脱矿釉质树脂渗透后的再矿化研究

目的 研究渗透树脂联合生物活性玻璃溶液对脱矿釉质治疗与再矿化后的牙齿颜色与硬度的影响.方法 将20块经脱矿液脱矿的釉质块用渗透树脂治疗后随机分为A组和B组,分别采用生物活性玻璃溶液和去离子水进行再矿化;对2组进行二次脱矿处理.采用HSV-1000IS显微硬度计和分光光度比色仪分别检测不同处理后2组即刻的硬度和颜色.结果...     

精氨酸联合生物活性玻璃对乳牙釉质龋再矿化的研究

目的 研究精氨酸联合生物活性玻璃对乳牙釉质早期龋的再矿化性能。方法 将乳牙人工龋样本随机分为5组：①6%生物活性玻璃组 ②6%生物活性玻璃+1%精氨酸组 ③6%生物活性玻璃+2%精氨酸组 ④6%生物活性玻璃+4%精氨酸组 ⑤去离子水组,并进行14天的pH循环。显微硬度仪检测釉质表面硬度,电镜观察釉质的表面形貌,能谱分析仪分析表面的钙磷含量及钙磷比。结果 各组表面硬度恢复率（%）分别为(54.49±2.44)、（65.95±4.11）、（67.00±2.03）、（63.73±1.64）、（8.46±2.63）;各组均形成新的钙化层,添加2%及4%精氨酸组的釉质表面最为平坦;精氨酸协同组钙磷含量及钙磷比均显著高于生物玻璃组,其中2%及4%精氨酸组钙磷比与正常釉质相似。结论 精氨酸与生物活性玻璃对乳牙早期龋的再矿化有协同作用,其中添加2%精氨酸组综合能力最佳。     

五倍子化学组分对脱矿牙釉质再矿化的影响

目的研究五倍子多酚性化合物(Galla chinensis extract,GCE)及其4个化学组分(GCE-A,GCE-B,GCE-C和GCE-D)对早期牙釉质龋的再矿化作用,初步追踪五倍子促牙釉质再矿化的有效成分。方法选择脱矿后显微硬度值为160～180努氏硬度的70个牛切牙釉质样本,随机分为7组,每天进行4次药物处理(1 min/次);药物包括4 g/L的GCE溶液(GCE组)、GCE-A溶液(GCE-A组),GCE-B溶液(GCE-B组),GCE-C溶液(GCE-C组)和GCE-D溶液(GCE-D组)、去离子水(DDW组,阴性对照)和1 g/L的氟化钠溶液(NaF组,阳性对照)。样本pH循环12 d后用显微放射照相定量分析循环前后病损的总矿物丢失量。结果 GCE组的矿物丢失量和病损深度明显低于阴性对照组,但仍高于阳性对照组(P<0.05);GCE的4个组分,即GCE-A、GCE-B、GCE-C、GCE-D都有一定的促进脱矿釉质再矿化作用(P<0.05),但效果明显差于相同浓度的GCE(P<0.05)。结论 GCE及其4个组分都有一定的促进脱矿釉质再矿化作用,GCE效果最佳。     

正常唾液及氟化物对脱矿年轻恒牙牙釉质的再矿化作用

目的:用显微硬度测量法研究正常人体唾液及氟化物对碳酸饮料酸蚀的年轻恒牙牙釉质的再矿化作用。方法:收集口腔正畸门诊减数拔牙所拔除的新鲜、健康年轻恒牙23颗,制成牙釉质样本90块,随机分为对照A组、实验B组及实验C组;每组又分为三个亚组(A1、A2、A3、B1、B2、B3、C1、C2、C3),其中A1、B1、C1浸泡在雪碧中1周、A2、B2、C2浸泡在芬达中1周、A3、B3、C3浸在百事可乐中1周,每组10个牙块。A组牙浸泡完后直接用显微硬度仪做表面硬度测试;B组牙用蒸馏水冲洗干净后分别浸泡于装有正常人体唾液的容器中,将容器置于37℃恒温箱中,定期摇动容器,1月后取出用显微硬度仪做表面硬度测试;C组牙则用蒸馏水冲洗干净后,每日早中晚3次用含氟牙膏涂布牙齿开窗处表面10 min,再分别放入装有正常人体唾液的容器中,将容器置于37℃恒温箱中,定期摇动容器,1月后取出用显微硬度仪做表面硬度测试。结果:正常人体唾液及氟化物均能使脱矿后年轻恒牙牙釉质表面硬度明显升高(P<0.05),且两者之间有统计学差异(P<0.05)。结论:正常人体唾液及氟化物对脱矿年轻恒牙的再矿化作用明显。     

