth of Streptococcus mutans (S. mutans) on enamel slabs with different composites was assessed. Ca and P ion releases and monomer cytotoxicity were measured. RESULTS Composite with DMAHDM and NACP had flexural strength of 84.9 ± 10.3 MPa (n = 6), matching that of a commercial control composite. Adding 3 % DMAHDM did not negatively affect the composite ion release. Under S. mutans biofilm, the marginal enamel hardness was 1.2 ± 0.1 GPa for the remineralizing and antibacterial group, more than 2-fold the 0.5 ± 0.07 GPa for control (p < 0.05). The polymerization shrinkage stress of the new composite was 40 % lower than that of traditional composite control (p < 0.05). The new monomers had fibroblast viability similar to that of traditional monomer control (p > 0.1). CONCLUSION A novel low-shrinkage-stress nanocomposite was developed with remineralizing and antibacterial properties. This new composite is promising to inhibit recurrent caries at the restoration margins by reducing polymerization stress and protecting enamel hardness.
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Affiliation(s)
- Ghalia Bhadila
- Ph.D. Program in Dental Biomedical Sciences, Biomaterials and Tissue Engineering Division, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Pediatric Dentistry, Faculty of Dentistry, King AbdulAziz University, Jeddah 21589, Saudi Arabia
| | - Xiaohong Wang
- Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA
| | - Wen Zhou
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; State Key Laboratory of Oral Diseases, Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, National Clinical Research Centre for Oral Diseases, Sichuan University, Chengdu, 610041, China
| | - Deepak Menon
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Mary Ann S Melo
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Silvia Montaner
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Thomas W Oates
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Michael D Weir
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
| | - Jirun Sun
- Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA.
| | - Hockin H K Xu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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18
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Aminoroaya A, Esmaeely Neisiany R, Nouri Khorasani S, Panahi P, Das O, Ramakrishna S. A Review of Dental Composites: Methods of Characterizations. ACS Biomater Sci Eng 2020; 6:3713-3744. [DOI: 10.1021/acsbiomaterials.0c00051] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alireza Aminoroaya
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Rasoul Esmaeely Neisiany
- Department of Materials and Polymer Engineering, Faculty of Engineering, Hakim Sabzevari University, Sabzevar 9617976487, Iran
| | - Saied Nouri Khorasani
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Parisa Panahi
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Oisik Das
- Material Science Division, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå 97187, Sweden
| | - Seeram Ramakrishna
- Centre for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
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19
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Palagummi SV, Hong T, Wang Z, Moon CK, Chiang MYM. Resin viscosity determines the condition for a valid exposure reciprocity law in dental composites. Dent Mater 2019; 36:310-319. [PMID: 31866065 DOI: 10.1016/j.dental.2019.12.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 12/04/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To provide conditions for the validity of the exposure reciprocity law as it pertains to the photopolymerization of dimethacrylate-based dental composites. METHODS Composites made from different mass ratios of resin blends (Bis-GMA/TEGDMA and UDMA/TEGDMA) and silanized micro-sized glass fillers were used. All the composites used camphorquinone and ethyl 4-dimethylaminobenzoate as the photo initiator system. A cantilever beam-based instrument (NIST SRI 6005) coupled with NIR spectroscopy and a microprobe thermocouple was used to simultaneously measure the degree of conversion (DC), the polymerization stress (PS) due to the shrinkage, and the temperature change (TC) in real time during the photocuring process. The instrument has an integrated LED light curing unit providing irradiances ranging from 0.01W/cm2 to 4W/cm2 at a peak wavelength of 460nm (blue light). Vickers hardness of the composites was also measured. RESULTS For every dental composite there exists a minimum radiant exposure required for an adequate polymerization (i.e., insignificant increase in polymerization with any further increase in the radiant exposure). This minimum predominantly depends on the resin viscosity of composite and can be predicted using an empirical equation established based on the test results. If the radiant exposure is above this minimum, the exposure reciprocity law is valid with respect to DC for high-fill composites (filler contents >50% by mass) while invalid for low-fill composites (that are clinically irrelevant). SIGNIFICANCE The study promotes better understanding on the applicability of the exposure reciprocity law for dental composites. It also provides a guidance for altering the radiant exposure, with the clinically available curing light unit, needed to adequately cure the dental composite in question.
