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Firoozmand LM, Alania Y, Bedran-Russo AK. Development and Assessment of Bioactive Coatings for the Prevention of Recurrent Caries Around Resin Composite Restorations. Oper Dent 2022; 47:E152-E161. [PMID: 35776958 DOI: 10.2341/20-299-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2021] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To develop hydrophilic resin-based surface coatings containing bioactive agents (proanthocyanidins from Vitis vinifera and calcium silicate) and assess their protective role at the dentin and enamel margins of cervical restorations against demineralization under simulated conditions of high and low caries activity. METHODS Suboptimal resin composite restorations were placed on cervical cavity preparations on buccal and lingual surfaces of thirty-two molars after a contamination protocol. Groups were divided according to the resin-based coatings (n=8): resin without bioactive (C), resin containing 2% enriched Vitis Vinifera (VVE), and resin coat containing 10% calcium silicate (CaSi). The control group did not receive a resin (NC). To simulate a hydrolyticenzymatic degradation, specimens were subjected to 2-month storage followed by incubation in esterase at 37°C for 8 days. Afterwards, recurrent caries was induced using a pH-proteolytic model on half of the specimens to simulate high caries activity, and the other half remained in simulated body fluid (SBF). Measurements of cross-section microhardness (KHN) and infiltration with rhodamine-B assessed the micropermeability (MP), the extent of demineralization (ED), and the demineralization area (DA). Data were analyzed using analysis of variance (ANOVA) and post-hoc tests (α=0.05). RESULTS VVE and CaSi presented higher cross-sectional KHN values for enamel and dentin (p<0.001). The bioactive coatings resulted in lower MP, ED, and DA compared to NC (p<0.005) in enamel and dentin. CaSi coating preserved the enamel from demineralization (p=0.160). CONCLUSION The application of bioactive coatings represents a potential strategy to protect the enamel-dentin margins of resin restorations.
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Affiliation(s)
- L M Firoozmand
- Leily Macedo Firoozmand, Department of Dentistry, Federal University of Maranhão, São Luis, MA, Brazil; Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Y Alania
- Yvette Alania, Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA; Department of General Dental Sciences, School of Dentistry, Marquette University, Milwaukee, WI, USA
| | - A K Bedran-Russo
- *Ana K. Bedran-Russo, Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA; Department of General Dental Sciences, School of Dentistry, Marquette University, Milwaukee, WI, USA
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Zheng Z, Xia Y, Liao C, Liu Y, Chai W, Niu E, Hu Z. Fabrication of starch-based multi-source integrated halogen-free flame retardant in improving the fire safety of polypropylene. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02804-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Alamgir M, Nayak GC, Mallick A, Sahoo S. Effects of TiO2 and GO nanoparticles on the thermomechanical properties of bioactive poly-HEMA nanocomposites. IRANIAN POLYMER JOURNAL 2021. [DOI: 10.1007/s13726-021-00948-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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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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The functions of hydrophobic elastic polyurethane combined with an antibacterial triclosan derivative in the dentin restoration interface. J Mech Behav Biomed Mater 2019; 102:103471. [PMID: 31622860 DOI: 10.1016/j.jmbbm.2019.103471] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/01/2019] [Accepted: 10/02/2019] [Indexed: 11/21/2022]
Abstract
Dentin restoration produces weak interfaces because of the effects of bacterial microflora, biofilms, and mechanical, thermal, and shrinkage stresses. This results in secondary caries. Therefore, hydrophobic elastic polyurethane (PU) containing different concentrations of triclosan derivatives was synthesized and applied to solve this problem. The antibacterial PU was characterized according to its tensile strength (TS) and elasticity (ε) via a universal testing machine, and water sorption (Wsp) and solubility testing (Wsl) was performed according to ISO 4049: 2009. Additionally, this study evaluated the antibacterial properties of PU against Streptococcus mutans (ATCC35668) and Escherichia coli (ATCC25922). A marginal leakage test was performed to evaluate the leakage prevention property. As a result, the antibacterial PU showed high TS (>17 MPa), high elasticity (ε > 65%), and low Wsp (>81.06 μg/mm3) and Wsl (>11.22 μg/mm3). The PU exhibited antibacterial effects against both Streptococcus mutans and Escherichia coli. The antibacterial rates were over 90% and >99% for the 3% and 5% groups, respectively. Moreover, the marginal level of leakage was 0. Based on the mechanical properties, Wsp and Wsl values and the antibacterial properties, the 3% group exhibited satisfactory performance and has been deemed a possible solution to reduce the occurrence of secondary caries.