饮料对牙釉质表面显微硬度影响的研究

目的：研究不同饮料对牙釉质表面显微硬度的影响。方法：用不同种类饮料处理牙釉质后,采用维氏显微硬度仪测定牙釉质的处理前和处理后的1－7d表面显微硬度的改变。结果：饮料能引起牙釉质表面显微硬度的降低,降低的程度与饮料的种类有关,不同种类饮料导致牙釉质表面显微硬度降低的强度不同,差异有统计学意义（P＜0.001）。随时间的延长,表面显微硬度也随之降低（P＜0.001）。结论：饮料对牙釉质都具有脱矿作用,脱矿随饮料接触牙齿时间的延长而增加。     

不同氟浓度涂膜对牙釉质表面显微硬度的影响

作者观察应用含不同浓度氟化钠涂膜后牙釉质表面显微硬度值的改变情况。实验将釉质随机分为A、B、C三组。先测出实验之前的显微硬度值。然后在这三组釉质表面分别涂上0．5％、1．5％、2．7％的氟化钠涂膜24小时．再测显微硬度。结果；三组不同浓度氟化钠涂膜均使牙釉质显微硬度值有显著提高。与处理前比较，具高度显著性差异。A组含0.5%氟化钠涂膜其显微硬度值的增加率仅是其它两组的一半，而B、C两组高浓度氟化钠涂膜之间其硬度值的增加率又几乎相同。这表明，在达到一定的氟浓度后，其硬度值不再增加。作者认为，使用含1.5%氟化钠涂腹对预防龋齿较为理想。     

含硅再矿化液中硅含量对脱矿牙釉质再矿化影响研究

目的    观察不同质量分数含硅再矿化液对脱矿牙釉质表面微观形貌的影响,探讨其对脱矿牙釉质的再矿化作用。方法    本研究于2014年4—8月在吉林大学口腔医院实验室进行。将牙釉质标本置于乳酸人工脱矿液中浸泡1周形成人工釉质龋,扫描电镜（SEM）观察确认人工釉质龋形成后,将脱矿釉质块随机分为5组,分别置于基础再矿化液（对照组）及含硅质量分数为0.5 × 10-6、1 × 10-6、8 × 10-6、16 × 10-6的再矿化液（实验组）中进行再矿化处理3周,SEM观察处理后人工釉质龋脱矿釉质表面的再矿化效果。结果    不同浓度含硅再矿化液都有促进脱矿釉质再矿化的作用,其中以含硅质量分数为8 × 10-6的再矿化液效果最为显著。当含硅质量分数为0.5 × 10-6  、1 × 10-6和8 × 10-6时,随着硅含量的增加脱矿牙釉质的再矿化程度增高;当含硅质量分数上升为16 × 10-6时,其再矿化程度则有所下降。结论    硅能够促进脱矿牙釉质再矿化,并且以再矿化液含硅质量分数为8 × 10-6的再矿化效果最为显著。     

不同浓度氟泡沫对牙釉质表面显微硬度的影响

目的：观察不同浓度氟泡沫对脱矿牙釉质表面显微硬度值的影响。方法：将牙釉质块随机分为A，B两组，脱矿30min后在两组牙釉质表面分别涂布0．9％中性氟化钠氟泡沫和1．23％酸性氟磷酸盐氟泡沫4min，并在人工唾液中浸泡30min,24h后测定牙釉质表面显微硬度值，结果：两组不同浓度氟泡沫涂布后牙釉质表面显微硬度值均有显著提高，人工唾液浸泡30min和24h，涂布1．23％酸性氟磷酸盐氟泡沫组的牙南表面显微硬度值均高于0．9％中性氟化钠氟泡沫组，统计学检验30min时有显著差异，24h无差异。结论：两种浓度的氟泡沫均可使牙釉质表面显微硬度显著提高，1．23％酸性氟磷酸盐氟泡沫影响效果优于0．9％中性氟化钠氟泡沫。     

Effect of air-abrasion pre-treatment with bioactive glass 45S5 on enamel surface loss after erosion/abrasion challenge

