四种自酸蚀粘接剂牙本质粘接界面纳米渗漏比较

目的 比较4种自酸蚀粘接剂牙本质粘接界面纳米渗漏及微观形态。方法 选取16颗无龋人离体第三磨牙,制备统一的牙本质玷污层,分别用4种自酸蚀粘接剂A( Adper Prompt)、B( iBond)、C(XenoⅢ)及D(SE Bond)按使用说明进行粘接处理,垂直粘接面切成0.9 mmx4.0 mm试件,避光贮存于氨...     

口内耐久实验对牙本质黏结强度和黏结界面纳米渗漏的影响

目的:观察并评价口内耐久实验对2种黏结剂(Prime＆Bond NT、CleadilTM SE Bond)牙本质黏结强度和黏结界面纳米渗漏的影响.方法:选取2只山羊口内32个磨牙,24 h、3个月前于颊侧预备牙颈部洞,分别用2种黏结剂按使用说明进行处理.拔除相应的牙齿标本,在实验切片机上流水冲洗下垂直于黏结界面切割出4个1.0 mm×1.0 mm×4.0 mm黏结试件,分别在TEM下观察其黏结界面纳米渗漏以及进行微拉伸强度(μTBs)测试.结果:黏结剂PB和CB 3个月组牙本质黏结强度均小于24 h组,相差显著(F=4.610,P<0.05;F=5.10,P<0.05);黏结剂PB 3个月组的牙本质黏结界面纳米渗漏值小于24 h组,且相差显著(F=4.983,P<0.05),CB的3个月组纳米渗漏值大于24 h组,但相差不显著(F=0.122,P>0.05).结论:口内耐久实验中,牙本质黏结强度随时间的延长而下降,不同类型黏结剂的牙本质黏结界面纳米渗漏的发展变化亦不同.     

黏结面润湿度对牙本质黏结界面纳米渗漏和黏结强度的影响

目的: 研究、比较不同黏结面湿润度对4种伞酸蚀黏结剂(OptiBond Solo、Single Bond、One-Step、Prime & Bond NT)牙本质黏结界面纳米渗漏和黏结强度的影响.方法:选取60个无龋损人磨牙,用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质黏结面玷污层,分别选用4种黏结剂在不同黏结而湿润度条件下进行黏结处理.每个牙齿垂直于黏结面切割出8个1.0 mm×1.0 mm×4.0 mm黏结试件,分别在TEM下观察其黏结界面纳米渗漏以及进行微拉伸强度(μTBS)测试.结果:4种黏结剂在润湿的黏结面上均取得了最高的牙本质黏结强度和较少的纳米渗漏.结论:通过合理控制黏结面润湿度,可以在提高牙本质黏结强度的同时,减少黏结界面纳米渗漏的产生.     

疏水涂层对自酸蚀粘接界面纳米渗漏的影响

目的 研究疏水涂层对自酸蚀粘接剂牙本质粘接界面纳米渗漏的影响.方法 选择新近拔除的32颗无龋人第三磨牙,去除(牙合)面釉质暴露牙本质层,随机分为4组,每组设实验组和对照组.对照组分别用Adper Prompt(AP)、iBond(IB)、Xeno III(XE) 和SE Bond(SE)按使用说明常规粘接,Protect liner F树脂修复;实验组于常规粘接后涂布疏水涂层,Protect liner F树脂修复.垂直于粘接界面切割出4个0.9mm×4mm的试件,经显影固定脱矿后,切成超薄切片,经铀、铅染色后于透射电镜下观察银离子的渗入情况.NIH图像分析软件量化比较纳米渗漏值,统计分析.结果 4种粘接剂纳米渗漏值AP>IB>XE>SE,SE组纳米渗漏较小,与其他3组间差异有统计学意义(P<0.05).疏水涂层运用后与粘接层紧密结合,粘接层明显增厚,纳米渗漏减少,与对照组的差异有统计学意义(P<0.05).结论 疏水涂层有助于形成厚而均一的粘接层,减少自酸蚀粘接界面纳米渗漏的产生.     

