Improved dental adhesive formulations based on reactive nanogel additives.
Current challenges in adhesive dentistry include over-hydrophilic bonding formulations, which facilitate water percolation through the hybrid layer and result in unreliable bonded interfaces. This study introduces nanogel-modified adhesives as a way to control the material's hydrophobic character without changing the basic monomer formulation (keeping water-chasing capacity and operatory techniques unaltered). Nanogel additives of varied hydrophobicity were synthesized in solution, rendering 10- to 100-nm-sized particles. A model BisGMA/HEMA solvated adhesive was prepared (control), to which reactive nanogels were added. The increase in adhesive viscosity did not impair solvent removal by air-thinning. The degree of conversion in the adhesive was similar between control and nanogel-modified materials, while the bulk dry and, particularly, the wet mechanical properties were significantly improved through nanogel-based network reinforcement and reduced water solubility. As preliminary validation of this approach, short-term micro-tensile bond strengths to acid-etched and primed dentin were significantly enhanced by nanogel inclusion in the adhesive resins.
Federal University of Pelotas, Brazil.
R R
RR
Morães
J W
JW
Garcia
N D
ND
Wilson
S H
SH
Lewis
M D
MD
Barros
B
B
Yang
C S
CS
Pfeifer
J W
JW
Stansbury
D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001892:Camphanes / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D055119:Elastic Modulus; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D018583:Pliability; D058105:Polymerization; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012995:Solubility; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D044366:Transition Temperature; D014783:Viscosity; D014867:Water / Q000737:chemistry
D001892:Camphanes; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; D014867:Water; C029824:urethane dimethacrylate luting resin; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate