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Al-Abd Al-Abbas MAF, Al-Badr RJ, Shamash MSA. Long-term water sorption/solubility of two dental bonding agents containing a colloidal dispersion of titanium dioxide. J Adv Pharm Technol Res 2023; 14:142-146. [PMID: 37255867 PMCID: PMC10226709 DOI: 10.4103/japtr.japtr_47_23] [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: 01/21/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 06/01/2023] Open
Abstract
The aim was to analyze the influence of the incorporation of 4% by mass of colloidal dispersion of titanium dioxide (TiO2) nanoparticles on the long-term water sorption and solubility of two commercial universal bonding agents. In vitro studies. A colloidal dispersion of TiO2 nanoparticles was formulated and blended into two commercial dental bonding agents, i.e., Ambar Universal (FGM, Brasil) and G-Premio Bond Universal (GC, America) at 4% by mass. Forty bonding agent discs were fabricated and segregated into four bonding agent groups of 10 discs each, i.e., GA: Ambar Universal (control), GB: Ambar Universal (4% TiO2 incorporated), GC: G-Premio Bond universal (control), and GD: G-Premio Bond (4% TiO2 incorporated). The bonding agent discs were developed by dispensing the bonding agents into a silicone cast of 5 mm diameter and 1 mm depth. After bonding agent discs were desiccated, the cured discs were weighed and kept in distilled water to be evaluated for water sorption and solubility over 1 year storage period. Statistical analysis was performed by independent variable t-test performed using the IBM SPSS software (Chicago, IL: SPSS Inc). The incorporated bonding agent groups (GA and GB) showed significantly lower (P < 0.05) water sorption and solubility following 1 year of water storage in comparison to the control bonding agents. Both GC and GD demonstrated remarkably lower water sorption and solubility than GA and GB. Incorporation of the colloidal dispersion of TiO2 nanoparticles at 4% by mass into the universal bonding agents has significantly reduced their water sorption and solubility contrast to their control groups.
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Affiliation(s)
| | - Rafid Jihad Al-Badr
- Department of Restorative Dentistry, College of Dentistry, Ahl Al Bayt University, Karbala, Iraq
| | - Muaid S Abbas Shamash
- Department of Oral Medicine, College of Dentistry, Ahl Al Bayt University, Karbala, Iraq
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Autonomous-Strengthening Adhesive Provides Hydrolysis-Resistance and Enhanced Mechanical Properties in Wet Conditions. Molecules 2022; 27:molecules27175505. [PMID: 36080272 PMCID: PMC9457668 DOI: 10.3390/molecules27175505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/18/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
The low-viscosity adhesive that is used to bond composite restorative materials to the tooth is readily damaged by acids, enzymes, and oral fluids. Bacteria infiltrate the resulting gaps at the composite/tooth interface, demineralize the tooth, and further erode the adhesive. This paper presents the preparation and characterization of a low-crosslink-density hydrophilic adhesive that capitalizes on sol-gel reactions and free-radical polymerization to resist hydrolysis and provide enhanced mechanical properties in wet environments. Polymerization behavior, water sorption, and leachates were investigated. Dynamic mechanical analyses (DMA) were conducted using water-saturated adhesives to mimic load transfer in wet conditions. Data from all tests were analyzed using appropriate statistical tests (α = 0.05). The degree of conversion was comparable for experimental and control adhesives at 88.3 and 84.3%, respectively. HEMA leachate was significantly lower for the experimental (2.9 wt%) compared to control (7.2 wt%). After 3 days of aqueous aging, the storage and rubbery moduli and the glass transition temperature of the experimental adhesive (57.5MPa, 12.8MPa, and 38.7 °C, respectively) were significantly higher than control (7.4MPa, 4.3 MPa, and 25.9 °C, respectively). The results indicated that the autonomic sol-gel reaction continues in the wet environment, leading to intrinsic reinforcement of the polymer network, improved hydrolytic stability, and enhanced mechanical properties.
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Kumar D, Bolskar RD, Mutreja I, Jones RS. Methacrylate Polymers With “Flipped External” Ester Groups: A Review. FRONTIERS IN DENTAL MEDICINE 2022. [DOI: 10.3389/fdmed.2022.923780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Current resin composites have favorable handling and upon polymerization initial physical properties that allow for efficient material replacement of removed carious tooth structure. Dental resin composites have long term durability limitations due to the hydrolysis of ester bonds within the methacrylate based polymer matrix. This article outlines the importance of ester bonds positioned internal to the carbon-carbon double bond in current methacrylate monomers. Water and promiscuous salivary/bacterial esterase activity can initiate ester bond hydrolysis that can sever the polymer backbone throughout the material. Recent studies have custom synthesized, with the latest advances in modern organic chemical synthesis, a novel molecule named ethylene glycol bis (ethyl methacrylate) (EGEMA). EGEMA was designed to retain the reactive acrylate units. Upon intermolecular polymerization of vinyl groups, EGEMA ester groups are positioned outside the backbone of the polymer chain. This review highlights investigation into the degradation resistance of EGEMA using buffer, esterase, and microbial storage assays. Material samples of EGEMA had superior final physical and mechanical properties than traditional ethylene glycol dimethacrylate (EGDMA) in all degradation assays. Integrating bioinformatics-based biodegradation predictions to the experimental results of storage media analyzed by LC/GC-MS revealed that hydrolysis of EGEMA generated small amounts of ethanol while preserving the strength bearing polymer backbone. Prior studies support investigation into additional custom synthesized methacrylate polymers with “flipped external” ester groups. The long term goal is to improve clinical durability compared to current methacrylates while retaining inherent advantages of acrylic based chemistry, which may ease implementation of these novel methacrylates into clinical practice.
