Document Detail


SEM-EDX study of prepared human dentine surfaces exposed to gingival retraction fluids.
MedLine Citation:
PMID:  16199281     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: To evaluate the effects of gingival retraction fluids (GRF) on prepared dentine surfaces, and to test the null-hypothesis that prior exposure of dentine surfaces for prolonged period to any of the fluids evaluated does not influence acid-etching of the exposed surfaces. METHODS: The investigation was carried out using SEM and energy-dispersive X-ray analysis (EDX). The GRF studied were Hemodent (HMDT), Astringedent (AST) and Ultradent buffered 25% Aluminium Chloride (ULTB). Longitudinal sections of 220-grit ground dentine surfaces were exposed to GRF for 0.5-, 1-, 2- and 5-min (n=4 each). Another group of samples was produced by 20s application of 35% phosphoric acid (PA) on GRF-pretreated dentine. Control samples were not exposed to GRF. Differences in etching effect-a function of the Ca-contents detected by EDX, were analysed using Friedman's and Wilcoxon's rank test (P<0.05). RESULTS: The SEM demonstrated the presence of a relatively non-porous amorphous dentine matrix, but many of the dentine tubule orifices remained occluded. Granular precipitates, which remained even after acid-etching, were noted on surfaces exposed to Hemodent for 5 min. Characteristic crystal growth was observed on surfaces exposed to Astringedent for 1- or 2-min prior to acid-etching. The EDX data demonstrated that there were differences in resulting Ca-content; ULTB >AST>HMDT>ULTB+PA>HMDT+PA>AST+PA>PA, but AST and HMDT were not significantly different. CONCLUSIONS: The exposure of dentine prepared surfaces to these three GRF altered its morphology and reduced the dentine's susceptibility to acid-etching, thus the null-hypothesis is rejected.
Authors:
Olalekan A Ayo-Yusuf; Cornel H Driessen; Andre J Botha
Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article     Date:  2005-04-07
Journal Detail:
Title:  Journal of dentistry     Volume:  33     ISSN:  0300-5712     ISO Abbreviation:  J Dent     Publication Date:  2005 Oct 
Date Detail:
Created Date:  2005-10-03     Completed Date:  2005-12-20     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0354422     Medline TA:  J Dent     Country:  England    
Other Details:
Languages:  eng     Pagination:  731-9     Citation Subset:  D; IM    
Affiliation:
Department of Community Dentistry, School of Dentistry, Room 6.43-2, Oral and Dental Hospital, University of Pretoria, P.O. box 1266, Pretoria 0001, South Africa. lekan.ayoyusuf@up.ac.za
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MeSH Terms
Descriptor/Qualifier:
Acid Etching, Dental*
Dental Materials / pharmacology*
Dentin / drug effects*,  ultrastructure
Electron Probe Microanalysis / methods
Humans
Microscopy, Electron, Scanning
Organic Chemicals / pharmacology
Statistics, Nonparametric
Chemical
Reg. No./Substance:
0/Dental Materials; 0/Organic Chemicals; 0/Ultradent drying agent

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


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