含长链烷基季铵盐纳米抗菌无机填料的复合树脂对人牙菌斑生物膜的影响

目的 合成含长链烷基季铵盐纳米抗菌无机填料的复合树脂,探讨其对人牙菌斑生物膜的影响。方法 制备含长链烷基季铵盐的纳米抗菌二氧化硅填料,经表面偶联处理后,分别以0%、5%、10%、15%及20%的质量分数添加到复合树脂中,以0%组作为对照组,用三点弯曲试验来检测其力学性能。建立人牙菌斑生物膜体外模型,通过菌落计数、乳酸代谢分析及活/死细菌染色等手段来评价复合树脂对人牙菌斑生物膜的影响。结果 与对照组相比,当复合树脂纳米抗菌无机填料的质量分数小于15%时,其力学性能没有明显改变（P>0.05）;当纳米抗菌无机填料的质量分数达到5%及以上时,复合树脂对人牙菌斑生物膜的代谢产生明显的抑制作用,显示出良好的抗菌性能（P<0.05）。结论 当抗菌无机填料的质量分数达到5%时,复合树脂具有较强的抗菌防龋功能。     

老化处理对含新型纳米抗菌无机填料复合树脂相关性能的影响

目的:探讨老化处理后,含新型纳米抗菌无机填料复合树脂相关性能的变化.方法:制备含长链烷基季铵盐的纳米抗菌二氧化硅填料,经表面偶联处理后,以10％的质量分数添加到复合树脂中,形成抗菌复合树脂,同时选取无抗菌性的商品化复合树脂Tetric N-Ceram作为对照.复合树脂试件在37℃蒸馏水中老化处理不同时间.用三点弯曲试验来检测其力学性能的变化.通过人牙菌斑生物膜菌落计数、乳酸代谢分析及活/死细菌染色等手段来评价抗菌性能的改变.结果:浸泡30d后,对照组和实验组复合树脂力学性能下降明显(P＜0.05),而后随着老化时间的延长,性能下降不明显(P＞0.05);随着老化时间的延长,实验组复合树脂对人牙菌斑生物膜的代谢仍然产生明显的抑制作用,显示出良好的抗菌性能(P＜0.05).结论:老化处理后,抗菌复合树脂力学性能下降而抗菌性没有明显的变化.     

含长链烷基季铵盐的纳米抗菌无机填料的合成及其在牙科复合树脂中的应用研究

目的 设计合成新型的含长链烷基季铵盐的纳米抗菌无机填料,以赋予牙科复合树脂更优良的抗菌性能。方法 在分子设计和筛选的基础上,制备了长链烷基季铵盐修饰的纳米抗菌二氧化硅填料,并对填料的抗菌性能进行评价。为进一步提高抗菌填料与树脂的结合力,采用硅烷偶联剂对抗菌填料表面进行了处理,并用红外光谱法对其结构特征进行分析;然后将新型纳米抗菌无机填料加入牙科复合树脂中,观察其在复合树脂基体中的分散情况,同时与商品化的Tetric N-Ceram纳米瓷化复合树脂进行对比;并以变异链球菌为对象,研究复合树脂的抗菌性能。结果 长链烷基季铵盐成功接枝到纳米二氧化硅颗粒表面;新型纳米抗菌无机填料的抗菌性能优于含短链烷基季铵盐的抗菌无机填料;偶联处理后的纳米抗菌无机填料在树脂基体中分散均匀,与树脂结合紧密,与Tetric N-Ceram纳米瓷化复合树脂类似;改性后的复合树脂抗菌性能良好。结论 含长链烷基季铵盐的纳米抗菌无机填料抗菌性能良好,经过表面偶联处理后可以很好地与牙科复合树脂共混,提高了牙科复合树脂的抗菌性能。     

