4种粘接剂对非龋性硬化牙本质粘接强度的实验研究

目的：比较4种牙本质粘接剂对牙颈部非龋性硬化牙本质的粘接强度。方法：选择具有典型牙颈部非龋性硬化牙本质的新鲜离体牙32个，随机分为4组，分别用Prime＆Bond NT、Contax、Xeno Ⅲ及Clearfil TRI—S Bond4种粘接剂和复合树脂粘接，24h后制作微拉伸试件，测试微拉伸强度，扫描电镜观察断裂模式并进行分类。结果：4种粘接剂对非龋性硬化牙本质的微拉伸强度分别为：Prime＆Bond NT 38．81＋11．75MPa。Contax 37．82±11．74MPa，Xenom 29．55±10．25MPa，Clearfil TRI—S Bond 38．63±12．17MPa，试件断裂多为混和破坏。结论：4种粘接剂对硬化牙本质粘接强度存在差异，XenoⅢ最低（P〈0．01），其余3种粘接材料两两比较无显著差异（P〉0．05）。     

五种牙本质粘接剂对乳牙牙本质粘接性能的比较

目的 检测5种牙本质粘接剂对乳牙牙本质的粘接性能,为牙本质粘接剂的临床使用提供依据.方法 按随机数表法将75颗因滞留拔除的乳磨牙分为5组,每组15颗.各标本磨除表面牙釉质,暴露的牙本质面分别根据不同粘接系统的说明进行酸蚀粘接,树脂充填.使用A(FL-Bond Ⅱ)、B(Clearfil Protect Bond)、C(Clearfil SE Bond)、D(AdperTM Easy One)、E(Single Bond 2)粘接系统进行粘接(分别为A、B、C、D、E组),用微拉伸测试仪检测微拉伸强度.扫描电镜观察样本的断裂类型.结果 各组的微拉伸强度分别为A组:(28.3±2.2)MPa,B组:(32.4±2.5)MPa,C组:(38.3±2.8) MPa,D组:(32.9±3.4)MPa,E组:(23.2±1.9) MPa,C组与A、E组差异有统计学意义(P＜0.01),C组与B组、D组差异无统计学意义(P＞0.05),A组与E组差异无统计学意义(P＞0.05).扫描电镜观察显示各组的断裂类型均以混合断裂为主,各组间无明显差异.结论 粘接剂B的粘接强度与粘接剂C和D相同,优于粘接剂E,可能更适用于乳牙的粘接.     

一步法自酸蚀粘接剂微拉伸粘接强度的研究

目的评价一步法白酸蚀粘接剂的牙本质微拉伸粘接强度，观察并分析样本断裂类型。方法选择新拔除的人无龋下颌第三磨牙12颗，分别用3种一步法、1种两步法的白酸蚀粘接剂进行牙本质粘接。用微拉伸测力仪测试粘接强度，并用体视显微镜和扫描电镜观察样本断裂类型。结果3种一步法白酸蚀粘接剂的微拉伸强度分别为：材料A（Adper Prompt）（23．36±2．55）MPa；材料B（Clearfil S^3 Bond）（30．46±3．82）MPa；材料C（Xenon Ⅲ）（34．59±3．46）MPa；1种两步法自酸蚀粘接剂材料D（Clearfil SE Bond）的微拉伸粘接强度为（45．06±5．29）MPa。材料D微拉伸粘接强度最高，与其他3组相比，差异具有统计学意义（P〈0．01）。样本断裂均发生于粘接界面，未观察到复合树脂或牙本质内聚破坏。结论一步法白酸蚀粘接剂的牙本质粘接强度低于两步法白酸蚀粘接剂，但多数仍可满足临床对树脂粘接强度的要求。     

丙酮基和酒精-水基牙本质粘接系统粘接强度比较及粘接界面观察

目的:比较丙酮基和酒精-水基两种不同溶剂类型的全酸蚀牙本质粘接系统粘接强度和粘接界面的微观形态。方法:选择24颗正畸治疗拔除的健康前磨牙,去除合面釉质层,随机分两组,每组选用一种 “两步法”全酸蚀牙本质粘接系统:以丙酮为溶剂的Prime & Bond NT(PB组)和以酒精和水为溶剂的Single Bond 2(SB2)组,粘接后进行微拉伸力检测。以扫描电镜(SEM)和激光共聚焦扫描电镜(LCSM)观察两种牙本质粘接系统的粘接界面。结果:粘接强度PB组(29.49±4.01) MPa,SB2组微拉伸粘接强度为,SB2组为(30.03±4.33) MPa,无统计学差异。两种牙本质粘接系统均可充分渗入脱矿牙本质表层的胶原纤维网和牙本质小管内,形成混合层和树脂突,SB组混合层薄而均匀,树脂突长。结论:不同溶剂类型的两组牙本质粘接系统微拉伸粘接强度无差异,全酸蚀牙本质粘接系统在湿粘接状态下可以对牙本质形成良好的渗透。     

