Document Detail


Reactivation of inactivated endogenous proteolytic activities in phosphoric acid-etched dentine by etch-and-rinse adhesives.
MedLine Citation:
PMID:  16687171     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Auto-degradation of collagen matrices occurs in resin-infiltrated dentine by the slow action of host-derived matrix metalloproteinases. As phosphoric acid-etching inactivates these endogenous enzymes, it is puzzling how hybrid layers created by simplified etch-and-rinse adhesives can degrade in vivo. This study tested the null hypothesis that there are no differences in the relative proteolytic activities of mineralised dentine, acid-etched dentine, and etch-and-rinse adhesive-treated acid-etched dentine. Powdered dentine prepared from extracted human teeth was treated with 17% EDTA, 10% phosphoric acid, or with five simplified etch-and-rinse adhesives that were applied to 10% phosphoric acid-etched dentine. The gelatinolytic activity of the dentine powder was assayed using fluorescein-labelled gelatine. TEM examination of the air-dried, treated dentine powder was performed to confirm the presence of remnant mineralised dentine after acid-etching. 17% EDTA significantly reduced the relative proteolytic activity (73.2%) of the untreated mineralised dentine powder (control), while 10% phosphoric acid-etched dentine exhibited the highest reduction (98.1%). Treating the acid-etched dentine powder with any of the five simplified etch-and-rinse adhesives resulted in the reactivation of the proteolytic activity, with a significant negative linear correlation (P<0.05) between the increases in fluorescence and the corresponding pH values of the adhesives. It is concluded that simplified etch-and-rinse adhesives can reactivate endogenous enzymatic activities in dentine that are previously inactivated by phosphoric acid-etching. The amount of enzyme reactivated may even exceed the original quantity present in untreated mineralised dentine. This provides an explanation for the degradation of hybrid layers after acid-etched dentine matrices are infiltrated with these adhesives.
Authors:
Annalisa Mazzoni; David H Pashley; Yoshihiro Nishitani; Lorenzo Breschi; Ferdinando Mannello; Leo Tjäderhane; Manuel Toledano; Edna L Pashley; Franklin R Tay
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2006-05-09
Journal Detail:
Title:  Biomaterials     Volume:  27     ISSN:  0142-9612     ISO Abbreviation:  Biomaterials     Publication Date:  2006 Sep 
Date Detail:
Created Date:  2006-05-22     Completed Date:  2006-08-30     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  8100316     Medline TA:  Biomaterials     Country:  England    
Other Details:
Languages:  eng     Pagination:  4470-6     Citation Subset:  IM    
Affiliation:
Department of SAU and FAL, University of Bologna, Bologna, Italy.
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MeSH Terms
Descriptor/Qualifier:
Dentin / chemistry*
Hydrolysis
Microscopy, Electron, Transmission
Phosphoric Acids / chemistry*
Grant Support
ID/Acronym/Agency:
R01 DE014911/DE/NIDCR NIH HHS; R01 DE015306/DE/NIDCR NIH HHS
Chemical
Reg. No./Substance:
0/Phosphoric Acids; 7664-38-2/phosphoric acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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