氟化钠壳聚糖凝胶对乳牙釉质抗酸能力的影响

目的 本实验通过研究氟化钠壳聚糖温敏凝胶对乳牙牙釉质表面抗酸蚀的作用,初步探讨氟化钠壳聚糖温敏凝胶在防治早期龋中的应用可能性。方法 配制氟化钠壳聚糖温敏凝胶,观察其基本性能,使用氟离子选择电极检测壳聚糖氟化钠凝胶氟离子的释放速率。制备乳前牙试件,随机分成4组,分别为多乐氟组、氟化钠壳聚糖凝胶组、壳聚糖空白凝胶处理组和空白对照组,进行乳酸脱钙实验,离子火焰法测试洗脱出的钙离子浓度。SPSS19.0对不同组钙离子浓度进行方差分析,统计结果。结果 壳聚糖氟化钠凝胶,常温下为淡黄色清亮黏稠液体,37 ℃时转变为乳白色的果冻状凝胶。壳聚糖氟化钠凝胶4 h氟离子的释放率为70.22%。氟化钠壳聚糖凝胶处理的乳前牙釉质试件,其脱出的钙离子浓度为4.29 mg/L,低于壳聚糖空白凝胶组(7.20 mg/L)及空白对照组(7.34 mg/L),有统计学差异;但和多乐氟组(4.22 mg/L)没有统计学差异(P>0.05)。结论 氟化钠壳聚糖凝胶可以提高乳前牙的釉质抗酸能力,有应用于预防乳前牙早期龋的可能性。     

氟离子导入对早期釉质龋再矿化效果的体外研究

目的研究氟离子导入法对早期釉质龋的再矿化效果。方法早期人工釉质龋模型样本经7 d pH循环及2 d再矿化处理,于扫描电镜(SEM)和激光共聚焦显微镜(CLSM)下摄片分析。结果 SEM图片示对照组呈粗糙酸蚀状釉质表面,1.23%酸性氟磷酸盐(APF)凝胶组及氟离子导入(FI)组釉质表面相对平整;CLSM图片分析示APF与FI组病损深度(H)分别为(40.51±4.26)、(41.90±6.83)μm,荧光面积(A)分别为(38 230.87±2 704.43)、(43 407.27±4 666.09)μm2,较对照组显著减小(PH,A<0.001),但2组间无统计学差异(PH=0.912,PA=0.679)。结论氟离子导入可有效促进早期釉质龋再矿化,且效果与1.23%酸性氟磷酸盐凝胶无异。     

天然药物没食子对早期釉质龋再矿化作用的研究

目的:观察没食子对早期釉质龋再矿化作用。方法:60个新鲜拔除的牛前牙,将标本唇面切割为10 mm×10 mm×2 mm的牙釉质小块,随机分为3组,进行脱矿处理,形成人工龋标本后置于再矿化液,分别用氟化钠、没食子、去离子水处理,经过12 d pH循环,药物作用过程前后采用荧光法检测进行定量研究,采用扫描电镜进行定性研究。结果:经过再矿化循环后,各组荧光量均有升高,由高到低依次为氟化钠、没食子、去离子水。统计分析没食子组与氟化钠组比较无明显差异(P>0.05),而与去离子水组比较有差异(P<0.05)。扫描电镜显示氟化物及没食子处理组有颗粒沉积,牙面恢复较为平坦,而去离子水组牙面恢复情况不及前2组。结论:没食子有利于增进早期釉质龋的再矿化作用。     

3种溶液对早期釉质龋再矿化作用的扫描电镜观察

目的观察比较碳酸氢钠溶液、氟化钠溶液及碳酸氢钠与氟化钠混合液对人工釉质龋的再矿化作用。方法选择因正畸拔除的前磨牙制备成牙釉质标本,用凝胶酸蚀法形成人工釉质龋模型,脱矿标本分别经碳酸氢钠溶液、氟化钠溶液及碳酸氢钠与氟化钠混合液及双蒸水浸泡1周后,扫描电镜观察比较经不同溶液处理的脱矿釉质标本表面形态差异。结果经碳酸氢钠溶液、氟化钠溶液及碳酸氢钠与氟化钠混合液浸泡的脱矿釉质表面均有不同程度矿物质沉积,其中,经碳酸氢钠与氟化钠混合液浸泡的脱矿釉质表面形成的沉积物更规则、明显。结论碳酸氢钠溶液能够促进脱矿釉质再矿化,且能增强氟化钠溶液对早期釉质龋的再矿化作用。     

