TY - JOUR
T1 - SEM-EDX study of prepared human dentine surfaces exposed to gingival retraction fluids
AU - Ayo-Yusuf, Olalekan A.
AU - Driessen, Cornel H.
AU - Botha, Andre J.
PY - 2005/10
Y1 - 2005/10
N2 - 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 20 s 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.
AB - 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 20 s 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.
KW - Acid etching
KW - Bonding
KW - Dentine
KW - Gingival retraction fluids
KW - Impression
KW - Permeability
KW - Smear layer
UR - http://www.scopus.com/inward/record.url?scp=26044473332&partnerID=8YFLogxK
U2 - 10.1016/j.jdent.2005.02.002
DO - 10.1016/j.jdent.2005.02.002
M3 - Article
C2 - 16199281
AN - SCOPUS:26044473332
SN - 0300-5712
VL - 33
SP - 731
EP - 739
JO - Journal of Dentistry
JF - Journal of Dentistry
IS - 9
ER -