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da Silva EVF, Goiato MC, Bitencourt SB, Finer Y, Brito VGB, Takamiya AS, de Oliveira SHP, Dos Santos DM. Effect of processing methods on the cytotoxicity of methyl methacrylate-based ocular prostheses: An in vitro study. Toxicol In Vitro 2021; 76:105211. [PMID: 34245821 DOI: 10.1016/j.tiv.2021.105211] [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: 04/30/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 11/25/2022]
Abstract
The study evaluated the influence of cycles and methods of an ocular prosthesis resin on cytotoxicity toward human conjunctival cells. Resins were polymerized by water bath (WB, 74 °C or 100 °C for 30 min to 9 h), microwave (MW, 1200 W, 3 to 14 min and 30 s at 0 to 720 W), or autopolymerization (AP, room temperature for 20 min ± 60 °C for 30 min). Degree of conversion (DC), cytotoxicity, level of inflammatory mediators, gene expression of different markers, and apoptosis were evaluated. Data were submitted to ANOVA and Tukey test (p < 0.05). WB with longer processing time at higher temperature had highest DC (85.6%) and higher TGF β1-gene expression (1.39); long cycle low power MW showed lowest DC (69.6%), lower cell proliferation (85.4%, MTT), and large IL-2 release (39,297 ng/mL). AP with additional processing time showed lower cell proliferation (75.3%, Alamar Blue), and AP polymerized at room temperature showed higher CASP 9-gene expression (1.21). AP methods showed higher IL-6 release (>277 pg/mL). Short cycle medium power MW had higher IL-23 release (534.2 pg/mL). MW (long and short cycles) and AP polymerizations have triggered a more intense inflammatory response. Among methods recommended by the manufacturer, WB showed high DC and less cytotoxicity.
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Affiliation(s)
- Emily Vivianne Freitas da Silva
- Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Sao Paulo State University (UNESP), Aracatuba, Sao Paulo, Brazil
| | - Marcelo Coelho Goiato
- Department of Dental Materials and Prosthodontics, Aracatuba Dental School, UNESP, Aracatuba, Sao Paulo, Brazil; Oral Oncology Center, São Paulo State University (Unesp), School of Dentistry, 1193 José Bonifácio St, Araçatuba, São Paulo 15050-015, Brazil.
| | - Sandro Basso Bitencourt
- Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Sao Paulo State University (UNESP), Aracatuba, Sao Paulo, Brazil
| | - Yoav Finer
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada; Institute of Biomedical Engineering, University of Toronto, Ontario, Canada
| | | | - Aline Satie Takamiya
- Oral Oncology Center, São Paulo State University (Unesp), School of Dentistry, 1193 José Bonifácio St, Araçatuba, São Paulo 15050-015, Brazil; Institute of Biomedical Engineering, University of Toronto, Ontario, Canada
| | - Sandra Helena Penha de Oliveira
- Oral Oncology Center, São Paulo State University (Unesp), School of Dentistry, 1193 José Bonifácio St, Araçatuba, São Paulo 15050-015, Brazil; Department of Basic Sciences, Aracatuba Dental School, UNESP, Aracatuba, Sao Paulo, Brazil
| | - Daniela Micheline Dos Santos
- Department of Dental Materials and Prosthodontics, Aracatuba Dental School, UNESP, Aracatuba, Sao Paulo, Brazil; Oral Oncology Center, São Paulo State University (Unesp), School of Dentistry, 1193 José Bonifácio St, Araçatuba, São Paulo 15050-015, Brazil
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Multifunctional monomer acts as co-initiator and crosslinker to provide autonomous strengthening with enhanced hydrolytic stability in dental adhesives. Dent Mater 2019; 36:284-295. [PMID: 31806495 DOI: 10.1016/j.dental.2019.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/31/2019] [Accepted: 11/15/2019] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate a new synthesized multifunctional monomer, aminosilane functionalized methacrylate (ASMA), containing polymerizable methacrylate, tertiary amine, and methoxysilane functionalities in dental adhesive formulations, and to investigate the polymerization kinetics, leachates, thermal and mechanical properties of copolymers. METHODS Adhesive contained HEMA/BisGMA (45/55, w/w) was used as a control, and mixtures based on HEMA/BisGMA/ASMA at the mass ratio of 45/(55-x)/x were used as experimental adhesive. Adhesives were characterized with regard to water miscibility, photo-polymerization behavior (Fourier transform infrared spectroscopy, FTIR), leached co-monomers (high performance liquid chromatography, HPLC), thermal properties (modulated differential scanning calorimeter, MDSC), and mechanical properties (dynamic mechanical analyzer, DMA). Stress relaxation times and the corresponding moduli, obtained from stress relaxation tests, are used in a simulated linear loading case. RESULTS As compared to the control, ASMA-containing adhesives showed higher water miscibility, lower viscosity, improved monomer-to-polymer conversion, significantly greater Tg and rubbery modulus. HPLC results indicated a substantial reduction of leached HEMA (up to 85wt%) and BisGMA (up to 55wt%) in ethanol. The simulation reveals that the ASMA-containing adhesive becomes substantially stiffer than the control. SIGNIFICANCE ASMA monomer plays multiple roles, i.e. it serves as both a co-initiator and crosslinker while also providing autonomous strengthening and enhanced hydrolytic stability in the adhesive formulations. This multifunctional monomer offers significant promise for improving the durability of the adhesive at the composite/tooth interface.
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Spencer P, Ye Q, Song L, Parthasarathy R, Boone K, Misra A, Tamerler C. Threats to adhesive/dentin interfacial integrity and next generation bio-enabled multifunctional adhesives. J Biomed Mater Res B Appl Biomater 2019; 107:2673-2683. [PMID: 30895695 PMCID: PMC6754319 DOI: 10.1002/jbm.b.34358] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/07/2019] [Accepted: 02/20/2019] [Indexed: 12/27/2022]
Abstract
Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary reason both composite and amalgam restorations fail is recurrent decay, for which composite restorations experience a 2.0-3.5-fold increase compared to amalgam. Recurrent decay is a pernicious problem-the standard treatment is replacement of defective composites with larger restorations that will also fail, initiating a cycle of ever-larger restorations that can lead to root canals, and eventually, to tooth loss. Unlike amalgam, composite lacks the inherent capability to seal discrepancies at the restorative material/tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal the interface, but the adhesive degrades, which can breach the composite/tooth margin. Bacteria and bacterial by-products such as acids and enzymes infiltrate the marginal gaps and the composite's inability to increase the interfacial pH facilitates cariogenic and aciduric bacterial outgrowth. Together, these characteristics encourage recurrent decay, pulpal damage, and composite failure. This review article examines key biological and physicochemical interactions involved in the failure of composite restorations and discusses innovative strategies to mitigate the negative effects of pathogens at the adhesive/dentin interface. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2466-2475, 2019.
