光活化消毒技术清除小鼠舌部白色念珠菌的实验研究

目的 建立小鼠急性假膜型念珠菌性口炎模型,观察光活化消毒技术（photoactivated disinfection,PAD）在体内清除白色念珠菌的效果,初步探索该技术应用于急性假膜型念珠菌性口炎的可行性。方法 选取6周龄雄性ICR小鼠,向已产生免疫抑制的小鼠舌背接种浓度为1×107CFU/mL的白色念珠菌菌液,成功建立急性假膜型念珠菌性口炎模型30只,随机分为对照组、光活化组,每组15只。光活化组小鼠舌背部涂抹1 mg/mL甲苯胺蓝溶液,孵育1 min,750 mW LED红光照射1 min后即刻与对照组小鼠行舌背真菌载量测定,48 h后再次对两组小鼠行舌背真菌载量测定,并行舌部组织病理学检查。结果 PAD处理后48 h,光活化组舌背白色假膜明显少于对照组。PAD处理后即刻和48 h,光活化组舌背真菌载量均明显低于对照组,差异具有统计学意义（P <0.05）。PAD处理后48 h,光活化组经HE染色显示较对照组上皮结构更加规则,未见微小脓肿;经PAS染色显示菌丝数量明显少于对照组,偶见菌丝侵入角化层,但未深入上皮层。结论 PAD能显著清除急性假膜型念珠菌性口炎小鼠舌部的白色念珠...     

光活化消毒治疗小鼠急性假膜型念珠菌性口炎的效果观察

目的:采用光活化消毒技术(Photo-activated disinfection, PAD)治疗小鼠急性假膜型念珠菌性口炎,观察治疗前后舌背病损变化及组织病理学变化,探讨PAD治疗急性假膜型念珠菌性口炎模型的效果,比较不同孵育时间对疗效的影响,为PAD治疗急性假膜型念珠菌性口炎提供实验依据。方法:选取6周龄雄性ICR小鼠,建立急性假膜型念珠菌性口炎模型36只并随机分为对照组、PAD治疗1组(以下称治疗1组)和PAD治疗2组(以下称治疗2组),每组12只。治疗前测量所有小鼠舌背病损面积。两治疗组小鼠舌背部涂抹1 mg/mL的甲苯胺蓝溶液,治疗1组孵育1 min,治疗2组孵育2 min,两组均给予750 mW LED红光照射1min。对照组小鼠不接受任何治疗。治疗后48 h,分别观察3组小鼠的临床表现,测量舌背病损面积,行组织病理学检查,评估PAD治疗小鼠急性假膜型念珠菌性口炎的效果。结果:PAD治疗前,3组舌背白色假膜病损评分差异无统计学意义(P>0.05)。治疗后48 h,两治疗组舌背假膜病损评分均低于对照组,具有统计学意义(P<0.05),两治疗组间舌背假膜病损评分差异...     

HMME—PDT对致龋模型中变形链球菌的杀伤作用及组织病理研究

目的：探讨光动力疗法（PDT）对大鼠口腔变形链球菌的杀伤作用。方法：以Wistar大鼠构建致龋模型,随机分成7组：照射60、90、120 s的PDT组、单纯光敏剂、单纯激光、0.2%NaF阳性组、0.9%生理盐水阴性组。选择半导体激光为光源,血卟啉单甲醚（HMME）为光敏剂。通过平板菌落计数法观察各组对变形链球菌的杀伤作用,组织病理观察大鼠口腔软组织变化。结果：平板菌落计数显示,与对照组比较,PDT防龋处理可使大鼠口腔中变形链球菌数量显著减少（P〈0.05）,光照时间为90s时对大鼠口腔软组织的损伤较小。结论：HMME-PDT可有效杀灭大鼠口腔中的变形链球菌,选择合适照射时间,不仅可以提高灭菌率还可减少对口腔其他组织的损伤。     

