1
|
Spencer P, Ye Q, Misra A, Chandler JR, Cobb CM, Tamerler C. Engineering peptide-polymer hybrids for targeted repair and protection of cervical lesions. FRONTIERS IN DENTAL MEDICINE 2022; 3. [PMID: 37153688 PMCID: PMC10162700 DOI: 10.3389/fdmed.2022.1007753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
By 2060, nearly 100 million people in the U.S. will be over age 65 years. One-third of these older adults will have root caries, and nearly 80% will have dental erosion. These conditions can cause pain and loss of tooth structure that interfere with eating, speaking, sleeping, and quality of life. Current treatments for root caries and dental erosion have produced unreliable results. For example, the glass-ionomer-cement or composite-resin restorations used to treat these lesions have annual failure rates of 44% and 17%, respectively. These limitations and the pressing need to treat these conditions in the aging population are driving a focus on microinvasive strategies, such as sealants and varnishes. Sealants can inhibit caries on coronal surfaces, but they are ineffective for root caries. For healthy, functionally independent elders, chlorhexidine varnish applied every 3 months inhibits root caries, but this bitter-tasting varnish stains the teeth. Fluoride gel inhibits root caries, but requires prescriptions and daily use, which may not be feasible for some older patients. Silver diamine fluoride can both arrest and inhibit root caries but stains the treated tooth surface black. The limitations of current approaches and high prevalence of root caries and dental erosion in the aging population create an urgent need for microinvasive therapies that can: (a) remineralize damaged dentin; (b) inhibit bacterial activity; and (c) provide durable protection for the root surface. Since cavitated and non-cavitated root lesions are difficult to distinguish, optimal approaches will treat both. This review will explore the multi-factorial elements that contribute to root surface lesions and discuss a multi-pronged strategy to both repair and protect root surfaces. The strategy integrates engineered peptides, novel polymer chemistry, multi-scale structure/property characterization and predictive modeling to develop a durable, microinvasive treatment for root surface lesions.
Collapse
|
2
|
Drozdov AD, Christiansen JD. Tension-compression asymmetry in the mechanical response of hydrogels. J Mech Behav Biomed Mater 2020; 110:103851. [PMID: 32957177 DOI: 10.1016/j.jmbbm.2020.103851] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/03/2020] [Accepted: 05/05/2020] [Indexed: 12/14/2022]
Abstract
Two factors play the key role in application of hydrogels as biomedical implants (for example, for replacement of damaged intervertebral discs and repair of spinal cord injuries): their stiffness and strength (measured in tensile tests) and mechanical integrity (estimated under uniaxial compression). Observations show a pronounced difference between the responses of hydrogels under tension and compression (the Young's moduli can differ by two orders of magnitude), which is conventionally referred to as the tension-compression asymmetry (TCA). A constitutive model is developed for the mechanical behavior of hydrogels, where TCA is described within the viscoplasticity theory (plastic flow is treated as sliding of junctions between chains with respect to their reference positions). The governing equations involve five material constants with transparent physical meaning. These quantities are found by fitting stress-strain diagrams under tension and compression on a number of pristine and nanocomposite hydrogels with various kinds of chemical and physical bonds between chains. Good agreement is demonstrated between the experimental data and results of simulation. The influence of volume fraction of nanoparticles, concentration of cross-links, and topology of a polymer network on material parameters is analyzed numerically.
Collapse
Affiliation(s)
- A D Drozdov
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg, 9220, Denmark.