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Affiliation(s)
- Paulette Spencer
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Mechanical Engineering, University of Kansas,1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Qiang Ye
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Linyong Song
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Ranganathan Parthasarathy
- Department of Civil Engineering, Tennessee State University, 3500 John A Merritt Blvd, Nashville, TN 37209, USA
| | - Kyle Boone
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Anil Misra
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Civil Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Candan Tamerler
- Institute for Bioengineering Research, School of Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Department of Mechanical Engineering, University of Kansas,1530 W. 15th Street, Lawrence, KS 66045-7609, USA
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Frukhtbeyn S, Van Dongen K, Sun J. Stoichiometry and Kinetics of Sequential Dimethacrylate Enzymolysis. J Dent Res 2019; 98:1037-1044. [PMID: 31329048 PMCID: PMC6651765 DOI: 10.1177/0022034519858975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The increasing use of methacrylate-based materials in tissue engineering and dental restorations demands detailed evaluation of enzymolysis of these materials due to toxicity, durability, and biocompatibility concerns. The objective of this study is to develop tools for assessing and ranking the enzymolysis kinetics of dimethacrylate (DMA) compounds. Triethyleneglycol DMA and diurethane DMA are employed as model DMAs for kinetic studies of 2-step enzymolysis by 2 esterases, pseudocholine esterase and cholesterol esterase. In addition, the intermediate hydrolysis products, mono-methacrylates (mono-MAs), are prepared via esterases. The kinetics of DMA enzymolysis are evaluated per the concentrations of DMA. The enzymolysis products are quantified by high-performance liquid chromatography. Additionally, stoichiometric analysis and a Berkeley Madonna model are employed to compare the efficacy of esterases in DMA enzymolysis. The chemical structure of mono-MAs is verified by proton and heteronuclear single quantum coherence (2D 1H-13C) nuclear magnetic resonance spectroscopy and mass spectrometry. In evaluating the ratio of sequential and simultaneous degradations of DMA and mono-MA, the stoichiometric analysis draws the same conclusions without using [mono-MA] as the experimental observation using [mono-MA]. The majority of the 4 esterase-DMA combinations undergo the sequential enzyme-catalyzed hydrolysis, from DMA to mono-MA to diol. However, cholesterol esterase is more effective than pseudocholine esterase in maintaining sequential degradation until >90% of DMA is decomposed. Both enzymolysis steps are first-order reactions. The mono-MAs are more hydrolysis resistant than DMAs. Moreover, esterase efficacy and selectivity on DMA enzymolysis are presented. The stoichiometric analysis provides valuable tools in assessing DMA enzymolysis when mono-MA is difficult to be obtained. The resistance of mono-MAs to enzymolysis suggests a need for thorough toxicity evaluations of these intermediate compounds. It also advocates the alternative approaches in designing and developing durable and biocompatible materials.
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Affiliation(s)
- S. Frukhtbeyn
- Volpe Research Center, American Dental Association Foundation, Frederick, MD, USA
| | - K. Van Dongen
- Volpe Research Center, American Dental Association Foundation, Frederick, MD, USA
| | - J. Sun
- Volpe Research Center, American Dental Association Foundation, Frederick, MD, USA
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Xu R, Yu F, Huang L, Zhou W, Wang Y, Wang F, Sun X, Chang G, Fang M, Zhang L, Li F, Tay F, Niu L, Chen J. Isocyanate-terminated urethane-based dental adhesive bridges dentinal matrix collagen with adhesive resin. Acta Biomater 2019; 83:140-152. [DOI: 10.1016/j.actbio.2018.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/28/2018] [Accepted: 11/05/2018] [Indexed: 12/17/2022]
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Xu Y, Zhang J, Wang H, Xie D. Preparation of a low viscosity urethane-based composite for improved dental restoratives. Dent Mater J 2018; 37:400-407. [PMID: 29553122 DOI: 10.4012/dmj.2017-162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Several new urethane-based dimethacrylates were synthesized, characterized and used to formulate the resin composites. Compressive strength (CS) was used as a screen tool to evaluate the mechanical property of the formed composites. Flexural strength, diametral tensile strength, water sorption, degree of conversion and shrinkage of the composites were also evaluated. The results show that most of the synthesized urethane-based dimethacrylates were solid, which are not suitable to dental filling restorations. However, it was found that liquid urethane-based dimethacrylates could be derivatized using asymmetrical methacrylate synthesis. Not only the newly synthesized urethane-based dimethacrylates showed lower viscosity values but also their constructed composites exhibited higher mechanical strengths. Without triethyleneglycol dimethacrylate (TEGDMA) addition, the new urethane-constructed composites showed significantly lower water sorption and shrinkage.
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Affiliation(s)
- Yuling Xu
- College of Chemical and Environmental Engineering, Wuhan Polytech University.,Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis
| | - Juntao Zhang
- College of Chemical and Environmental Engineering, Wuhan Polytech University
| | - Haibo Wang
- College of Chemical and Environmental Engineering, Wuhan Polytech University
| | - Dong Xie
- Department of Biomedical Engineering, Indiana University-Purdue University at Indianapolis
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Xu Y, Wang H, Xie D. Preparation of new low viscosity urethane dimethacrylates for dental composites. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2017; 29:1011-1025. [PMID: 28784029 DOI: 10.1080/09205063.2017.1364098] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Urethane-based polymers are very biocompatible in many biomedical applications. This study reports the synthesis of new low viscosity urethane dimethacrylates and evaluation of the formed composites. New urethane dimethacrylates were synthesized and formulated to form the composites. Compressive strength was used as a primary tool to evaluate the mechanical property. Water sorption, solubility, degree of conversion, flexural strengths and shrinkage were also investigated. It was found that liquid urethane dimethacrylates could be synthesized by derivatizing isocyanates with asymmetrical methacrylates. By eliminating diluent triethylene glycol dimethacrylate, the new urethane dimethacrylate-composed composites showed significantly higher modulus, lower water sorption, lower solubility and lower shrinkage, as compared to commercial BisGMA- and UDMA-based ones.
