口腔黏固剂种类及与牙本质黏接的强度

目的:探讨不同种类黏固剂与牙本质黏接强度的差异,以期为临床提供参考。方法:应用计算机检索维普数据库中黏固剂与牙本质黏结强度有关的文献,检索时限1998-01/2009-10。中文关键词:黏固剂;牙本质;黏结强度。对资料进行初审,并查看每篇文献后的引文,共入选相关文献22篇。结果:牙本质黏固剂是指用于牙本质表面的黏固剂,它可增强修复体的固位力,改善位于牙本质的洞壁的封闭性。水门汀类材料和树脂材料是口腔修复临床工作中常用的材料,近年来有了很大的发展。树脂基黏固剂较水基类水门汀黏固剂的优点是抗压强度高,溶解度小,微渗漏率小,调和状态下黏度小,对被黏体的湿润程度高,且与牙体组织有较好的化学性黏接,因此表现出优于水门汀黏接剂的黏接性能。树脂黏接剂已发展到第6、7代,其特点是单瓶装、自酸蚀、无需混合、黏接强度保持在18～25MPa,这类树脂黏接剂显著提高了医生的劳动效率,降低了人为失误的可能。结论:没有一种黏固剂、黏接方法适用于所有的口腔修复体,需按患者的个体情况,医疗条件和医师自身掌握理论和实践知识的程度,来选择合适的黏接方案。此外,随着修复材料的快速更新,和人们对修复质量要求的提高,黏接技术也必将不断发展。     

黏结剂不同使用方式对全酸蚀树脂水门汀与牙本质间黏结性能的影响

背景：在临床治疗过程中,修复体连同黏结材料一同脱落及产生微小渗孔等情况常有发生,因此,探究黏结剂不同使用方式对全酸蚀树脂水门汀与牙本质间黏结性能的影响具有重要的临床意义。 目的：对比黏结剂不同使用方式对全酸蚀树脂水门汀与牙本质间黏结性能的影响。 方法：获取无龋人新鲜拔除的第二磨牙90颗,随机均分为3组,均于常温水冲洗下打磨消除牙冠部位牙釉质,露出牙本质以制备标准黏结面,分别进行不使用黏结剂处理(对照组)、使用经过光照的全酸蚀树脂水门汀处理(实验2组)、使用未经过光照的全酸蚀树脂水门汀处理(实验1组),检测处理后即刻、处理后再经老化处理的微拉伸黏结强度。 结果与结论：处理后即刻,对照组、实验1组、实验2组的微拉伸黏结强度分别为(8.089±3.431),(11.671±2.561),(8.821±2.513) MPa,组间两两比较差异均有显著性意义(P < 0.05);处理后再经老化处理,对照组、实验1组、实验2组的微拉伸黏结强度分别为(1.069±0.421),(7.621±2.061),(4.821±1.513) MPa,组间两两比较差异均有显著性意义(P < 0.05)。表明全酸蚀树脂水门汀与牙本质的结合在黏结剂不同方法的使用中,无论长期还是短期均是使用不光照处理的黏结剂效果最佳。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

不同粘接系统对纤维桩粘接强度的影响

背景：粘接界面尤其是根管壁-粘接剂间是纤维桩修复后接构的薄弱环节,加强粘接剂与根管壁间粘接对提高纤维桩的修复成功率,有重要临床指导意义。 目的：比较自酸蚀粘接系统和全酸蚀粘接系统对纤维桩粘接强度的影响。 方法：选用30颗单根管前牙用于纤维桩粘接实验,每颗牙选用逐步后退法进行预备并进行根管充填。样本分为3组,自酸蚀粘接组、全酸蚀粘接组和空白对照组分别应用自酸蚀粘接系统、全酸蚀粘接系统、传统磷酸酸蚀法处理根管内壁。 结果与结论：自酸蚀粘接组、全酸蚀粘接组和空白对照组的粘接强度分别为(3.24±0.76),(4.09±0.54),(2.85±0.89) MPa。两两相比,不同粘接方法对纤维桩的粘接强度差异均有显著性意义(P < 0.05);扫描电镜观察发现全酸蚀粘接组混合层与牙本质和纤维桩粘接紧密,自酸蚀粘接组混合层只与纤维桩粘接紧密,与牙本质未形成有效连接。提示全酸蚀粘接系统的粘接强度优于自酸蚀粘接系统,具有良好的纤维桩固位性能。     