牙本质黏结界面的微渗漏与纳米渗漏

目的：观察牙本质黏结界面微渗漏与纳米渗漏,探讨两者的关系。方法：在离体人磨牙的颊、舌侧颈部制备盒形单面洞（直径3mm,洞深2mm）,将牙分为2组,每组5个牙。对2组牙的窝洞分别应用黏结剂Single Bond、Clearfil SE Bond,然后充填复合树脂并光照固化。所有牙齿进行冷热循环5000次,之后在牙齿表面涂指甲油。将牙齿浸泡于500g/L氨化硝酸银液（pH8.0）中,24h后再浸泡于显影液中8h。随后将牙纵向剖开,暴露充填物剖面,在体视显微、扫描电镜下观察剖面充填物龈缘渗漏情况。结果：所有牙剖面修复体龈缘均存在程度不同的微渗漏,有微渗漏的黏结界面处并未发现因黏结原因所造成的裂缝或微裂隙,但在混合层内观察到纳米渗漏。结论：牙本质黏结界面的微渗漏染色不一定因界面裂缝所致,界面无裂缝的纳米渗漏同样可造成微渗漏染色。     

不同溶剂黏结剂对牙本质黏结界面纳米渗漏的影响

目的:观察、比较黏结剂中溶剂的不同对牙本质黏结界面纳米渗漏的影响.方法:选取20个无龋损人磨牙,用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质黏结面玷污层,分别选用含不同溶剂的4种黏结剂OptiBond Solo(OB)、Single Bond(SB)、One-Step(OS)、Prime＆Bond NT(PB)进行黏结处理;每个牙齿垂直于黏结面切割出4个4 mm×0.9 mm×4mm黏结试件,避光贮存于氨化硝酸银液中24 h,在TEM下观察、比较牙本质黏结界面纳米渗漏.结果:2种丙酮基黏结剂OS(11.73±2.03)%和PB(11.54±2.18)%的纳米渗漏值之间无显著性差异,而它们均明显小于乙醇/水基黏结剂OB(14.27±2.07)%和SB(12.94±1.81)%.结论:黏结剂中溶剂的不同对其牙本质黏结界面纳米渗漏程度影响显著.     

诺丽对冠部牙本质粘接强度及纳米渗漏的影响

目的 探讨诺丽（Morinda citrifolia juice,MCJ）联合乙二胺四乙酸盐（ethylene diaminete traacetic acid,EDTA）根管冲洗对冠部牙本质粘接强度及纳米渗漏的影响,并与临床上最常用的根管冲洗液次氯酸钠（sodium hypochlorite,NaClO）相比较,为临床应用提供参考。方法 本研究已通过单位伦理审查委员会批准。选取63颗因正畸拔除的人前磨牙,去除表面釉质暴露牙本质平面后,根据冲洗液不同随机分为对照组（蒸馏水组）和6个实验组,即：A组2.5%NaClO、B组5.25%NaClO、C组6%MCJ、D组2.5%NaClO-17%EDTA、E组5.25%NaClO-17%EDTA和F组6%MCJ-17%EDTA(n=9),分别用相应冲洗液浸泡20 min后,在其表面分层堆积4 mm×4 mm×3 mm的Z350树脂块,每组选取6个样本,低速切割机将每个样本切割成1 mm×1 mm×8 mm的试件条,进行微拉伸粘接强度测试,随后在体视显微镜下观察断裂类型;每组剩余的3个样本经老化后切割成1 mm厚的薄片,进行界面纳米渗漏测试以及扫...     

