Analysis of chemical interaction of 4-MET with hydroxyapatite using XPS.
Each dental adhesive contains a specific functional monomer that determines its actual adhesive performance to tooth tissue. 4-methacryloxyethyl trimellitic acid (4-MET) is well-known as one of the functional monomers mostly available and consequently widely used in commercial adhesives. We therefore characterized the chemical interaction of 4-MET with hydroxyapatite (HAp) using X-ray Photoelectron Spectroscopy (XPS). XPS revealed that the peak representing -COO- of 4-MET shifted to a lower binding energy, when 4-MET was adsorbed onto HAp. Deconvolution of this shifted peak disclosed two components with a peak representing unreacted carboxyl groups and ester groups, and a peak suggesting chemical bonding of other carboxyl groups to Ca of HAp. XPS spectra of HAp treated with 4-MET also disclosed the surface to be enriched in calcium and decreased in phosphorus, indicating that phosphorus was extracted at a relatively higher rate than calcium. It can thus be concluded that true chemical bonding of 4-MET with calcium present in HAp occurred, as it was proven using XPS.
Nagakane
Kouji
K
Department of Biomaterials Science, Graduate School of Biomaterials Science, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8553, Japan.
Yoshida
Yasuhiro
Y
Hirata
Isao
I
Fukuda
Ryuichi
R
Nakayama
Youichi
Y
Shirai
Kenichi
K
Ogawa
Tatsuyuki
T
Suzuki
Kazuomi
K
Van Meerbeek
Bart
B
Okazaki
Masayuki
M
D002118:Calcium / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D001840:Dental Bonding; D017886:Durapatite / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D014233:Tricarboxylic Acids / Q000737:chemistry*
C074233:4-Met adhesion promoting monomer; D008689:Methacrylates; D019279:Resin Cements; D014233:Tricarboxylic Acids; D002245:Carbon Dioxide; C041069:carboxyl radical; D010758:Phosphorus; D017886:Durapatite; D002118:Calcium