硅橡胶中纳米二氧化钛对白色念珠菌生长影响的初探

目的 通过研究纳米二氧化钛对硅橡胶体外抗白色念珠菌性能的影响,探讨用纳米二氧化钛改善硅橡胶抗白色念珠菌性能的可靠性.方法 硅橡胶中加入质量分数分别为0.5%、1.0%、1.5%、2.0%的纳米二氧化钛抗菌剂,分别记为A、B、C、D组,对照组硅橡胶不加纳米二氧化钛,采用薄膜密着法在光照和无光照条件下测定各组硅橡胶对白色念珠菌的抗菌作用.结果 光照条件下,A、B、C、D组菌落数[分别为(439.0±21.9)CFU、(289.3±7.8)CFU、(173.0±7.6)CFU、(86.7±3.9)CFU]与对照组[(597.3±5.5)CFU]的差异均有统计学意义(P<0.05);非光照条件下,A、B、C、D组菌落数[分别为(543.7±22.8)CFU、(478.0±17.0)CFU、(422.7±21.8)CFU、(283.0±12.1)CFU]与对照组[(611.3±10.0)CFU]的差异均有统计学意义(P<0.05).D组抗菌性能最好,无光照条件下,抑菌率为53.7%;光照条件下,抑菌率可达85.9%.结论 添加了纳米二氧化钛抗菌剂的硅橡胶在光照和无光照条件下均能抑制白色念珠菌生长,随着纳米二氧化钛质量分数的增加,硅橡胶抑菌效果增强.纳米二氧化钛质量分数相同时,光照下硅橡胶的抑菌性比无光照强.     

光活化消毒技术根管内消毒效果的研究

目的利用体外实验和临床试验评估光活化消毒技术（PAD）进行根管消毒的效果。方法体外选择30颗单根管牙根建立粪肠球菌ATCC29212感染模型,分为3组。用PAD技术进行根管消毒并取样,质量分数为2.5%的NaClO冲洗和生理盐水冲洗分别作为阳性和阴性对照组。临床选取50例慢性根尖周炎病例,随机分为2组。根管预备时质量分数为2.5%的NaClO溶液冲洗。预备后组1采用PAD消毒,组2用生理盐水冲洗。预备前后取样,所有样本接种于脑心浸液（BHI）培养基培养后记录菌落数。结果体外实验：PAD组细菌减少了99.86%,阳性对照组减少了100%,阴性对照组减少了96.94%。PAD组细菌回复10例均为阳性,阳性对照组6例,阴性对照组10例。临床试验：根管机械预备后细菌减少了99.98%。组1中PAD消毒后细菌培养均为阴性,组2细菌减少了36%。2组差异无统计学意义（P〉0.05）。结论 PAD单独使用可以降低根管内粪肠球菌的数量,但效果低于NaClO。临床PAD技术辅助根管预备可以进一步降低细菌的数量。     

抗菌肽rHBD3对义齿软衬材料表面白色念珠菌黏附性能的影响

目的：初步评价重组人β防御素3(rHBD3)对附着于义齿软衬硅橡胶材料表面白色念珠菌的抑菌效果。方法：在软衬硅橡胶试件上面接种0.1 mL的白色念珠菌,然后将试件分别浸泡在25 μg/mL rHBD3和5.25%NaClO溶液中5、10、30、60 min。将接种过菌液的一面的试件放置在BHI琼脂培养板上15 s。隔天计算菌落数,采用SPSS10.0软件包对数据进行双因素方差分析。利用激光共聚焦显微镜观察rHBD3对白色念珠菌形成的细菌生物膜的作用。结果：白色念珠菌菌落数在rHBD3作用不同时间后,变化有显著差异(P<0.05)。30 min后,rHBD3与5.25%NaClO组间无显著差异。白色念珠菌生物膜在rHBD3作用30 min后, SYTO9/PI染色显示死菌的数量明显增多。结论：rHBD3不仅能够消除软衬表面白色念珠菌等微生物的感染,而且对其形成的细菌生物膜也有很好的抑菌效果。rHBD3用于软衬材料的清洁维护,为预防义齿性口炎的发生提供了实验依据。     

内源性Farnesol对变异链球菌脱矿作用的研究

[摘要] 目的 观察内源性Farnesol处理变异链球菌后牙釉质脱矿的变化。方法 放置牙釉质切片于培养皿中,实验分5组,前3组加入变异链球菌菌悬液的同时分别添加去离子水、白色念珠菌24h上清、白色念珠菌菌悬液,第四组加入白色念珠菌菌悬液（实验组）,去离子水组为空白对照组。采用原子吸收分光光度法检测不同时间点（24、48、72h）菌悬液中钙离子的浓度。 结果 加入白色念珠菌24 h上清组钙离子的浓度在24、48、72h分别测得（80.26±1.63）、（81.14±1.24）、（78.31±0.76）μg/ml,明显低于其它变异链球菌组,实验组与对照组相比也有显著性差(P<0.05)。变异链球菌作用牙釉质的脱矿过程受到白色念珠菌分泌的Farnesol的调控,其脱矿作用受到明显的抑制。结论 内源性Farnesol可抑制变异链球菌对牙釉质的脱矿作用。     