| | - J deC Christiansen
- Department of Materials and Production, Aalborg University, Fibigerstraede 16, Aalborg, 9220, Denmark
| |
Collapse
|
3
|
Sarikaya R, Song L, Ye Q, Misra A, Tamerler C, Spencer P. Evolution of Network Structure and Mechanical Properties in Autonomous-Strengthening Dental Adhesive. Polymers (Basel) 2020; 12:polym12092076. [PMID: 32932724 PMCID: PMC7570171 DOI: 10.3390/polym12092076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/03/2020] [Accepted: 09/10/2020] [Indexed: 11/16/2022] Open
Abstract
The inherent degradation property of most dental resins in the mouth leads to the long-term release of degradation by-products at the adhesive/tooth interface. The by-products increase the virulence of cariogenic bacteria, provoking a degradative positive-feedback loop that leads to physicochemical and mechanical failure. Photoinduced free-radical polymerization and sol‒gel reactions have been coupled to produce a novel autonomous-strengthening adhesive with enhanced hydrolytic stability. This paper investigates the effect of network structure on time-dependent mechanical properties in adhesives with and without autonomous strengthening. Stress relaxation was conducted under 0.2% strain for 8 h followed by 40 h recovery in water. The stress‒time relationship is analyzed by nonlinear least-squares data-fitting. The fitted Prony series predicts the sample’s history under monotonic loading. Results showed that the control failed after the first loading‒unloading‒recovery cycle with permanent deformation. While for the experimental sample, the displacement was almost completely recovered and the Young’s modulus increased significantly after the first test cycle. The experimental polymer exhibited higher degree of conversion, lower leachate, and time-dependent stiffening characteristics. The autonomous-strengthening reaction persists in the aqueous environment leading to a network with enhanced resistance to deformation. The results illustrate a rational approach for tuning the viscoelasticity of durable dental adhesives.
Collapse
Affiliation(s)
- Rizacan Sarikaya
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
- Department of Mechanical Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Linyong Song
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
| | - Qiang Ye
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
- Correspondence: (Q.Y.); (P.S.); Tel.: +1-785-864-1746 (Q.Y.); +1-785-864-8140 (P.S.); Fax: +1-785-864-1742 (Q.Y.); +1-785-864-1742 (P.S.)
| | - Anil Misra
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
- Department of Civil Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Candan Tamerler
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
- Department of Mechanical Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Bioengineering Program, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Paulette Spencer
- Institute for Bioengineering Research, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; (R.S.); (L.S.); (A.M.); (C.T.)
- Department of Mechanical Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Bioengineering Program, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- Correspondence: (Q.Y.); (P.S.); Tel.: +1-785-864-1746 (Q.Y.); +1-785-864-8140 (P.S.); Fax: +1-785-864-1742 (Q.Y.); +1-785-864-1742 (P.S.)
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Giorgio I, dell’Isola F, Andreaus U, Alzahrani F, Hayat T, Lekszycki T. On mechanically driven biological stimulus for bone remodeling as a diffusive phenomenon. Biomech Model Mechanobiol 2019; 18:1639-1663. [DOI: 10.1007/s10237-019-01166-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/08/2019] [Indexed: 10/26/2022]
|
6
|
Parthasarathy R, Misra A, Song L, Ye Q, Spencer P. Structure-property relationships for wet dentin adhesive polymers. Biointerphases 2018; 13:061004. [PMID: 30558430 PMCID: PMC6296910 DOI: 10.1116/1.5058072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/23/2022] Open
Abstract
Dentin adhesive systems for composite tooth restorations are composed of hydrophilic/hydrophobic monomers, solvents, and photoinitiators. The adhesives undergo phase separation and concomitant compositional change during their application in the wet oral environment; phase separation compromises the quality of the hybrid layer in the adhesive/dentin interface. In this work, the adhesive composition in the hybrid layer can be represented using the phase boundaries of a ternary phase diagram for the hydrophobic monomer/hydrophilic monomer/water system. The polymer phases, previously unaccounted for, play an important role in determining the mechanical behavior of the bulk adhesive, and the chemomechanical properties of the phases are intimately related to the effects produced by differences in the hydrophobic-hydrophilic composition. As the composition of the polymer phases varies from hydrophobic-rich to hydrophilic-rich, the amount of the adsorbed water and the nature of polymer-water interaction vary nonlinearly and strongly correlate with the change in elastic moduli under wet conditions. The failure strain, loss modulus, and glass transition temperature vary nonmonotonically with composition and are explained based upon primary and secondary transitions observed in dynamic mechanical testing. Due to the variability in composition, the assignment of mechanical properties and the choice of suitable constitutive models for polymer phases in the hybrid layer are not straightforward. This work investigates the relationship between composition and chemomechanical properties of the polymer phases formed on the water-adhesive phase boundary using quasistatic and dynamic mechanical testing, mass transfer experiments, and vibrational spectroscopy.