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Affiliation(s)
- Yuling Xu
- a College of Chemical and Environmental Engineering , Wuhan Polytech University , Wuhan , China.,b Department of Biomedical Engineering, Purdue School of Engineering and Technology , Indiana University-Purdue University at Indianapolis , Indianapolis , IN , USA
| | - Haibo Wang
- a College of Chemical and Environmental Engineering , Wuhan Polytech University , Wuhan , China
| | - Dong Xie
- b Department of Biomedical Engineering, Purdue School of Engineering and Technology , Indiana University-Purdue University at Indianapolis , Indianapolis , IN , USA
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Melinte V, Buruiana T, Chibac A, Mares M, Aldea H, Buruiana EC. New acid BisGMA analogs for dental adhesive applications with antimicrobial activity. Dent Mater 2016; 32:e314-e326. [PMID: 27671467 DOI: 10.1016/j.dental.2016.09.026] [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: 03/11/2016] [Revised: 07/08/2016] [Accepted: 09/03/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To achieve bisphenol A glycerolate dimethacrylate (BisGMA) analogs with reduced viscosity to be used in the formulation of dental adhesives containing biocidal components. METHODS A series of low-viscosity BisGMA derivatives (η: 39-12Pas) modified with 30, 60 and, respectively 80mol% carboxylic acid units were synthesized and characterized. Hydrogen bonding interactions in our monomers, the photopolymerization behavior and implicitly the conversion degree (DC) for some experimental adhesive formulations containing acid-modified BisGMA, commercial BisGMA (only in F1-F3), triethyleneglycol dimethacrylate and 2-hydroxyethyl methacrylate were examined by FTIR spectroscopy. The water effects on the photocrosslinked networks together with the flexural strength/modulus were also investigated. The adhesive penetration into the dentin surface was surveyed by SEM analysis, and the antimicrobial activity triggered by the incorporation of 0.5wt% AgNO3, 10wt% zinc methacrylate or 1wt% triclosan methacrylate in selected adhesive formulations on the growth of Streptococcus mutans and Candida albicans strains was evidenced. RESULTS The contribution of the hydrogen bonding interactions was found to be lower in BisGMA derivatives than in non-modified BisGMA, and the DC varied between 56.5 (F6) and 83.7% (F1) compared with a control formulation based on BisGMA:TEGDMA (DC=58.2%). The flexural strength and flexural modulus varied in the range 33.7MPa (F6)-54.4MPa (F8)MPa and 0.64 (F6)-1.43 (F8)GPa, respectively. SEM observation of adhesive-dentin interface revealed the formation of resin tags for the carboxyl-containing adhesive, while for the control adhesive they are hardly formed. Also, the microorganism development was inhibited, the proposed materials displaying antimicrobial activity. SIGNIFICANCE The experimental formulations based on carboxyl-functionalized BisGMA exhibit a similar or even improved behavior over control sample, suggesting their potential applicability as antimicrobial dental adhesives.
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Affiliation(s)
- Violeta Melinte
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi, Romania
| | - Tinca Buruiana
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi, Romania.
| | - Andreea Chibac
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi, Romania
| | - Mihai Mares
- Laboratory of Antimicrobial Chemotherapy, "Ion Ionescu de la Brad" University, 8 Sadoveanu Alley, 700489 Iasi, Romania
| | - Horia Aldea
- Dental Office, 17 T. Vladimirescu Street, Iasi, Romania
| | - Emil C Buruiana
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, 700487 Iasi, Romania
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Song L, Ye Q, Ge X, Misra A, Spencer P. Mimicking nature: Self-strengthening properties in a dental adhesive. Acta Biomater 2016; 35:138-52. [PMID: 26883773 DOI: 10.1016/j.actbio.2016.02.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 02/10/2016] [Accepted: 02/11/2016] [Indexed: 10/22/2022]
Abstract
Chemical and enzymatic hydrolysis provoke a cascade of events that undermine methacrylate-based adhesives and the bond formed at the tooth/composite interface. Infiltration of noxious agents, e.g. enzymes, bacteria, and so forth, into the spaces created by the defective bond will ultimately lead to failure of the composite restoration. This paper reports a novel, synthetic resin that provides enhanced hydrolytic stability as a result of intrinsic reinforcement of the polymer network. The behavior of this novel resin, which contains γ-methacryloxyproyl trimethoxysilane (MPS) as its Si-based compound, is reminiscent of self-strengthening properties found in nature. The efforts in this paper are focused on two essential aspects: the visible-light irradiation induced (photoacid-induced) sol-gel reaction and the mechanism leading to intrinsic self-strengthening. The FTIR band at 2840cm(-1) corresponding to CH3 symmetric stretch in -Si-O-CH3 was used to evaluate the sol-gel reaction. Results from the real-time FTIR indicated that the newly developed resin showed a limited sol-gel reaction (<5%) during visible-light irradiation, but after 48h dark storage, the reaction was over 65%. The condensation of methoxysilane mainly occurred under wet conditions. The storage moduli and glass transition temperature of the copolymers increased in wet conditions with the increasing MPS content. The cumulative amounts of leached species decreased significantly when the MPS-containing adhesive was used. The results suggest that the polymethacrylate-based network, which formed first as a result of free radical initiated polymerization, retarded the photoacid-induced sol-gel reaction. The sol-gel reaction provided a persistent, intrinsic reinforcement of the polymer network in both neutral and acidic conditions. This behavior led to enhanced mechanical properties of the dental adhesives under conditions that simulate the wet, oral environment. STATEMENT OF SIGNIFICANCE A self-strengthening dental adhesive system was developed through a dual curing process, which involves the free radical photopolymerization followed by slow hydrolysis and condensation (photoacid-induced sol-gel reaction) of alkoxylsilane groups. The concept of "living" photoacid-induced sol-gel reaction with visible-light irradiation was confirmed in the polymer. The sol-gel reaction was retarded by the polymethacrylate network, which was generated first; the network extended the life and retained the activity of silanol groups. The self-strengthening behavior was evaluated by monitoring the mechanical properties of the hybrid copolymers under wet conditions. The present research demonstrates the sol-gel reaction in highly crosslinked network as a potentially powerful strategy to prolong the functional lifetime of engineered biomaterials in wet environments.