小檗碱对白色念珠菌细胞周期的影响

目的 应用流式细胞仪测定小檗碱对白色念珠菌细胞周期的影响,初步探索小檗碱抑制白色念珠菌的作用机制.方法 将白色念珠菌(ATCC76615)培养在含不同质量浓度(0.16、0.08、0.04及0 g/L)小檗碱的酵母浸出粉胨葡萄糖培养基中,培养6、12和24h后应用流式细胞仪检测该药物对白色念珠菌(ATCC76615)细胞生长周期的影响.结果 白色念珠菌(ATCC76615)在与小檗碱作用12h时,随着药物质量浓度的增高(0、0.04、0.08、0.16 g/L)增殖指数(分别为98.8、82.4、75.6、54.1)均显著降低(P＜0.001).结论 小檗碱对白色念珠菌的细胞生长周期具有抑制作用,其最佳作用时间为12h.     

K+和pH 4.0乙酸对根面牙本质胶原蛋白降解影响的实验研究

目的 :观察K+ 、乙酸 (HAc)、胰蛋白酶对根面牙本质胶原蛋白降解的影响。方法 :制备根面牙本质粉 ,置于 0 .1mol/L乙酸和 0 .15moL/L氯化钾 (KCl)液中 ,对乙酸、KCl和HEPES缓冲液作对照 ,加入5 0 μg/mL 胰蛋白酶 ,37℃孵育 ,分别于 1、7、14、2 1、2 8d离心后 ,取上清液作羟脯氨酸分析和Ca2 + 测定。结果 :0 .15mol/LKCl组K+ 和pH 4 .0乙酸能明显增加根面牙本质胶原蛋白的降解量 ,同时加入两者降解更为明显。HAc-KCl组与HAc组之间 ,在孵育处理 7d后 ,胶原蛋白降解量有显著性差异 (P <0 .0 5 ) ;Ca2 + 释放量在 2 8d内均无显著性差异 (P >0 .0 5 )。HAc组和HAc -KCl组与HEPES组和HEPES -KCl组相比 ,在所测 2 8d内胶原蛋白降解量和Ca2 + 释放量均有极显著性差异 (P <0 .0 1)。HEPES组与HEPES -KCl组Ca2 + 释放量无显著性差异 (P >0 .0 5 ) ,孵育 7d后 ,胶原蛋白降解量有显著性差异 (P <0 .0 5 )。结论 :K+ 、pH 4 .0乙酸对根面牙本质胶原蛋白的降解具有协同促进作用     

聚酰胺－胺对白色念珠菌和牙龈卟啉单胞菌的抗菌性研究

目的 评价聚酰胺-胺对纯钛表面白色念珠菌和牙龈卟啉单胞菌黏附的影响.方法 将64个纯钛试件采用抽签法随机分为8组.A、A1为对照组,B、B1聚酰胺－胺处理,C、C1唾液处理,D、D1聚酰胺-胺+唾液处理,A、B、C、D4组试件加入2 ml白色念珠菌菌液；A1、B1、C1、D1组试件加入牙龈卟啉单胞菌液.试件于白色念珠菌和牙龈卟啉单胞菌液中培养,染色,荧光观察.结果A、B、C、D4组白色念珠菌黏附量值为227.1±17.6、175.4±17.0、340.7±26.0和283.5±27.8,析因设计方差分析结果显示聚酰胺－胺处理组的菌黏附量减少(F=46.405,P＜0.001)；A1、B1、C1、D1组黏附的牙龈卟啉单胞菌活菌率为(59.42±2.76)％、(40.97±1.93)％、(63.03±1.99)％和(43.92±2.27)％,聚酰胺-胺处理组的活菌率低于未处理组(F =552.037,P＜0.001).结论聚酰胺－胺对纯钛表面黏附的白色念珠菌和牙龈卟啉单胞菌均有抑制作用.     