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Affiliation(s)
- Sri Vikram Palagummi
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Taeseung Hong
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States; Department of Materials Science and Engineering, Pukyong National University, Busan, Republic of Korea
| | - Zhengzhi Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei, China
| | - Chang Kwon Moon
- Department of Materials Science and Engineering, Pukyong National University, Busan, Republic of Korea
| | - Martin Y M Chiang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, MD, United States.
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20
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Wang Z. Spatial and temporal tunability of magnetically-actuated gradient nanocomposites. SOFT MATTER 2019; 15:3133-3148. [PMID: 30864576 DOI: 10.1039/c9sm00124g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Natural biological materials usually adopt functional gradient designs within interfacial regions to fulfil unusual mechanically-challenging demands. Manufacturing analogous gradients to alleviate premature failures for synthetic interfaces has remained challenging until recently, where magnetically-actuated gradient nanocomposites (MA-G-NCs) have emerged as a promising processing technique. The essence of this technique lies in controlling the spatial distribution of nanoreinforcements (usually particles) inside a polymer matrix through a magnetophoresis process. Herein, we present a theory-experiment-combined study on the evolution kinetics and equilibrium distribution of the nanoparticles during the magnetophoresis process and consequently to explore the spatial and temporal tunability of the MA-G-NCs. Using a simplified drift-diffusion theory as the guide, we determine two critical processing parameters for the MA-G-NCs: the applied magnetic field and the actuation duration. By systematically varying these two parameters independently, we experimentally demonstrate that the profile of the nanoparticle distribution inside the MA-G-NCs can be finely tuned both spatially and temporally. In order to quantify the volume fraction of the nanoparticles along the cross section of the MA-G-NCs, we propose a mechanics-based method by site-specifically measuring the local elastic modulus and converting back to the volume fractions based on an established modulus-fraction correlation. The nanoparticle concentration profiles obtained thereby are validated by morphological characterizations and also agree well with theoretical predictions based on the drift-diffusion theory. Our combined results indicate that the magnetophoresis-induced evolution of the nanoparticles follows approximately the drift-diffusion transport process and the gradient profile of the MA-G-NCs is highly controllable and programmable. The presented study not only advances the fundamental understanding of the evolution kinetics of the nanoparticles under the effect of magnetophoresis, but also establishes the critical processing-structure-property relationships for the MA-G-NCs that should guide future development of customized interfaces with desired mechanical and physical property gradients.
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Affiliation(s)
- Zhengzhi Wang
- Department of Engineering Mechanics, School of Civil Engineering, Wuhan University, Wuhan, Hubei 430072, China.
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21
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Palagummi SV, Landis FA, Chiang MYM. Real-time synchronous measurement of curing characteristics and polymerization stress in bone cements with a cantilever-beam based instrument. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:035102. [PMID: 29604748 PMCID: PMC5834317 DOI: 10.1063/1.5025476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 02/07/2018] [Indexed: 06/08/2023]
Abstract
An instrumentation capable of simultaneously determining degree of conversion (DC), polymerization stress (PS), and polymerization exotherm (PE) in real time was introduced to self-curing bone cements. This comprises the combination of an in situ high-speed near-infrared spectrometer, a cantilever-beam instrument with compliance-variable feature, and a microprobe thermocouple. Two polymethylmethacrylate-based commercial bone cements, containing essentially the same raw materials but differ in their viscosity for orthopedic applications, were used to demonstrate the applicability of the instrumentation. The results show that for both the cements studied the final DC was marginally different, the final PS was different at the low compliance, the peak of the PE was similar, and their polymerization rates were significantly different. Systematic variation of instrumental compliance for testing reveals differences in the characteristics of PS profiles of both the cements. This emphasizes the importance of instrumental compliance in obtaining an accurate understanding of PS evaluation. Finally, the key advantage for the simultaneous measurements is that these polymerization properties can be correlated directly, thus providing higher measurement confidence and enables a more in-depth understanding of the network formation process.