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Buruiana T, Melinte V, Aldea H, Pelin IM, Buruiana EC. A new fluorinated urethane dimethacrylate with carboxylic groups for use in dental adhesive compositions. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 62:96-104. [PMID: 26952402 DOI: 10.1016/j.msec.2016.01.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 01/06/2016] [Accepted: 01/15/2016] [Indexed: 11/30/2022]
Abstract
A urethane macromer containing hexafluoroisopropylidene, poly(ethylene oxide) and carboxylic moieties (UF-DMA) was synthesized and used in proportions varying between 15 and 35 wt.% (F1-F3) in dental adhesive formulations besides BisGMA, triethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate. The FTIR and (1)H ((13)C) NMR spectra confirmed the chemical structure of the UF-DMA. The experimental adhesives were characterized with regard to the degree of conversion, water sorption/solubility, contact angle, diffusion coefficient, Vickers hardness, and morphology of the crosslinked networks and compared with the specimens containing 10 wt.% hydroxyapatite (HAP) or calcium phosphate (CaP). The conversion degree (after 180 s of irradiation with visible light) ranged from 59.5% (F1) to 74.8% (F3), whereas the water sorption was between 23.15 μg mm(-3) (F1) and 40.52 μg mm(-3) (F3). Upon the addition of HAP or CaP this parameter attained values of 37.82-49.14 μg mm(-3) (F1-F3-HAP) and 34.58-45.56 μg mm(-3), respectively. Also, the formation of resin tags through the infiltration of a dental composition (F3) was visualized by SEM analysis. The results suggest that UF-DMA taken as co-monomer in dental adhesives of acrylic type may provide improved properties in the moist environment of the mouth.
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Affiliation(s)
- Tinca Buruiana
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi, Romania.
| | - Violeta Melinte
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Horia Aldea
- Gr. T. Popa University of Medicine and Pharmacy, Faculty of Dentistry, 16 University Str., 700115 Iasi, Romania
| | - Irina M Pelin
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi, Romania
| | - Emil C Buruiana
- Polyaddition and Photochemistry Department, Petru Poni Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, 700487 Iasi, Romania
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Ge X, Ye Q, Song L, Spencer P, Laurence JS. Effect of crosslinking density of polymers and chemical structure of amine-containing monomers on the neutralization capacity of dentin adhesives. Dent Mater 2015; 31:1245-53. [PMID: 26342639 DOI: 10.1016/j.dental.2015.08.153] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 06/18/2015] [Accepted: 08/17/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Neutralization of the acidic micro-environment at the tooth/material interface is expected to provide enhanced durability for dental composite restorations. The objective of this study is to explore the effect of amine-containing monomer formulations and the crosslinking density of the resultant polymers on the neutralization capacity. MATERIALS AND METHODS The co-monomer system was varied systematically to obtain different proportions of Bisphenol A glycerolate dimethacrylate (BisGMA) and 2-hydroxyethyl methacrylate (HEMA), while maintaining a constant amount of amine-containing methacrylate monomer. A series of amine-containing monomers covering a range of pKa values were examined. Crosslinking density of formed copolymers was controlled by adjusting the weight content of the dimethacrylate monomer BisGMA. Lactic acid (LA) was used as a probe to analyze the effectiveness of the basic polymers to neutralize acid. The neutralization capacity of each amine-containing crosslinked copolymer was characterized by measuring pH as a function of time when the specimens were soaked in 1-mM LA solution, and the results were compared to the control formulations composed solely of BisGMA and HEMA. Polymer surfaces were examined using the methyl orange (MO) assay to quantify the amount of accessible amine groups. RESULTS For each amine-containing crosslinked co-polymer, the neutralization capacity is enhanced by decreasing crosslinking density (e.g., by reducing BisGMA concentration in the formulation). In addition, more amine groups were accessible when crosslinking density was decreased. For different amine-containing polymers with the same BisGMA concentration, the neutralization capacity is higher when the amino monomers with higher pKa values were used in the formulations. SIGNIFICANCE This is the first time that the neutralization capacity based on crosslinked dental polymers has been studied. The information is important for future development of durable dentin adhesives.
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Affiliation(s)
- Xueping Ge
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Qiang Ye
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Linyong Song
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Paulette Spencer
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA; Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA.
| | - Jennifer S Laurence
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA.
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15
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Song L, Ye Q, Ge X, Spencer P. Compositional design and optimization of dentin adhesive with neutralization capability. J Dent 2015; 43:1132-1139. [PMID: 26144189 DOI: 10.1016/j.jdent.2015.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/04/2015] [Accepted: 06/26/2015] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVES The objective of this work was to investigate the polymerization behavior, neutralization capability, and mechanical properties of dentin adhesive formulations with the addition of the tertiary amine co-monomer, 2-N-morpholinoethyl methacrylate (MEMA). METHODS A co-monomer mixture based on HEMA/BisGMA (45/55, w/w) was used as a control adhesive. Compared with the control formulation, the MEMA-containing adhesive formulations were characterized comprehensively with regard to water miscibility of liquid resin, water sorption and solubility of cured polymer, real-time photopolymerization kinetics, dynamic mechanical analysis (DMA), and modulated differential scanning calorimetry (MDSC). The neutralization capacity was characterized by monitoring the pH shift of 1mM lactic acid (LA) solution, in which the adhesive polymers were soaked. RESULTS With increasing MEMA concentrations, experimental copolymers showed higher water sorption, lower glass transition temperature and lower crosslinking density compared to the control. The pH values of LA solution gradually increased from 3.5 to about 6.0-6.5 after 90 days. With the increase in crosslinking density of the copolymers, the neutralization rate was depressed. The optimal MEMA concentration was between 20 and 40 wt%. CONCLUSIONS As compared to the control, the results indicated that the MEMA-functionalized copolymer showed neutralization capability. The crosslinking density of the copolymer networks influenced the neutralization rate.
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Affiliation(s)
- Linyong Song
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Qiang Ye
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA.
| | - Xueping Ge
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Paulette Spencer
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; University of Kansas, Department of Mechanical Engineering, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA.