新型纳米抗菌无机填料抗菌防龋作用的动物实验研究

目的：探讨表面枝接长链烷基季铵盐的新型纳米抗菌无机填料在大鼠口腔内的抗菌防龋功能.方法：选取5周龄SD雄性大鼠20只,口腔内接种变形链球菌,同时辅以致龋饮食,建立大鼠口腔龋病模型;并随机分成实验组和对照组,每组10只.实验组以自行合成的新型纳米抗菌无机填料刷洗牙齿而对照组则用以普通的纳米二氧化硅无机填料.4周后进行大鼠口腔变形链球菌菌落计数;随后处死大鼠,鼠齿按照Keyes龋齿计分标准进行计分,所有结果进行统计学分析.结果：实验组大鼠口腔变形链球菌菌落计数少于二氧化硅处理组（P＜0.05）;Keyes计分结果显示,实验组大鼠牙齿验面窝沟及平滑面龋损均低对照组（P＜0.05）.结论：大鼠动物实验表明,新型纳米抗菌无机填料具有明显的抗菌防龋功能.     

牙科用氧化锆增韧纳米复相铝瓷粉体的制备与性能研究

目的 研制牙科用氧化锆增韧纳米复相铝瓷粉体并测试其理化性能，探讨影响铝瓷粉体性能的制备工艺。方法 表面诱导沉淀法制备纳米复相铝瓷粉体，记录分散剂加入量及pH值对氧化铝悬浮液沉降物体积的影响；观察超声时间对粉体团聚的影响；X射线衍射分析添加稳定剂前后粉体晶相的组成，扫描电子显微镜下观察其形貌。结果 pH=9、分散剂加入量wt=0．2％～0．3％时，悬浮液分散性好；超声处理后粉体粒径下降；稳定剂处理后复相铝瓷粉体含有单斜相和四方相氧化锆。在原始颗粒较大的氧化铝表面均匀分布着直径约80～100nm的氧化锆细颗粒。结论 控制制备工艺，采用表面诱导沉淀法可得到粒度细、分散好的氧化锆增韧纳米复相铝瓷粉体；经稳定剂处理后，复相铝瓷中的氧化锆成为部分稳定氧化锆。     

氧化锆粉体粒度与氟硅云母玻璃陶瓷强度的关系

目的:研究氧化锆粉体粒度与材料增韧补强效果之间的关系.方法:在氟硅云母玻璃粉中添加等量但不同粉体粒度的氧化锆(粒径分别为50nm和10nm),制备氧化锆质量百分数为25的复合粉体,经冷等静压成型后遵循烧结热制度进行烧结,用扫描电镜观察其显微结构,X线衍射确定物象组成及含量,测定样本的抗弯强度和断裂韧性.以未添加氧化锆的氟硅云母玻璃烧结体为对照.结果:添加等量、不同粒度Zr02(纳米组和微米组)的氟硅云母玻璃陶瓷复合材料,其中纳米组增韧增强效果最明显,抗弯强度达到(224.8±9.30)Mpa,断裂韧性达到(2.54:±0.10)Mpa.m1/2.结论:纳米氧化锆粉体制备的复合材料抗弯曲强度和断裂韧性都显著高于微米氧化锆粉体制备的复合材料.     

水中浸泡对自修复抗菌复合树脂性能影响的实验研究

目的 合成新型牙科自修复抗菌复合树脂,并探讨水中浸泡对其相关性能的影响。方法 在前期研究的基础上,制备含牙科自修复单体三乙二醇二甲基丙烯酸酯的微胶囊,以7.5%的质量百分比添加到含长链烷基季铵盐修饰的纳米抗菌二氧化硅填料的复合树脂中,生成自修复抗菌复合树脂,并以商品化的Tetric N-Ceram纳米瓷化复合树脂作为对照。复合树脂试件在37 ℃蒸馏水中浸泡处理不同时间,用三点弯曲试验来检测其力学性能;用单刃V形切口梁法来测试其断裂韧性及自修复效率;建立人牙菌斑生物膜体外模型,通过菌落计数、乳酸代谢分析等手段来评价其抗菌性能。结果 浸泡30 d后,对照组和实验组所有复合树脂力学性能及断裂韧性下降明显（P<0.05）,而后随着浸泡时间的延长,下降不明显（P>0.05）;水浸泡处理对自修复效率没有明显影响（P>0.05）,浸泡270 d后仍然可以获得64%的自修复效率;随着浸泡时间的延长,与对照组相比,实验组复合树脂对人牙菌斑生物膜的代谢仍然可以产生明显的抑制作用（P<0.05）,而实验组各时间段之间菌落计数及乳酸产生量则没有明显差异（P>0.05）,显示出良好的抗菌性能。结论 水中浸泡可以明显影响自修复抗菌复合树脂的力学性能,而自修复特性及抗菌性能则没有明显的变化。     