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Affiliation(s)
- Sri Vikram Palagummi
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Forrest A Landis
- Penn State University-York Campus, York, Pennsylvania 17403, USA
| | - Martin Y M Chiang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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22
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Bienek DR, Frukhtbeyn SA, Giuseppetti AA, Okeke UC, Skrtic D. Antimicrobial Monomers for Polymeric Dental Restoratives: Cytotoxicity and Physicochemical Properties. J Funct Biomater 2018; 9:jfb9010020. [PMID: 29495522 PMCID: PMC5872106 DOI: 10.3390/jfb9010020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 02/14/2018] [Accepted: 02/22/2018] [Indexed: 12/16/2022] Open
Abstract
A trend for the next generation of polymeric dental restoratives is to incorporate multifunctional capabilities to regulate microbial growth and remineralize tooth surfaces. Polymerizable 2-(methacryloyloxy)-N-(2-(methacryloyloxy)ethyl)-N,N-dimethylethan-1-aminium bromide (IDMA1) and N,N′-([1,1′-biphenyl]-2,2′-diylbis(methylene))bis(2-(methacryloyloxy)-N,N-dimethylethan-1-aminium) bromide (IDMA2), intended for utilization in bi-functional antimicrobial and remineralizing composites, were synthesized, purified with an ethanol-diethyl ether-hexane solvent system, and validated by nuclear magnetic resonance (1H and 13C NMR) spectroscopy, mass spectrometry, and Fourier-transform infrared spectroscopy. When incorporated into light-curable urethane dimethacrylate (UDMA)/polyethylene glycol-extended UDMA (PEG-U)/ethyl 2-(hydroxymethyl)acrylate (EHMA) (assigned UPE) resins, IDMAs did not affect the overall resins’ hydrophilicity/hydrophobicity balance (water contact angle: 60.8–65.5°). The attained degrees of vinyl conversion (DVC) were consistently higher in both IDMA-containing copolymers and their amorphous calcium phosphate (ACP) composites (up to 5% and 20%, respectively) reaching 92.5% in IDMA2 formulations. Notably, these high DVCs values were attained without an excessive increase in polymerization stress. The observed reduction in biaxial flexure strength of UPE-IDMA ACP composites should not prevent further evaluation of these materials as multifunctional Class V restoratives. In direct contact with human gingival fibroblasts, at biologically relevant concentrations, IDMAs did not adversely affect cell viability or their metabolic activity. Ion release from the composites was indicative of their strong remineralization potential. The above, early-phase biocompatibility and physicochemical tests justify further evaluation of these experimental materials to identify formulation(s) suitable for clinical testing. Successful completion is expected to yield a new class of restoratives with well-controlled bio-function, which will physicochemically, mechanically, and biologically outperform the conventional Class V restoratives.
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Affiliation(s)
- Diane R Bienek
- Volpe Research Center, ADA Foundation, Gaithersburg, MD 20899, USA.
| | | | | | | | - Drago Skrtic
- Volpe Research Center, ADA Foundation, Gaithersburg, MD 20899, USA.
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Wang X, Huyang G, Palagummi SV, Liu X, Skrtic D, Beauchamp C, Bowen R, Sun J. High performance dental resin composites with hydrolytically stable monomers. Dent Mater 2018; 34:228-237. [DOI: 10.1016/j.dental.2017.10.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 10/05/2017] [Accepted: 10/18/2017] [Indexed: 12/19/2022]
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24
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Jones BH, Wheeler DR, Black HT, Stavig ME, Sawyer PS, Giron NH, Celina MC, Lambert TN, Alam TM. Stress Relaxation in Epoxy Thermosets via a Ferrocene-Based Amine Curing Agent. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00501] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Brad H. Jones
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - David R. Wheeler
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Hayden T. Black
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Mark E. Stavig
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Patricia S. Sawyer
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Nicholas H. Giron
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Mathias C. Celina
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Timothy N. Lambert
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
| | - Todd M. Alam
- Sandia National
Laboratories, Albuquerque, New Mexico 87185, United States
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25
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Sarkar S, Baker PJ, Chan EP, Lin-Gibson S, Chiang MYM. Quantifying the sensitivity of the network structure and properties from simultaneous measurements during photopolymerization. SOFT MATTER 2017; 13:3975-3983. [PMID: 28504293 PMCID: PMC5942882 DOI: 10.1039/c7sm00419b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present a method that combines experimental and computational approaches to assess a comprehensive set of structural and functional evolution during a network formation process via photopolymerization. Our work uses the simultaneous measurement of the degree of conversion, polymerization stress, the change in reaction temperature, and shrinkage strain in situ. These measurements are combined with the theory of viscoelastic materials to deduce the relaxation time and frequency-dependent modulus of the polymerizing network. The relaxation time and degree of conversion are used to demonstrate the effect of processing parameters (e.g. curing protocol adjusted by the light intensity) in creating different network structures for the same initial resin. We describe experimental trends using effective medium calculations on a cross-linked polymer network model. In particular, we show that the effect of curing conditions on the spatial heterogeneity in crosslink density can be quantified using multiparametric measurements and modeling. Collectively, the present method is a way to examine holistically the complex structural and functional evolution of the network formation process.