氟化钠泡沫和凝胶对牛牙釉质表面显微硬度的影响

目的：评价氟化钠泡沫和氟化钠凝胶对牛牙釉质表面显微硬度的影响。方法：采用新鲜牛牙釉质块为标本,应用显微硬度计测量分别采用氟化钠泡沫、氟化钠凝胶进行矿化试验和抗龋试验后的釉质块表面显微硬度。结果：试验前和矿化试验后的釉质表面显微硬度相比,使用氟化钠泡沫组增加率为54．41％－21．32％,使用氟化钠凝胶组增加率为47．26％－25．36％。试验前和抗龋试验后的釉质表面显微硬度相比,使用氟化钠泡沫组降低率为24．88％－33．19％,使用氟化钠凝胶组降低率为30．97％－38．66％,而空白对照组降低率为41．26％。结论：氟化钠泡沫对釉质表面显微硬度的影响和氟化钠凝胶相比无显著差异,用氟化钠泡沫改善釉质表面显微硬度与氟化钠凝胶具有相同效果。     

多乐氟预防碳酸饮料对乳牙釉质脱矿的体外研究

目的:证实多乐氟能预防碳酸饮料对乳牙牙釉质的脱矿作用。方法:将72个乳牙釉质块随机分成4组,每组18块。人工唾液为对照组(A);可乐碳酸饮料浸泡组(B);多乐氟处理后可乐浸泡组(C);氟化泡沫处理后可乐浸泡组(D)。A组试件不作处理,B组试件浸泡于可乐中30 min,取出后用去离子水冲洗干净放置约4 min,再次浸泡于可乐中30 min,如此循环直至12 h。实验C、D组釉质块分别浸在多乐氟、氟化泡沫涂抹4 min后,后续处理同B组。上述处理后试件分别用扫描电镜、能谱分析仪检测釉质表面的形态变化及Ca²⁺、P³⁺含量( 重量百分比)。结果:对A组相比,可乐浸泡可致乳牙釉质表面脱矿;氟化物处理后可降低釉质表面的脱矿程度,并使晶体颗粒体积变大,其表面Ga²⁺、P³⁺含量的降低程度也低于B组,差异有统计学意义(P<0.05)。结论:多乐氟可抑制乳牙釉质在碳酸饮料中的脱矿,效果较好,并能促进其再矿化。     

体外应用氟化物对牙酸蚀症再矿化效果的评价-显微硬度测定

目的 用显微硬度测量法研究氟化物对碳酸饮料酸蚀后的乳牙釉质的再矿化作用.方法 收集临床拔除的滞留第二乳磨牙共16颗,制成牙釉质样本.经碳酸饮料浸泡,每天2次,每次10分钟,共5天后,分为对照组(A组)、2%氟化钠溶液组(B组)、含1.23%氟离子凝胶组(C组)和含低氟过饱和钙磷溶液矿化液组(含氟10ppm)(D组)四组,每组16个牙块.经不同的氟化物处理釉质表面,每天1次,每次2分钟,共5天.分别在酸蚀前、酸蚀后和再矿化后用显微硬度计测定釉质表面硬度.数据使用SPSS10.0统计软件包进行单因素方差分析(ANOVA).结果 饮料酸蚀后的牙釉质表面硬度值明显下降.与对照组相比,经2%氟化钠溶液和1.23%氟离子凝胶组处理后的牙釉质表面硬度值均比处理前显著上升(分别为P=0.031和P=0.017),这两组之间的差异无显著性;矿化液处理后的牙釉质表面硬度值无显著变化(P=0.894).结论 显微硬度测定实验显示高浓度的氟制剂2%氟化钠溶液和含1.23%氟离子凝胶能够显著地促进酸蚀釉质再矿化;低氟浓度矿化液在短时间内对酸蚀釉质再矿化作用不明显.     

