Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide sc...Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.展开更多
To clean out the smear layer on teeth surface, and protect the teeth medulla, the experiment applied the study observing the cleanup of six groups of surface smear layer of dental caries and the tubule plugs reserving...To clean out the smear layer on teeth surface, and protect the teeth medulla, the experiment applied the study observing the cleanup of six groups of surface smear layer of dental caries and the tubule plugs reserving effect after using of different cavity cleansers with the help of SEM. The result implied that both the acidic preparations and chelator could clean out the smear layer on teeth surface in some way, but the later one could also reserve partial tubule plugs, which reduce the stimulation to the teeth medulla. So the chelator is better cleansers in clinical use.展开更多
The aim of this study is to evaluate the influence of Tooth Mousse （TM） application, smear layer removal, and storage time on resin-dentin microtensile bond strength （pTBS）. Dentin specimens were divided into two ...The aim of this study is to evaluate the influence of Tooth Mousse （TM） application, smear layer removal, and storage time on resin-dentin microtensile bond strength （pTBS）. Dentin specimens were divided into two groups： （1） smear layer covered; （2） smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive （Clearfil SE Bond （CSE）; Kuraray Medical, Tokyo, Japan）, an all-in-one adhesive （G-Bond （GB）; GC Corp, Tokyo, Japan）, and a total-etch adhesive （Adper Single Bond 2 （SB）; 3M ESPE, St. Paul, MN, USA）, the specimens were stored for 3 d or 6 months in deionized water at 37 ℃, and pTBS was tested and analyzed. With the exception of SB （no TM application） and GB, the pTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage （P≤0.001）. Bond strength of GB decreased significantly when using EDTA （3 d storage, P〈0.05）. TM application only increased the pTBS of GB （no EDTA） and SB （with EDTA） after 3 d （P≤0.02）. Comparing the adhesives after 3 d of storage, CSE exhibited the greatest pTBS values followed by GB and SB （P≤0.02）. The factors of adhesive, EDTA, and TM did not show any significant impact on pTBS when specimens were stored for 6 months （P〉0.05）. The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on pTBS of dentin bonds after a period of 6 months.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(No.2010JC030)
文摘Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.
文摘To clean out the smear layer on teeth surface, and protect the teeth medulla, the experiment applied the study observing the cleanup of six groups of surface smear layer of dental caries and the tubule plugs reserving effect after using of different cavity cleansers with the help of SEM. The result implied that both the acidic preparations and chelator could clean out the smear layer on teeth surface in some way, but the later one could also reserve partial tubule plugs, which reduce the stimulation to the teeth medulla. So the chelator is better cleansers in clinical use.
基金Project supported by the National Natural Science Foundation of China(Nos.81271955 and 30973350)the Zhejiang Provincial Natural Science Foundation of China(No.Y2080338)
文摘The aim of this study is to evaluate the influence of Tooth Mousse （TM） application, smear layer removal, and storage time on resin-dentin microtensile bond strength （pTBS）. Dentin specimens were divided into two groups： （1） smear layer covered; （2） smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive （Clearfil SE Bond （CSE）; Kuraray Medical, Tokyo, Japan）, an all-in-one adhesive （G-Bond （GB）; GC Corp, Tokyo, Japan）, and a total-etch adhesive （Adper Single Bond 2 （SB）; 3M ESPE, St. Paul, MN, USA）, the specimens were stored for 3 d or 6 months in deionized water at 37 ℃, and pTBS was tested and analyzed. With the exception of SB （no TM application） and GB, the pTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage （P≤0.001）. Bond strength of GB decreased significantly when using EDTA （3 d storage, P〈0.05）. TM application only increased the pTBS of GB （no EDTA） and SB （with EDTA） after 3 d （P≤0.02）. Comparing the adhesives after 3 d of storage, CSE exhibited the greatest pTBS values followed by GB and SB （P≤0.02）. The factors of adhesive, EDTA, and TM did not show any significant impact on pTBS when specimens were stored for 6 months （P〉0.05）. The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on pTBS of dentin bonds after a period of 6 months.
