Reconfigurable Dual Peptide Tethered Polymer System Offers a Synergistic Solution for Next Generation Dental Adhesives.

Resin-based composite materials have been widely used in restorative dental materials due to their aesthetic, mechanical, and physical properties. However, they still encounter clinical shortcomings mainly due to recurrent decay that develops at the composite-tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal this interface, but the adhesive seal is inherently defective and readily damaged by acids, enzymes, and oral fluids.

Probing the mineralized tissue-adhesive interface for tensile nature and bond strength.

The mechanical performance of the dentin-adhesive interface contributes significantly to the failure of dental composite restorations. Rational material design can lead to enhanced mechanical performance, but this requires accurate characterization of the mechanical behavior at the dentin-adhesive interface. The mechanical performance of the interface is typically characterized using bond strength tests, such as the micro-tensile test.

Antimicrobial Peptide-Polymer Conjugates for Dentistry.

Bacterial adhesion and growth at the composite/adhesive/tooth interface remain the primary cause of dental composite restoration failure. Early colonizers, including , play a critical role in the formation of dental caries by creating an environment that reduces the adhesive's integrity. Subsequently, other bacterial species, biofilm formation, and lactic acid from demineralize the adjoining tooth.

Bioinspired multifunctional adhesive system for next generation bio-additively designed dental restorations.

Resin-based composite has overtaken dental amalgam as the most popular material for the repair of lost or damaged tooth structure. In spite of the popularity, the average composite lifetime is about half that of amalgam restorations. The leading cause of composite-restoration failure is decay at the margin where the adhesive is applied.

Evolution of Network Structure and Mechanical Properties in Autonomous-Strengthening Dental Adhesive.

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.

Multifunctional monomer acts as co-initiator and crosslinker to provide autonomous strengthening with enhanced hydrolytic stability in dental adhesives.

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).

Threats to adhesive/dentin interfacial integrity and next generation bio-enabled multifunctional adhesives.

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.

Peptide Mediated Antimicrobial Dental Adhesive System.

The most common cause for dental composite failures is secondary caries due to invasive bacterial colonization of the adhesive/dentin (a/d) interface. Innate material weakness often lead to an insufficient seal between the adhesive and dentin. Consequently, bacterial by-products invade the porous a/d interface leading to material degradation and dental caries.

Structure-property relationships for wet dentin adhesive polymers.

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.

New silyl-functionalized BisGMA provides autonomous strengthening without leaching for dental adhesives.

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.

Modulating pH through lysine integrated dental adhesives.

Objectives: The objective of this study was to explore the effect of lysine integration to dental adhesives with respect to the polymerization kinetics, neutralization capacities in the acidic microenvironment, dynamic mechanical properties, and thermal properties.

Materials And Method: Lysine was incorporated into liquid resin formulations at 2.5 and 5.

Fabrication of hybrid crosslinked network with buffering capabilities and autonomous strengthening characteristics for dental adhesives.

Unlabelled: Ingress of bacteria and fluids at the interfacial gaps between the restorative composite biomaterial and the tooth structure contribute to recurrent decay and failure of the composite restoration. The inability of the material to increase the pH at the composite/tooth interface facilitates the outgrowth of bacteria. Neutralizing the microenvironment at the tooth/composite interface offers promise for reducing the damage provoked by cariogenic and aciduric bacteria.

Probing the neutralization behavior of zwitterionic monomer-containing dental adhesive.

Objective: To investigate the polymerization kinetics, neutralization behavior, and mechanical properties of amine-functionalized dental adhesive cured in the presence of zwitterionic monomer, methacryloyloxyethyl phosphorylcholine (MPC).

Methods: The control adhesive was a mixture based on HEMA/BisGMA/2-N-morpholinoethyl methacrylate (MEMA) (40/30/30, w/w/w). The control and experimental formulations containing MPC were characterized with regard to water miscibility of liquid resins, photopolymerization kinetics, water sorption and solubility, dynamic mechanical properties and leachables from the polymers (aged in ethanol).

Self-Strengthening Hybrid Dental Adhesive via Visible-light Irradiation Triple Polymerization.

A self-strengthening methacrylate-based dental adhesive system was developed by introducing an epoxy cyclohexyl trimethoxysilane (TS) which contains both epoxy and methoxysilyl functional groups. The experimental formulation, HEMA/BisGMA/TS (22.5/27.