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Zhou W, Liu S, Zhou X, Hannig M, Rupf S, Feng J, Peng X, Cheng L. Modifying Adhesive Materials to Improve the Longevity of Resinous Restorations. Int J Mol Sci 2019; 20:ijms20030723. [PMID: 30744026 PMCID: PMC6387348 DOI: 10.3390/ijms20030723] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/23/2019] [Accepted: 02/04/2019] [Indexed: 11/16/2022] Open
Abstract
Dental caries is a common disease on a global scale. Resin composites are the most popular materials to restore caries by bonding to tooth tissues via adhesives. However, multiple factors, such as microleakage and recurrent caries, impair the durability of resinous restorations. Various innovative methods have been applied to develop adhesives with particular functions to tackle these problems, such as incorporating matrix metalloproteinase inhibitors, antibacterial or remineralizing agents into bonding systems, as well as improving the mechanical/chemical properties of adhesives, even combining these methods. This review will sum up the latest achievements in this field.
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Affiliation(s)
- Wen Zhou
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- Department of Cariology and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
| | - Shiyu Liu
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- Department of Cariology and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- Department of Cariology and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
| | - Matthias Hannig
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University Hospital, Homburg/Saar, Germany.
| | - Stefan Rupf
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University Hospital, Homburg/Saar, Germany.
| | - Jin Feng
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
- Department of Geriatric Dentistry, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
| | - Xian Peng
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
- Department of Cariology and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
- National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu 610041, China.
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Song L, Ye Q, Ge X, Misra A, Tamerler C, Spencer P. New silyl-functionalized BisGMA provides autonomous strengthening without leaching for dental adhesives. Acta Biomater 2019; 83:130-139. [PMID: 30366133 DOI: 10.1016/j.actbio.2018.10.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/30/2018] [Accepted: 10/22/2018] [Indexed: 12/27/2022]
Abstract
Resin-based composite has overtaken dental amalgam as the most popular material for direct restorative dentistry. In spite of this popularity the clinical lifetime of composite restorations is threatened by recurrent decay. Degradation of the adhesive leads to gaps at the composite/tooth interface-bacteria, bacterial by-products and fluids infiltrate the gaps leading to recurrent decay and composite restoration failure. The durability of resin-dentin bonds is a major problem. We address this problem by synthesizing silyl-functionalized BisGMA (e.g., silyl-BisGMA), formulating dental adhesives with the new monomer and determining the physicochemical properties and leaching characteristics of the silyl-BisGMA adhesives. Silyl-BisGMA was synthesized by stoichiometric amounts of BisGMA and 3-isocyanatopropyl trimethoxysilane (IPTMS). The control adhesive was a mixture based on HEMA/BisGMA (45/55, w/w). In the experimental formulations, BisGMA was partially or completely replaced by silyl-BisGMA. Water miscibility, polymerization behavior (Fourier transform infrared spectroscopy, FTIR), thermal property (modulated differential scanning calorimetry, MDSC), mechanical properties in dry and wet conditions (dynamic mechanical analysis, DMA), and leached species (HPLC) were investigated. Data from all tests were submitted to appropriate statistical analysis (α = 0.05). Silyl-BisGMA-containing adhesives exhibited comparable water miscibility, lower viscosities, and significantly improved degree of conversion of CC bond as compared to the control. After 4 weeks aqueous aging, the glass transition temperature and rubbery moduli of the experimental copolymers were significantly greater than the control (p < 0.05). HPLC results indicated a substantial reduction of leached HEMA (up to 99 wt%) and BisGMA (up to 90 wt%). By introducing silyl-functional group, the new BisGMA derivative exhibited potential as a monomer that can lead to dental adhesives with improved mechanical properties and reduced leaching under conditions relevant to the oral environment. STATEMENT OF SIGNIFICANCE: The low-viscosity adhesive that bonds the composite to the tooth (enamel and dentin) is intended to seal and stabilize the composite/tooth interface, but it degrades leading to a breach at the composite/tooth margin. As the most popular crosslinking monomer in adhesives, Bisphenol A-glycerolate dimethacrylate (BisGMA) has limitations, e.g. susceptible to hydrolysis and concomitant property degradation. A methoxysilyl-functionalized BisGMA derivative (silyl-BisGMA) was introduced in this work to respond to these limitations. Our results indicated that by introducing silyl-BisGMA, higher crosslinked networks were obtained without sacrificing the homogeneity, and the leached amount of HEMA was reduced up to 99%. This novel resin offers potential benefits including prolonging the functional lifetime of dental resin materials.