十种纳米填料光固化复合树脂聚合收缩性能的比较与评价

目的 探讨10种纳米填料光固化复合树脂的聚合收缩情况,评价纳米填料在光固化复合树脂聚合收缩性能中的作用.方法 采用激光位移传感器进行非接触式测量,实时监测10种纳米填料光固化树脂(CM:Clearfil Majesty; CX:Ceram·X;F:Fulfil;E:Estelite α;PM:Premisa; TN:Tetric N-Ceram restorative;S:Spectrum TPH3;TB:Tetric Bulk Fill;Z:Z350XT;P:P90)的聚合收缩情况.测量光固化时的体积收缩率、收缩速率峰值以及到达峰值的时间.采用单因素方差分析10种材料的差异.结果 10种纳米填料光固化树脂的体积收缩率差异有统计学意义(P＜0.01).10种纳米填料光固化树脂的体积收缩率范围为1.20％ ～ 3.09％,P＜PM ＜Z≈E ＜TN≈CM≈TB ＜CX ＜S ＜F,其中Z与E、TN与CM间差异无统计学意义,体积收缩率较接近.收缩速率峰值范围为2.14～ 14.76 μm/s,到达峰值的时间范围为3.29～5.39 s.结论 10种纳米填料复合树脂的聚合收缩差异显著,填料含量和粒径对复合树脂聚合收缩有一定影响作用,增加填料含量,减小纳米填料的粒径,有助于降低聚合收缩率.     

不同形貌氧化锌对复合树脂抗变异链球菌活性的影响

目的研究3种不同形貌氧化锌（ZnO）对复合树脂抗菌性能的影响。方法液体稀释法测试纳米级ZnO粉、四针状氧化锌晶须（T-ZnOw）和微米级ZnO粉对变异链球菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。然后按5％的比例分别将3种ZnO添加于化学固化型复合树脂粉剂中,用薄膜覆盖法测定老化处理前后树脂的抗菌率,并比较其差异。结果纳米级ZnO粉、T-ZnOw和微米级ZnO粉的MIC分别为78.13、312.50、1 250.00 μg/mL;MBC分别为156.25、625.00、1 250.00 μg/mL。添加了纳米级ZnO粉、T-ZnOw和微米级ZnO粉的复合树脂老化处理前的抗菌率分别为（93.58±5.95）％、（89.42±4.11）％、（78.97±3.90）％;老化处理后的抗菌率分别为（89.01±7.91）％、（84.63±4.72）％、（72.27±3.89）％。结论添加3种不同形貌的ZnO均能增强复合树脂的抗菌活性,其中纳米级ZnO的抗菌性最强,微米级ZnO最弱,而T-ZnOw在比表面积较小的情况下仍表现出较强的抗菌作用。     

不同晶须及晶须用量对复合树脂力学性能的影响

目的：比较碳化硅晶须（SiCw）、硼酸铝晶须（ABw）、氧化锌晶须（ZnOw）增强复合树脂的弯曲性能,筛选最优配方。方法：测定复合树脂的弯曲强度和弯曲弹性模量：结果：β-SiCw熔附SiO2纳米粒子（β-SiCw／SiO2）、ABw熔附SiO2纳米粒子（ABw／SiO2）、ZnOw（四针状）均可以提高复合树脂的弯曲性能。本实验条件下复合树脂弯曲性能的最佳方案是：填料为ABw／SiO2,用量为60％时。结论：每一种晶须填料均可以提高复合树脂的弯曲强度和弯曲弹性模量,提高的程度与填料的用量相关。     

