在使用单塞技术后,空隙的存在和分布与不同的密封器放置方法在带有峡谷的运河中
Yu-Qi Ma1,2, Yu-Hong Liang3
1Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices& Beijing Key Laboratory of Digital Stomatology & NHC Key Laboratory of Digital Stomatology & NMPA Key Laboratory for Dental Materials, Beijing, China.
Journal of dental sciences
|January 28, 2025
概括
与被动单塞相比,双向螺旋或超声密封器的放置显著减少了带着河峡的根通道中的空隙. 这些方法提高了单塞技术的有效性.
科学领域:
- 牙周内科医院 牙周内科医院 牙周内科医院
- 牙科材料科学 牙科材料科学
背景情况:
- 带状峡湾等不规则结构的根通道堵塞对单 (SC) 技术提出了挑战.
- 空洞形成仍然是内牙治疗结果的一个重大问题.
研究的目的:
- 为了评估空隙的存在和分布,使用SC与不同的密封器放置方法.
- 为了比较模拟的根通道中的密封剂放置技术,这些根通道具有带状峡谷.
主要方法:
- 测试了四个堵塞组:被动单密封器放置 (SCP),双向螺旋 (BS),超声波支持 (U) 和垂直紧缩 (VC).
- 使用3D打印的根管模型与模拟的地峡.
- 使用微计算机断层扫描 (micro-CT) 和切片分析进行空洞分析,以计算空洞的百分比面积 (PAV) 和空洞的百分比体积 (PVV).
主要成果:
- 与被动单密封器 (SCP) 相比,双向螺旋 (BS) 和超声波支持的 (U) 密封器放置显著减少了空隙.
- 平均PAV为BS和U的21%,而垂直压缩 (VC) 的33%,SCP的45%.
- 微型CT显示,与SCP (46% PVV) 相比,BS (25% PVV) 和U (29% PVV) 的地峡空隙体积减少.
结论:
- 双向螺旋或超声波支持的密封器放置改善了带有地峡的根通道中的单闭塞性能.
- 这些先进的密封器输送方法提供了一种更有效的方法来减少复杂运河解剖中的空隙.
相关概念视频
Total Voids in Concrete
94
Total voids in concrete encompass gel water volume, capillary pores, and entrapped air. Gel water (retained within the cement hydration products) and physically entrapped or adsorbed water are significant for the hydration process. For complete hydration, it's estimated that the space needed for the products of a cubic centimeter of cement doubles. Capillary pores constitute the unoccupied space within the hydrated cement paste, with their size largely influenced by the water-to-cement...
94
Porosity in Cement Paste
110
The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
The balance of water to cement in the mix is...
The balance of water to cement in the mix is...
110
Masonry Cavity Walls
608
Cavity walls feature a hollow space between the outer and inner wythes, connected only by corrosion-resistant metal ties. When water seeps through the outer wythe, it descends within this cavity, intercepted by flashing and eventually exiting through weep holes. To enhance moisture resistance, the inner wythe's cavity side often receives damp-proofing, doubling as an air barrier. The cavity can also house insulation to mitigate heat transfer.
Maintaining a clean cavity during construction...
Maintaining a clean cavity during construction...
608
Preplaced Aggregate Concrete
91
Preplaced aggregate concrete is ideal for construction environments that are not easily accessible. The process begins by properly wetting the gap-graded coarse aggregates to remove the dirt, then placing it in the form and compacting it. Voids are filled with a mortar mix pumped under pressure through slotted pipes. This mortar typically consists of Portland cement, pozzolan, fine aggregates, water, and a fluidizing aid. The pozzolan helps reduce bleeding and segregation while improving the...
91
Cavity Drainage and Flashings in Masonry walls
70
Typically, a cavity wall consists of two wythes separated by a gap of at least 2 inches, which may contain insulation while still maintaining a minimum clear space of 1 inch to facilitate adequate drainage. Advanced methods like the insertion of a continuous drainage mat can further reduce this space while ensuring effective moisture expulsion.
Weep holes, strategically placed at the base of the cavity, are critical for draining accumulated water. These openings are created by leaving head...
Weep holes, strategically placed at the base of the cavity, are critical for draining accumulated water. These openings are created by leaving head...
70
Pore Size Distribution
83
In concrete, the pore size distribution significantly influences the material's properties. Capillary pores, markedly larger than gel pores, form a vast network within partially hydrated cement paste, reducing the concrete's strength and increasing its permeability. This heightened permeability leads to a greater risk of damage from environmental factors like freeze-thaw cycles and chemical attacks, with the extent of vulnerability also being tied to the water-to-cement ratio.
Adequate...
Adequate...
83