冷热循环对牙本质黏结界面纳米渗漏的影响

目的：探讨冷热循环对牙本质黏结界面纳米渗漏的影响。方法：用透射电镜观察3种黏结系统(Adper Prompt，U-Bond，Opti Bond)有无冷热循环作用下，牙本质黏结界面银沉积情况，并用NIH图像分析软件量化处理，以银沉积面积占混合层面积的百分比来评价纳米渗漏程度。结果：各实验组和对照组银沉积面积百分比分别为AP(9．27％，8.96％)、UB(9．62％，8．75％)、OB(8．18％，9.20％)。结论：研究中所用黏结系统都不能避免纳米渗漏产生；短期冷热循环对自酸蚀黏结系统黏结界面纳米渗漏有增加的趋势。     

循环加载对牙本质黏结界面纳米渗漏的影响

目的:探讨循环加载对牙本质黏结界面纳米渗漏的影响。方法:选用3种黏结系统:Prime & BondNT(NT),Adper Prompt(AP)和Contax。用扫描电镜(SEM)观察这3种黏结系统在有无循环加载的作用下,牙本质黏结断面银渗漏情况,并用NHl图像分析软件量化处理,以界面银沉积面积占断裂界面的百分比来评价纳米渗漏程度。结果:各对照组银沉积面积的百分比分别为NT(11.48%±2.84%)、AP(21.18%±3.66%)、Contax(14.30%±2.52%),实验组分别为NT(25.20%±4.69%)、AP(38.96%±8.78%)、Contax(29.94%±4.51%)。结论:无论加载与否,所用3种黏结系统都不能避免纳米渗漏的产生;循环加载使黏结系统黏结界面纳米渗漏增加,尤其以AP最为显著。     

牙本质粘接界面微渗漏的二维形态

目的观察牙本质粘接界面微渗漏的二维形态。方法去除磨牙面釉质,暴露牙本质,分别用3种粘接剂（Prime & Bond NT、Contax和Adper Prompt）粘接牙本质,其上制作复合树脂冠。顺牙齿长轴,在相互垂直的两个方向片切牙齿,制备条状试样。每个牙齿制备的试样为两组,一组进行冷热循环10 000次,另一组不冷热循环,之后相继浸泡于氨化硝酸银溶液及显影液中,然后测定微拉伸粘接强度。最后在扫描电镜下观察界面破坏和混合破坏试样的断面。结果粘接界面微渗漏的二维形态呈各种不同的树枝状,从边缘伸向中心,冷热循环后的微渗漏程度明显加重。结论牙本质粘接界面的微渗漏并非是从外到里齐头并进,而是呈树枝状,其程度与粘接剂种类和是否进行冷热循环有关。     

Effects of etching time of primary dentin on interface morphology and microtensile bond strength

OBJECTIVES: To determine the influence of different etching times (5, 15 or 30 s) on the morphology and micro-tensile bond strength (muTBS) of primary dentin. METHODS: For muTBS study, nine primary molars were randomly distributed in three experimental groups. Three Class I cavities per tooth were drilled and etched (37% orthophosphoric acid gel for 5, 15 or 30 s). Excite adhesive was applied and cavities restored with a resin composite (Tetric Ceram). Composite/dentin bars (ca. 1 mm2 section) were obtained from teeth and tested in tension until debonding. Means of muTBS results were compared with ANOVA and Student-Neuman-Keuls post hoc tests. Morphology: Three occlusal cavities were prepared in five primary molars. Each cavity was etched and restored as described for previous groups and teeth were sectioned mesio-distally. One half of each tooth was prepared for using under optical microscopy using Masson's trichromic dye technique and the other half was examined by SEM. RESULTS: muTBS mean (S.D.) results (in MPa) were 5 s etch: 6.20 (2.81), 15 s: 13.43 (5.91), 30 s: 13.04 (5.67). muTBS groups were Excite 5 s < Excite 15 s = Excite 30 s. Masson's trichromic technique stained the demineralized dentin layer red in all specimens. The mean (S.D.) thickness of the demineralized layers (in mu) were 5 s: 3.28 (1.23), 15 s: 3.83 (1.26), 30 s: 4.44 (1.70). There is a statistically significant linear relationship between time of application of etching and mean depth of demineralized layer. This relationship was established as depth (in mu) = 3.08 + 0.05 time (in s). SIGNIFICANCE: The minimum adequate etching time for primary dentin is 15s.     