3M Adper Prompt 自酸蚀粘结剂治疗牙本质过敏的近期疗效观察

目的了解3M Adper Prompt 治疗牙本质过敏的疗效.方法于2004年11月-2005年3月间采用 3M Adper Prompt 自酸蚀粘结剂与75%氟化钠甘油糊剂给左右对称的同名牙进行脱敏对比观察.将确诊为牙本质过敏症的42例,共51对牙,随机分为两组.治疗组用3M Adper Prompt粘结剂,对照组用75%氟化钠甘油,在统一的疗效标准下进行即刻、一周、1个月、3个月四时段的疗效对比.结果第一,二时段的疗效二者无显著性差异.而第三,四时段的疗效3M Adper Prompt明显优于氟化钠甘油糊剂.结论 3M Adper Prompt是一种比较理想的脱敏剂.     

光学相干层析成像无损监测不同表面处理后树脂充填界面

目的使用光学相干层析成像(OCT)观察不同方法处理牙本质后牙本质-树脂粘接界面的表现差异。方法选取20颗因治疗需要拔除的人前磨牙, 去除牙齿冠方1/3暴露牙本质, 随机分为A、B、C、D共4组, 每组5颗牙。于各组牙齿牙本质表面涂抹粘接剂并光固化后, 保持A组及C组牙齿表面干燥条件下树脂粘接。于B组及D组牙齿牙本质表面喷洒水雾模拟唾液污染后树脂粘接。在牙本质树脂粘接后使用OCT对样本扫描成像。结果牙本质-树脂粘接界面缺陷在OCT图像上显示为显著高亮度影像, 与周围正常组织及粘接区域分界清晰。无论是在激光蚀刻后或是酸蚀剂蚀刻后, 干燥条件下的树脂粘接并不能完全杜绝牙本质-树脂粘接界面缺陷的发生, 水汽污染条件下树脂粘接后的粘接界面缺陷更加明显。结论 OCT系统在牙本质树脂粘接过程中可对牙本质及牙本质-树脂粘接界面进行有效监测, 能准确显示牙本质-树脂粘接界面缺陷, 具有作为临床治疗过程实时监测系统的潜力。相比于激光蚀刻技术, 磷酸酸蚀剂蚀刻操作简便, 且能减少干燥或污染状态下牙本质-树脂粘接界面缺陷的发生。     

不同表面处理对Ceramage聚合瓷黏结强度的影响

背景：长期以来修复材料与基牙的黏接技术一直是口腔修复学的研究热点,其中尤为引人关注的是黏结工件的表面处理工艺。 目的：对比观察8种表面处理方法对Ceramage聚合瓷黏结强度的影响,筛选适合Ceramage聚合瓷的表面处理方法。 方法：将Ceramage聚合瓷制成试件80个,随机分成8组,分别采用喷砂,酸蚀,偶联剂,喷砂+酸蚀,喷砂+偶联剂,酸蚀+偶联剂,喷砂+酸蚀+偶联剂处理聚合瓷表面并与树脂黏结剂黏结,对照组不进行任何处理。在37 ℃水浴24 h后测试样本剪切强度,并用扫描电镜观察处理后的聚合瓷表面形貌。 结果与结论：各组的剪切强度值由高到低分别为：喷砂+酸蚀+偶联剂处理组(31.12±2.81) MPa,喷砂+酸蚀组(27.62±1.70) MPa,酸蚀+偶联剂组(27.31±2.18) MPa,喷砂+偶联剂组(26.91±1.97) MPa,喷砂组(24.23±2.03) MPa,偶联剂组(23.50± 2.19) MPa,酸蚀组(17.61±2.14) MPa,对照组(8.13±0.63) MPa,除喷砂组、偶联剂组之间,喷砂+酸蚀组、喷砂+偶联剂组、酸蚀+偶联剂组之间比较差异无显著性意义外(P > 0.05),其余组间比较差异均有显著性意义(P  < 0.05)。结果显示7种表面处理方法都提高了黏结强度,喷砂、酸蚀联合硅烷偶联剂处理的聚合瓷黏结强度最高,是适合Ceramage聚合瓷黏结的表面处理方法。     