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Affiliation(s)
- Swarnavo Sarkar
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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26
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Kalliecharan D, Germscheid W, Price RB, Stansbury J, Labrie D. Shrinkage stress kinetics of Bulk Fill resin-based composites at tooth temperature and long time. Dent Mater 2016; 32:1322-1331. [DOI: 10.1016/j.dental.2016.07.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/25/2016] [Indexed: 11/29/2022]
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Diniz AC, Bandeca MC, Pinheiro LM, Dos Santosh Almeida LJ, Torres CR, Borges AH, Pinto SC, Tonetto MR, De Jesus Tavarez RR, Firoozmand LM. Influence of Different Etching Modes on Bond Strength to Enamel using Universal Adhesive Systems. J Contemp Dent Pract 2016; 17:820-825. [PMID: 27794152 DOI: 10.5005/jp-journals-10024-1937] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
INTRODUCTION The adhesive systems and the techniques currently used are designed to provide a more effective adhesion with reduction of the protocol application. The objective of this study was to evaluate the bond strength of universal adhesive systems on enamel in different etching modes (self-etch and total etch). MATERIALS AND METHODS The mesial and distal halves of 52 bovine incisors, healthy, freshly extracted, were used and divided into seven experimental groups (n = 13). The enamel was treated in accordance with the following experimental conditions: FUE-Universal System - Futurabond U (VOCO) with etching; FUWE - Futurabond U (VOCO) without etching; SB-Total Etch System - Single Bond 2 (3M); SBUE-Universal System - Single Bond Universal (3M ESPE) with etching; SBUWE - Single Bond Universal (3M ESPE) without etching; CLE-Self-etch System - Clearfil SE Bond (Kuraray) was applied with etching; CLWE - Clearfil SE Bond (Kuraray) without etching. The specimens were made using the composite spectrum TPH (Dentsply) and stored in distilled water (37 ± 1°C) for 1 month. The microshear test was performed using the universal testing machine EMIC DL 2000 with the crosshead speed of 0.5 mm/minute. The bond strength values were analyzed using statistical tests (Kruskal-Wallis test and Mann-Whitney test) with Bonferroni correction. RESULTS There was no statistically significant difference between groups (p < 0.05), where FUE (36.83 ± 4.9 MPa) showed the highest bond strength values and SBUWE (18.40 ± 2.2 MPa) showed the lowest bond strength values. The analysis of adhesive interface revealed that most failures occurred between the interface composite resin and adhesive. CONCLUSION The universal adhesive system used in dental enamel varies according to the trademark, and the previous enamel etching for universal systems and the self-etch both induced greater bond strength values. CLINICAL SIGNIFICANCE Selective enamel etching prior to the application of a universal adhesive system is a relevant strategy for better performance bonding.
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Affiliation(s)
- Ana Cs Diniz
- Department of Post-Graduate Program in Dentistry, CEUMA University, Renascença, São Luís, Brazil, e-mail:
| | - Matheus C Bandeca
- Department of Post-Graduate Program in Dentistry, CEUMA University, Renascença, São Luís, Brazil
| | - Larissa M Pinheiro
- Department of Dentistry, Federal University of Maranhão (UFMA), São Luís, Brazil
| | | | - Carlos Rg Torres
- Department of Restorative Dentistry, Institute of Science and Technology of São José dos Campos - São Paulo State University - UNESP, São José dos Campos, Brazil
| | - Alvaro H Borges
- Department of Post-Graduate Program in Integrated Dental Science, University of Cuiabá, Cuiabá, Brazil
| | - Shelon Cs Pinto
- Department of Dentistry, State University of Ponta Grossa Ponta Grossa, Brazil
| | - Mateus R Tonetto
- Department of Post-Graduate Program in Integrated Dental Science, University of Cuiabá, Cuiabá, Brazil
| | - Rudys R De Jesus Tavarez
- Department of Post-Graduate Program in Dentistry, CEUMA University, Renascença, São Luís, Brazil
| | - Leily M Firoozmand
- Department of Dentistry, Federal University of Maranhão (UFMA), São Luís, Brazil
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Lima MA, Bastos IN, Cella N. Quartz crystal microbalance and photoacoustic measurements in dental photocuring. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:093903. [PMID: 27782581 DOI: 10.1063/1.4963309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Photocured dental resins are used extensively in restorative procedures in dentistry. Inadequate curing reduces the lifetime of the dental restoration, and consequently it is essential to precisely measure the polymerisation kinetics. In this study, two techniques, Quartz Crystal Microbalance (QCM) and Photoacoustic Spectroscopy (PAS), were used to monitor the real-time cure and to obtain the optical absorption spectra of resins, respectively. From the PAS measurements, the precise peaks of absorption were identified, and were used as the appropriate wavelength of the photocuring light in the QCM monitoring. The combined use of these techniques allows reliable determination of the duration of the phases of physical and chemical changes that occur during photocuring. Two commercial dental resins were tested, and the results confirmed the advantages of using PAS and QCM to study polymerisation kinetics.
