Solvation of dried dentin matrix by water and other polar solvents.
OBJECTIVE
To develop a simple method for measuring the degree of solvation of dried, demineralized dentin matrix by water and other polar solvents. The null hypothesis was that there are no differences in expansion forces produced by different polar solvents.


METHODS
Midcoronal dentin discs were prepared from extracted, unerupted human third molars. The discs were cut into square specimens with surface areas of 2 x 2, 3 x 3 and 4 x 4 mm and thicknesses of 0.5, 1.0 and 1.5 mm. After demineralization in 0.5 M EDTA (pH 7), the dimensions of the specimens were measured both wet and dry. Dry specimens were held between two parallel steel plates connected to a 50 N load cell which measured the solvation force when water or other polar solvents were added. After measuring the expansion force induced by water, the specimens were fixed in glutaraldehyde and the trials repeated. On additional specimens, repeated measures of expansion forces were obtained using water, methanol, ethanol, n-propanol, n-butanol, ethylene glycol, formamide, hydroxyethylmethacrylate, N,N-dimethyl formamide and acetone in unfixed specimens.


RESULTS
Water produced hydration forces as high as 204 g before, and 428 g after glutaraldehyde treatment. The hydration force correlated better with specimen thickness than with surface area. Water solvated the matrix faster than methanol > ethanol > formamide > ethylene glycol. Hydroxyethylmethacrylate, N,N-dimethyl formamide and acetone were unable to solvate the dried matrix. Regression analysis of solvation force vs. Hansen's solubility parameters for dispersive, polar and hydrogen bonding forces demonstrated that solvation force correlations were highest with hydrogen bonding solubility parameters. Measurements of solvation forces provides a simple method for determining solvent-collagen matrix interactions.
Pashley
David H
DH
Dept of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta 30912-1129, USA. dpashley@mail.mcg.edu
Carvalho
Ricardo M
RM
Tay
Franklin R
FR
Agee
Kelli A
KA
Lee
Kwang-Won
KW
D020001:1-Butanol / Q000494:pharmacology; D000433:1-Propanol / Q000494:pharmacology; D000096:Acetone / Q000494:pharmacology; D000704:Analysis of Variance; D002614:Chelating Agents / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003648:Decalcification Technique; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D003808:Dentin Solubility / Q000187:drug effects*; D003890:Desiccation; D004126:Dimethylformamide / Q000494:pharmacology; D004492:Edetic Acid / Q000737:chemistry; D000431:Ethanol / Q000494:pharmacology; D019855:Ethylene Glycol / Q000494:pharmacology; D005404:Fixatives / Q000737:chemistry; D005559:Formamides / Q000494:pharmacology; D005976:Glutaral / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D008689:Methacrylates / Q000494:pharmacology; D000432:Methanol / Q000494:pharmacology; D011312:Pressure; D012044:Regression Analysis; D012997:Solvents / Q000737:chemistry / Q000494:pharmacology*; D013223:Statistics as Topic; D014867:Water / Q000737:chemistry / Q000494:pharmacology*
D002614:Chelating Agents; D005404:Fixatives; D005559:Formamides; D008689:Methacrylates; D012997:Solvents; D014867:Water; D000096:Acetone; D000431:Ethanol; C031066:formamide; C005044:hydroxyethyl methacrylate; D004126:Dimethylformamide; D020001:1-Butanol; D000433:1-Propanol; D004492:Edetic Acid; D019855:Ethylene Glycol; D005976:Glutaral; D000432:Methanol