Postgraduate student, Postgraduate in Dental Materials, Department of Restorative Dentistry, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
Postgraduate student, Department of Physical, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
J Prosthet Dent. 2017 Oct;118(4):535-539. doi: 10.1016/j.prosdent.2017.01.001. Epub 2017 Mar 6.
The current application of nanotechnology in dentistry is limited to nanoparticles incorporated into adhesive systems and composite resins. Dental stone is a widely used material, and the incorporation of silica nanoparticles is still unexplored.
The purpose of this in vitro study was to evaluate the mechanical properties of dental stone after the addition of silica nanoparticles in different concentrations.
A total of 180 specimens were prepared, 90 for each dental stone (Durone and Fuji Rock). For the control group (CG), no silica particles were added, while test group TGnI had silica nanoparticles added to 1 wt%, and test group TGnV had silica nanoparticles added to 5 wt%. The roughness, diametral tensile strength (DTS), and compressive strength were measured 24 hours after the start of spatulation.
The mean roughness values for Durone were 0.55, 0.36, and 0.28 μm for CG, TGnI, and TGnV; for Fuji Rock, the mean roughness values were 0.47 for CG, 0.31 for TGnI, and 0.35 μm for TGnV. The mean DTS values for Durone were 6.0, 5.1, and 5.0 MPa for CG, TGnI, and TGnV, respectively, and for Fuji Rock, the mean DTS values were 6.4, 5.2, and 4.5 MPa for CG, TGnI, and TGnV, respectively. The mean compressive strength values for Durone were 35.4, 32.7, and 32.4 MPa for CG, TGnI, and TGnV, respectively, and for Fuji Rock, the mean compressive strength values were 42.9, 31.2, and 29.8 MPa for CG, TGnI, and TGnV respectively.
Surface roughness was statistically lower for the Durone and Fuji Rock stones (P<.001) when silica nanoparticles were added. The addition of silica nanoparticles did not significantly affect the DTS and compressive strength of Durone compared with CG (P>.05) but did affect the DTS of Fuji Rock when 5 wt% was added and the compressive strength in both concentrations (P<.05).
目前纳米技术在牙科中的应用仅限于将纳米颗粒加入到粘接系统和复合树脂中。牙科石膏是一种广泛使用的材料，而添加二氧化硅纳米颗粒仍未得到探索。
本体外研究的目的是评估不同浓度的二氧化硅纳米颗粒添加到牙科石膏后的机械性能。
共制备了 180 个样本，每个牙科石膏（Durone 和 Fuji Rock）各 90 个。对于对照组（CG），未添加二氧化硅颗粒，而实验组 TGnI 添加了 1wt%的二氧化硅纳米颗粒，实验组 TGnV 添加了 5wt%的二氧化硅纳米颗粒。在开始调拌后 24 小时测量粗糙度、直径拉伸强度（DTS）和抗压强度。
Durone 的平均粗糙度值分别为 CG 组的 0.55μm、TGnI 组的 0.36μm 和 TGnV 组的 0.28μm；对于 Fuji Rock，CG 组的平均粗糙度值为 0.47μm，TGnI 组为 0.31μm，TGnV 组为 0.35μm。Durone 的平均 DTS 值分别为 CG 组的 6.0MPa、TGnI 组的 5.1MPa 和 TGnV 组的 5.0MPa，而 Fuji Rock 的平均 DTS 值分别为 CG 组的 6.4MPa、TGnI 组的 5.2MPa 和 TGnV 组的 4.5MPa。Durone 的平均抗压强度值分别为 CG 组的 35.4MPa、TGnI 组的 32.7MPa 和 TGnV 组的 32.4MPa，而 Fuji Rock 的平均抗压强度值分别为 CG 组的 42.9MPa、TGnI 组的 31.2MPa 和 TGnV 组的 29.8MPa。
当添加二氧化硅纳米颗粒时，Durone 和 Fuji Rock 石材的表面粗糙度显著降低（P<.001）。与 CG 相比，添加二氧化硅纳米颗粒对 Durone 的 DTS 和抗压强度没有显著影响（P>.05），但当添加 5wt%时，对 Fuji Rock 的 DTS 有影响，对两种浓度的抗压强度都有影响（P<.05）。