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Affiliation(s)
- Marcenilda A Lima
- Instituto Politécnico, IPRJ, Universidade do Estado do Rio de Janeiro, UERJ, P.O. Box 97282, 28.625-570 Nova Friburgo, Rio de Janeiro, Brazil
| | - Ivan N Bastos
- Instituto Politécnico, IPRJ, Universidade do Estado do Rio de Janeiro, UERJ, P.O. Box 97282, 28.625-570 Nova Friburgo, Rio de Janeiro, Brazil
| | - Norberto Cella
- Instituto Politécnico, IPRJ, Universidade do Estado do Rio de Janeiro, UERJ, P.O. Box 97282, 28.625-570 Nova Friburgo, Rio de Janeiro, Brazil
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29
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Medel S, Bosch P, Grabchev I, Shah PK, Liu J, Aguirre-Soto A, Stansbury JW. Simultaneous Measurement of Fluorescence, Conversion and Physical/mechanical Properties for Monitoring Bulk and Localized Photopolymerization Reactions in Heterogeneous Systems. RSC Adv 2016; 6:41275-41286. [PMID: 27213038 PMCID: PMC4871629 DOI: 10.1039/c6ra06341a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An FT-NIR spectrometer, rheometer and fluorescence spectrophotometer were coupled for the real-time monitoring of polymerization reactions, allowing the simultaneous tracking of polymerization kinetics, storage modulus as well as fluorescence. In this study, a methacrylate functionalized dansyl chromophore (DANSMA) was synthesized and two different nanogels were made from urethane dimethacrylate and isobornyl methacrylate. Two series of resin formulations were prepared using the DANSMA probe, ethoxylated bisphenol A dimethacrylate as the matrix monomer, Irgacure® 651 as the initiator and the dispersed, monomer-swollen nanogels to give clear UV-curable resins. Placement of the fluorescent probe either throughout the resin or linked into the nanogel before its dispersion in the matrix provides a tool to study how the nanogel structure affects local network development by means of fluorescence from the DANSMA probe. We demonstrate the potential of this new technique using a composite as the two phase system (resin and polymerizable nanogel) including a dansyl derivative as a polymerizable probe to follow the reactions that are taking places in both phases.
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Affiliation(s)
- S. Medel
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, 80303, CO, USA
- Department of Macromolecular Chemistry, Institute of Polymer Science and Technology, ICJP-CSIC, Juan de la Cierva 3, E-28006, Madrid, Spain
| | - P. Bosch
- Department of Macromolecular Chemistry, Institute of Polymer Science and Technology, ICJP-CSIC, Juan de la Cierva 3, E-28006, Madrid, Spain
| | - I. Grabchev
- Sofia University “St. Kliment Ohridski”, Faculty of Medicine, 1470, Sofia, Bulgaria
| | - P. K. Shah
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, 80303, CO, USA
| | - J. Liu
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, 80303, CO, USA
| | - A. Aguirre-Soto
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, 80303, CO, USA
| | - J. W. Stansbury
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 3415 Colorado Ave., Boulder, 80303, CO, USA
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Denver, 12800 East 19 Ave., Aurora, 80045, CO, USA
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Wang Z, Chiang MYM. System compliance dictates the effect of composite filler content on polymerization shrinkage stress. Dent Mater 2016; 32:551-60. [PMID: 26916062 DOI: 10.1016/j.dental.2016.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 12/09/2015] [Accepted: 01/15/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The effect of filler content in dental restorative composites on the polymerization shrinkage stress (PS) is not straightforward and has caused much debate in the literature. Our objective in this study was to clarify the PS/filler content relationship based on analytical and experimental approaches, so that guidelines for materials comparison in terms of PS and clinical selection of dental composites with various filler content can be provided. METHODS Analytically, a simplified model based on linear elasticity was utilized to predict PS as a function of filler content under various compliances of the testing system, a cantilever beam-based instrument used in this study. The predictions were validated by measuring PS of composites synthesized using 50/50 mixtures of two common dimethacrylate resins with a variety of filler contents. RESULTS Both experiments and predictions indicated that the influence of filler content on the PS highly depended on the compliance of the testing system. Within the clinic-relevant range of compliances and for the specific sample configuration tested, the PS increased with increasing filler content at low compliance of instrument, while increasing the compliance caused the effect of filler content on the PS to gradually diminish. Eventually, at high compliance, the PS inverted and decreased with increasing filler content. SIGNIFICANCE This compliance-dependent effect of filler content on PS suggests: (1) for materials comparison in terms of PS, the specific compliance at which the comparison being done should always be reported and (2) clinically, composites with relatively lower filler content could be selected for such cavities with relatively lower compliance (e.g. a Class-I cavity with thick tooth walls or the basal part in a cavity) and vice versa in order to reduce the final PS.