脱矿牙本质与四种粘接剂的粘接强度测试及粘接界面观察

目的比较脱矿牙本质与4种全酸蚀或自酸蚀粘接剂的粘接强度及粘接界面超微结构的差异,以期对临床治疗有所指导。方法选择20颗面龋坏的离体磨牙,在龋显示剂的指示下去除牙本质龋的感染层,保留脱矿牙本质。平齐龋洞洞底平面,去除冠向牙体组织,作为粘接面。选择临床常用的2种全酸蚀粘接剂:材料A(All Bond2)、材料B(Prime&BondNT)和2种自酸蚀粘接剂:材料C(ClearfilSEBond)、材料D(XenoⅢ),分别按说明书要求粘接。用慢速锯将样本牙切为粘接面积约0.9mm×0.9mm的长方体试件。体视显微镜下将试件分为正常牙本质组和脱矿牙本质组,用微拉伸测试仪检测粘接强度。扫描电镜观察各组试件粘接界面的超微形态。结果方差分析提示牙本质类型和粘接剂对微拉伸粘接强度的影响均有统计学意义(P<0.05)。对正常牙本质,不同粘接剂的微拉伸粘接强度差异无统计学意义(P>0.05);对于脱矿牙本质,材料D的微拉伸粘接强度较其他粘接剂明显降低(P<0.05)。扫描电镜下观察脱矿牙本质的混合层多孔稀疏,树脂突短少,无侧枝形成。结论对脱矿牙本质,本项实验中全酸蚀粘接剂的粘接强度优于自酸蚀粘接剂。     

牙本质粘接剂粘接强度与界面形态的研究

目的:采用一种新的界面处理方法,对不同类型牙本质粘接剂的粘接强度与界面形态进行研究.方法:选取人无龋磨牙,暴露咬合面牙本质,分别使用3 种粘接剂(Single Bond,SB;Clearfil SE Bond,SE;Clearfil S3 Bond,S3)制备粘接样本.粘接样本切割成粘接界面约为0.9 mm×0.9 mm的柱形小条,用微拉伸测力仪测试粘接强度(n=15).另外将粘接样本依次用6 mol/L盐酸、5%次氯酸钠和0.08 mg/ml透明质酸酶溶液处理,扫描电镜观察粘接界面形态.结果: 3 种粘接剂的牙本质粘接强度分别为:SB (35.50±6.40) MPa,SE (45.06±5.29) MPa,S3 (30.46±3.82) MPa,三者之间差异具有统计学意义(P<0.05).SB粘接界面的树脂突长约9～12 μm,部分样本出现混合层易与粘接剂层分离.SE形成的树脂突长约9～14 μm,无混合层与粘接剂层分离现象.使用S3后,树脂突稀疏,长约4～7 μm,混合层与粘接剂层结合紧密.结论:牙本质粘接剂的粘接界面形态与粘接强度存在一定的相关性.     

试样形状及截面积对牙本质微拉伸粘接强度测试的影响

目的:比较不同的试样形状与粘接面积对牙本质微拉伸粘接强度测试的影响.方法:将12 颗人无龋第三磨牙制备牙本质平面,按照产品说明进行树脂粘接.分别制备2 种形状和2 种粘接面积的试样:条状1 mm×1 mm,2 mm×1 mm;沙漏状1 mm×1 mm,2 mm×1 mm,每组3 颗牙齿15 个试样,用微拉伸测力仪测试试样微拉伸粘接强度,用SPSS 11.0软件对所得数据作统计学分析.并在体视显微镜下观察试样断裂类型.结果:4组试样的微拉伸粘接强度分别为:条状1 mm×1 mm组(31.83±8.62) MPa;条状2 mm×1 mm组(28.41±4.54)MPa;沙漏状1 mm×1 mm组(30.94±6.12)MPa;沙漏状2 mm×1 mm组(30.91±4.52) MPa,4 组数据在统计学上差异无显著性(P＞0.05).3个沙漏状试样发生牙本质内聚破坏,其余试样的断裂类型均为界面断裂.结论:试样形状(条状或沙漏状)和粘接面积(1 mm×1 mm或2 mm×1 mm)对牙本质微拉伸粘接强度测试无显著影响.     

