One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared ...One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared tooth. Bleeding and contamination from the crevicular fluid may compete for space with the impression material within the sulcus, leading to indistinct preparations and a lack of detail at the margin. In addition, such procedures might damage the PDL and cause permanent recession. Flowable composite cable, as opposed to traditional retraction cords, offers the proper marginal seal and visibility during the impression record because of its lower viscosity, improved adaptability, and elastic properties. The aim of this report is to present a brand-new, innovative method for controlling gingival hemorrhage in addition to the gingival retraction in restorative and prosthodontic treatment by utilizing a flowable composite during the final impression record procedure. In these case reports, the flowable composite cord technique is used instead of traditional gingival cords to modify and refine the gingival tissue before taking the traditional final impression or digital scan. Two cases were done for patients undergoing fixed prosthodontics and veneer treatment within a 2-year follow-up period. In addition, the flowable composite cord was used as temporary restoration before the final prosthetic cementation or under the provisional crowns. As a result, clean and healthy gingival tissues render cementation of the final prosthesis quicker and easier to perform. The patients in both cases claimed that their prosthodontic treatments, which involved the application of a flowable composite cord to temporarily retraction the gingiva, had produced good outcomes at the yearlong follow-up. In conclusion, the flowable composite cord technique is found to be a useful tool to improve the quality of impressions in fixed prosthodontics by providing excellent access for impression material to record fine details of the finish line of the prepared tooth structure, and to alter the inflamed tissue into a healthy tissue.展开更多
Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated material...Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated materials are still unclear.Various aspect ratio,volume fraction of polyvinyl alcohol fibre(PVAF),and various water-binder ratio were employed to prepare a total of 26 groups of fibre reinforced alkali-activated composite(FRAAC).The influence of PVAF fibre factor(product of fiber volume fraction and length-diameter ratio)on flowability,compactness,strength,and crack fractal dimension of FRAAC was researched.The influence of water-binder ratio on the plastic viscosity of FRAAC was more significant than that on the yield stress.When fibre factor was lower than critical value of 150,the influence of fibres could be overlooked.The reason was that the space between fibres was distant,so the flowability of FRAAC was not impacted by PVAF.At this time,fibres were challenging to restrict the cracks in matrix and increase their mechanical properties.When fibre factor was higher than critical value 150 and lower than density packing value 450,the flexural strength,compressive strength and crack fractal dimension of FRAAC were considerably enhanced,and the FRAAC could still flow easily under dead weight.When fibre factor were above 450,noteworthy fibre balling considerably decreased the flowability,leading to poor solidity and reduced compressive strength.Hence,the ideal content of PVAF in alkali activated composite is between 150/(l/d)and 450/(l/d).展开更多
Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An a...Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.展开更多
目的比较玻璃离子水门汀与流动树脂垫底对深龋近髓磨牙充填后的疼痛及术后敏感性。方法120颗深龋近髓磨牙,随机分为对照组,玻璃离子水门汀组和流动树脂组,每组40颗患牙。对照组采用dycal护髓,玻璃离子水门汀组采用dycal护髓和玻璃离子...目的比较玻璃离子水门汀与流动树脂垫底对深龋近髓磨牙充填后的疼痛及术后敏感性。方法120颗深龋近髓磨牙,随机分为对照组,玻璃离子水门汀组和流动树脂组,每组40颗患牙。对照组采用dycal护髓,玻璃离子水门汀组采用dycal护髓和玻璃离子水门汀垫底,流动树脂组采用dycal护髓和流动树脂垫底,酸蚀粘接后,3组上层均加压充填3M ESPE Filtek^(TM)P60复合树脂。分别于修复后1天,1周,1个月,3个月采用疼痛程度标尺(Visual Analog scales,VAS)记录自觉疼痛程度,采用Ryge评价标准记录对压缩空气刺激的敏感性。结果术后1天、1周、1个月和3个月,对照组与两个实验组之间自觉疼痛程度上差异有统计学意义(P<0.05),各观察期两实验组之间自觉疼痛程度差异无统计学意义(P>0.05)。术后1天和1周,3组之间的术后敏感发生率差异无统计学意义(P>0.05),术后1个月和3个月,玻璃离子水门汀组和流动树脂组与对照组之间差异有统计学意义(P<0.05),而玻璃离子组与流动树脂组之间差异没有统计学意义(P>0.05)。结论在深龋近髓磨牙充填中,双垫底治疗可以降低术后疼痛以及敏感的发生,玻璃离子水门汀和流动树脂之间没有本质区别。展开更多