人天然牙的高分辨X线微区衍射分析

通过使用X线微区衍射法直接对人天然牙表面正常牙釉质、牙本质及龋坏组织三个测量点进行检测,以测试X'pert Pro型衍射仪对人天然牙正常和早期龋损组织晶体结构改变的检测能力.结果显示,牙磷灰石由多种物相构成,是一种生物混晶,主要物相为羟基磷灰石,龋坏组织中可能有新物相的形成.从正常牙釉质到牙本质再到龋坏组织,晶体a轴逐渐增大,c轴基本不变.晶体晶胞参数计算结果:正常牙釉a=9.550(A),c=6.883(A);正常牙本质a=9.554(A),c=6.883(A);龋坏组织a=9.558(A),c=6.884(A).晶粒尺寸计算结果:正常牙釉质D002=27.600 nm;正常牙本质D002=16.561 nm;龋坏组织D002=13.163 nm.结晶性:正常牙釉质＞正常牙本质＞龋坏组织.结果表明采用新型高分辨X线衍射仪可以非常方便地对牙齿进行X线衍射微区分析.     

酸蚀牙面后黏结树脂嵌体修复牙体的抗力性能

背景：树脂嵌体修复牙体缺损在一定程度上可减少修复后牙齿的折裂,但嵌体经不同方法黏结处理后对牙体抗力的影响未见报道。 目的：了解复合树脂经不同方法处理后修复牙体的抗力特性。 方法：将40颗无龋人前磨牙制作近中-牙合面-远中洞型洞,随机分成4组：其中一组备洞后未进行修复作为对照组,其他3组分别以可乐丽菲露光固化复合树脂直接充填,可乐丽菲露光固化复合树脂嵌体直接黏结和酸蚀黏结修复。 结果与结论：①力学模型静态力学加载实验结果：树脂直接充填组、树脂嵌体直接黏结和酸蚀黏结组断裂载荷均高于对照组(P < 0.05),前3组断裂载荷比较组间差异无显著性意义(P > 0.05),树脂嵌体酸蚀黏结组断裂载荷最大。②扫描电镜观察结果：树脂直接充填组断裂位于牙本质层和树脂之间,几乎无树脂残留,有较多孔隙;树脂嵌体直接黏结组大量牙本质基体与树脂间断裂,有较少树脂残留;树脂嵌体酸蚀黏结组牙与树脂之间无气泡、无缝隙、相互嵌合、紧密接触;对照组,树脂直接充填、直接黏结、酸蚀黏结组分别出现10,5,3,1个样本树脂内聚破坏断裂。表明经酸蚀处理复合树脂嵌体可提高牙体力学性能。     