不同根管冲洗液和冲洗方法对粪肠球菌清除作用的体外研究

目的 比较不同冲洗液和冲洗方法对根管内粪肠球菌的清除效果。方法 建立120颗人完整单根管前磨牙粪肠球菌感染根管模型,随机分组,分别采用不同冲洗液(0.9% NaCl,0.5% NaClO,3% NaClO)及冲洗方法(注射针头冲洗,超声荡洗,RinsEndo系统处理,超声荡洗协同RinsEndo系统联用)进行根管清理。无菌吸潮纸尖取样,平板菌落计数法计算CFU值,计算细菌清除率,运用SPSS 22.0软件进行统计分析,P<0.05时差异具有统计学意义。结果 使用0.9% NaCl及0.5% NaClO冲洗液时,注射针头冲洗组细菌清除率明显低于超声荡洗及RinsEndo系统处理组(P<0.001);使用3% NaClO冲洗液的各组不同的冲洗方法,细菌清除率的差异无统计学意义(P=0.556)。而无论采用哪种冲洗方法,3% NaClO溶液的细菌清除效果均优于0.5% NaClO溶液和0.9% NaCl溶液(P<0.001)。结论 不同根管冲洗液在一定程度上会影响根管冲洗方法对根管内粪肠球菌的清除效果。     

Architectural analysis, viability assessment and growth kinetics of Candida albicans and Candida glabrata biofilms

The human fungal pathogen Candida is able to form biofilms in almost all the medical devices in current use. Indeed, biofilm formation is a major virulence attribute of microorganisms and account for a majority of human infections. Therefore, understanding processes appertaining to biofilm development is an important prerequisite for devising new strategies to prevent or eradicate biofilm-related infections. In the present study we used an array of both conventional and novel analytical tools to obtain a comprehensive view of Candida biofilm development. Enumeration of colony forming units, colorimetric (XTT) assay, Scanning Electron Microscopy (SEM) and novel Confocal Laser Scanning Microscopy (CLSM) coupled with COMSTAT software analyses were utilised to evaluate growth kinetics; architecture and viability of biofilms of a reference (ATCC) and a clinical strain each of two Candida species, C. albicans and C. glabrata. Biofilm growth kinetics on a polystyrene substrate was evaluated from the initial adhesion step (1.5 h) up to 72 h. These analyses revealed substantial inter- and intra-species differences in temporal organisation of Candida biofilm architecture, spatiality and cellular viability, while reaching maturity within a period of 48 h, on a polystyrene substrate. There were substantial differences in the growth kinetics upon methodology, although general trend seemed to be the same. Detailed architectural analysis provided by COMSTAT software corroborated the SEM and CSLM views. These analyses may provide a strong foundation for down stream molecular work of fungal biofilms.     

Osteogenic effect of Drynariae rhizoma extracts and Naringin on MC3T3-E1 cells and an induced rat alveolar bone resorption model

Objective

To investigate if Drynariae rhizoma (DR) and its main ingredient Naringin could reduce alveolar bone loss by stimulating the proliferation and differentiation of osteoblasts.

Materials and methods

The effect of DR water (DRWE), ethanolic extract (DREE), and Naringin on MC3T3-E1 cells was evaluated respectively by MTT method and by measuring the activity of alkaline phosphatase (ALP activity) as well as the level of osteocalcin in medium. Bone mineral density (BMD) detection, osteoclast counting by tartrate resistant acid phosphatase staining, and histopathological analysis were performed in an induced rat model of alveolar bone resorption after gastric perfusion with DR extracts or Naringin.

Results

DRWE and Naringin effectively increased the proliferation of MC3T3-E1 cells, whilst DREE and Naringin enhanced the differentiation of osteoblastic cells. The in vivo study indicated an elevated BMD value in the tooth-periodontal tissues from DRWE, DREE and Naringin treated groups after 10, 20 and 30 days of perfusion (P < 0.05). In DRWE treated group, the number of osteoclasts at days 10, 20 and 30 decreased remarkably as compared to the corresponding negative controls (P < 0.05), and no osteoclast could be found at day 30. New non-calcified bone-like matrix attached by osteoblasts at the root furcation was also shown.

Conclusions

DR could be a supplementary medicine for periodontal therapy as it could reduce bone resorption in rat model of alveolar bone resorption and exert osteogenic effect on osteoblasts.     