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Sauro S, Lin CY, Bikker FJ, Cama G, Dubruel P, Soria JM, D''Onofrio A, Gillam D. Di-Calcium Phosphate and Phytosphingosine as an Innovative Acid-Resistant Treatment to Occlude Dentine Tubules. Caries Res 2016; 50:303-9. [DOI: 10.1159/000445444] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 03/14/2016] [Indexed: 11/19/2022] Open
Abstract
The present investigation evaluated the ability of an experimental di-calcium phosphate (DCP) desensitising agent used alone or combined with phytosphingosine (PHS) to occlude dentine tubules and resist a citric acid (CA) or artificial saliva (AS) challenge. Three groups of human dentine specimens (DS) were treated with the following: (1) PHS alone, (2) DCP or (3) a combination of PHS and DCP. Dentine hydraulic conductance of DS was evaluated using a digital flow sensor at 6.9 kPa. The average fluid volume for each of the treated DS was used to calculate the total dentine permeability reduction (%P) prior to and following CA immersion for 1 min or AS immersion for 4 weeks. The treated DS were subjected to both scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy analysis. Statistically significant differences (%P) were identified between the groups by ANOVA and Fisher's multiple comparison test (p < 0.05), respectively. Interestingly, both PHS and DCP appeared to work synergistically. DS treated with DCP or PHS/DCP demonstrated a significant reduction (%P) prior to and following CA or AS challenge (p < 0.05). Both the SEM and FTIR analyses showed consistent brushite crystals occluding the dentine tubules. Conversely, the application of PHS alone failed to demonstrate any significant reduction of dentine permeability (p > 0.05) or show any evidence of occlusion of the dentine tubules. DCP can be used alone or combined with PHS to decrease the dentine permeability as well as to resist a CA and AS challenge. These results would, therefore, suggest that DCP may be a suitable treatment option for dentine hypersensitivity.
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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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Spencer P, Ye Q, Misra A, Goncalves SEP, Laurence JS. Proteins, pathogens, and failure at the composite-tooth interface. J Dent Res 2014; 93:1243-9. [PMID: 25190266 DOI: 10.1177/0022034514550039] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In the United States, composites accounted for nearly 70% of the 173.2 million composite and amalgam restorations placed in 2006 (Kingman et al., 2012), and it is likely that the use of composite will continue to increase as dentists phase out dental amalgam. This trend is not, however, without consequences. The failure rate of composite restorations is double that of amalgam (Ferracane, 2013). Composite restorations accumulate more biofilm, experience more secondary decay, and require more frequent replacement. In vivo biodegradation of the adhesive bond at the composite-tooth interface is a major contributor to the cascade of events leading to restoration failure. Binding by proteins, particularly gp340, from the salivary pellicle leads to biofilm attachment, which accelerates degradation of the interfacial bond and demineralization of the tooth by recruiting the pioneer bacterium Streptococcus mutans to the surface. Bacterial production of lactic acid lowers the pH of the oral microenvironment, erodes hydroxyapatite in enamel and dentin, and promotes hydrolysis of the adhesive. Secreted esterases further hydrolyze the adhesive polymer, exposing the soft underlying collagenous dentinal matrix and allowing further infiltration by the pathogenic biofilm. Manifold approaches are being pursued to increase the longevity of composite dental restorations based on the major contributing factors responsible for degradation. The key material and biological components and the interactions involved in the destructive processes, including recent advances in understanding the structural and molecular basis of biofilm recruitment, are described in this review. Innovative strategies to mitigate these pathogenic effects and slow deterioration are discussed.