纳米羟基磷灰石封闭牙本质小管的效果

背景：纳米羟基磷灰石是优良的生物活性材料,对脱矿牙釉质和牙本质具有一定的保护作用,但其溶液对脱矿牙本质再矿化的作用及其机制尚不明确。目的：探讨纳米羟基磷灰石用于防治牙本质敏感症和牙本质龋的可行性。方法：收集废弃的人双尖牙标本,制备出72份牙本质薄片,分6组处理：A组脱矿后浸入10%纳米羟基磷灰石溶液中,B组脱矿后浸入6%生物活性玻璃溶液中,C组脱矿后浸入10%纳米羟基磷灰石与6%生物活性玻璃复合溶液中,D组脱矿后浸入0.05%NaF溶液中,E组脱矿后浸入人工唾液中,F组脱矿后浸入去离子水中,每组12个样本。处理14 d后,扫描电镜下观察样本工作面,利用能谱分析仪检测样本表面成分,激光共聚焦显微镜下检测牙本质罗丹明B染色情况。结果与结论：(1)扫描电镜观察：A组牙本质小管口被完全封闭,牙本质表面被一层紧密连接的颗粒物均匀覆盖;C组牙本质小管部分封闭;B、D、E组牙本质表面及牙本质小管内见少量散在颗粒物,牙本质小管口呈开放状;F组牙本质表面及牙本质小管内未见颗粒物沉积,牙本质小管口呈开放状态;(2)X射线能谱分析：A组Ca/P比为1.61,最接近健康牙本质理论值,Ca/P比高于B、E、F组...     

纤维树脂桩核修复体力学性能与不同牙体剩余量的关系

背景：牙体组织剩余量与纤维树脂桩核修复体的抗折强度密切相关。 目的：采用体外应力分析方法比较不同牙体残余量对纤维树脂桩核修复体抗疲劳强度的影响。 方法：将36颗离体人下颌单根管前磨牙随机均分为4组,进行牙根管预备与填充后,A组平齐基准平面横断磨除冠部牙体;B组,牙冠近远中斜形损耗,远端牙本质领圈高度2 mm,逐渐减少到近中端时牙本质领圈高度为0 mm;C组,牙冠横行缺失,留2 mm健康牙本质;D组,保留完整冠部牙体组织。各组常规桩道预备后进行黏结处理,将Para post fiber lux 玻璃纤维桩置入桩道内,采用动态力学加载设备对试件进行加载。 结果与结论：4组荷载力值大小为D组> C组> B组> A组,组间两两比较差异有显著性意义(P < 0.05)。实验样本折裂形式大致可分为牙冠斜行折裂、牙颈部横行折裂、牙颈部斜行折裂及牙根折裂等4种。A组发生牙颈部横行折裂7颗、牙颈部斜行折裂2颗;B组发生牙冠斜行折裂4颗、牙颈部斜行折裂5颗;C组发生牙颈部斜行折裂6颗、牙根中部折裂3颗;D组发生牙颈部斜行折裂7颗、牙根中部折裂2颗。表明当牙体残余量较多时,牙齿受到的咬合应力也会从颈缘转移到根部,整体水平也随着减低,纤维树脂桩核修复体的强度也会随着增强,因此在临床实践中应尽可能多保存牙体组织。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

Microtensile bond strength of etch and rinse versus self-etch adhesive systems

The aim of this study was to compare the microtensile bond strength of the etch and rinse adhesive versus one-component or two-component self-etch adhesives. Twelve intact human molar teeth were cleaned and the occlusal enamel of the teeth was removed. The exposed dentin surfaces were polished and rinsed, and the adhesives were applied. A microhybride composite resin was applied to form specimens of 4?mm height and 6?mm diameter. The specimens were sectioned perpendicular to the adhesive interface to produce dentin-resin composite sticks, with an adhesive area of approximately 1.4?mm(2). The sticks were subjected to tensile loading until failure occurred. The debonded areas were examined with a scanning electron microscope to determine the site of failure. The results showed that the microtensile bond strength of the etch and rinse adhesive was higher than that of one-component or two-component self-etch adhesives. The scanning electron microscope examination of the dentin surfaces revealed adhesive and mixed modes of failure. The adhesive mode of failure occurred at the adhesive/dentin interface, while the mixed mode of failure occurred partially in the composite and partially at the adhesive/dentin interface. It was concluded that the etch and rinse adhesive had higher microtensile bond strength when compared to that of the self-etch adhesives.     