Collapse
Affiliation(s)
- Ranganathan Parthasarathy
- Department of Civil and Architectural Engineering, Tennessee State University, 3500 John A Merritt Blvd, Nashville, Tennessee 37209
| | - Anil Misra
- Department of Civil and Environmental Engineering, Institute for Bioengineering Research, University of Kansas, 5104B Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Linyong Song
- Institute for Bioengineering Research, University of Kansas, 5104A Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Qiang Ye
- Institute for Bioengineering Research, University of Kansas, 5101E Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Paulette Spencer
- Department of Mechanical Engineering, Institute for Bioengineering Research, University of Kansas, 3111 Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| |
Collapse
|
7
|
Ye Q, Abedin F, Parthasarathy R, Spencer P. Photoinitiators in Dentistry: Challenges and Advances. PHOTOPOLYMERISATION INITIATING SYSTEMS 2018. [DOI: 10.1039/9781788013307-00297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Photopolymerization is used in a wide range of clinical applications in dentistry and the demand for dental materials that can restore form, function and esthetics is increasing rapidly. Simultaneous with this demand is the growing need for photoinitiators that provide effective and efficient in situ polymerization of dental materials using visible light irradiation. This chapter reviews the fundamentals of Type I and II photoinitiators. The advantages and disadvantages of these photoinitiators will be considered with a particular focus on parameters that affect the polymerization process in the oral cavity. The chapter examines recent developments in photoinitiators and opportunities for future research in the design and development of photoinitiators for dental applications. Future research directions that employ computational models in conjunction with iterative synthesis and experimental methods will also be explored in this chapter.
Collapse
Affiliation(s)
- Qiang Ye
- Institute for Bioengineering Research, School of Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
| | - Farhana Abedin
- Electromechanical Engineering Technology program, College of Engineering, California State Polytechnic University Pomona 3801 W. Temple Ave Pomona CA 91768 USA
| | - Ranganathan Parthasarathy
- Nanomaterials Research Lab, Tennessee State University 3500 John A Merritt Blvd Nashville TN 37209 USA
| | - Paulette Spencer
- Institute for Bioengineering Research, School of Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
- Department of Mechanical Engineering, University of Kansas 1530 W. 15th St Lawrence KS 66045 USA
| |
Collapse
|
8
|
Giorgio I, Harrison P, dell'Isola F, Alsayednoor J, Turco E. Wrinkling in engineering fabrics: a comparison between two different comprehensive modelling approaches. Proc Math Phys Eng Sci 2018; 474:20180063. [PMID: 30220866 PMCID: PMC6127399 DOI: 10.1098/rspa.2018.0063] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 07/12/2018] [Indexed: 11/12/2022] Open
Abstract
We consider two 'comprehensive' modelling approaches for engineering fabrics. We distinguish the two approaches using the terms 'semi-discrete' and 'continuum', reflecting their natures. We demonstrate a fitting procedure, used to identify the constitutive parameters of the continuum model from predictions of the semi-discrete model, the parameters of which are in turn fitted to experimental data. We, then, check the effectiveness of the continuum model by verifying the correspondence between semi-discrete and continuum model predictions using test cases not previously used in the identification process. Predictions of both modelling approaches are compared against full-field experimental kinematic data, obtained using stereoscopic digital image correlation techniques, and also with measured force data. Being a reduced order model and being implemented in an implicit rather than an explicit finite-element code, the continuum model requires significantly less computational power than the semi-discrete model and could therefore be used to more efficiently explore the mechanical response of engineering fabrics.