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Affiliation(s)
- P Spencer
- Department of Mechanical Engineering Bioengineering Research Center
| | - Q Ye
- Bioengineering Research Center
| | - A Misra
- Bioengineering Research Center Department of Civil Engineering, University of Kansas, Lawrence, KS, USA
| | - S E P Goncalves
- School of Dentistry of São José dos Campos, UNESP, Univ Estadual Paulista, São José dos Campos, SP, Brazil
| | - J S Laurence
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA
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Ge X, Ye Q, Song L, Misra A, Spencer P. Synthesis and evaluation of novel siloxane-methacrylate monomers used as dentin adhesives. Dent Mater 2014; 30:1073-87. [PMID: 24993811 DOI: 10.1016/j.dental.2014.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 05/07/2014] [Accepted: 06/09/2014] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The objectives of this study were to synthesize two new siloxane-methacrylate (SM) monomers for application in dentin adhesives and to investigate the influence of different functionality of the siloxane-containing monomers on the adhesive photopolymerization, water sorption, and mechanical properties. METHODS Two siloxane-methacrylate monomers (SM1 and SM2) with four and eight methacrylate groups were synthesized. Dentin adhesives containing BisGMA, HEMA and the siloxane-methacrylate monomers were photo-polymerized. The experimental adhesives were compared with the control adhesive (HEMA/BisGMA, 45/55, w/w) and characterized with regard to degree of conversion (DC), water miscibility of the liquid resin, water sorption and dynamic mechanical analysis (DMA). RESULTS The experimental adhesives exhibited improved water miscibility as compared to the control. When cured in the presence of 12 wt% water to simulate the wet environment of the mouth, the SM-containing adhesives showed DC comparable to the control. The experimental adhesives showed higher rubbery modulus than the control under dry conditions. Under wet conditions, the mechanical properties of the formulations containing SM monomer with increased functionality were comparable with the control, even with more water sorption. SIGNIFICANCE The concentration and functionality of the newly synthesized siloxane-methacrylate monomers affected the water miscibility, water sorption and mechanical properties of the adhesives. The experimental adhesives show improved water compatibility compared with the control. The mechanical properties were enhanced with an increase of the functionality of the siloxane-containing monomers. The results provide critical structure/property relationships and important information for future development of durable, versatile siloxane-containing 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
| | - Anil Misra
- Department of Civil 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.
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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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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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Bai X, Wu N, Liu Y, Zhang Y, Wang Y. Ethyl-4-(Dimethylamino) benzoate initiation of the spontaneous polymerization of aqueous acidic adhesive formulations in the presence of a base. J Appl Polym Sci 2013. [DOI: 10.1002/app.39368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Oguri M, Yoshida Y, Yoshihara K, Miyauchi T, Nakamura Y, Shimoda S, Hanabusa M, Momoi Y, Van Meerbeek B. Effects of functional monomers and photo-initiators on the degree of conversion of a dental adhesive. Acta Biomater 2012; 8:1928-34. [PMID: 22293580 DOI: 10.1016/j.actbio.2012.01.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 12/12/2011] [Accepted: 01/10/2012] [Indexed: 11/25/2022]
Abstract
Besides functional and cross-linking monomers, dental adhesives contain a photo-initiator system for polymerization, thereby providing physico-mechanical strength to the adhesive-tooth interface. Few studies have investigated the effect of the functional monomer and polymerization-initiation system on the polymerization efficiency of the adhesive. Here, we tested the effect of two different functional monomers (MAC-10 vs. SR) and two photo-initiator systems, camphorquinone-amine (CQ) vs. borate (BO), on the degree of conversion (DC) of different adhesive formulations. The DC of the CQ-cured adhesive formulations was significantly affected by the MAC-10 monomer. This should be ascribed to the known inactivation of the amine co-initiator through acid-base reaction. However, the SR monomer did not decrease the DC, which could be attributed to a "gel effect" or the so-called "Trommsdorff-Norrish" phenomenon of enhanced DC with more viscous resins, and to the more favorable availability of CC double bonds. In contrast, the DC of the BO-cured adhesive formulations was not affected by any acidic monomer. It is concluded that the degree of conversion of an adhesive can be affected by the functional monomer, but this depends on the kind of photo-initiator system used. As bond durability depends, among other factors, on the strength and thus degree of conversion of the adhesive, potential interaction between adhesive ingredients and the photo-initiator system definitely needs to be studied further.