An investigation of the shear bond strength of compomer restorative material to enamel and dentine

The aim of this study was to investigate the effect of one step adhesives on the shear bond strength of a compomer restorative material to both enamel and dentine. Human extracted teeth were used for the study. Ten samples were prepared for both enamel and dentine specimens for each of the five groups: Tooth, no etch, Prime and Bond NT (P+B NT); tooth, Non-Rinse Conditioner (NRC), P+B NT; tooth, NRC, Prime and Bond 2.1 (P+B 2.1); tooth, etch, P+B NT; tooth, etch, P+B 2.1. The specimens were subjected to bond testing. The shear bond strength was measured using an Inston 1193 testing machine using a cross head speed of 1 mm/minute. The specimens were tested to destruction. The results show that for the enamel specimens the highest bond strength was recorded for those specimens subjected to Etch, P+B 2.1 (22.1 MPa) and Etch P+B NT (20.0 MPa). The groups of specimens which did not undergo etching had very low bond strengths ranging from 11.4 MPa for NRC, P+B 2.1, 8.5 MPa for NRC P+B NT to 6.9 MPa for P+B NT. For the dentine specimens, for all of the groups, the shear bond strengths were low. Those groups subjected to etching produced the highest values of 7.9 MPa for NRC P+B 2.1 with the lowest value of 6.1 MPa for NRC P+B NT. These bond strengths were significantly lower than those achieved for bonding to enamel. Prime and Bond NT and Prime and Bond 2.1, used in conjunction with acid etching, produce satisfactory bond strengths of compomer restorative material to enamel. Bond strengths to dentine were low.     

Bonding characteristics of newly developed all-in-one adhesives

This study evaluated the microtensile bond strength and the interfacial morphology of newer adhesives. The occlusal surfaces of extracted teeth were ground flat for random allocation to four equal groups. Resin composite was bonded to each surface using either Clearfil SE Bond [SEB], Clearfil Protect Bond [PB], G-Bond [GB], or an experimental adhesive, SSB-200 [SSB]. After storage for 24 h in water at 37 degrees C, they were sectioned into beams (cross-sectional area 1 mm(2)) for microtensile bond strength testing (muTBS) at a crosshead speed of 1 mm/min. The load at failure of each was recorded; the data were analyzed by one-way ANOVA and Games Howell tests. The surfaces of the fractured specimens were observed using SEM. For the ultra-morphology of the interface, the occlusal surfaces of four more teeth were prepared as before and a thin layer of flowable resin composite was bonded to each surface using one of the four adhesives.The mean muTBS ranged from 39.68 MPa (GB) to 64.97 MPa (SEB). There were no statistical differences between SEB and SSB, or between PB and GB (p > 0.05). The muTBS of SEB and SSB were significantly greater than that of PB and GB (p < 0.05). SEMs of the fractured surfaces revealed a mixed (cohesive/interfacial) failure. TEM examination highlighted differences in the hybrid layer; SEB had a thicker layer than the others. In conclusion, the newer all-in-one adhesives produced a thin hybrid layer but varied in their bond strengths. The 2-step self-etching adhesives do not necessarily produce higher bond strengths than that of the all-in-one systems.     

Influence of organic acids present in the oral biofilm on the microtensile bond strength of adhesive systems to human dentin

This study evaluated the influence of organic acids present in the oral biofilm on the microtensile bond strength (μTBS) of adhesive systems to human dentin. Sixty occlusal dentin surfaces were wet ground with 600 grit SiC abrasive paper and divided into four groups according to the adhesive systems: Scotchbond Multipurpose (SMP), Adper Single Bond 2, Adper Scotchbond SE (ASE), and Clearfill SE Bond (CSE). After the adhesive systems were applied, a block of resin composite was built up on the dentin surfaces. After 24 h storage in distilled water at 37°C, the teeth were perpendicularly cut to obtain beams (1 mm(2)). For each adhesive system, the beams were divided into three groups according to storage media: artificial saliva (AS); propionic acid (PA), and lactic acid (LA). After 7 days storage at 37°C, the beams were submitted to μTBS testing. The μTBS ranged from 36.0 ± 1.6 (ASE-PA) to 52.5 ± 1.2 (CSE-AS). For all adhesive systems, the μTBS values after storage in PA were lower than those in AS. Except for the SMP, the values of μTBS after storage in LA were lower than those in AS. The adhesive ASE presented the lowest values of μTBs in the three media. The acids present in the oral biofilm may affect the bond strength of adhesive systems to human dentin.     