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Affiliation(s)
- Zhengzhi Wang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States
| | - Martin Y M Chiang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, United States.
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Polymerization stress evolution of a bulk-fill flowable composite under different compliances. Dent Mater 2016; 32:578-86. [PMID: 26861171 DOI: 10.1016/j.dental.2016.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 01/18/2016] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To use a compliance-variable instrument to simultaneously measure and compare the polymerization stress (PS) evolution, degree of conversion (DC), and exotherm of a bulk-fill flowable composite to a packable composite. METHODS A bulk-fill flowable composite (Filtek Bulk-fill, FBF) and a conventional packable composite (Filtek Z250, Z250) purchased from 3M ESPE were investigated. The composites were studied using a cantilever-beam based instrument equipped with an in situ near infrared (NIR) spectrometer and a microprobe thermocouple. The measurements were carried out under various instrumental compliances (ranging from 0.3327μm/N to 12.3215μm/N) that are comparable to the compliances of clinically prepared tooth cavities. Correlations between the PS and temperature change as well as the DC were interpreted. RESULTS The maximum PS of both composites at 10min after irradiation decreased with the increase in the compliance of the cantilever beam. The FBF composite generated a lower final stress than the Z250 sample under instrumental compliances less than ca. 4μm/N; however, both materials generated statistically similar PS values at higher compliances. The reaction exotherm and the DC of both materials were found to be independent of compliance. The DC of the FBF sample was slightly higher than that of the packable Z250 composite while the peak exotherm of FBF was almost double that of the Z250 composite. For FBF, a characteristic drop in the PS was observed during the early stage of polymerization for all compliances studied which was not observed in the Z250 sample. This drop was shown to relate to the greater exotherm of the less-filled FBF sample relative to the Z250 composite. SIGNIFICANCE While the composites with lower filler content (low viscosity) are generally considered to have lower PS than the conventional packable composites, a bulk-fill flowable composite was shown to produce lower PS under a lower compliance of constraint as would be experienced if the composite was used as the base material in clinical procedures.
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32
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Correlation between polymerization shrinkage stress and C-factor depends upon cavity compliance. Dent Mater 2016; 32:343-52. [PMID: 26778403 DOI: 10.1016/j.dental.2015.11.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 08/19/2015] [Accepted: 11/20/2015] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The literature reports inconsistent results regarding using configuration factor (C-factor) as an indicator to reflect the generation of polymerization shrinkage stress (PS) from dental restorative composites due to the constraint of cavity configuration. The current study aimed at unraveling the complex effects of C-factor on PS based on analytical and experimental approaches together, such that the reported inconsistency can be explained and a significance of C-factor in clinic can be comprehensively provided. METHODS Analytical models based on linear elasticity were established to predict PS measured in instruments (testing systems) with different compliances, and complex effects of C-factor on PS were derived. The analyses were validated by experiments using a cantilever beam-based instrument and systematic variation of instrumental compliance. RESULTS For a general trend, PS decreased with increasing C-factor when measured by instruments with high compliance. However, this trend gradually diminished and eventually reversed (PS became increased with increasing C-factor) by decreasing the system compliance. SIGNIFICANCE Our study indicates that the correlation between PS and C-factor are highly dependent on the compliance of testing instrument for PS measurement. This suggests that the current concept on the role of C-factor in the stress development and transmission to tooth structures, higher C-factor produces higher PS due to reduced flow capacity of more confined materials, can be misleading. Thus, the compliance of the prepared tooth (cavity) structure should also be considered in the effect of C-factor on PS.
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