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16
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Dixit N, Settle JK, Ye Q, Berrie CL, Spencer P, Laurence JS. Grafting MAP peptide to dental polymer inhibits MMP-8 activity. J Biomed Mater Res B Appl Biomater 2014; 103:324-31. [PMID: 24889674 DOI: 10.1002/jbm.b.33205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/15/2014] [Accepted: 04/29/2014] [Indexed: 11/06/2022]
Abstract
Matrix metalloproteinases (MMPs) are a class of zinc and calcium-dependent endopeptidases responsible for degrading extracellular matrix (ECM) components. Their activity is critical for both normal biological function and pathological processes (Dejonckheere et al., Cytokine Growth Factor Rev 2011;22:73-81). In dental restorations, the release and subsequent acid activation of MMPs contributes to premature failure. In particular, MMP-8 accelerates degradation by cleaving the collagen matrix within the dentin substrate in incompletely infiltrated aged bonded dentin (Buzalaf et al., Adv Dent Res 2012;24:72-76), hastening the need for replacement of restorations. Therefore, development of a dental adhesive that better resists MMP-8 activity is of significant interest. We hypothesize that modification of the polymer surface with an inhibitor would disable MMP-8 activity. Here, we identify the metal abstraction peptide (MAP) as an inhibitor of MMP-8 and demonstrate that tethering MAP to methacrylate polymers effectively inhibits catalysis. Our findings indicate complete inhibition of MMP-8 is achievable using a grafting approach. This strategy has potential to improve longevity of dental adhesives and other polymers and enable rational design of a new generation of biocompatible materials.
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Affiliation(s)
- Namrata Dixit
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, 66045-7609
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17
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Song L, Ye Q, Ge X, Misra A, Laurence JS, Berrie CL, Spencer P. Synthesis and evaluation of novel dental monomer with branched carboxyl acid group. J Biomed Mater Res B Appl Biomater 2014; 102:1473-84. [PMID: 24596134 DOI: 10.1002/jbm.b.33126] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 01/23/2014] [Accepted: 02/18/2014] [Indexed: 11/07/2022]
Abstract
To enhance the water miscibility and increase the mechanical properties of dentin adhesives, a new glycerol-based monomer with vinyl and carboxylic acid, 4-((1,3-bis(methacryloyloxy)propan-2-yl)oxy)-2-methylene-4-oxobutanoic acid (BMPMOB), was synthesized and characterized. Dentin adhesive formulations containing 2-hydroxyethyl methacrylate (HEMA), 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (BisGMA), and BMPMOB were characterized with regard to real-time photopolymerization behavior, water sorption, dynamic mechanical analysis, and microscale three-dimensional internal morphologies and compared with HEMA/BisGMA controls. The experimental adhesive copolymers showed higher glass transition temperature and rubbery moduli, as well as improved water miscibility compared to the controls. The enhanced properties of the adhesive copolymers indicated that BMPMOB is a promising comonomer for dental restorative materials.
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Affiliation(s)
- Linyong Song
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, 66045; School of Chemistry and Chemical Engineering, Anhui University, Hefei, China
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18
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Laurence JS, Nelson BN, Ye Q, Park J, Spencer P. Characterization of Acid-neutralizing Basic Monomers in Co-solvent Systems by NMR. INT J POLYM MATER PO 2014; 63:361-367. [PMID: 25400302 DOI: 10.1080/00914037.2013.845192] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Metabolic activity of the oral microbiota leads to acidification of the microenvironment and promotes demineralization of tooth structure at the margin of composite restorations. The pathogenic impact of the biofilm at the margin of the composite restoration could be reduced by engineering novel dentin adhesives that neutralize the acidic micro-environment. Integrating basic moieties into methacrylate derivatives has the potential to buffer against acid-induced degradation, and we are investigating basic monomers for this purpose. These monomers must be compatible with existing formulations, which are hydrophobic and marginally miscible with water. As such, cosolvent systems may be required to enable analysis of monomer function and chemical properties. Here we present an approach for examining the neutralizing capacity of basic methacrylate monomers in a water/ethanol co-solvent system using NMR spectroscopy. NMR is an excellent tool for monitoring the impact of co-solvent effects on pKa and buffering capacity of basic monomers because chemical shift is extremely sensitive to small changes that most other methods cannot detect. Because lactic acid (LA) is produced by oral bacteria and is prevalent in this microenvironment, LA was used to analyze the effectiveness of basic monomers to neutralize acid. The 13C chemical shift of the carbonyl in lactic acid was monitored as a function of ethanol and monomer concentration and each was correlated with pH to determine the functional buffering range. This study shows that the buffering capacity of even very poorly water-soluble monomers can be analyzed using NMR.
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Affiliation(s)
- Jennifer S Laurence
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Benjamin N Nelson
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | - Qiang Ye
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | - Jonggu Park
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | - Paulette Spencer
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA ; Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
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19
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Delaviz Y, Finer Y, Santerre JP. Biodegradation of resin composites and adhesives by oral bacteria and saliva: A rationale for new material designs that consider the clinical environment and treatment challenges. Dent Mater 2014; 30:16-32. [DOI: 10.1016/j.dental.2013.08.201] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 08/05/2013] [Accepted: 08/05/2013] [Indexed: 01/25/2023]
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20
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Bohaty BS, Ye Q, Misra A, Sene F, Spencer P. Posterior composite restoration update: focus on factors influencing form and function. Clin Cosmet Investig Dent 2013; 5:33-42. [PMID: 23750102 PMCID: PMC3666491 DOI: 10.2147/ccide.s42044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 12/01/2022] Open
Abstract
Restoring posterior teeth with resin-based composite materials continues to gain popularity among
clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common
aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite
restorations, however, have higher failure rates, more recurrent caries, and increased frequency of
replacement. Investigators across the globe are researching new materials and techniques that will
improve the clinical performance, handling characteristics, and mechanical and physical properties
of composite resin restorative materials. Despite such attention, large to moderate posterior
composite restorations continue to have a clinical lifetime that is approximately one-half that of
the dental amalgam. While there are numerous recommendations regarding preparation design,
restoration placement, and polymerization technique, current research indicates that restoration
longevity depends on several variables that may be difficult for the dentist to control. These
variables include the patient’s caries risk, tooth position, patient habits, number of
restored surfaces, the quality of the tooth–restoration bond, and the ability of the
restorative material to produce a sealed tooth–restoration interface. Although clinicians
tend to focus on tooth form when evaluating the success and failure of posterior composite
restorations, the emphasis must remain on advancing our understanding of the clinical variables that
impact the formation of a durable seal at the restoration–tooth interface. This paper
presents an update of existing technology and underscores the mechanisms that negatively impact the
durability of posterior composite restorations in permanent teeth.