Microtensile bond strength of composite resin to human enamel prepared using erbium: Yttrium aluminum garnet laser

The Erbium: Yttrium Aluminum Garnet (YAG) laser used for preparation of cavity can alter the substrate and it could influence the bond strength of enamel. The aim of this in vitro study was to evaluate the influence of Er:YAG laser's energy using microtensile bond test. Three groups were obtained (cavity preparation) and each group was divided into two subgroups (adhesive system). After that the adhesive protocol was performed, sections with a cross-sectional area of 0.8 mm2 (+/-0.2 mm2) were obtained. The specimens were mounted in a universal testing machine (0.5 mm/min). Statistical analysis showed a decrease in bond strength for lased groups (p < 0.01) and when the total-etching adhesive system was used the laser 300 mJ subgroup showed higher bond strength compared to the laser 250 mJ (p < 0.01). It was concluded that the cavities prepared using laser appear less receptive to adhesive procedures than conventional bur-cut cavities.     

Deproteinized dentin: a favorable substrate to self-bonding resin cements?

The adhesive performance on deproteinized dentin of different self-adhesive resin cements was evaluated through microtensile bond strength (μTBS) analysis and scanning electron microscopy (SEM). Occlusal dentin of human molars were distributed into different groups, according to the categories: adhesive cementation with two-step bonding systems-control Groups (Adper Single Bond 2 + RelyX ARC/3M ESPE; One Step Plus + Duolink/Bisco; Excite + Variolink I/Ivoclar Vivadent) and self-adhesive cementation-experimental groups (Rely X Unicem/3M ESPE; Biscem/Bisco; MultiLink Sprint/Ivoclar Vivadent). Each group was subdivided according to the dentin approach to: α, maintenance of collagen fibers and β, deproteinization. The mean values were obtained, and submitted to ANOVA and Tukey test. Statistical differences were obtained to the RelyX Unicem groups (α = 13.59 MPa; β = 30.19 MPa). All the BIS Group specimens failed before the mechanical tests. Dentinal deproteinization provided an improved bond performance for the self-adhesive cement Rely X Unicem, and had no negative effect on the other cementing systems studied.     

In vitro microTBS of one-bottle adhesive systems: sound versus artificially-created caries-affected dentin

This in vitro study aimed to evaluate a pH-cycling model for simulation of caries-affected dentin (CAD) surfaces, by comparing the bond strength of etch-and-rinse adhesive systems on sound and artificially-created CAD. Dentin substrates with different mineral contents and morphological patterns were created by submitting buccal bovine dentin to the following treatments: (1) immersion in artificial saliva during the experimental period (sound dentin, SD), or (2) induction to a CAD condition by means of a dynamic pH-cycling model (8 cycles, demineralization for 3 h followed by mineralization for 45 h). The bond strength of Excite or Prime and Bond NT adhesive systems was assessed using the microtensile bond strength (microTBS) test. Dentin microhardness was determined by cross-sectional Knoop evaluations. Resin-dentin morphology after the treatments was examined by scanning electron microscopy. SD produced significantly higher microTBS than CAD for both adhesives evaluated, without differences between materials. CAD exhibited lower microhardness than SD. Morphological analysis showed marked distinctions between SD and CAD bonded interfaces. Under the conditions of this study, differences in morphological pattern and dentin mineral content may help to explain resin-dentin bond strengths. The proposed pH-cycling model may be a suitable method to simulate CAD surfaces for bonding evaluations.     