Effects of various finishing methods on staining and accumulation of Streptococcus mutans HS-6 on composite resins

Microfilled and conventional composite resins, polished by different methods were tested for their staining and for bacterial accumulation in vitro. All 4 composite resins showed their characteristic staining tendencies for either Tobacco or Oil orange depending on their physicochemical properties and surface roughness. The effect of these factors seemed to depend on the substance adsorbed and the nature of the resins. Thus, in Tobacco solution immersion test, white point-polished surface showed the highest value of staining, which was followed by smooth surface and finished surface in this order, except one (Clearfil), in which the order was reversed. In the Oil orange solution immersion test, staining tendencies showed little correlation with surface roughness, but the hydrophobicity of the resin seemed to be an important factor.Polished surface accumulated more bacteria than smooth surface in the in vitro test of bacterial accumulation. However, no appreciable difference was observed among these 4 resins having an equal roughness.     

Thickness and microhardness of deciduous tooth enamel with known DLX3 mutation

Aim

To investigate the thickness and hardness of teeth affected by a 2-bp deletion (c.561_562delCT) in the DLX3 gene.

Methods and materials

Extracted maxillary deciduous second molar was collected from the affected individual at age 12 years 7 months. Samples were sectioned buccolingually after embedding in epoxy resin. We measured the enamel thickness and microhardness and performed an elemental analysis using an electron probe microanalyser.

Results

On average, the hardness of the enamel with a 2-bp deletion in DLX3 was about 53% of normal enamel hardness. The mutant enamel thickness was about half of the thickness of the normal control. The calcium level in the enamel with the 2-bp deletion was slightly decreased, while the magnesium level was slightly increased, in comparison to levels measured for normal teeth.

Conclusion

This study shows that enamel affected by a 2-bp deletion in DLX3 has reduced thickness as well as diminished microhardness. These data may explain the severe attrition and interdental spacing observed in affected individuals.     

高果糖玉米糖浆对变形链球菌合成细胞外多糖能力的影响

目的 应用蒽酮法,分别测定和比较变形链球菌代谢高果糖玉米糖浆（high-fructose cornsyrup,HFCS）和蔗糖所合成的细胞外多糖的含量,研究变形链球菌利用高果糖玉米糖浆合成细胞外多糖的能力。方法 配制质量浓度为0.25%、0.5%、1%、3%和5%的高果糖玉米糖和蔗糖培养基,将变形链球菌UA159接种其中,37℃微需氧培养24h后,用蒽酮法测定各培养基中所合成的细胞外水溶性和水不溶性多糖的含量。结果 除0.25%组和0.5%组中HFCS和蔗糖培养基中所合成的胞外水溶性多糖没有差异（P > 0.05）外,其它各组两培养基中所合成的胞外水溶性多糖均有差异,且蔗糖明显高于HFCS（P < 0.05）。5组浓度的HFCS组和蔗糖培养基中所合成的胞外水不溶性多糖均存在差异且蔗糖组明显高于HFCS（P < 0.05）。结论 在本实验设定的糖浓度范围内,变形链球菌利用高果糖玉米糖浆合成细胞外多糖的能力尤其是合成细胞外水不溶性多糖的能力较蔗糖弱。     

Tenacious adhesion of Actinobacillus actinomycetemcomitans strain CU1000 to salivary-coated hydroxyapatite

Adherence of Actinobacillus actinomycetemcomitans to hard-tissue surfaces was evaluated by comparing a phenotypically stable, well-maintained clinical isolate (strain CU1000) to Streptococcus gordonii G9B, an extensively studied oral-colonizing bacterium. Standard innocula of radiolabelled bacteria were added to saliva-coated hydroxyapatite (SHA) and the ratio of bound to unbound cells counted. Several other clinical isolates as well as laboratory strain Y4 were studied. In other experiments, cell detachment from SHA was compared in static and shaking vessels to calculate controlled desorption of cells over time. A sonic-displacement assay was used to measure avidity of binding to HA and SHA. To better define the attachment properties of CU1000, bacteria were treated with a variety of agents including detergents, salts and enzymes before or after incubation with SHA. Results indicated that CU1000 bound better than G9B (a minimum of 10-fold greater; p≤0.05) and did not desorb from SHA, while G9B desorbed to equilibrium in 4 h. Furthermore, Langmuir isotherm calculations indicated that, unlike G9B, CU1000 did not follow second-order adsorption kinetics and thus did not achieve saturation. In addition, of the agents tested only periodate reduced attachment and resulted in detachment of CU1000 from surfaces. These experiments suggest that clinical isolates of A. actinomycetemcomitans possess unique binding properties that promote adsorption to and impede desorption from SHA. The characteristics described for the actinobacillus in this study have been previously underestimated, appear to be mediated by glycoconjugates, and may resemble attachment described for several biofilm-forming, non-oral pathogens.     