Effect of Partition of Photo-initiator Components and Addition of Iodonium Salt on the Photopolymerization of Phase-Separated Dental Adhesive.

The polymerization kinetics of physically separated hydrophobic- and hydrophilic-rich phases of a model dental adhesive have been investigated. The two phases were prepared from neat resin containing 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycerolate dimethacrylate (BisGMA) in the ratio of 45:55 (wt/wt). Neat resins containing various combinations of popular photo-initiating compounds, e.

Mimicking nature: Self-strengthening properties in a dental adhesive.

Unlabelled: 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.

Probing the dual function of a novel tertiary amine compound in dentin adhesive formulations.

Objectives: A novel tertiary amine compound containing three methacrylate-urethane groups was synthesized for application in dentin adhesives. The synthesis, photopolymerization kinetics, and leaching were examined in an earlier study using this novel compound as the co-initiator (0.5 and 1.

Tris(trimethylsilyl)silane as a co-initiator for dental adhesive: Photo-polymerization kinetics and dynamic mechanical property.

Objectives: The purpose of this study was to evaluate the polymerization behavior of a model dentin adhesive with tris(trimethylsilyl)silane (TTMSS) as a co-initiator, and to investigate the polymerization kinetics and mechanical properties of copolymers in dry and wet conditions.

Methods: A co-monomer mixture based on HEMA/BisGMA (45/55, w/w) was used as a model dentin adhesive. The photoinitiator system included camphorquinone (CQ) as the photosensitizer and the co-initiator was ethyl-4-(dimethylamino) benzoate (EDMAB) or TTMSS.

The influence of water on visible-light initiated free-radical/cationic ring-opening hybrid polymerization of methacrylate/epoxy: Polymerization kinetics, crosslinking structure and dynamic mechanical properties.

The objective of this study was to determine the influence of water on the polymerization kinetics, crosslinking structure and dynamic mechanical properties of methacrylate/epoxy polymers cured by visible-light initiated free-radical/cationic ring-opening hybrid polymerization. Water-containing formulations were prepared by adding ~4-7 wt% DO depending on the water miscibility of monomer resins. The water-containing adhesives were compared with the adhesives photo-cured in the absence of water.

Synthesis of Highly Monodispersed CdS/SiO2 Core-Shell Nanoparticles and Their Photocatalytic Activities.

Monodispersed CdS/SiO2 core-shell composite nanoparticles with effective photocatalytic activity were successfully synthesized. The structure and morphologies of composite nanoparticles were characterized by XRD, FTIR, TEM, and high-resolution transmission electron microscopy (HRTEM). Results showed that the CdS/SiO2 composite nanoparticles exhibited obvious core-shell structure, and that the thickness of the SiO2 shell could be reduced by either increasing the water/alcohol volume ratio or decreasing TEOS amount.

Effect of crosslinking density of polymers and chemical structure of amine-containing monomers on the neutralization capacity of dentin adhesives.

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.

Compositional design and optimization of dentin adhesive with neutralization capability.

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).

Synthesis and evaluation of a novel co-initiator for dentin adhesives: polymerization kinetics and leachables study.

A new tertiary amine co-initiator (TUMA) containing three methacrylate-urethane groups was synthesized for application in dentin adhesives. The photopolymerization kinetics and leaching of unreacted components from methacrylate-based dental polymers formulated with this new co-initiator were determined. The newly synthesize co-initiator showed good chemical stability and decreased amine release from the initiator system.

Development of methacrylate/silorane hybrid monomer system: Relationship between photopolymerization behavior and dynamic mechanical properties.

Resin chemistries for dental composite are evolving as noted by the introduction of silorane-based composites in 2007. This shift in the landscape from methacrylate-based composites has fueled the quest for versatile methacrylate-silorane adhesives. The objective of this study was to evaluate the polymerization behavior and structure/property relationships of methacrylate-silorane hybrid systems.

Visible-Light Initiated Free-Radical/Cationic Ring-Opening Hybrid Photopolymerization of Methacrylate/Epoxy: Polymerization Kinetics, Crosslinking Structure, and Dynamic Mechanical Properties.

The effects of polymerization kinetics and chemical miscibility on the crosslinking structure and mechanical properties of polymers cured by visible-light initiated free-radical/cationic ring-opening hybrid photopolymerization are determined. A three-component initiator system is used and the monomer system contains methacrylates and epoxides. The photopolymerization kinetics is monitored in situ by Fourier transform infrared-attenuated total reflectance.