Pre-cementation procedures’ effect on dental zirconias with different yttria content

ObjectveSeveral pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars.The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia.MethodsTwo dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF₂ and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength.Results and SignificanceAir-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF₂ showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF₂ was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention.     

Importance of tetragonal phase in high-translucent partially stabilized zirconia for dental restorations

ObjectivesFor the use of partially stabilized zirconia (PSZ) as high-translucent zirconia, the importance of cubic phase (c-ZrO₂) is commonly emphasized without much attention for the remaining tetragonal phase (t-ZrO₂). The aim is to understand whether the crystal structure and microstructure of t-ZrO₂ have paramount influences on the properties of PSZ.MethodsTwo grades of 5 mol% yttria-stabilized PSZ ceramics were prepared by different processing routes. A 5 mol % yttria co-precipitated zirconia (T5Y) was compared with a 3 and 8 mol% yttria-stabilized powder mixture grade with a bimodal grain size distribution (B5Y). The phase composition and lattice parameters were studied with x-ray diffraction (XRD) and Rietveld analysis. Mechanical properties were compared in terms of hardness, toughness and biaxial bending strength with Weibull analysis. Their translucency and aging stability were also characterized, and the microstructure before and after aging were followed by scanning electron microscopy (SEM).ResultsT5Y and B5Y having similar phase composition (about 40% t- and 60% c-ZrO₂) showed the same basic properties (density, hardness and toughness), but the lattice parameters of t-ZrO₂ and the concomitant microstructure were completely different. The t-ZrO₂ phase in T5Y had a higher yttria content and a lower tetragonality (c/a) of 1.0126 ± 0.0002, whereas the t-ZrO₂ phase in B5Y was comparable to that in conventional 3Y-TZPs with a tetragonality of 1.0153 ± 0.0002. Consequently, B5Y showed a lower strength with lower Weibull modulus, being less translucent and more aging susceptible as compared to T5Y. The translucency and aging susceptibility of B5Y were even comparable to those of conventional 3Y-TZP.SignificanceNot only the phase composition with high cubic phase content but also the lattice parameters and the yttria content in the remaining t-ZrO₂ played a determinant role for PSZs to be used as ‘high-translucent’ zirconia.     

Antibacterial activity and physical properties of conventional glass-ionomer cements containing chlorhexidine diacetate/cetrimide mixtures

Statement of the Problem: Hand excavation instruments are not as efficient as that with rotary burs in atraumatic restorative treatment (ART). Purpose: To evaluate the antibacterial activity (ABA), microhardness numbers (VHN), and cumulative fluoride releasing (CFR) patterns of conventional GICs (Fuji IX (FX) and Ketac Molar (KM)) containing chlorhexidine diacetate/cetrimide mixtures (2.5%/2.5%) (AB). Materials and Methods: The powders of ABs were added to powders of FX and KM selected as experimental groups (EXPs). FX and KM were assigned as controls (CNTs). ABA against S.mutans (MS) and L.casei (LB) were examined between 1–90 days. VHN were calculated after 24 hours and CFR patterns measured between 1–30 days. Analysis of variance was used for comparison (p < 0.05) Results: Differences were found between EXPs regarding MS levels at days 1, 7 and 60 as well as for LB at all time periods (p < 0.05). VHN decreased in EXPs compared to CNTs (p < 0.05), and no differences were found between EXPs (p > 0.05). CFR patterns tended to decrease in EXPs compared to the CNTs, but no differences were found between EXPs (p > 0.05) CLINICAL SIGNIFICANCE These mixtures could be recommended for ART procedures to provide beneficial antibacterial effects without seriously deteriorating the physical properties of selected GICs. (J Esthet Restor Dent 23:46–56, 2011)     