两种脱敏剂对牙本质粘接剂粘接强度的影响

目的 探讨两种脱敏剂对牙本质粘接剂粘接强度和微观形态的影响,以期对临床治疗有所指导.方法 将30颗完整且无龋的人第三磨牙去除(牙合)面釉质,采用随机数字表法随机分为3组:C组(对照组)、U组(UltraEZTM处理)和M组(MI Paste处理);每组10颗牙齿.C组不做处理,U组和M组分别使用相应脱敏剂对暴露的牙本质表面进行处理.3组样本牙再各随机分为两个小组,每小组5颗牙,分别用粘接剂A(Single Bond 2)和B(Xeno Ⅲ)粘接,用复合树脂修复达4～5 mm.用慢速锯将牙齿切成粘接面积为0.9 mm×0.9 mm的长方体试件,用微拉伸测试仪测试微拉伸强度,作为粘接强度,对其进行单因素方差分析.每组随机挑选3个试件对粘接界面进行扫描电镜观察.结果 对于粘接剂A,U组粘接强度[(14.58±2.31)MPa]与C组[(15.82±2.18)MPa]的差异无统计学意义(P>0.05),而M组粘接强度[(9.90±0.79)MPa]降低.对于粘接剂B,U组粘接强度[(10.55±1.06)MPa]与C组[(10.73±1.07)MPa]的差异无统计学意义(P>0.05),而M组粘接强度[(8.74±0.87)MPa]降低.扫描电镜见各组混合层均较致密,M组两种粘接剂的树脂突较短且稀少.结论 两种脱敏剂对粘接剂粘接强度的影响不同,U组脱敏剂对全酸蚀和自酸蚀粘接剂的粘接强度无明显影响,而M组脱敏剂可降低两种粘接剂的粘接强度.     

含精氨酸的牙本质脱敏剂对玻璃陶瓷与牙本质微拉伸粘接强度及粘接界面的影响

目的：评估含8%精氨酸的脱敏牙膏与含0.8%精氨酸的脱敏漱口液对玻璃陶瓷和牙本质间微拉伸粘接强度及粘接界面的影响。方法：选择10颗正畸减数离体牙,去除牙合面釉质,暴露牙本质后,沿近远中向纵行切割分成3等分,依照牙本质处理方式的不同分为脱敏牙膏组,脱敏漱口液组及对照组。用RelyXTM Unicem 2自混自粘接树脂水门汀将牙本质面与玻璃陶瓷瓷块粘接。24 h后,将试件制备成横截面为1.0 mm ×1.0 mm的试件,用微拉伸仪测定粘接强度,用体式显微镜观察断裂类型,并用扫描电子显微镜观察粘接界面。结果：脱敏牙膏组(16.15±3.37) MPa和脱敏漱口液组(15.29±3.05) MPa微拉伸强度小于对照组(20.82±4.17) MPa（P<0.05）,脱敏牙膏组和脱敏漱口液组之间无显著性差异(P>0.05)。扫描电镜显示,对照组有树脂突深入牙本质小管,脱敏牙膏与脱敏漱口液组均无树脂突伸入牙本质小管。结论：含8%精氨酸的牙膏与含0.8%精氨酸的漱口液均可通过影响树脂突的形成降低玻璃陶瓷与牙本质的微拉伸粘接强度。     

