Dissolution of bio-active dentine matrix components by mineral trioxide aggregate.
OBJECTIVE
To analyze the soluble components of setting and set mineral trioxide aggregate (MTA), assess the abilities of two varieties of MTA and Ca(OH)(2) solutions to solubilise dentine matrix proteins (DMPs) and determine if these extracts contain signalling molecules important to pulpal repair and regeneration.


METHODS
The metallic ion composition of solutions of white and grey MTA (pH 11.7), 0.02M Ca(OH)(2) (pH 11.9) and 10% EDTA (pH 7.2) was determined using atomic absorption spectroscopy. Extracellular dentine matrix components from powdered human dentine were extracted using all solutions over 14 days. Extracts were analysed for concentrations of non-collagenous proteins (NCPs) and glycosaminoglycans (GAGs), and protein profiles were examined using 1D-polyacrylamide gel electrophoresis (1D-PAGE). ELISAs for TGF-beta1 and adrenomedullin (ADM) were also performed.


RESULTS
Aluminium, calcium, potassium, and sodium ions were detected in both white and grey MTA solutions. MTA and Ca(OH)(2) solutions liberated similar amounts of GAGs and NCPs although yields were considerably lower than those obtained using the EDTA solution. 1D-PAGE analysis demonstrated differences in protein profiles solubilised from dentine for all solutions. All extracts contained TGF-beta1 and ADM, EDTA solution liberated significantly greater amounts of TGF-beta1, and Ca(OH)(2) and grey MTA solutions released more ADM.


CONCLUSIONS
These data imply that when placed clinically soluble components of set and setting MTA may release dentine matrix components that potentially influence cellular events for dentine repair and regeneration.
Tomson
Phillip L
PL
Oral Biology, School of Dentistry, The University of Birmingham, St Chad's Queensway, Birmingham B4 6NN, UK. p.l.tomson@bham.ac.uk
Grover
Liam M
LM
Lumley
Philip J
PJ
Sloan
Alastair J
AJ
Smith
Anthony J
AJ
Cooper
Paul R
PR
D053607:Adrenomedullin / Q000032:analysis; D017607:Aluminum Compounds / Q000737:chemistry / Q000494:pharmacology*; D017610:Calcium Compounds / Q000737:chemistry / Q000494:pharmacology*; D002126:Calcium Hydroxide / Q000737:chemistry / Q000494:pharmacology; D003808:Dentin Solubility / Q000187:drug effects*; D004338:Drug Combinations; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000187:drug effects*; D006025:Glycosaminoglycans / Q000032:analysis; D006801:Humans; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology*; D010750:Phosphoproteins / Q000737:chemistry / Q000187:drug effects*; D012387:Root Canal Filling Materials / Q000737:chemistry / Q000494:pharmacology*; D017640:Silicates / Q000737:chemistry / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1 / Q000032:analysis
D017607:Aluminum Compounds; D017610:Calcium Compounds; C513309:DMP1 protein, human; D004338:Drug Combinations; D016326:Extracellular Matrix Proteins; D006025:Glycosaminoglycans; D010087:Oxides; D010750:Phosphoproteins; D012387:Root Canal Filling Materials; D017640:Silicates; D053773:Transforming Growth Factor beta1; C086631:mineral trioxide aggregate; D053607:Adrenomedullin; D002126:Calcium Hydroxide