Adhesive layer properties as a determinant of dentin bond strength

The goal of this study is to evaluate the hypothesis that the properties of the resin adhesive might affect the microtensile bond strength (MTBS) of multibottle dental adhesive system. In order to alter the properties, the experimental resin adhesives containing 2,2-bis (4-2-hydroxy-3-methacryloyloxypropoxyphenyl)propane (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) at various ratios were prepared. Degree of conversion immediately after curing (DC-immed), degree of conversion at 48 h after curing (DC-48h) of a thin coat of the experimental adhesives, the flexural strength (FS) of the bulk specimens made of the experimental adhesives, pH, viscosity at shear rate of 1 S(-1), and the microtensile bond strength (MTBS) values of the adhesives to dentin were investigated. The maximum MTBS and FS values of the resin adhesives were observed when the ratio of Bis-GMA/TEGDMA was 60/40. However, pH and viscosity values increased with increasing Bis-GMA content in the adhesives. When Bis-GMA content was more than 60 wt %, the viscosity increased exponentially and restricted the DC and FS, and accordingly decreased the bond strength. The stronger the resin adhesives were, the higher the bond strength to dentin could be obtained.     

Elemental distributions and microtensile bond strength of the adhesive interface to normal and caries-affected dentin

The aim of this study was to evaluate the microtensile bond strength (microTBS) and the elemental contents of the adhesive interface created to normal versus caries-affected dentin. Extracted human molars with coronal carious lesions were used in this study. A self-etching primer/adhesive system (Clearfil Protect Bond) was applied to flat dentin surfaces with normal and caries-affected dentin according to the manufacturer's instructions. After 24 h water storage, the bonded specimens were cross-sectioned and subjected to a microTBS test and electron probe microanalysis for the elemental distributions [calcium (Ca), phosphorus (P), magnesium (Mg), and nitrogen (N)] of the resin-dentin interface after gold sputter-coating. The microTBS to caries-affected dentin was lower than that of normal dentin. The demineralized zone of the caries-affected dentin-resin interface was thicker than that of normal dentin (approximately 3 microm thick in normal dentin; 8 microm thick in caries-affected dentin), and Ca and P in both types of dentin gradually increased from the interface to the underlying dentin. The caries-affected dentin had lost most of its Mg content. The distributions of the minerals, Ca, P, and Mg, at the adhesive interface to caries-affected dentin were different from normal dentin. Moreover, a N peak, which was considered to be the collagen-rich zone resulting from incomplete resin infiltration of exposed collagen, was observed to be thicker within the demineralized zone of caries-affected dentin compared with normal dentin.     

Adhesion of a self-etching system to dental substrate prepared by Er:YAG laser or air abrasion

The purpose of this study was to assess the microtensile bond strength of a self-etching adhesive system to enamel and dentin prepared by Er:YAG laser irradiation or air abrasion, as well as to evaluate the adhesive interfaces by scanning electron microscopy (SEM). For microtensile bond strength test, 80 third molars were randomly assigned to five groups: Group I, carbide bur, control (CB); II, air abrasion with standard tip (ST); III, air abrasion with supersonic tip (SP); IV, Er:YAG laser 250 mJ/4 Hz (L250); V, Er:YAG laser 300 mJ/4 Hz (L300). Each group was divided into two subgroups (n = 8) (enamel, E and dentin, D). E and D surfaces were treated with the self-etching system Adper Prompt L-Pop and composite buildups were done with Filtek Z-250. Sticks with a cross-sectional area of 0.8 mm(2) (+/-0.2 mm(2)) were obtained and the bond strength tests were performed. Data were submitted to ANOVA and Tukey's test. For morphological analysis, disks of 30 third molars were restored, sectioned and prepared for SEM. Dentin presented the highest values of adhesion, differing from enamel. Laser and air-abrasion preparations were similar to enamel. Dentin air-abrasion with standard tip group showed higher bond strength results than Er:YAG-laser groups, however, air-abrasion and Er:YAG laser groups were similar to control group. SEM micrographs revealed that, for both enamel and dentin, the air-abrasion and laser preparations presented irregular adhesive interfaces, different from the ones prepared by rotary instrument. It was concluded that cavity preparations accomplished by both Er:YAG laser energies and air abrasion tips did not positively influence the adhesion to enamel and dentin.