Inhibitory effect on S. mutans by fluoride-treated conventional and resin-reinforced glass ionomer cements

The aim of the present study was to study the effect of fluoride gel treatment on fluoride release and inhibition of acid production of Streptococcus mutans by different glass ionomer cements. Test slabs of four glass ionomer materials were fitted into the bottom of a test tube. A layer of S. mutans cells was centrifuged onto the test slabs, and the specimens were incubated for 4 h in 1.7% sucrose solution. Incubations were made using fresh, aged (29 d), aged and F-treated (1.25% F-gel), and aged, F-treated and aged samples ( n = 15 per group). After each incubation, pH and F contents of the fluid phase were determined. The freshly mixed glass ionomer samples released large amounts of fluoride, and the pH fall in the fluid phase was significantly inhibited. For aged samples, the fluoride release decreased strongly and no inhibitory effect on acid production by S. mutans was seen. After application of fluoride gel, fluoride release and inhibitory effect were significantly higher than initially for all glass ionomer cements. In conclusion, all glass ionomer cements were able to take up fluoride and subsequently release it, which resulted in reestablishment of their antibacterial effect. The patterns of fluoride release and antibacterial action were virtually the same for conventional and resin-reinforced glass ionomer cements.     

Effects of apigenin and tt‐farnesol on glucosyltransferase activity,biofilm viability and caries development in rats

Propolis, a resinous hive product secreted by Apis mellifera bees, has been shown to reduce the incidence of dental caries in rats. Several compounds, mainly polyphenolics, have been identified in propolis. Apigenin and tt‐farnesol demonstrated biological activity against mutans streptococci. We determined here their effects, alone or in combination, on glucosyltransferase activity, biofilm viability, and development of caries in rats. Sprague‐Dawley rats were infected with Streptococcus sobrinus 6715 and treated topically twice daily as follows: (1) tt‐farnesol, (2) apigenin, (3) vehicle control, (4) fluoride, (5) apigenin +tt‐farnesol, and (6) chlorhexidine. Apigenin (1.33 mM) inhibited the activity of glucosyltransferases in solution (90–95%) and on the surface of saliva‐coated hydroxyapatite beads (35–58%); it was devoid of antibacterial activity. tt‐Farnesol (1.33 mM) showed modest antibacterial activity against biofilms and its effects on glucosyltransferases were minimal. The incidence of smooth‐surface caries was significantly reduced by apigenin +tt‐farnesol (60%), fluoride (70%), and chlorhexidine (72%) treatments compared to control (P < 0.05).     

Preparation of Zn doped mesoporous silica nanoparticles (Zn-MSNs) for the improvement of mechanical and antibacterial properties of dental resin composites

ObjectiveThe purpose of this work was to explore the enhancement effect of zinc doped mesoporous silica nanoparticles (Zn-MSNs), which could form micromechanical interlocking with resin matrix and sustainably release Zn²⁺, on the mechanical and antibacterial properties of the dental resin composites.MethodsZn-MSNs were prepared by a sol–gel method, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N₂ adsorption/desorption. The mechanical properties of the dental composites reinforced by Zn-MSNs were measured by a universal mechanical testing machine. Antibacterial activities of dental composites were evaluated by both qualitative and quantitative analysis using Streptococcus mutans (S. mutans). The cytotoxicity of the Zn-MSNs filled dental composites was investigated by osteoblasts (OBs).ResultsThe synthesized Zn-MSNs possessed good monodispersity with an average particle size of about 138 nm. The mechanical properties of the composites gradually increased with the increase of the content of Zn-MSNs. The flexural strength, flexural modulus, compressive strength and micro-hardness of the composites containing 15 wt% Zn-MSNs were 31.21%, 50.47%, 53.83% and 26.79% higher than the samples with no Zn-MSNs, respectively. The antibacterial performance was significantly improved by the addition of Zn-MSNs and the antibacterial rate of the composite with 15 wt% of Zn-MSNs reached 100%. Cytotoxicity tests revealed that all the composites were biocompatible during OBs incubation.SignificanceThe prepared Zn-MSNs can effectively improve the mechanical and antibacterial properties of the dental resin composites.     