ObjectivesThe aim of this in vitro study was to evaluate the effect of air-abrasion surface pre-treatment with bioactive glass (BAG) 45S5 on enamel surface loss after erosion/abrasion challenge.MethodsTwenty-four sound bovine incisors were used for this study. Four experimental groups (n = 12) were assigned as follows: Group 1 was the negative control group, Group 2 specimens were treated with a SnF₂ gel (positive control group), Group 3 specimens were air-abraded with BAG 45S5 (ProSylc) and Group 4 received both treatments. The specimens were submitted to erosion/abrasion challenge using a common soft drink. Enamel surface loss was evaluated using an optical profilometer. Additionally, surface roughness (VSI method) and surface microhardness (Vickers method) changes were evaluated, as well as SEM and EDS analyses were performed on enamel surface. The data were statistically analyzed using one-way ANOVA and Tukey’s post-hoc test at a level of significance a = 0.05.ResultsSurface pre-treatment with BAG 45S5 reduced surface loss in comparison with negative control group (p < 0.001), which exhibited the highest surface loss of the experimental groups (p < 0.05). The positive control group (SnF₂ treatment) and Group 4 specimens, which received both air-abrasion pre-treatment and SnF₂ treatment, presented the lowest surface loss (p < 0.05), but did not show significant differences to each other (p = 0.65).SignificanceAir-abrasion pre-treatment with BAG 45S5 may be beneficial as an in-office preventive method for the limitation of enamel erosive wear induced by excessive consumption of soft drinks. The clinical significance of the results regarding this preventive method should be confirmed by clinical studies.     

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.     

树脂浸润对人工龋表面硬度及变异链球菌生物膜形成的影响

目的研究树脂浸润技术对人工龋模型表面显微硬度（SMH）的影响及对变异链球菌生物膜的作用。 方法收集因正畸需要拔除的无龋坏前磨牙,制取釉质块共17个,其中5个用于研究树脂浸润治疗对人工龋模型SMH的影响,每个牙块分别于脱矿前（0 h）、脱矿24 h后、树脂浸润治疗后等不同时间点测量得到3组数据,自身前后对比。余下12个用于研究树脂浸润治疗对人工龋模型表面变异链球菌生物膜生长的影响,其中6个为空白对照组、6个为树脂浸润处理组,分别在4、24 h观测菌斑生物膜情况。以维氏表面微硬度仪检测人工龋模型SMH,以激光共聚焦扫描显微镜检测人工龋模型表面菌斑生物膜生物量、厚度、活菌百分比等。数据分别以配对t检验和独立样本t检验进行统计分析。 结果脱矿前釉质面SMH值为（316.07 ± 13.54）HV,脱矿24 h后为（22.44 ± 1.73）HV,树脂浸润治疗后为（139.45 ± 21.46）HV,两两比较差异有统计学意义（脱矿前-脱矿后t= 55.879,P<0.001;脱矿后-治疗后t=-14.400,P<0.001;脱矿前-治疗后t = 14.090,P<0.001）。变异链球菌生物膜检测中,4及24 h树脂浸润处理组生物量[（0.59 ± 0.24）、（9.53 ± 1.49）μm³/μm²]均低于空白对照组的生物量[（1.01 ± 0.30）、（15.47 ± 7.32）μm³/μm²],差异有统计学意义（t_{4 h}= 3.232,P_{4 h}= 0.005;t_{24 h}= 2.384,P_{24 h}= 0.042）;4及24 h树脂浸润处理组活菌百分比[（48.73 ± 8.54）%、（60.49 ± 5.33）%]均高于空白对照组的活菌百分比[（31.84 ± 7.30）%、（34.87 ± 10.72）%],差异有统计学意义（t_{4 h}=-4.508,P_{4 h}<0.001;t_{24 h}=-6.419,P_{24 h}<0.001）。树脂浸润处理组24 h生物膜厚度为（6.44 ± 1.51）μm,低于空白对照组的生物膜厚度（12.78 ± 7.17）μm,差异有统计学意义（t= 2.592,P= 0.030）。 结论树脂浸润治疗应用于早期人工龋模型上,能明显改善脱矿牙面的SMH,具有良好的机械性能;同时具有抑制变异链球菌生物膜形成的作用。     

Microscopic investigation of artificially demineralized surface enamel exposed to controlled intra-oral periods

BACKGROUND: Arrest and regression of enamel caries is generally followed by clinical surface changes in enamel. The aim of this study was to evaluate microscopic surface changes in demineralized enamel submitted to toothbrushing with a fluoridated dentifrice or to a fluoridated gel in situ. METHODS: Enamel blocks demineralized by an acidic gel, were built in plates of five volunteers during three periods of 14 days each: exposure to the oral cavity (C+); brushing with a fluoridated dentifrice three times a days (B); application of a 2 per cent sodium fluoride gel and exposure to the oral cavity (F). Eight blocks were kept in 100 per cent humidity under refrigeration as negative controls (C-). RESULTS: Stereomicroscopic examination revealed that 15, 47.4 and 30 per cent of samples from C+, B and F presented enamel cavitation after the experimental period. The demineralized enamel area in these groups decreased considerably compared to C-, both in cavitated and non-cavitated samples, although it was statistically significant only in cavitated samples from B (p=0.003; t test). Scanning electron microscopy revealed that C+ and F retained irregularities caused by the acid challenge, while B presented a more leveled profile of the enamel surface. CONCLUSIONS: Exposure of demineralized enamel to intra-oral periods reduced the demineralized enamel area. Tooth brushing enhanced this reduction, because of surface abrasion.     