Collapse
Affiliation(s)
- I Giorgio
- DISG, Università di Roma La Sapienza, Rome, Italy.,International Research Center, M&MoCS, L'Aquila, Italy
| | - P Harrison
- School of Engineering, University of Glasgow, Glasgow, UK.,International Research Center, M&MoCS, L'Aquila, Italy
| | - F dell'Isola
- DISG, Università di Roma La Sapienza, Rome, Italy.,International Research Center, M&MoCS, L'Aquila, Italy
| | - J Alsayednoor
- School of Engineering, University of Glasgow, Glasgow, UK
| | - E Turco
- Department of Architecture, Design and Urban planning, University of Sassari, Alghero, Italy.,International Research Center, M&MoCS, L'Aquila, Italy
| |
Collapse
|
9
|
Parthasarathy R, Misra A, Ouyang L. Finite-temperature stress calculations in atomic models using moments of position. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:265901. [PMID: 29767631 DOI: 10.1088/1361-648x/aac52f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Continuum modeling of finite temperature mechanical behavior of atomic systems requires refined description of atomic motions. In this paper, we identify additional kinematical quantities that are relevant for a more accurate continuum description as the system is subjected to step-wise loading. The presented formalism avoids the necessity for atomic trajectory mapping with deformation, provides the definitions of the kinematic variables and their conjugates in real space, and simplifies local work conjugacy. The total work done on an atom under deformation is decomposed into the work corresponding to changing its equilibrium position and work corresponding to changing its second moment about equilibrium position. Correspondingly, we define two kinematic variables: a deformation gradient tensor and a vibration tensor, and derive their stress conjugates, termed here as static and vibration stresses, respectively. The proposed approach is validated using MD simulation in NVT ensembles for fcc aluminum subjected to uniaxial extension. The observed evolution of second moments in the MD simulation with macroscopic deformation is not directly related to the transformation of atomic trajectories through the deformation gradient using generator functions. However, it is noteworthy that deformation leads to a change in the second moment of the trajectories. Correspondingly, the vibration part of the Piola stress becomes particularly significant at high temperature and high tensile strain as the crystal approaches the softening limit. In contrast to the eigenvectors of the deformation gradient, the eigenvectors of the vibration tensor show strong spatial heterogeneity in the vicinity of softening. More importantly, the elliptic distribution of local atomic density transitions to a dumbbell shape, before significant non-affinity in equilibrium positions has occurred.
Collapse
Affiliation(s)
- Ranganathan Parthasarathy
- Department of Mathematical Sciences, Box 9616, Tennessee State University, 3500 John A Merritt Blvd, Nashville, TN 37209-1561, United States of America
| | | | | |
Collapse
|
10
|
Misra A, Parthasarathy R, Ye Q, Singh V, Spencer P. Swelling equilibrium of dentin adhesive polymers formed on the water-adhesive phase boundary: experiments and micromechanical model. Acta Biomater 2014; 10:330-42. [PMID: 24076070 PMCID: PMC3843361 DOI: 10.1016/j.actbio.2013.09.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/29/2013] [Accepted: 09/17/2013] [Indexed: 11/21/2022]
Abstract
During their application to the wet, oral environment, dentin adhesives can experience phase separation and composition change, which can compromise the quality of the hybrid layer formed at the dentin-adhesive interface. The chemical composition of polymer phases formed in the hybrid layer can be represented using a ternary water-adhesive phase diagram. In this paper, these polymer phases are characterized using a suite of mechanical tests and swelling experiments. The experimental results were evaluated using a granular micromechanics-based model incorporating poro-mechanical effects and polymer-solvent thermodynamics. The variation in the model parameters and model-predicted polymer properties was studied as a function of composition along the phase boundary. The resulting structure-property correlations provide insight into interactions occurring at the molecular level in the saturated polymer system. These correlations can be used for modeling the mechanical behavior of the hybrid layer, and are expected to aid in the design and improvement of water-compatible dentin adhesive polymers.
Collapse
Affiliation(s)
- A Misra
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA; Civil, Environmental and Architectural Engineering Department, Learned Hall, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA.
| | | | | | | | | |
Collapse
|