2种牙本质黏结系统对不同深度牙本质微拉伸黏结强度的比较

目的:比较2种不同类型的牙本质黏结系统对深层牙本质和浅层牙本质的微拉伸黏结强度的影响.方法:20颗因正畸拔除的第一前磨牙,在釉牙本质界附近去除冠向牙体组织,暴露牙本质平面.按产品说明书要求,分别黏结全酸蚀黏结剂Prime ＆ Bond NT (PB)和自酸蚀黏结剂FL-Bond(FB),蓝色光固化复合树脂修复.黏结好的标本储于37±10℃的蒸馏水中24h后,将样本片切为0.9 mm±0.9 mm的柱状形态.测量样奉黏结界面与髓腔顶部之间的剩余牙本质的厚度(remaining dentin thickness,RDT),RDT≥3mm者为浅层牙本质组,RDT≤2mm者为深层牙本质组,进行微拉伸黏结强度测试,加载速度1mm/min.体视显微镜下观察断裂类型.采用SPSS11.5软件包对结果进行统计学分析.结果:各实验组的微拉伸黏结强度分别为浅层/FB组(22.63±5.43)MPa、浅层/PB组(28.13±7.80)MPa、深层/FB组(18.65.63±5.44)MPa、深层/PB组(26.82±4.85)MPa,全酸蚀黏结剂PB的黏结强度显著高于自酸蚀黏结剂FB(P<0.05).牙本质深度不同,对微拉伸黏结强度的影响无显著差异(P>0.05).各组的断裂类型多为黏结界面断裂.结论:在离体牙上进行微拉伸黏结强度测试时,牙本质深度不同.对全酸蚀黏结剂和自酸蚀黏结剂的黏结强度无显著影响.     

5种牙本质粘结系统粘结强度的比较

目的用微拉伸粘结强度检测法评价5种不同类型的牙本质粘结系统与正常牙本质的粘结强度,用体视显微镜分析其断裂类型。方法选择25颗正畸治疗拔除的健康前磨牙,去除面釉质层,随机均分为5组。选用5种牙本质粘结系统:传统三步法全酸蚀粘结系统All-Bond2组、两步法全酸蚀粘结系统Prime&BondNT组、两步法自酸蚀粘结系统Fluoro-Bond组、一步法自酸蚀粘结系统XenoⅢ组和一步法自酸蚀粘结系统iBond组,分别用于暴露的表层牙本质面上,再用蓝色复合树脂恢复牙冠至要求高度。用低速锯将牙齿片切为横截面积约0.81mm2的长方体状样本,用微拉伸测试仪检测其粘结强度,加载速度为1mm/min。用体视显微镜观察样本断端形态。用SPSS11.5对微拉伸粘结强度测试值进行统计学分析。结果5种牙本质粘结系统的微拉伸粘结强度分别为All-Bond2组(28.74±5.15)MPa,Prime&BondNT组(25.85±3.37)MPa、Fluoro-Bond组(20.60±2.96)MPa、Xeno组(22.93±3.97)MPa、iBond组(25.67±4.72)MPa。All-Bond2组的微拉伸粘结强度与Prime&BondNT组测值之间差异无显著性,高于Fluoro-Bond组、Xeno组和iBond组,后两者的测值间差异无显著性,Fluoro-Bond组和Xeno组亦无显著差异。体视显微镜观察结果显示,绝大部分样本的断裂类型都是粘结面型断裂。结论5种牙本质粘结系统与正常牙本质的粘结强度存在差异,All-Bond2的粘结强度最高,但临床操作复杂,技术要求较高;XenoⅢ、iBond使用方法较简单,对牙髓的影响可能较小。     

Microtensile and tensile bond strength of single-bottle adhesives: a new test method

To evaluate the tensile and microtensile bond strength of five single-bottle adhesives to dentine, extracted human molar teeth were used. For each tooth dentine was exposed on the occlusal surface by cutting with an isomet saw and the remaining part was mounted in a plastic ring using dental stone. The tested adhesive materials were: Scotchbond 1, Syntac SC, One-Step, Prime & Bond 2.1 and Clearfil SE Bond. The adhesive was applied to either 1 mm(2) of dentine or a circular area with a diameter of 3.9 mm. Composite resin Clearfil AP-X was placed to the adhesives using a Teflon split mould 3.9 mm in diameter and 2.5 mm in height. Tensile and microtensile bond strengths were measured using a universal testing machine at a crosshead speed of 0.5 mm min(-1). Under tensile mode, the bond strengths were 16.7 +/- 3.5, 15.2 +/- 2.5, 11.5 +/- 3.2, 13.7 +/- 2.6, 20.9 +/- 4.2 MPa for each material. Under microtensile mode, the bond strengths were 52.5 +/- 9.5, 55.3 +/- 8.3, 40.5 +/- 5.2, 37.5 +/- 8.7, 60 +/- 6.21 MPa. Fracture pattern of bonded specimens showed 66% cohesive dentine failure in samples tested for tensile bond strength. For the microtensile test, failures were mainly adhesive at the interface between adhesive and dentine (94%).     