Relationship between nanoleakage and microtensile bond strength at the resin-dentin interface

To evaluate the correlation between microtensile dentin bond strength (microTBS) and silver ion penetration, two total-etch 3-step and one self-etch 2-step system were investigated. OptiBond FL adhesive was applied to flat occlusal dentin on six non-carious human molars, and a resin composite "crown" was formed in 2 mm increments. After 24-hour water storage, the teeth were sectioned with a low-speed diamond saw to obtain four-square sticks (approximately 2 mm X 2 mm) per tooth. Cylindrical tensile test specimens were formed with an 0.5 mm2 cross-sectional area. Nail varnish was applied to the dentin within 0.5-1.0 mm of the interface before immersing in 50% silver nitrate for 15 minutes. Following silver fixation, tensile testing was performed in a Zwick UTM at 1 mm/minute using a passive gripping fixture to obtain 72-hour microTBS [23.9 MPa]. The percentage area of silver penetration was measured on debonded specimens using light microscopy and Image-Pro Plus Software [89%]. The procedures were repeated using Scotchbond Multi-Purpose Plus [microTBS = 27.8 MPa; nanoleakage = 67%] and Clearfil SE bond [microTBS = 36 MPa; nanoleakage = 55%]. No significant correlation between microtensile bond strength and nanoleakage was found for all systems. A weak-to-moderate negative relationship was found between microTBS and nanoleakage for OptiBond FL (Spearman r = -0.3844). No correlation was found for the remaining adhesive systems. The correlation between these two common laboratory measurements appears to be adhesive-system dependent.     

A 2-year evaluation of moisture on microtensile bond strength and nanoleakage.

OBJECTIVES: This study evaluated the effect of moisture on the resin-dentin mu-bond strength (BS) and silver nitrate uptake (SNU) of three adhesive systems (Single Bond, One-Step and Syntac Single Component) soon after bonding (IM) and after 2 years of water storage (2Y). METHODS: Dentin surfaces were bonded on a dry (D), moist (W) or over-wet surfaces (OW). After restorations were constructed, specimens were stored in water (37 degrees C/24h). Resin-dentin sticks were prepared (0.8mm(2)) and they were divided for immediate (IM) and 2-year storage (2Y) testing. Half of the specimens from each period of time were tested in tension at 0.5mm/min and the other half was immersed in silver nitrate and examined by SEM-EDX. The data was analyzed by three-way repeated measures ANOVA and Tukey's tests (alpha=0.05). RESULTS: The overall BS (MPa) in the IM group under W condition was higher than in D and OW groups. After 2Y, the BS in W was lower than in the IM group, however higher than in the D and OW for OS and SB. The overall silver nitrate deposition (%) in the IM group under D, W and OW were similar. In the 2Y groups, the nanoleakage was higher than IM groups, however the increase was less pronounced in the W condition. SIGNIFICANCE: Higher BS and a significantly lower nitrate uptake were observed for IM groups, for OS and SB. Under W conditions, the BS reduction over time was less pronounced and less nitrate uptake occurred.     

Effect of acid etching time and technique on interfacial characteristics of the adhesive-dentin bond using differential staining

Dentin bonding using the total-etch method has been claimed to be technique-sensitive. The aim of this study is to examine the effect of acid-etch variations on the dentin demineralization and interfacial structure of the adhesive-dentin bond using a differential staining technique. Single Bond adhesive with 35% phosphoric acid gel was used. The occlusal one-third of the crown was removed from 60 extracted, unerupted human third molars. Smear layers were created by abrading the dentin with 600 grit SiC under water for 30 s. The prepared teeth were randomly assigned to four groups according to etching time (Group 1, 10 s; Group 2, 15 s; Group 3, 30 s; Group 4, 60 s). In each group, the etching gel was: (i) applied and spread to the dentin surface and left to stand undisturbed; (ii) applied and gently agitated during etching; (iii) applied without using dispensing tips for the syringe and left for the same period as above. After rinsing, the etched dentin was then treated with the adhesive per manufacturers' instructions. 3-5 micro m thin sections of the adhesive/dentin (a/d) interface were cut with a microtome and stained with Goldner's trichrome. Stained, thin sections from each prepared tooth were imaged with light microscopy. The depth and extent of dentin demineralization, and the a/d interdiffusion zone were clearly visible by this differential staining microtechnique. The thickness of the interdiffusion zone increased as a function of etching time. However, the etchant gel application methods have a significant influence on dentin demineralization. Although agitating acid gel facilitates the penetration and etching into dentin, it should not be recommended, especially for longer etching time. These results indicated that the etching technique has a large effect on the profile of both dentin demineralization and interfacial structure.     