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16
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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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17
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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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18
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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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19
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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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20
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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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21
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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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22
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Szczepanska J, Poplawski T, Synowiec E, Pawlowska E, Chojnacki CJ, Chojnacki J, Blasiak J. 2-hydroxylethyl methacrylate (HEMA), a tooth restoration component, exerts its genotoxic effects in human gingival fibroblasts trough methacrylic acid, an immediate product of its degradation. Mol Biol Rep 2011; 39:1561-74. [PMID: 21617943 PMCID: PMC3249584 DOI: 10.1007/s11033-011-0895-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 05/17/2011] [Indexed: 12/21/2022]
Abstract
HEMA (2-hydroxyethyl methacrylate), a methacrylate commonly used in dentistry, was reported to induce genotoxic effects, but their mechanism is not fully understood. HEMA may be degraded by the oral cavity esterases or through mechanical stress following the chewing process. Methacrylic acid (MAA) is the primary product of HEMA degradation. In the present work we compared cytotoxic and genotoxic effects induced by HEMA and MAA in human gingival fibroblasts (HGFs). A 6-h exposure to HEMA or MAA induced a weak decrease in the viability of HGFs. Neither HEMA nor MAA induced strand breaks in the isolated plasmid DNA, but both compounds evoked DNA damage in HGFs, as evaluated by the alkaline comet assay. Oxidative modifications to the DNA bases were monitored by the DNA repair enzymes Endo III and Fpg. DNA damage induced by HEMA and MAA was not persistent and was removed during a 120 min repair incubation. Results from the neutral comet assay indicated that both compounds induced DNA double strand breaks (DSBs) and they were confirmed by the γ-H2AX assay. Both compounds induced apoptosis and perturbed the cell cycle. Therefore, methacrylic acid, a product of HEMA degradation, may be involved in its cytotoxic and genotoxic action.
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Affiliation(s)
- Joanna Szczepanska
- Department of Developmental Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Tomasz Poplawski
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Ewelina Synowiec
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Elzbieta Pawlowska
- Department of Developmental Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Cezary J. Chojnacki
- Department of Gastroenterology and Internal Medicine, Medical University of Lodz, Plac Hallera 1, 91-647 Lodz, Poland
| | - Jan Chojnacki
- Department of Gastroenterology and Internal Medicine, Medical University of Lodz, Plac Hallera 1, 91-647 Lodz, Poland
| | - Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
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23
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Liu Y, Tjäderhane L, Breschi L, Mazzoni A, Li N, Mao J, Pashley DH, Tay FR. Limitations in bonding to dentin and experimental strategies to prevent bond degradation. J Dent Res 2011; 90:953-68. [PMID: 21220360 DOI: 10.1177/0022034510391799] [Citation(s) in RCA: 421] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The limited durability of resin-dentin bonds severely compromises the lifetime of tooth-colored restorations. Bond degradation occurs via hydrolysis of suboptimally polymerized hydrophilic resin components and degradation of water-rich, resin-sparse collagen matrices by matrix metalloproteinases (MMPs) and cysteine cathepsins. This review examined data generated over the past three years on five experimental strategies developed by different research groups for extending the longevity of resin-dentin bonds. They include: (1) increasing the degree of conversion and esterase resistance of hydrophilic adhesives; (2) the use of broad-spectrum inhibitors of collagenolytic enzymes, including novel inhibitor functional groups grafted to methacrylate resins monomers to produce anti-MMP adhesives; (3) the use of cross-linking agents for silencing the activities of MMP and cathepsins that irreversibly alter the 3-D structures of their catalytic/allosteric domains; (4) ethanol wet-bonding with hydrophobic resins to completely replace water from the extrafibrillar and intrafibrillar collagen compartments and immobilize the collagenolytic enzymes; and (5) biomimetic remineralization of the water-filled collagen matrix using analogs of matrix proteins to progressively replace water with intrafibrillar and extrafibrillar apatites to exclude exogenous collagenolytic enzymes and fossilize endogenous collagenolytic enzymes. A combination of several of these strategies should result in overcoming the critical barriers to progress currently encountered in dentin bonding.