Microtensile bond strengths of seven dentin adhesive systems.

OBJECTIVES: The purpose of this study was to evaluate the microtensile bond strengths of seven dentin adhesive systems (Solid Bond, EBS-Multi, PermaQuik, One Coat Bond, Gluma One Bond, Prime & Bond NT/NRC and Clearfil Liner Bond 2V) and their respective fracture modes. METHODS: Superficial occlusal dentin of extracted human molars was exposed, finished with wet 600-grit silicon carbide paper, and a block of resin composite bonded with the above adhesives according to the manufacturers' instructions. The teeth were kept in tap water for 24 h at 37 degrees C, sectioned to obtain three or four bar-shaped specimens, which were then shaped to an hour-glass form of 1.2 +/- 0.02 mm diameter. The specimens were stressed at a crosshead speed of 1 mm/min until rupture of the bond. The mean bond strengths were compared using one-way ANOVA and LSD tests. The frequency of fracture modes was compared using Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: Mean microtensile bond strengths ranged from (17.8 +/- 7.0) MPa for Solid Bond to (36.0 +/- 8.1) MPa for Clearfil Liner Bond 2V. The bond strength of Clearfil Liner Bond 2V and PermaQuik (30.8 +/- 8.5 MPa) were not significantly different, and were higher than all other materials. Bond strengths of Solid Bond (17.8 +/- 7.0) MPa, EBS-Multi (18.7 +/- 5.0) MPa, One Coat Bond (21.9 +/- 5.6) MPa, and Gluma One Bond (23.4 +/- 5.2) MPa were not significantly different. SEM examination indicated that Solid Bond, EBS-Multi and One Coat Bond showed no significant difference in failure modes but were significantly different from PermaQuik, Prime & Bond NT/NRC and Clearfil Liner Bond 2V. SIGNIFICANCE: The self-etching primer system, Clearfil Liner Bond 2V, provided the simplest bonding technique, and together with PermaQuik exhibited greatest bond strength to dentin.     

Effects of sodium ascorbate on microtensile bond strength of total-etching adhesive system to NaOCl treated dentine

OBJECTIVE: The purpose of this study was to determine the microtensile bond strengths of total etching adhesive systems to pulpal chamber wall dentine after treated with various irrigants. METHODS: Thirty extracted human third molars were cut horizontally to expose the pulp horn. The roof of the pulp chamber and pulp tissues were removed. The teeth were then divided into five groups of five specimens each to treat with various irrigants. Specimens in each group were treated as follows: group 1, with water for 10 min; group 2, with sodium hypochlorite for 10 min; group 3, with sodium hypochlorite for 10 min and water for 10 min; group 4, with sodium hypochlorite for 10 min and sodium ascorbate for 10 min; group 5, with sodium hypochlorite for 10 min, sodium ascorbate for 10 min and water 10 min. Treated specimens were dried, bonded with a total-etching adhesive system (single bond) and restored with a resin composite (Z250) then kept for 24 h before determination of the microtensile bond strengths. RESULTS: Group 2 (20.96+/-9.23 MPa) demonstrated significantly lower bond strengths than group 1 (30.06+/-10.44 MPa). No significant differences in bond strengths were found between group 3 (23.08+/-6.94) and group 2. Group 4 (40.55+/-8.99) demonstrated higher bond strengths than group 2. However, there were no significant differences between group 5 (24.55+/-9.73 MPa) and group 2. CONCLUSIONS: Sodium hypochlorite significantly reduced the bond strengths of the adhesive when a total-etching was applied. The application of sodium ascorbate on sodium hypochlorite treated dentine significantly improved the bond strengths.     