PEG-CL/LA膜负载甲硝唑药物的体外缓释及抗菌性能研究

目的 研究以聚乙二醇-聚己内酯-丙交酯（PEG-CL/LA）为聚合物载体的甲硝唑缓释膜的体外抗菌和药物释放性能,旨在研制一种新型的具有抗菌作用的药物缓释膜。方法 用紫外分光光度法测定5wt%、8wt%及10wt%甲硝唑药膜中药物的体外释放度;选用牙周可疑致病菌具核梭杆菌（Fn）和致龋菌变异链球菌（Sm）,采用抑菌圈法研究3种药膜对厌氧菌和兼性厌氧菌的抗菌性能。结果（1）药膜在载药量为5wt%~10wt%时具有较好的缓释性能,药物释放时间随着甲硝唑含量的增加而缩短,3种比例的载药膜的药物释放时间均可达7天以上,其中,5wt%药膜可达10天。（2）随着药物含量增加,抗菌作用逐渐增强,5wt%载药膜对Sm和Fn的抑菌圈直径分别为（8.00±0.16） mm和（8.07±0.09） mm;8wt%载药膜为（10.13±0.19） mm和（11.13±0.09） mm;10wt%载药膜为（12.07±0.09） mm和（19.33±0.94） mm。该药膜对具核梭杆菌的抑制作用强于对变异链球菌的抑制作用。结论 PEG-CL/LA载药膜对牙周致病菌的抑制作用效果明显,且具有良好的药物缓释性能,是一种有望用来辅助治疗牙周疾病的药物膜。     

Nitrogen doped titanium dioxide as an aesthetic antimicrobial filler in dental polymers

ObjectiveTo develop an aesthetic resin composite using a nitrogen-doped titanium dioxide (NTiO₂) filler that possesses antimicrobial properties against cariogenic bacteria.MethodsN-TiO₂ powder was manufactured by calcining commercial TiO₂ with urea. Free radical release from the N-TiO₂ powder under visible light irradiation was analysed using UV-Vis spectrophotometry. The N-TiO₂ powder was incorporated into a dental resin and the photocatalytic activity assessed using a dye under both visible light and dark conditions. Using XTT assay to measure the cellular metabolic activity, the antibacterial properties of the N-TiO₂ /resin composite discs were tested using Streptococcus mutans.ResultsDoping nitrogen of TiO₂ resulted in a band gap shift towards the visible light spectrum, which enabled the powder to release reactive oxygen species when exposed to visible light. When incorporated into a dental resin, the N-TiO₂/resin composite still demonstrated sustained release of reactive oxygen species, maintaining its photocatalytic activity and showing an antibacterial effect towards Streptococcus mutans under visible light conditions.SignificanceN-TiO₂ filled resin composite shows great promise as a potential aesthetic resin based adhesive for orthodontic bonding.     

Spray-drying-assisted fabrication of CaF2/SiO2 nanoclusters for dental restorative composites