表没食子儿茶素没食子酸酯对乳牙早期釉质龋的再矿化作用

目的 通过体外实验研究,观察天然药物表没食子儿茶素没食子酸酯对乳牙早期釉质龋的再矿化作用.方法 将门诊因乳牙滞留拔除的上颌乳中切牙30颗按照随机数字表分为3组,实验组(表没食子儿茶素没食子酸酯组)、阳性对照组(NaF组)和空白对照组(人工唾液组),每组10颗,进行体外实验.采用显微硬度计测定标本脱矿前后和pH循环后的硬度值,扫描电镜观察乳牙釉质块再矿化后表面形态结构的改变.结果 pH循环后3组乳牙釉质块表面显微硬度组间两两比较差异均具有统计学意义(F=1199.975,P<0.05),阳性对照组和实验组较空白对照组乳牙釉质龋的表面显微硬度高(q=41.986,P<0.05vs实验组;q=68.174,P<0.05vs阳性对照组),但表没食子儿茶素没食子酸酯再矿化效果较NaF低(q=26.188,P<0.05).扫描电镜的结果显示,实验组和阳性对照组在乳牙釉质表面均有大量沉积物存在,空白对照组的乳牙釉质表面呈蜂窝状,凹凸不平,沉积物较少.结论 表没食子儿茶素没食子酸酯在体外实验的研究中,具有促进乳牙早期人工釉质龋再矿化的作用.     

氟纳米羟基磷灰石对早期釉质龋再矿化影响的研究

目的:研究氟纳米羟基磷灰石对早期釉质龋再矿化的影响,比较它与纳米羟基磷灰石、氟化钠和人工唾液的再矿化效果。方法:选取新鲜拔出的牛切牙40颗,制成人工龋模型,露出唇侧面,其余部分涂布双层指甲油。置于盛有脱矿液的容器中37℃脱矿3d,使用显微硬度仪测量脱矿后釉质的显微硬度。扫描电镜下观察脱矿后的釉质表面的平滑状态。然后随机分为4组。用软毛刷将相应试剂涂刷在釉质表面,3次/d,3～4min/次。人工唾液组直接将釉质块浸泡其中。10d后进行显微硬度和扫描电镜观察。实验前后统计采用配对t检验。结果:氟纳米羟基磷灰石组的显微硬度较脱矿后和对照组硬度值增加,有统计学意义(P<0.05),扫描电镜观察釉质表面变平滑。结论:氟纳米羟基磷灰石对早期釉质龋的再矿化效果较好。     

氟纳米羟基磷灰石对早期根面龋再矿化效果的实验研究

目的:通过实验研究氟纳米羟基磷灰石对早期根面龋的再矿化效果,并与纳米羟基磷灰石、氟化泡沫和氟化钠溶液的再矿化效果进行比较。方法:制备人工早期根面龋模型41个,使用扫描电镜观察脱矿后的根面的表面形态及用数显显微硬度计测量脱矿后根面的显微硬度。将40个根面龋模型随机分为5组:空白对照组、氟纳米羟基磷灰石组、纳米羟基磷灰石组、氟化泡沫组和氟化钠溶液组。每组使用其相应的试剂处理,经7 d pH循环及20d再矿化处理,于扫描电镜观察和显微硬度计测量。统计采用单因素方差分析并作LSD-t检验,实验前后采用单样本t检验。结果:氟纳米羟基磷灰石组扫描电镜观察根表面有大量晶粒沉积且平滑,其硬度值与脱矿后和其他组硬度值比较,有统计学意义(P<0.05)。结论:氟纳米羟基磷灰石对早期根面龋有较好的再矿化效果。     

奥乐V护牙剂对早期釉质龋再矿化作用的研究

目的 观察奥乐V护牙剂对早期釉质龋的再矿化作用。方法 将50个牛牙釉质块建立人工龋模型后随机分为5组：奥乐V护牙剂组、GC护牙素组、氟化钠（NaF）组、奥乐V护牙剂+NaF组、去离子水（DDW）组,分别进入 pH循环模型。采用显微硬度计测定各组标本脱矿前和pH循环后的釉质表面硬度值,扫描电镜观察各组再矿化后釉 质表面形态结构的改变。结果 各实验组经再矿化处理后其表面显微硬度均明显提高（P<0.001）,奥乐V护牙剂组再矿化后其表面显微硬度低于NaF组（P<0.001）,但与GC护牙素组间差异无统计学意义（P>0.05）;再矿化后奥乐V护牙剂组釉质表面有较大颗粒沉积。结论 奥乐V护牙剂具有促早期人工釉质龋再矿化的作用。     