Long-term durability of resin dentin interface: nanoleakage vs. microtensile bond strength

This study tested the hypothesis that long-term durability of resin bonds to dentin is directly related to the nanoleakage of dentin bonding systems. Extracted human third molars were ground flat with 600-grit SiC paper under running water to expose middle dentin. Clearfil Liner Bond 2V (LB2V) or Fluoro Bond (FB) was applied to dentin surfaces according to the manufacturer's instructions. A crown was built-up with Clearfil AP-X resin composite, and the specimens were stored in water for 24 hours at 37 degrees C. The bonded assemblies were vertically sectioned into approximately 0.7 mm thick slabs and trimmed for microtensile bond test. All slabs were immersed in individual bottles of water at 37 degrees C, which was changed every day. Specimens were incubated for one day, and three, six, and nine months, and at the specified time period, they were randomly divided to two subgroups: 50% AgNO3 and the control. In the 50% AgNO3 subgroup, the slabs were immersed for one hour in 50% AgNO3, followed by exposure in a photo-developing solution for 12 hours just prior to debonding. The specimens in the control subgroup were soaked in water until debonding. Then, all specimens were subjected to microtensile bond testing. The debonded specimens of the AgNO3 subgroup had micrographs subjected to image analysis by NIH Image PC (Scion, Fredrick, MD, USA), and the area of silver penetration was quantitated. The bond strength data and silver penetration areas were subjected to two- and three-way ANOVA and Fisher's PLSD test at the 95% level of confidence. Regression analysis was used to test the relationship between bond strengths and the silver penetration area at each time period. For both adhesive systems, the bond strengths gradually decreased over time, although there were no statistically significant differences in the FB bond strength among the four time periods tested (p>0.05). Silver penetration in specimens bonded with LB2V and FB gradually increased over time. Regression analysis showed a higher correlation between bond strength and silver penetration at 9 months for specimens bonded with LB2V (R2=0.844) than at shorter time periods. The authors speculate that hydrolytic degradation within the hybrid layer gradually increased due to water penetration through nanoleakage channels, resulting in lower bond strengths and interfacial failure after as little as nine months.     

循环加载后牙本质粘结强度与界面纳米渗漏之间相关性的研究

目的 研究循环加载后三种牙本质粘结剂界面银渗漏面积与微拉伸粘结强度之间的相关性.方法 36颗新鲜拔除的无龋第三磨牙垂直牙体长轴除去冠部釉质,在牙合面制备盒型洞,随机分成3组,分别用粘结剂粘结Prime&Bond NT(NT)、Adper Prompt(AP)、Contax,复合树脂充填.每组再随机分成实验组和对照组.实验组以50N大小的力进行循环加载.加载10000次.制备测试微拉伸粘结强度的条状试件.硝酸银染色.在拉力试验机上测定粘结强度,并用NlH图像分析软件量化计算界面的银沉积面积百分比.结果 循环加载前,三种粘结剂的界面银渗漏面积与微拉伸粘结强度未表现出明显的相关性(P＞0.05).加载后,界面银渗漏面积与微拉伸强度表现出相关性(P＜0.05).结论 循环加载使三种粘结剂界面的银渗漏面积的增大以及微拉伸粘结强度的降低,并且加载后界面的银渗漏面积与微拉伸粘结强度表现出显著的相关性.