title: A biomimetic approach to ameliorate dental hypersensitivity by amorphous polyphosphate microparticles.
abstract: Dental hypersensitivity has become one of the most common and most costly diseases in the world, even though those maladies are very rarely life threatening. Using amorphous microparticles, fabricated from the natural polymer (polyphosphate), we intend to reseal the dentinal tubules exposed and reduce by that the hypersensitivity.
  
  
  
  Amorphous microparticles (termed aCa-polyP-MP) were prepared from Na-polyphosphate (polyP) and CaCl2, then incubated with human teeth. The potential of the microparticles to plug the dentinal tubules was determined by microscopic and spectroscopic techniques.
  
  
  
  We demonstrate that, in contrast to polyP, the aCa-polyP-MP efficiently reseal dentinal tubules exposed at the tooth surface. Scanning electron microscopical (SEM) and energy dispersive X-ray spectroscopic (EDX) studies showed that the tooth cement and dentin surfaces, incubated with aCa-polyP-MP, form a nearly homogenous, approximately 50-μm thick solid polyP layer on the tooth cement and dentin surfaces, while no coating on the tooth surface, incubated with Na-polyP [Ca(2+)], was observed. Determination of the mechanical properties of the polyP coating revealed a Martens hardness of 3.85±0.64GPa and a reduced elastic modulus of 94.72±8.54GPa already after a 3h exposure to the aCa-polyP-MP, which become close to those of the natural enamel (4.33±0.69GPa and 101.61±8.52GPa, respectively) after prolonged incubation periods. In addition, aCa-polyP-MP turned out to display morphogenetic activity. Incubation of precursor odontoblasts cultures in the presence of aCa-polyP-MP resulted in a 7-fold increase of the steady-state-expression level of the gene encoding for the alkaline phosphatase (ALP) during a 7 d incubation period.
  
  
  
  Ca-polyP microparticles, consisting of the biocompatible natural polymer polyP, provide a potential sealing material for dentinal tubules on the tooth surface.
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany. Electronic address: wmueller@uni-mainz.de.
authors.forename: Werner E G
authors.initials: WE
authors.lastname: Müller
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
authors.forename: Meik
authors.initials: M
authors.lastname: Neufurth
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
authors.forename: Emad
authors.initials: E
authors.lastname: Tolba
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
authors.forename: Shunfeng
authors.initials: S
authors.lastname: Wang
authors.affiliation: Hannover Medical School, Department of Conservative Dentistry and Periodontology, Carl Neuberg Str 1, D-30625 Hannover, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Geurtsen
authors.affiliation: Laboratory of Advanced Materials of Ministry of Education of China, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Qingling
authors.initials: Q
authors.lastname: Feng
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
authors.forename: Heinz C
authors.initials: HC
authors.lastname: Schröder
authors.affiliation: ERC Advanced Investigator Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany. Electronic address: wang013@uni-mainz.de.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
mesh_terms: D032701:Biomimetics; D003804:Dentin; D003807:Dentin Sensitivity; D006801:Humans; D008855:Microscopy, Electron, Scanning; D011122:Polyphosphates
chemical_list: D011122:Polyphosphates
keywords: Dental coating; Dental hypersensitivity; Dentinal tubules; Microparticles; Polyphosphate