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Affiliation(s)
- Y Liu
- Department of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hankou District, Wuhan 430030, People's Republic of China
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24
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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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25
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Park JG, Ye Q, Topp EM, Spencer P. Enzyme-catalyzed hydrolysis of dentin adhesives containing a new urethane-based trimethacrylate monomer. J Biomed Mater Res B Appl Biomater 2009; 91:562-571. [PMID: 19582843 PMCID: PMC2758931 DOI: 10.1002/jbm.b.31430] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A new trimethacrylate monomer with urethane-linked groups, 1,1,1-tri-[4-(methacryloxyethylamino-carbonyloxy)-phenyl]ethane (MPE), was synthesized, characterized, and used as a comonomer in dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA, 45% w/w) and 2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane (BisGMA, 30% w/w) in addition to MPE (25% w/w) were formulated with H(2)O at 0 (MPE0), 8 (MPE8), and 16 wt % water (MPE16) to simulate the wet demineralized dentin matrix and compared with controls [HEMA /BisGMA, 45/55 w/w, at 0 (C0), 8 (C8), and 16 wt % water (C16)]. The new adhesive showed a degree of double bond conversion and mechanical properties comparable with control, with good penetration into the dentin surface and a uniform adhesive/dentin interface. On exposure to porcine liver esterase, the net cumulative methacrylic acid (MAA) released from the new adhesives was dramatically (p < 0.05) decreased relative to the control, suggesting that the new monomer improves esterase resistance.
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Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045
| | - Qiang Ye
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045
| | - Elizabeth M. Topp
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS 66047
| | - Paulette Spencer
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045,Department of Mechanical Engineering, University of Kansas, Lawrence, KS, 66045, Address all correspondence to Dr. Paulette Spencer. Tel.: +1 785 864 8140; fax: 1 785 864 5254;
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26
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Park JG, Ye Q, Topp EM, Lee CH, Kostoryz EL, Misra A, Spencer P. Dynamic mechanical analysis and esterase degradation of dentin adhesives containing a branched methacrylate. J Biomed Mater Res B Appl Biomater 2009; 91:61-70. [PMID: 19358261 PMCID: PMC2990471 DOI: 10.1002/jbm.b.31374] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A study of the dynamic mechanical properties and the enzymatic degradation of new dentin adhesives containing a multifunctional methacrylate are described. Adhesives contained 2-hydroxyethyl methacrylate, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane, and a new multifunctional methacrylate with a branched side chain-trimethylolpropane mono allyl ether dimethacrylate (TMPEDMA). Adhesives were photopolymerized in the presence of 0, 8, and 16 wt % water to simulate wet bonding conditions in the mouth and compared with control adhesives. The degree of conversion as a function of irradiation time was comparable for experimental and control adhesives. In dynamic mechanical analysis, broad tan delta peaks were obtained for all samples, indicating that the polymerized networks are heterogeneous; comparison of the full-width-at-half-maximum values obtained from the tan delta curves indicated increased heterogeneity for samples cured in the presence of water and/or containing TMPEDMA. The experimental adhesive showed higher T(g) and higher rubbery modulus indicating increased crosslink density when compared with the control. The improvement in esterase resistance afforded by adhesives containing the TMPEDMA is greater when this material is photopolymerized in the presence of water, suggesting better performance in the moist environment of the mouth. The improved esterase resistance of the new adhesive could be explained in terms of the densely crosslinked network structure and/or the steric hindrance of branched alkyl side chains.
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Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, USA
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27
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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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28
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Eslick JC, Ye Q, Park J, Topp EM, Spencer P, Camarda KV. A computational molecular design framework for crosslinked polymer networks. Comput Chem Eng 2009; 33:954-963. [PMID: 23904665 DOI: 10.1016/j.compchemeng.2008.09.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Crosslinked polymers are important in a very wide range of applications including dental restorative materials. However, currently used polymeric materials experience limited durability in the clinical oral environment. Researchers in the dental polymer field have generally used a time-consuming experimental trial-and-error approach to the design of new materials. The application of computational molecular design (CMD) to crosslinked polymer networks has the potential to facilitate development of improved polymethacrylate dental materials. CMD uses quantitative structure property relations (QSPRs) and optimization techniques to design molecules possessing desired properties. This paper describes a mathematical framework which provides tools necessary for the application of CMD to crosslinked polymer systems. The novel parts of the system include the data structures used, which allow for simple calculation of structural descriptors, and the formulation of the optimization problem. A heuristic optimization method, Tabu Search, is used to determine candidate monomers. Use of a heuristic optimization algorithm makes the system more independent of the types of QSPRs used, and more efficient when applied to combinatorial problems. A software package has been created which provides polymer researchers access to the design framework. A complete example of the methodology is provided for polymethacrylate dental materials.
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Affiliation(s)
- J C Eslick
- Department of Chemical and Petroleum Engineering, The University of Kansas, 1530 W. 15th St., Lawrence, KS 66045, United States
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