H+-induced tension development in demineralized dentin matrix.
Recent atomic force microscopy studies have shown that acid-etching dentin causes the surface to recede. The purpose of this work was to test the hypothesis that acidic solutions can cause contraction of demineralized dentin matrix. Small beams of dentin were cut from extracted human third molars. The central region of each specimen was completely demineralized in EDTA. Specimens held in a tester were immersed in acidic solutions, and the amount of tension was recorded. Test variables included gauge length, cross-sectional area, pre-strain, and pH. The results showed that immersion of demineralized dentin in acidic solutions caused tension that was directly related both to H+ concentration at pH < 2 and to pre-strain. The contractile stress development (ca. 0.2-0.4 MPa) was sufficient to cause a collapse of demineralized dentin matrix. The mechanism for this effect probably involves H+-induced conformation changes in the collagen matrix.
Pashley
D H
DH
Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta 30912-1129, USA. dpashley@mail.mcg.edu
Zhang
Y
Y
Carvalho
R M
RM
Rueggeberg
F A
FA
Russell
C M
CM
D000134:Acid Etching, Dental / Q000009:adverse effects*; D000704:Analysis of Variance; D003094:Collagen / Q000187:drug effects; D003648:Decalcification Technique; D003799:Dental Stress Analysis; D003804:Dentin / Q000737:chemistry* / Q000187:drug effects*; D004548:Elasticity; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016018:Least-Squares Analysis; D010756:Phosphoric Acids / Q000009:adverse effects; D011489:Protein Denaturation; D012044:Regression Analysis; D013500:Surface Tension / Q000187:drug effects; D016707:Tissue Fixation
D010756:Phosphoric Acids; D003094:Collagen; C030242:phosphoric acid