Effects of a non-rinse conditioner on the enamel of primary teeth

The aim of this in vitro study was to evaluate by scanning electron microscopy the morphological aspects of the enamel of primary teeth after etching with 36% phosphoric acid or a non-rinse conditioner. Ten naturally exfoliated anterior primary teeth were selected. The samples were subjected to prophylaxis with pumice paste and water using a low-speed hand piece. Etching was done on the buccal surface. Specimens were divided into 2 groups: G1 (n=10): etching with 36% phosphoric acid gel - Conditioner 36 (Dentsply) for 20 s, followed by water rinse for 15 s; G2 (n=10): etching with NRC - Non Rinse Conditioner (Dentsply) for 20 s, followed by air drying for 15 s. The samples were dehydrated, mounted on metal stubs, coated with gold and observed with Jeol JSM-6100 scanning electron microscope. Electron-micrographic analysis showed that both etching agents were effective for etching the enamel of primary teeth causing the formation of microporosities on the enamel surface, although the etching pattern was more effective with the use of 36% phosphoric acid gel.     

Correlation between fissure discoloration, Diagnodent measurements, and caries depth: an in vitro study

PURPOSE: This in vitro study was performed to correlate the presence of discoloration on occlusal surfaces with its histological depth and assess its influence on Diagnodent measurements in a group of permanent and primary teeth. METHODS: Ninty-five primary and 95 permanent third molars were randomly selected from a pool of macroscopically intact teeth. One site of the fissure on each occlusal surface was selected and categorized according to its discoloration. Each site was measured 3 times with Diagnodent. The teeth were prepared histologically and evaluated according to their caries extent under a microscope (final magnification x 12.8). RESULTS: In the group of permanent teeth with dark brown or black discoloration (N=23), 13% showed dentinal caries, 57% were sound or had an initial enamel lesion, and 30% had a deep enamel lesion. In the group of primary teeth with dark brown and black discoloration (N=19), 42% presented dentinal caries, 42% showed deep enamel caries, and 16% had an initial enamel lesion. The difference between permanent and primary teeth was statistically significant (P<.05). Discolored fissures showed higher Diagnodent values than nondiscolored or opaque fissures in both groups (independent of their caries status). CONCLUSIONS: The presence of brown or dark spots on fissures were not useful for the prediction of dentinal caries for permanent teeth. In primary teeth, however, a higher correlation between fissure discoloration and dentinal lesions was found. Diagnodent tends to overscore discolored surfaces.     

Enamel hypoplasia in coeliac children: a potential clinical marker of early diagnosis.

AIM: To assess at the scansion electron microscope (SEM) the structural aspects of enamel hypoplasia (EH) in coeliac disease (CD) with the aim to investigate our hypothesis of a possible significant difference between structural characteristics of EH in CD affected patients and EH of non-coeliac patients. If the presence of specific features of the EH associated with CD were demonstrated, these findings would represent for the dentist early non-invasive clinical markers of diagnosis of CD in case of suspected disease. METHODS: We analysed at SEM two samples of enamel fragments from hypoplasic teeth, both deciduous and permanent, harvested from 10 coeliac children (18 permanent teeth, 6 deciduous teeth; study group) and 10 non-coeliac children (16 permanent teeth, 4 deciduous teeth; control group) treated for dental caries, dental extractions for extensive caries lesions or deciduous teeth exfoliation. RESULTS: Significant structural differences were noted between EH of non-coeliac patients and same dental ? lesion in the group with CD. In the study group, EH defects were predominantly located on the central and lateral incisors, upper and lower, both deciduous and permanent, and on the first permanent molars, and were always simmetrical. EH of permanent teeth of CD affected patients was characterised by prisms more irregularly distributed with irregular margins and less interprismatic substance than observed in non-coeliac EH. The deciduous teeth of the study group showed shorter enamel prisms with a non-parallel direction up to convergence and less interprismatic substance than observed in the control group. CONCLUSION: This morphological analysis at SEM of the hypoplasic enamel defects of a group of coeliac children, the first published in literature, demonstrates that the EH of deciduous and permanent teeth in CD is highly hypomineralised with shorter prisms, more irregularly distributed and less interprismatic substance than observed in the non-coeliac EH. More data are needed to validate the significance OF our observations with the aim to assess if this simple, non-invasive microscopic analysis can be considered effective for the early identification of silent cases of CD that otherwise would not be diagnosed in the paediatric age.     

