Background For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a ...Background For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration.Methods The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than △E 1.8 between the two ceramic samples. So, △E 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients＇ satisfaction. Results When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core （△E = 0.3）. The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown （△E = 2.0）, but with opaque covering, the color effect became more clinically satisfactory （△E = 1.8）. Conclusions It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.展开更多
In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with ...In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.展开更多
目的构建以高级实践护士(advanced practice nurse,APN)岗位胜任力为导向的护理硕士专业学位(master of nursing specialist,MNS)研究生核心能力指标体系。方法于2023年4-7月通过文献回顾拟定以APN岗位胜任力为导向的MNS研究生核心能力...目的构建以高级实践护士(advanced practice nurse,APN)岗位胜任力为导向的护理硕士专业学位(master of nursing specialist,MNS)研究生核心能力指标体系。方法于2023年4-7月通过文献回顾拟定以APN岗位胜任力为导向的MNS研究生核心能力指标体系初稿,采用德尔菲法修订并确定指标体系,运用层次分析法确定各指标权重。结果形成的以APN岗位胜任力为导向的MNS研究生核心能力指标体系包括一级指标4项、二级指标12项和三级指标39项。2轮专家函询问卷有效回收率均为100%,专家权威系数分别为0.82、0.88,肯德尔和谐系数分别为0.176、0.165,差异均有统计学意义(P<0.001)。结论构建的以APN岗位胜任力为导向的MNS研究生核心能力指标体系科学合理、内容全面、针对性强,涵盖临床能力、科研能力、教学能力、领导能力多个方面,可为提高MNS研究生的教育质量提供理论依据。展开更多
文摘Background For esthetic consideration, dentin color post core materials were normally used for all-ceramic crown restorations. However, in some cases, clinicians have to consider combining a full ceramic crown with a metal post core. Therefore, this experiment was conducted to test the esthetical possibility of applying cast metal post core in a full ceramic crown restoration.Methods The color of full ceramic crowns on gold and Nickel-Chrome post cores was compared with the color of the same crowns on tooth colored post cores. Different try-in pastes were used to imitate the influence of a composite cementation on the color of different restorative combinations. The majority of patients could not detect any color difference less than △E 1.8 between the two ceramic samples. So, △E 1.8 was taken as the objective evaluative criterion for the evaluation of color matching and patients＇ satisfaction. Results When the Empress 2 crown was combined with the gold alloy post core, the color of the resulting material was similar to that of a glass fiber reinforced resin post core （△E = 0.3）. The gold alloy post core and the try-in paste did not show a perceptible color change in the full ceramic crowns, which indicated that the color of the crowns might not be susceptible to change between lab and clinic as well as during the process of composite cementation. Without an opaque covering the Ni-Cr post core would cause an unacceptable color effect on the crown （△E = 2.0）, but with opaque covering, the color effect became more clinically satisfactory （△E = 1.8）. Conclusions It may be possible to apply a gold alloy post core in the Empress 2 full ceramic crown restoration when necessary. If a non-extractible Ni-Cr post core exists in the root canal, it might be possible to restore the tooth with an Empress 2 crown after covering the labial surface of the core with one layer of opaque resin cement.
基金Funded by the Construction Engineering Special Fund of Taishan Scholars(No.201511106)the Youth Scientific Research Funds of School of Stomatology,Shandong University(No.2018QNJJ01)+1 种基金Shandong Medical and Health Science and Technology Development Plan(No.2017WS112)National Key Research and Development Program of China(No.2016YFC1102705)
文摘In order to investigate how to enhance the teeth fracture resistance after the post and core treatment, an in vitro study was conducted to measure the fracture resistance of endodontically treated teeth restored with cast post and core with two kinds of surface treatment technology and acid etching preparation on the dentinal surface. Sixty-four recently extracted human single-rooted first premolars were endodontically treated and sectioned approximately 1.5 mm above the cementoenamel junction to remove the coronal portion. Each specimen received a cast post, core build-up and a metal alloy crown restoration. All teeth were randomly divided into the smooth surface post, core repair group, the sand blasting surface post, and core repair group, each group was divided into 10 s, 30 s, 60 s acid corrosion treatment group and control group. In acid test groups, an acid etching solution was applied for 10, 30 and 60 seconds, respectively, to the root canal wall surface. Each specimen was embedded in acrylic resin block and tested in an electronic universal testing machine. Fracture loads results showed that canal acid etching could increase teeth fracture resistance strength both in smooth groups and sandblasting group, and achieved the best effect when acid etching for 30 s. Sand spray treatment on the surface of the cast metal post can improve the flexural strength of the teeth after postcrown restoration. Acid etching on the root canal wall surfaces and sand spray treatment on the surface of the cast metal post can improve the flexural strength of the root after post-crown restoration. Therefore, these two methods could be used to strengthen the tooth fracture resistance, and maintain the long-term therapeutic effect of cast post and core restoration.
文摘目的构建以高级实践护士(advanced practice nurse,APN)岗位胜任力为导向的护理硕士专业学位(master of nursing specialist,MNS)研究生核心能力指标体系。方法于2023年4-7月通过文献回顾拟定以APN岗位胜任力为导向的MNS研究生核心能力指标体系初稿,采用德尔菲法修订并确定指标体系,运用层次分析法确定各指标权重。结果形成的以APN岗位胜任力为导向的MNS研究生核心能力指标体系包括一级指标4项、二级指标12项和三级指标39项。2轮专家函询问卷有效回收率均为100%,专家权威系数分别为0.82、0.88,肯德尔和谐系数分别为0.176、0.165,差异均有统计学意义(P<0.001)。结论构建的以APN岗位胜任力为导向的MNS研究生核心能力指标体系科学合理、内容全面、针对性强,涵盖临床能力、科研能力、教学能力、领导能力多个方面,可为提高MNS研究生的教育质量提供理论依据。