The effects of nicotine and cotinine on Porphyromonas gingivalis colonisation of epithelial cells

Smoking is a risk factor for development of periodontitis. Porphyromonas gingivalis is an important colonizer of the subgingival crevice and is a major pathogenic agent in the initiation and progression of severe forms of periodontal disease. However, the effect of major cigarette's derivatives on P. gingivalis is poorly understood. The purpose of this study was to determine the influence of nicotine and cotinine on bacterial colonisation to epithelial cells. KB cells monolayers and P. gingivalis ATCC 33277 were exposed to 0.1, 10 and 100 μg/mL of nicotine and cotinine concentrations. The epithelial cells were incubated for 24 h while P. gingivalis was exposed to these substances until reach early logarithmic phase. After the incubation period, P. gingivalis ability to colonize KB cells was assayed. The number of cell-associated/invasive bacteria was assessed by counting the colony-forming unities. 100 μg/mL cotinine significantly increased P. gingivalis association and invasion of epithelial cells, when the bacteria was exposed to this substance (p < 0.05; ANOVA – Tukey test). No other condition or drug altered the bacteria colonisation ability (p > 0.05). These data indicated that cotinine may interfere with P. gingivalis ability to associate and invade the epithelial cells. Further studies are needed to investigate whether oral cells might be more susceptible to be colonized by P. gingivalis in smokers.     

载地塞米松中空碳羟基磷灰石微球的合成与体外释放研究

目的 制备碳羟基磷灰石中空微球,构建地塞米松药物缓释系统,为其作为活髓保存剂应用于临床提供实验数据。方法 以甘氨酸（Gly）和十二烷基磺酸钠（SDS）组成的"核-壳"式复合物为模板,合成碳羟基磷灰石中空微球。利用场发射扫描电镜（FESEM）、高分辨透射电子显微镜（HRTEM）、X射线衍射仪（XRD）、氮气吸附脱附分析（BET）分别对其形貌、物相、比表面积及孔径进行表征分析。通过与无Gly组对比,探讨中空微球的形成机理。将地塞米松载入碳羟基磷灰石中空微球构成体外缓释系统,计算载药率、包封率和药物体外缓释时间。结果 成功制备直径为2~4 μm针状中空碳羟基磷灰石微球,该微球具有良好的载药性（载药率12.1%~34.8%）和体外药物缓释性能,缓慢释放达30天,几乎无突释现象。结论 合成的碳羟基磷灰石中空微球类似骨和牙齿的无机物主要组成成分,载药率和包封率均较高,微球中药物缓慢释放接近线性。     

Effects of Galla chinensis on inhibition of demineralization of regular bovine enamel or enamel disposed of organic matrix

Objective

This in vitro study was undertaken to assess the effects of Galla chinensis extract on inhibition of enamel caries-like demineralization and to elucidate the role of the organic matrix of enamel in this process.

Design

Either regular or enamel disposed of its organic matrix both of bovine origin were exposed to a demineralizing solution for 3 days (pH 4.5). Specimes were additionally treated with either 4 g/L of G. chinensis extraction (GCE) or double distilled water (DDW) four times daily for 5 min each time. Regular enamel exposed accordingly to sodium fluoride (1 g/L) during the demineralizing period served as positive control. After exposure mineral loss and lesion depth of all samples were analysed by transversal microradiography. One-way ANOVA and Student-Newman-Keuls test were used to compare the differences amongst groups. A factorial ANOVA was chosen to test the interaction between GCE and enamel organic matrix.

Results

Mineral loss and lesion depth of specimens in the positive control group were significantly lower compared to all other groups. Regular enamel treated with GCE showed significantly lower values compared to regular enamel treated with DDW or to enamel disposed of its organic matrix (p < 0.05). These three groups revealed similar values (p > 0.05). Significant interaction between GCE and enamel organic matrix with respect to both outcomes could be observed (p < 0.05).

Conclusions

G. chinensis inhibits enamel caries-like demineralization in vitro. However, its potential seems to be weaker compared to sodium fluoride. The organic matrix of enamel was shown to play a substantial role in the observed mechanism.