Effect of fluoride containing bleaching agents on enamel surface properties

OBJECTIVES: To evaluate the effects of fluoridated bleaching agents and post-bleaching fluoridation treatment on the whitening efficiency and microhardness of bovine enamel. METHODS: Twenty five freshly extracted bovine incisors were cut into halves, embedded and then divided into the following five groups: Group 1, untreated controls; Group 2, treatment with 10% carbamide peroxide (CP) bleaching agent; Group 3, treatment with 10% CP followed by a 0.9% sodium fluoride gel application, Group 4, treatment with 10% CP containing 0.11% fluoride; Group 5, treatment with an experimental bleaching agent consisting of 10% CP and 0.37% fluoride. Groups 2-5 were treated 8h per day for 14 days then immersed in saliva for 2 weeks. Enamel morphology changes were evaluated under SEM on Day 14. Changes in enamel color and microhardness were evaluated on Days 7 and 14, and compared with the baseline data. Additionally, microhardness was determined on post-bleaching Days 21 and 28. RESULTS: After 2 weeks, an erosion pattern was noted on the specimens in Groups 2 and 3. Groups 4 and 5 showed a milder demineralized pattern. All the bleached enamel specimens revealed increased whiteness and overall color value. Groups 2 and 3 showed significantly decreased enamel microhardness compared to their baseline data. The specimens treated with fluoridated bleaching agents showed relatively less reduction in enamel microhardness than those treated with nonfluoridated agents during the bleaching treatment. CONCLUSIONS: The fluoridated bleaching agents produced less demineralization of surface morphology and microhardness. The addition of fluoride did not impede the whitening effect.     

Prevention of enamel demineralization after tooth bleaching by bioactive glass incorporated into toothpaste

Background: The aim of this study was to determine the effects of bleaching on the structure of the enamel layer of teeth and the potential of the commercial bioactive glass NovaMin® in two different toothpastes to remineralize such regions of the enamel. Three aspects were considered: the extent and nature of the alterations in the enamel after application of the bleaching agents; the extent of remineralization after application of two commercial toothpastes containing bioactive glass; and whether or not there were differences between the toothpastes in terms of their effectiveness in promoting remineralization. Methods: Bleaching agent based on 16% carbamide peroxide was applied to the enamel surface of freshly extracted human molars for 8 minutes, once a day for 7 days. After the bleaching cycles, the enamel surface was analysed by SEM and EDX. Results: The results obtained in the study lead to the conclusion that application of 16% carbamide peroxide causes distinct morphological changes to the enamel surface which vary from mild to severe. Subsequent treatment with either of the toothpastes containing the bioactive glass NovaMin® resulted in the formation of a protective layer on the enamel surface, consisting of bioactive glass deposits, with only slight differences between the two brands. Application of these dentifrices also caused increases in the Ca and P content of the enamel layer, returning it to that of undamaged enamel. Conclusions: Remineralizing toothpastes should be used after bleaching, in order to repair any damage to the mineral tissue caused by these procedures.     

乳牙釉质表面的脱矿与再矿化的体外研究

目的运用共聚焦激光扫描显微镜（CLSM）评价离体乳牙釉质表面的脱矿与再矿化行为。方法临床选取无龋健康的上颌乳切牙36颗,于唇面中央开3个1 mm×1 mm的窗a、b、c。开窗面a进行酸蚀、再矿化处理,b进行酸蚀处理,c不进行任何处理。将36个样本随机分为3组,组1、2、3的开窗面a在酸蚀后分别进行再矿化24h、48h及72h。然后运用CLSM技术测量开窗面a、b、c的总荧光量（TF）、平均荧光量（AF）及荧光面积（A）。对正态分布资料,用t检验进行统计分析,对非正态分布资料,则使用非参数分析,统计学差异指标为P〈0.05。结果开窗面b、c间TF、AF、A差异均有显著性（P〈0.05）,各组别（不同矿化时间）开窗面a、b间TF、AF及A差异均有显著性（P〈0.05）,开窗面a、c间TF、AF及A差异均有显著性（P〈0.05）。结论 CLSM能有效地评价乳牙釉质的脱矿与再矿化行为。