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Affiliation(s)
- Brenda S Bohaty
- Department of Pediatric Dentistry, University of Missouri-Kansas City School of Dentistry, Kansas City, MO, USA; ; Department of Pediatric Dentistry, Children's Mercy Hospital, Kansas City, MO, USA
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Ye Q, Park J, Parthasarathy R, Pamatmat F, Misra A, Laurence JS, Marangos O, Spencer P. Quantitative analysis of aqueous phase composition of model dentin adhesives experiencing phase separation. J Biomed Mater Res B Appl Biomater 2012; 100:1086-92. [PMID: 22331596 DOI: 10.1002/jbm.b.32675] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 12/18/2011] [Accepted: 12/22/2011] [Indexed: 11/05/2022]
Abstract
There have been reports of the sensitivity of our current dentin adhesives to excess moisture, for example, water-blisters in adhesives placed on over-wet surfaces, and phase separation with concomitant limited infiltration of the critical dimethacrylate component into the demineralized dentin matrix. To determine quantitatively the hydrophobic/hydrophilic components in the aqueous phase when exposed to over-wet environments, model adhesives were mixed with 16, 33, and 50 wt % water to yield well-separated phases. Based upon high-performance liquid chromatography coupled with photodiode array detection, it was found that the amounts of hydrophobic BisGMA and hydrophobic initiators are less than 0.1 wt % in the aqueous phase. The amount of these compounds decreased with an increase in the initial water content. The major components of the aqueous phase were hydroxyethyl methacrylate (HEMA) and water, and the HEMA content ranged from 18.3 to 14.7 wt %. Different BisGMA homologues and the relative content of these homologues in the aqueous phase have been identified; however, the amount of crosslinkable BisGMA was minimal and, thus, could not help in the formation of a crosslinked polymer network in the aqueous phase. Without the protection afforded by a strong crosslinked network, the poorly photoreactive compounds of this aqueous phase could be leached easily. These results suggest that adhesive formulations should be designed to include hydrophilic multimethacrylate monomers and water compatible initiators.
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Affiliation(s)
- Qiang Ye
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas 66045-7609, USA.
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22
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Park J, Ye Q, Spencer P, Laurence JS. Determination of neutralization capacity and stability of a basic methacrylate monomer using NMR. INT J POLYM MATER PO 2012; 61:144-153. [PMID: 22544985 DOI: 10.1080/00914037.2011.574660] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The durability of dental resin depends on the stability of the polymer. The neutralizing capacity of a basic methacrylate monomer and its chemical stability were measured using nuclear magnetic resonance (NMR) spectroscopy. Lactic acid solution was titrated with 2-(dimethylamino)ethylmethacrylate (DMAEMA) or 2-hydroxyethylmethacrylate (HEMA) and its chemical shifts monitored. Addition of DMAEMA alters the chemical shift proportionally to pH neutralization, whereas HEMA has no impact. Chemical shifts were used to quantify both the change in pH and monomer stability. The results demonstrate that neutralization by basic monomer can be achieved and that this can be measured using an NMR assay.
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Affiliation(s)
- Jonggu Park
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
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23
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Spencer P, Jonggu Park QY, Misra A, Bohaty BS, Singh V, Parthasarathy R, Sene F, de Paiva Gonçalves SE, Laurence J. Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target? BRAZILIAN DENTAL SCIENCE 2012; 15:4-18. [PMID: 24855586 PMCID: PMC4028112 DOI: 10.14295/bds.2012.v15i1.790] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2023] Open
Abstract
Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.
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Affiliation(s)
- Paulette Spencer
- Department of Mechanical Engineering - Bioengineering Research Center - University of Kansas - Lawrence - KS
| | | | - Anil Misra
- Bioengineering Research Center - Department of Civil Engineering - University of Kansas - Lawrence - KS
| | - Brenda S Bohaty
- Department of Pediatric Dentistry - University of Missouri - Kansas City - School of Dentistry - Kansas City - MO
| | - Viraj Singh
- Department of Mechanical Engineering - Bioengineering Research Center - University of Kansas - Lawrence - KS
| | | | - Fábio Sene
- Department of Restorative Dentistry - State University of Londrina - School of Dentistry - Londrina - Brazil
| | - Sérgio Eduardo de Paiva Gonçalves
- Department of Restorative Dentistry - School of Dentistry of São José dos Campos - UNESP - Univ Estadual Paulista - São José dos Campos - SP - Brazil
| | - Jennifer Laurence
- Department of Pharmaceutical Chemistry - University of Kansas - Lawrence - KS
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Park J, Ye Q, Singh V, Kieweg SL, Misra A, Spencer P. Synthesis and evaluation of novel dental monomer with branched aromatic carboxylic acid group. J Biomed Mater Res B Appl Biomater 2011; 100:569-76. [PMID: 22114017 DOI: 10.1002/jbm.b.31987] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 09/01/2011] [Accepted: 09/20/2011] [Indexed: 11/06/2022]
Abstract
A new glycerol-based dimethacrylate monomer with an aromatic carboxylic acid, 2-((1,3-bis(methacryloyloxy)propan-2-yloxy)carbonyl)benzoic acid (BMPB), was synthesized, characterized, and proposed as a possible dental co-monomer for dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA) and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (BisGMA) in addition to BMPB were formulated with water at 0, 5, 10, and 15 wt % to simulate wet, oral conditions, and photo-polymerized. Adhesives were characterized with regard to viscosity, real-time photopolymerization behavior, dynamic mechanical analysis, and microscale 3D internal morphologies and compared with HEMA/BisGMA controls. When formulated under wet conditions, the experimental adhesives showed lower viscosities (0.04-0.07 Pa s) as compared to the control (0.09-0.12 Pa s). The experimental adhesives showed higher glass transition temperature (146-157°C), degree of conversion (78-89%), and rubbery moduli (33-36 MPa), and improved water miscibility (no voids) as compared to the controls (123-135°C, 67-71%, 15-26 MPa, and voids, respectively). The enhanced properties of these adhesives suggest that BMPB with simple, straightforward synthesis is a promising photocurable co-monomer for dental restorative materials.