Microtensile bond strength of tooth-colored materials to primary tooth dentin

PURPOSE: This study measured the microtensile bond strengths of 2 tooth-colored restorative materials with and without conditioning of primary teeth dentin, and examined the micromorphology of the debonded surfaces and material-dentin interfaces. METHODS: Cylindrical specimens of packable composite resin (PCR) and resin-modified glass ionomer cement (RMGIC) bonded to dentin of primary teeth were ground to an hourglass shape and tested for microtensile bond strength. The debonded surfaces and material-dentin interfaces were prepared and examined under a scanning electron microscope (SEM). RESULTS: The microtensile bond strength values (mean +/- SD, in MPa) of PCR (Filtek P60 with Single Bond) and RMGIC (Fuji II LC), with or without the application of Cavity Conditioner (14.8 +/- 5.36, 12.01 +/- 4.43, 11.94 +/- 4.60, respectively), did not differ significantly (P > .05). Partial adhesive and partial cohesive failures within the restorative material predominated. The distributions of failure modes did not differ significantly between groups (P > .05). Under SEM, each material was seen to be closely adapted to dentin. Dentinal tubules were enlarged with etching, and the depth of penetration of resin tags of PCR was greater than for RMGIC. Smear plugs were incompletely removed by cavity conditioning. CONCLUSIONS: The bond strength of the PCR, Filtek P60 with Single Bond, to dentin of primary teeth was comparable to that of the RMGIC, Fuji II LC. Conditioning of the cavity preparation with Cavity Conditioner did not improve the bond strength of Fuji II LC. The distribution of failure modes did not differ between materials.     

Effect of bur-cut dentin on bond strength using two all-in-one and one two-step adhesive systems

PURPOSE: To compare the microtensile bond strength (MTBS) of two all-in-one adhesive systems and one experimental two-step self-etching adhesive system to two types of bur-cut dentin. MATERIALS AND METHODS: Using one of the three adhesives, Xeno CF Bond (Xeno), Prompt L-Pop (PL), or the experimental two-step system ABF (ABF), resin composite was bonded to flat buccal and root dentin surfaces of eight extracted human premolars. These surfaces were produced using either regular-grit or superfine-grit diamond burs. After storage overnight in 37 degrees C water, the bonded specimens were sectioned into six or seven slices approximately 0.7 mm thick perpendicular to the bonded surface. They were then subjected to microtensile testing. The surfaces of the fractured specimens were observed microscopically to determine the failure mode. In addition, to observe the effect of conditioning, the two types of bur-cut dentin surfaces were conditioned with the adhesives, rinsed with acetone, and observed with SEM. RESULTS: When Xeno and PL were bonded to dentin cut with a regular-grit diamond bur, MTBS values were lower than to superfine bur-cut dentin, and failures occurred adhesively at the interface, whereas the experimental two-step adhesive showed no significant difference in microtensile bond strength between two differently cut surfaces. CONCLUSION: The all-in-one adhesives tested here improved bond strengths when bonded to superfine bur-cut dentin as a substrate, whereas the experimental two-step adhesive system showed unchanged bonding to both regular and superfine bur-cut dentin surfaces.     

Effect of solvent type on microtensile bond strength of a total-etch one-bottle adhesive system to moist or dry dentin

This study evaluated the effect of organic solvent (acetone or ethanol) on the microtensile bond strengths (MTBS) of an adhesive system applied to dry and moist dentin. Sixteen extracted human third molars were ground to expose a flat occlusal dentin surface and acid etched for 20 seconds (20% phosphoric acid gel, Gluma Etch 20 Gel, Heraeus/Kulzer). After rinsing the acid etchant, an ethanol-based one-bottle adhesive system was applied to the mesial half of the occlusal dentin surface. An acetone-based, one-bottle adhesive system was applied to the distal half of the ground dentin surface. The teeth were randomly assigned to groups. In Group 1, the etched dentin was thoroughly air dried and an ethanol-based one-bottle adhesive system was applied (Gluma Comfort Bond, Heraeus/Kulzer) (GCB). In Group 2, the etched dentin was thoroughly air dried and an acetone-based one-bottle adhesive system was applied (Gluma One Bond, Heraeus/Kulzer)(GOB). In Group 3, excess moisture was removed after acid etching, leaving a moist dentin surface and a one-bottle ethanol-based adhesive was applied (Gluma Comfort Bond). In Group 4, excess moisture was removed after acid etching, leaving a moist dentin surface and an acetone-based adhesive was applied (Gluma One Bond). A hybrid resin composite (Venus, Heraeus/Kulzer) was applied to the bonded surface in four 1-mm increments and light cured according to manufacturer's directions. The specimens were then sectioned with a slow-speed diamond saw in two perpendicular directions to obtain sticks with a cross-section of 0.5 +/- 0.05 mm2. The microtensile bond strength (MTBS) test was performed with a Bencor device in an Instron machine at a crosshead speed of 0.5 mm/minute. The data were subjected to a two-way ANOVA and Scheffé Post hoc test (p < 0.05). The experimental MTBS measured for dry dentin were Group 1 = 37.0 +/- 10.6 and Group 2 = 34.7 +/- 9.0 in MPa (mean +/- SD); and on moist dentin, Group 3 = 50.7 +/- 11.0 and Group 4 = 38.5 +/- 10.5 in MPa (mean +/- SD). The ethanol based adhesives resulted in higher MTBS than acetone-based adhesive (p < 0.008) and bonding to moist dentin resulted in higher MTBS (p < 0.001). GCB applied on moist dentin resulted in statistically higher bond strengths than the other groups. The highest MTBS were achieved with the use of an ethanol-based adhesive to moist dentin.     

