Autonomous-Strengthening Adhesive Provides Hydrolysis-Resistance and Enhanced Mechanical Properties in Wet Conditions

Abstract

The low-viscosity adhesive that is used to bond composite restorative materials to the tooth is readily damaged by acids, enzymes, and oral fluids. Bacteria infiltrate the resulting gaps at the composite/tooth interface, demineralize the tooth, and further erode the adhesive. This paper presents the preparation and characterization of a low-crosslink-density hydrophilic adhesive that capitalizes on sol-gel reactions and free-radical polymerization to resist hydrolysis and provide enhanced mechanical properties in wet environments. Polymerization behavior, water sorption, and leachates were investigated. Dynamic mechanical analyses (DMA) were conducted using water-saturated adhesives to mimic load transfer in wet conditions. Data from all tests were analyzed using appropriate statistical tests (α = 0.05). The degree of conversion was comparable for experimental and control adhesives at 88.3 and 84.3%, respectively. HEMA leachate was significantly lower for the experimental (2.9 wt%) compared to control (7.2 wt%). After 3 days of aqueous aging, the storage and rubbery moduli and the glass transition temperature of the experimental adhesive (57.5MPa, 12.8MPa, and 38.7 °C, respectively) were significantly higher than control (7.4MPa, 4.3 MPa, and 25.9 °C, respectively). The results indicated that the autonomic sol-gel reaction continues in the wet environment, leading to intrinsic reinforcement of the polymer network, improved hydrolytic stability, and enhanced mechanical properties.

Bioactive Dental Resin Composites with MgO Nanoparticles

“…Visible light triggers the transfer of electrons–protons between the excited CQ and DMAEMA, generating amine free radicals and enabling the polymerization of methacrylate monomers . The conversion degree of aliphatic CC bonds is positively correlated to the abrasive resistance of dental resin composites .…”

“…Visible light triggers the transfer of electrons−protons between the excited CQ and DMAEMA, generating amine free radicals and enabling the polymerization of methacrylate monomers. 61 The conversion degree of aliphatic C�C bonds is positively correlated to the abrasive resistance of dental resin composites. 11 The FTIR spectra and DC results in Figure 6 show that the polymerization had a significant reduction in M 10 S 68 and M 15 S 63 , suggesting that the conversion degree of aliphatic C�C bonds in the experimental composites was inhibited when the addition of MgONPs reached 10 wt %.…”

Engineered Peptides Enable Biomimetic Route for Collagen Intrafibrillar Mineralization

“…This study is the further investigation of our research on designing a self-strengthening peptide-functionalized dental adhesive to improve the integrity and durability of the adhesive/dentin (a/d) interface. Our previous work focused on improving the adhesive through the development of peptide-tethered-polymer systems [ 16 ] and self-strengthening adhesive formulations [ 1 , 15 ]. Here we designed an engineered peptide (CBP-HABP1) enabling collagen intrafibrillar mineralization to promote enclosure of demineralized collagen fibrils and help to improve the integrity and durability of the a/d interface.…”

“…Polymeric restorative materials have revolutionized the treatment of dental caries by allowing clinicians a “one-of-a kind” in situ tissue engineering approach afforded by resin–dentin bonding [ 1 , 2 , 3 , 4 , 5 ]. Despite significant advances in composite resins for treating teeth, the low durability of the current dental adhesives continues to be a major health burden.…”

“…The Global Oral Health Status 2022 report released by the World Health Organization (WHO) estimated 2 billion people worldwide suffer from caries in their permanent teeth [ 6 , 7 ]. The retention of composite resins relies on the adhesive system, which infiltrates into the collagen matrix to adhere to dentin [ 1 , 8 , 9 , 10 , 11 ]. Adhesion and adhesive performance on dentin are especially challenging due to the complexity of dentin, a mineralized dynamic biological composite tissue composed of 70% hydroxyapatite (HA), 30% type I collagen, multiple non-collagenous proteins, and water [ 12 , 13 , 14 ].…”