ObjectiveThe objective of this study is to develop novel CaF₂/SiO₂ nanoclusters (NCs) fillers, which can endow the dental resin composites (DRCs) with excellent mechanical properties, stable and sustained fluoride ion release, and good antibacterial activity.MethodsThe CaF₂/SiO₂ NCs were efficiently fabricated by assembling CaF₂/SiO₂ nanoparticles (NPs) as building blocks with a spray-drying technology. CaF₂/SiO₂ NCs with different SiO₂ coating amounts (20 wt%, 50 wt% and 80 wt%) were incorporated into the DRCs at the filler content of 55 wt% for the measurement of mechanical properties including flexural strength, flexural modulus, compressive strength, and hardness. The effect of the filling amount of CaF₂/50SiO₂ NCs (50 represents 50 wt% SiO₂ coating amount) in the DRCs was investigated, while CaF₂/50SiO₂ NPs were adopted as comparison group. The fluoride ion release and antibacterial activity of the DRCs with the optimal mechanical performances were evaluated. Furthermore, the statistical analyses were performed for mechanical properties.ResultsSpherical CaF₂/50SiO₂ NCs with an average size of 2.4 µm were obtained at the feed rate of 7.4 mL/min and the CaF₂/50SiO₂ NPs solid content of 2 wt% in the suspension. The optimum comprehensive performances of the DRCs can be achieved by filling 55 wt% CaF₂/50SiO₂ NCs. Compared with CaF₂/50SiO₂ NPs, the filling amount of CaF₂/50SiO₂ NCs was increased by 5 wt% (50–55 wt%), and under the same filling amount of 50 wt%, the flexural strength, flexural modulus, compressive strength, and hardness of the DRCs containing CaF₂/50SiO₂ NCs were improved by 9.8%, 17.7%, 7.5% and 69.8%, respectively. Furthermore, the DRCs filled with 50 wt% CaF₂/50SiO₂ NCs exhibited more cumulative F-release by 126% and more stable F-release rate than the counterpart filled with 50 wt% CaF₂/50SiO₂ NPs after immersed for 1800 h. And 55 wt% CaF₂/50SiO₂ NCs filled DRCs could inhibit the growth of S. mutans, reaching an antibacterial ratio of 93%.SignificanceThe spray-dried CaF₂/50SiO₂ NCs are promising fillers for the development of high-performance multifunctional DRCs.     

高透、超透氧化锆陶瓷半透明度和弯曲强度的比较

目的 比较不同氧化锆(高透、超透)材料的光学与机械性能,为新型氧化锆材料的研发 及临床应用提供实验依据。方法 实验组为高透型氧化锆(高透 A、高透 B、高透 C)和超透型氧化锆组 (超透 A、超透 B、超透 C),对照组为玻璃陶瓷。切取边长 7 mm、厚度分为 3 个水平(0.5、1.0、1.5 mm, n=6)的正方形试件共 126 个用于检测试件的半透明度;切取长 25 mm、宽 4 mm、厚 1.2 mm,倒角 0.1 mm 的试件共 90 个(n=15)用于检测弯曲强度。比较各组内及组间差异,使用单因素方差分析统计数据 结果。结果 (1)3 种厚度的玻璃陶瓷半透明度显著高于其他组别(P<0.01)。品牌相同时 :3 种厚度下的 超透 A 半透明度均优于高透 A(P<0.01);0.5 mm 与 1.5 mm 的高透 B 与超透 B 无明显差异,1.0 mm 的超 透 B 优于高透 B(P<0.01);厚度为 0.5 mm 和 1.0 mm 时,高透 C 与超透 C 的差异无统计学意义;厚度 1.5 mm 时,超透 C 半透明度优于高透 C(P<0.01)。氧化锆类型相同时 :厚度为 0.5 mm 的高透 C、超透 A、超透 B 和超透 C 的半透明度为各组最优(P<0.01);厚度为 1.0 mm 时,高透 B、超透 B 为各组最优(P<0.01);厚度为 1.5 mm 时,高透 B、超透 B 的半透明度为各组最优(P<0.01)。(2)品牌相同时,高透型氧化锆的 弯曲强度均优于超透型(P<0.01);氧化锆类型相同时 :高透 B、超透 A 和超透 B 的弯曲强度为各组最优 (P<0.01)。结论 (1)超透氧化锆半透明度不低于同品牌高透氧化锆,差异与厚度有关。(2)3 种厚度的 玻璃陶瓷半透明度最优。(3)高透氧化锆弯曲强度显著优于超透氧化锆,两者均高于 300 MPa。