离体牙储存方式对牙本质黏结剂微拉伸强度的影响

目的：对比研究不同的离体牙储存方法和时间对牙本质黏结剂Single Bond微拉伸强度的影响。方法：选用30颗因正畸拔除的第一前磨牙,随机分为5组。拔除后立即分别放人4℃的0．02％麝香草酚水溶液、10％甲醛溶液、1％氯胺溶液、蒸馏水中储存,以及用湿纱布包裹-20℃冰箱中储存。分别在储存的第10天、90天取出,在牙冠殆面表层牙本质上使用牙本质黏结剂Single Bond,复合树脂Z250黏结修复,测定牙本质黏结剂的微拉伸强度值。选用新鲜拔除的前磨牙作为对照组。用体视显微镜和扫描电子显微镜观察微拉伸强度测试样本的断裂类型。用SPSS11．5软件对牙本质黏结剂的微拉伸强度值做双因素方差分析。结果：不同的储存方法对牙本质黏结剂微拉伸强度有显著影响(P=0．01),与新鲜拔除的牙比较,蒸馏水中4℃储存(P=0．024)和0．02％麝香草酚水溶液4℃储存(P=0．008)的离体牙的微拉伸强度显著降低;不同的储存时间对牙本质黏结剂的微拉伸强度影响无统计学差异(P=0．279)。所有微拉伸强度测试样本的断裂均发生在黏结界面。结论：离体牙储存方法对牙本质黏结剂Single Bond的黏结强度有重要影响,建议使用离体牙评价牙本质黏结剂的黏结强度时,选用新鲜拔除的牙、-20℃冷冻的牙或1％氯胺溶液4℃储存的牙,以减小不必要的实验误差。     

Microtensile testing of dentin adhesives.

OBJECTIVES: This study was conducted in order to compare the microtensile and shear bond strengths of five commercial dentin adhesive systems. Scotchbond Multipurpose with maleic acid (SM), Scotchbond Multipurpose with phosphoric acid (SP), Scotchbond Multipurpose Plus (SBP), Clearfil Liner Bond System (CL), and Prime and Bond (PB) were tested. METHODS: Thirty extracted unerupted third molars, in groups of six teeth per adhesive system, were prepared for microtensile testing. The specimens were tested following a 24 h incubation at 37 degrees C in normal saline. Shear bond testing was performed on 35 additional teeth, using seven teeth per adhesive system. After testing, the fracture sites were observed using light microscopy and a scanning electron microscope to determine the type of failure involved. RESULTS: The microtensile test results (mean +/- SD) were SM, 24.6 +/- 7.2 MPa; SP, 28.8 +/- 11.8 MPa; SBP, 22.7 +/- 6.5 MPa; PB, 25.5 +/- 9.4 MPa; and CL, 36.8 +/- 10.0 MPa. A Bonferroni post-hoc test showed significantly (p < 0.05) greater strength for CL compared to SM, SP, SBP, and PB. The shear bond strength test results were SM, 19.4 +/- 4.4 MPa; SP, 24.5 +/- 8.4 MPa; SBP, 15.3 +/- 4.9 MPa; PB, 23.2 +/- 7.1 MPa; and CL, 24.8 +/- 3.5 MPa. No statistically significant differences were found among the shear bond strength test results. The shear bond test produced significantly more failures within dentin and composite than the microtensile method. SIGNIFICANCE: It is concluded that the microtensile test produced a more definitive assessment of adhesive bond strength than the shear bond test. Microtensile testing showed CL to be significantly stronger than SM, SP, SBP, and PB (p < 0.05).