文摘One of the most challenging factors affecting impression quality and good marginal fit is the gingival retraction method, which aims to separate the gingiva from the tooth to expose the finishing line of the prepared tooth. Bleeding and contamination from the crevicular fluid may compete for space with the impression material within the sulcus, leading to indistinct preparations and a lack of detail at the margin. In addition, such procedures might damage the PDL and cause permanent recession. Flowable composite cable, as opposed to traditional retraction cords, offers the proper marginal seal and visibility during the impression record because of its lower viscosity, improved adaptability, and elastic properties. The aim of this report is to present a brand-new, innovative method for controlling gingival hemorrhage in addition to the gingival retraction in restorative and prosthodontic treatment by utilizing a flowable composite during the final impression record procedure. In these case reports, the flowable composite cord technique is used instead of traditional gingival cords to modify and refine the gingival tissue before taking the traditional final impression or digital scan. Two cases were done for patients undergoing fixed prosthodontics and veneer treatment within a 2-year follow-up period. In addition, the flowable composite cord was used as temporary restoration before the final prosthetic cementation or under the provisional crowns. As a result, clean and healthy gingival tissues render cementation of the final prosthesis quicker and easier to perform. The patients in both cases claimed that their prosthodontic treatments, which involved the application of a flowable composite cord to temporarily retraction the gingiva, had produced good outcomes at the yearlong follow-up. In conclusion, the flowable composite cord technique is found to be a useful tool to improve the quality of impressions in fixed prosthodontics by providing excellent access for impression material to record fine details of the finish line of the prepared tooth structure, and to alter the inflamed tissue into a healthy tissue.
基金funding of Henan Province Transportation Science and Technology Plan Project(2021J3).
文摘Fibre can enhance the mechanical properties of cement-based composites,but fibre also degrades their workability.However,the quantitative effects of fiber content and length-diameter ratio on alkali-activated materials are still unclear.Various aspect ratio,volume fraction of polyvinyl alcohol fibre(PVAF),and various water-binder ratio were employed to prepare a total of 26 groups of fibre reinforced alkali-activated composite(FRAAC).The influence of PVAF fibre factor(product of fiber volume fraction and length-diameter ratio)on flowability,compactness,strength,and crack fractal dimension of FRAAC was researched.The influence of water-binder ratio on the plastic viscosity of FRAAC was more significant than that on the yield stress.When fibre factor was lower than critical value of 150,the influence of fibres could be overlooked.The reason was that the space between fibres was distant,so the flowability of FRAAC was not impacted by PVAF.At this time,fibres were challenging to restrict the cracks in matrix and increase their mechanical properties.When fibre factor was higher than critical value 150 and lower than density packing value 450,the flexural strength,compressive strength and crack fractal dimension of FRAAC were considerably enhanced,and the FRAAC could still flow easily under dead weight.When fibre factor were above 450,noteworthy fibre balling considerably decreased the flowability,leading to poor solidity and reduced compressive strength.Hence,the ideal content of PVAF in alkali activated composite is between 150/(l/d)and 450/(l/d).
文摘Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal film.Digital radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the computer.Five readings were taken and means were calculated.One-Way Anova and Tamhane post hoc tests were performed.While G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity value.Posterior composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable composites.Enamel and body shades of the composite brands have also statistically significant differences in radiopacity scores.Eventually,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.
文摘目的比较玻璃离子水门汀与流动树脂垫底对深龋近髓磨牙充填后的疼痛及术后敏感性。方法120颗深龋近髓磨牙,随机分为对照组,玻璃离子水门汀组和流动树脂组,每组40颗患牙。对照组采用dycal护髓,玻璃离子水门汀组采用dycal护髓和玻璃离子水门汀垫底,流动树脂组采用dycal护髓和流动树脂垫底,酸蚀粘接后,3组上层均加压充填3M ESPE Filtek^(TM)P60复合树脂。分别于修复后1天,1周,1个月,3个月采用疼痛程度标尺(Visual Analog scales,VAS)记录自觉疼痛程度,采用Ryge评价标准记录对压缩空气刺激的敏感性。结果术后1天、1周、1个月和3个月,对照组与两个实验组之间自觉疼痛程度上差异有统计学意义(P<0.05),各观察期两实验组之间自觉疼痛程度差异无统计学意义(P>0.05)。术后1天和1周,3组之间的术后敏感发生率差异无统计学意义(P>0.05),术后1个月和3个月,玻璃离子水门汀组和流动树脂组与对照组之间差异有统计学意义(P<0.05),而玻璃离子组与流动树脂组之间差异没有统计学意义(P>0.05)。结论在深龋近髓磨牙充填中,双垫底治疗可以降低术后疼痛以及敏感的发生,玻璃离子水门汀和流动树脂之间没有本质区别。