硅对人恒前磨牙早期釉质龋再矿化影响的扫描电镜观察

目的:借助扫描电镜观察硅对脱矿釉质再矿化的影响.方法:用基础再矿化液和加硅的再矿化液对脱矿后的离体恒前磨牙牙釉质标本进行再矿化处理,用扫描电镜观察其表面形态及组织学变化.结果:对照组蜂巢状结构清晰,凹陷底部见球状沉积物,已变浅.实验组蜂巢状结构不清晰,大量微球状和球状颗粒沉积,凹陷变浅,有的地方已经填平,呈光滑形态.结...     

Effect of Nd:YAG laser combined with fluoride on the prevention of primary tooth enamel demineralization

Most studies dealing with the caries preventive action of Nd:YAG laser have been done in permanent teeth and studies on primary teeth are still lacking. The aim of this study was to evaluate in vitro the effect of Nd:YAG laser combined or not with fluoride sources on the acid resistance of primary tooth enamel after artificial caries induction by assessing longitudinal microhardness and demineralization depth. Sixty enamel blocks obtained from the buccal/lingual surface of exfoliated human primary molars were coated with nail polish/wax, leaving only a 9 mm2 area exposed on the outer enamel surface, and randomly assigned to 6 groups (n=10) according to the type of treatment: C-control (no treatment); APF: 1.23% acidulated phosphate fluoride gel; FV: 5% fluoride varnish; L: Nd:YAG laser 0.5 W/10 Hz in contact mode; APFL: fluoride gel + laser; FVL: fluoride varnish + laser. After treatment, the specimens were subjected to a des-remineralization cycle for induction of artificial caries lesions. Longitudinal microhardness data (%LMC) were analyzed by the Kruskal-Wallis test and demineralization depth data were analyzed by oneway ANOVA and Fisher's LSD test (á=0.05). APFL and APF groups presented the lowest percentage of microhardness change (p<0.05). Demineralization depth was smaller in all treated groups compared with the untreated control. In conclusion, Nd:YAG laser combined or not with fluoride gel/varnish was not more effective than fluoride alone to prevent enamel demineralization within the experimental period.     

Prevalence of dental caries and enamel defects in Connecticut Head Start children

PURPOSE: The aim of this study was to determine the prevalence of dental caries and enamel defects in a sample of predominantly African American and Hispanic children from an inner city Head Start program located in Connecticut. METHODS: A total of 517 children were examined for dental caries and enamel defects. Children's caries experience was described using the dmfs/t indices, and dental defects were described using a modified developmental defects of enamel index. RESULTS: The mean dmfs was 3.0, and 38% of the children had caries. The prevalence of enamel defects was 49%. When analyzed by race/ethnicity no significant differences in dmfs scores or the prevalence of defects were observed. The majority of defects were located on anterior teeth, and the type of defect varied with the location. On the buccal surface of canines, hypoplasia accounted for 70% of the lesions. On maxillary anterior teeth, linear opacities accounted for 50% of the lesions. A positive association between enamel defects and caries was observed. CONCLUSIONS: The prevalence of caries and defects in these Head Start children was high, with most defects located on anterior teeth. Enamel defects were associated with an increased caries incidence.     

Effects of carbamide peroxide containing bleaching agents on the morphology and subsurface hardness of enamel

The purpose of this study is to evaluate the effects of nightguard bleaching agents (Karisma and Yotuel) on the enamel surface of forty anterior teeth. Ten teeth of each group were evaluated with SEM and ten teeth of each group were tested with a microhardness tester Morphologic alterations were observed on the enamel surfaces with SEM. Karisma group showed a significant decrease in enamel hardness (p<0.05) and microhardness values of enamel were increased significantly in Yotuel group (p<0.05).