目的:探讨牙根纵裂(vertical root fractures,VRF)发生的牙合因素。方法:应用T-ScanⅢ咬合分析仪对8例VRF患者及个别正常牙合者分别进行正中及侧方咬合记录,定量数据牙合力百分比值(tooth occlusal force percent-ages,T-FP)、双侧牙合...目的:探讨牙根纵裂(vertical root fractures,VRF)发生的牙合因素。方法:应用T-ScanⅢ咬合分析仪对8例VRF患者及个别正常牙合者分别进行正中及侧方咬合记录,定量数据牙合力百分比值(tooth occlusal force percent-ages,T-FP)、双侧牙合力百分比值(two sides force percentages,TS-FP)、牙合力不对称指数(asymmetry index of occlusal force,AOF)、闭合时间(occlusion time,OT)、侧方牙合分离时间(disclusion time,DT)采用配对资料的符号秩和检验分析,定性数据早接触、牙合力中心点(center of force,COF)位置及偏移方向采用Fisher确切概率法检验分析,检验水准α=0.05,P<0.05差异有统计学意义。结果:VRF组T-FP、AOF、OT、DT大于正常对照组,差异具有统计学意义(P<0.05);2组COF位置差异具有统计学意义(P<0.05),TS-FP、早接触发生率、COF偏移方向差异无统计学意义(P>0.05)。结论:VRF患者全口牙合力分布不均衡,双侧牙合力分布不对称,牙合接触稳定性差。展开更多
The addition of ectomycorrhizal fungi(ECMF),beneficial rhizosphere microorganisms,to the soil can pro-mote plant growth and resistance.Here,Populus davidi-ana×Populus bolleana tissue culture seedlings were grown ...The addition of ectomycorrhizal fungi(ECMF),beneficial rhizosphere microorganisms,to the soil can pro-mote plant growth and resistance.Here,Populus davidi-ana×Populus bolleana tissue culture seedlings were grown for 3 months in soils inoculated with one of the species,then seedlings were assessed for mycorrhizal colonization rate and growth,physiological and root traits.Suillus luteus and Populus involutus each formed ectomycorrhizal associa-tions with the seedlings.Seedling height,ground diameter,biomass,and leaf area were significantly greater after treat-ment with ECMF than in the non-inoculated controls.Treat-ment improved all physiological and root variables assessed(chlorophylls and carotenoids,cellulose,and soluble sugars and proteins;root length,surface area,projected area,mean diameter,volume,number of root tips).Seedlings inocu-lated with S.luteus outperformed those inoculated with P.involutus.展开更多
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
This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation...This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography （CBCT） were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.展开更多
文摘目的:探讨牙根纵裂(vertical root fractures,VRF)发生的牙合因素。方法:应用T-ScanⅢ咬合分析仪对8例VRF患者及个别正常牙合者分别进行正中及侧方咬合记录,定量数据牙合力百分比值(tooth occlusal force percent-ages,T-FP)、双侧牙合力百分比值(two sides force percentages,TS-FP)、牙合力不对称指数(asymmetry index of occlusal force,AOF)、闭合时间(occlusion time,OT)、侧方牙合分离时间(disclusion time,DT)采用配对资料的符号秩和检验分析,定性数据早接触、牙合力中心点(center of force,COF)位置及偏移方向采用Fisher确切概率法检验分析,检验水准α=0.05,P<0.05差异有统计学意义。结果:VRF组T-FP、AOF、OT、DT大于正常对照组,差异具有统计学意义(P<0.05);2组COF位置差异具有统计学意义(P<0.05),TS-FP、早接触发生率、COF偏移方向差异无统计学意义(P>0.05)。结论:VRF患者全口牙合力分布不均衡,双侧牙合力分布不对称,牙合接触稳定性差。
基金part of the Liaoning Provincial Department of Education project LJKZ0684supported by the National Natural Science Foundation of China (31800542)
文摘The addition of ectomycorrhizal fungi(ECMF),beneficial rhizosphere microorganisms,to the soil can pro-mote plant growth and resistance.Here,Populus davidi-ana×Populus bolleana tissue culture seedlings were grown for 3 months in soils inoculated with one of the species,then seedlings were assessed for mycorrhizal colonization rate and growth,physiological and root traits.Suillus luteus and Populus involutus each formed ectomycorrhizal associa-tions with the seedlings.Seedling height,ground diameter,biomass,and leaf area were significantly greater after treat-ment with ECMF than in the non-inoculated controls.Treat-ment improved all physiological and root variables assessed(chlorophylls and carotenoids,cellulose,and soluble sugars and proteins;root length,surface area,projected area,mean diameter,volume,number of root tips).Seedlings inocu-lated with S.luteus outperformed those inoculated with P.involutus.
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This case report is to present a maxillary first molar with one O-shaped root, which is an extended C-shaped canal system. Patient with chronic apical periodontitis in maxillary left first molar underwent replantation because of difficulty in negotiating all canals. Periapical radiographs and cone-beam computed tomography （CBCT） were taken. All roots were connected and fused to one root, and all canals seemed to be connected to form an O-shape. The apical 3 mm of the root were resected and retrograde filled with resin-modified glass ionomer. Intentional replantation as an alternative treatment could be considered in a maxillary first molar having an unusual O-shaped root.