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Affiliation(s)
- Jonggu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, Kansas
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25
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Ye Q, Park J, Laurence JS, Parthasarathy R, Misra A, Spencer P. Ternary phase diagram of model dentin adhesive exposed to over-wet environments. J Dent Res 2011; 90:1434-8. [PMID: 21960682 DOI: 10.1177/0022034511423398] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
When adhesives and/or composites are bonded to the tooth, water in the environment can interfere with proper interface formation. Formation of water blisters and phase separation at the adhesive/dentin interface have appeared as new types of bond defects. To better understand this problem, we determined the near-equilibrium partition of the hydrophobic/hydrophilic components when exposed to over-wet environments. Model methacrylate-based adhesives were mixed with different amounts of water to yield well-separated aqueous and resin phases. It was found that less than 0.1% BisGMA but nearly one-third of the HEMA diffused into the aqueous phase, leaving the remaining resin phase relatively hydrophobic. A partial phase diagram was created for the ternary BisGMA/HEMA/water system. All the experimental phase partitioning data were plotted, and the points lay on a binodal curve that separated the single-phase region from the two-phase region. We obtained the 3 tie lines by connecting the 2 points of each conjugate pair of the phase partitioning data from the 3 sets of tripartite mixtures. Information about solubility, water miscibility, distribution ratio, and phase partitioning behavior could be obtained quantitatively. This type of phase diagram will provide a more thorough understanding of current adhesive performance and elucidate directions for further improvement.
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Affiliation(s)
- Q Ye
- Bioengineering Research Center, University of Kansas, Lawrence, KS 66045-7609, USA.
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26
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The influence of chemical structure on the properties in methacrylate-based dentin adhesives. Dent Mater 2011; 27:1086-93. [PMID: 21816460 DOI: 10.1016/j.dental.2011.07.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 05/18/2011] [Accepted: 07/13/2011] [Indexed: 11/20/2022]
Abstract
OBJECTIVES The objective of this study was to investigate the influence of the chemical structure of methacrylate monomers used in dentin adhesives on degree of conversion (DC), water sorption, and dynamic mechanical properties. MATERIALS AND METHODS Experimental adhesives containing 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA), 2-hydroxyethyl methacrylate (HEMA), and co-monomer, 30/45/25 (w/w) were photo-polymerized. Ethyleneglycol dimethacrylate (EGDM), diethyleneglycol dimethacrylate (DEGDM), triethyleneglycol dimethacrylate (TEGDMA), 1,3-glycerol dimethacrylate (GDM), and glycerol trimethacrylate (GTM) were used as a co-monomer. The adhesives were characterized with regard to DC, water sorption, and dynamic mechanical analysis and compared to control adhesive [HEMA/BisGMA, 45/55 (w/w)]. RESULTS DC and water sorption increased with an increase in the number of ethylene glycol units in the monomer. Experimental adhesive containing GDM showed significantly higher storage moduli (p<0.05) in both dry and wet samples than experimental adhesives containing EGDM or DEGDM. The rubbery moduli of adhesives containing GDM and GTM were found to be significantly greater (p<0.05) than that of the control. Adhesives containing GTM exhibited the widest tanδ curves, indicating the greatest structural heterogeneity. SIGNIFICANCE The hydrophilicity, functionality and size of monomers in dentin adhesives affected the water sorption, solubility, crosslink density and heterogeneity of the polymer network. The experimental adhesives containing GDM and GTM showed higher rubbery moduli, indicating higher crosslink density accompanied by a decrease in the homogeneity of the polymer network structure.
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Spencer P, Ye Q, Park J, Topp EM, Misra A, Marangos O, Wang Y, Bohaty BS, Singh V, Sene F, Eslick J, Camarda K, Katz JL. Adhesive/Dentin interface: the weak link in the composite restoration. Ann Biomed Eng 2010; 38:1989-2003. [PMID: 20195761 PMCID: PMC2871971 DOI: 10.1007/s10439-010-9969-6] [Citation(s) in RCA: 294] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Accepted: 02/12/2010] [Indexed: 11/30/2022]
Abstract
Results from clinical studies suggest that more than half of the 166 million dental restorations that were placed in the United States in 2005 were replacements for failed restorations. This emphasis on replacement therapy is expected to grow as dentists use composite as opposed to dental amalgam to restore moderate to large posterior lesions. Composite restorations have higher failure rates, more recurrent caries, and increased frequency of replacement as compared to amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and premature failure. Under in vivo conditions the bond formed at the adhesive/dentin interface can be the first defense against these noxious, damaging substances. The intent of this article is to review structural aspects of the clinical substrate that impact bond formation at the adhesive/dentin interface; to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.
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Affiliation(s)
- Paulette Spencer
- Department of Mechanical Engineering, University of Kansas, 1530 W 15th St, Lawrence, KS 66045, USA.
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28
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Park JG, Ye Q, Topp EM, Misra A, Spencer P. Water sorption and dynamic mechanical properties of dentin adhesives with a urethane-based multifunctional methacrylate monomer. Dent Mater 2009; 25:1569-75. [PMID: 19709724 DOI: 10.1016/j.dental.2009.07.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 07/22/2009] [Accepted: 07/24/2009] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Our previous study showed the synthesis and characterization of a novel urethane-linked trimethacrylate monomer for use as a co-monomer in dentin adhesives. The objective of this work was to further investigate the performance of dentin adhesives containing a new monomer, with particular emphasis on the water sorption and viscoelastic behavior of the crosslinked networks. MATERIALS AND METHODS Dentin adhesives contained 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA), 2-hydroxyethyl methacrylate (HEMA), and a new multifunctional methacrylate with urethane-linked groups-1,1,1-tri-[4-(methacryloxyethylaminocarbonyloxy)-phenyl]ethane (MPE) and were photo-polymerized in the presence or absence of water. Adhesives were characterized with regard to degree of conversion (DC), viscosity, water sorption/solubility, and dynamic mechanical analysis (DMA) and compared with BisGMA/HEMA controls. RESULTS The experimental adhesives exhibited DC and solubility comparable to that of the control, regardless of the presence or absence of water. All the experimental adhesives tested showed less water sorption, lower tandelta peak heights, and higher rubbery modulus than the control. SIGNIFICANCE Dentin adhesives containing a new multifunctional methacrylate showed better dynamic thermomechanical properties and water sorption relative to controls, without compromising DC and solubility. Thus, MPE, when included as a component of methacrylate dentin adhesives, may provide enhanced durability in the moist environment of the mouth.
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Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
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