Comparison between universal adhesives and two‐step self‐etch adhesives in terms of dentin bond fatigue durability in self‐etch mode

This aim of this study was to compare universal adhesives and two‐step self‐etch adhesives in terms of dentin bond fatigue durability in self‐etch mode. Three universal adhesives – Clearfil Universal, G‐Premio Bond, and Scotchbond Universal Adhesive – and three‐two‐step self‐etch adhesives – Clearfil SE Bond, Clearfil SE Bond 2, and OptiBond XTR – were used. The initial shear bond strength and shear fatigue strength of resin composite bonded to adhesive on dentin in self‐etch mode were determined. Scanning electron microscopy observations of fracture surfaces after bond strength tests were also made. The initial shear bond strength of universal adhesives was material dependent, unlike that of two‐step self‐etch adhesives. The shear fatigue strength of Scotchbond Universal Adhesive was not significantly different from that of two‐step self‐etch adhesives, unlike the other universal adhesives. The shear fatigue strength of universal adhesives differed depending on the type of adhesive, unlike those of two‐step self‐etch adhesives. The results of this study encourage the continued use of two‐step self‐etch adhesive over some universal adhesives but suggest that changes to the composition of universal adhesives may lead to a dentin bond fatigue durability similar to that of two‐step self‐etch adhesives.     

Relationship between enamel bond fatigue durability and surface free‐energy characteristics with universal adhesives

The relationship between enamel bond fatigue durability and surface free‐energy characteristics with universal adhesives was investigated. The initial shear bond strengths and shear fatigue strengths of five universal adhesives to enamel were determined with and without phosphoric acid pre‐etching. The surface free‐energy characteristics of adhesive‐treated enamel with and without pre‐etching were also determined. The initial shear bond strength and shear fatigue strength of universal adhesive to pre‐etched enamel were higher than those to ground enamel. The initial shear bond strength and shear fatigue strength of universal adhesive to pre‐etched enamel were material dependent, unlike those to ground enamel. The surface free‐energy of the solid (γ_S) and the hydrogen‐bonding force () of universal adhesive‐treated enamel were different depending on the adhesive, regardless of the presence or absence of pre‐etching. The bond fatigue durability of universal adhesives was higher to pre‐etched enamel than to ground enamel. In addition, the bond fatigue durability to pre‐etched enamel was material dependent, unlike that to ground enamel. The surface free‐energy characteristics of universal adhesive‐treated enamel were influenced by the adhesive type, regardless of the presence or absence of pre‐etching. The surface free‐energy characteristics of universal adhesive‐treated enamel were related to the results of the bond fatigue durability.     

Shear fatigue strength of resin composite bonded to dentin at physiological frequency

The purpose of this study was to examine the shear fatigue strengths of a resin composite bonded to dentin. Three adhesive systems – a two‐step self‐etch adhesive (OptiBond XTR; Kerr) and two universal adhesives [Scotchbond Universal (3M ESPE) and G‐Premio Bond (GC)] – were used in self‐etch mode to bond a resin composite to dentin at a physiologic frequency of 2 Hz over 50,000, 100,000, and 1,000,000 cycles. A staircase method of fatigue testing was used. Twenty specimens were used for each test condition. There was no significant difference in shear fatigue strength across the cycling periods for the three individual adhesives. Differences in shear fatigue strength were found among the three adhesives within each cycling period. Regardless of the adhesive used in self‐etch mode for bonding a resin composite to dentin, shear fatigue strength was not influenced by the number of cycles used for testing.     

Influence of application method on surface free‐energy and bond strength of universal adhesive systems to enamel

The aim of the present study was to determine the influence of different adhesive application methods and etching modes on enamel bond effectiveness of universal adhesives using shear bond strength (SBS) testing and surface free‐energy (SFE) measurements. The adhesives Scotchbond Universal, All‐Bond Universal, Adhese Universal, and G‐Premio Bond were used. Prepared bovine enamel specimens were divided into four groups, based on type of adhesive, and subjected to the following surface treatments: (i) total‐etch mode with active application; (ii) total‐etch mode with inactive application; (iii) self‐etch mode with active application; and (iv) self‐etch mode with inactive application. Bonded specimens were subjected to SBS testing. The SFE of the enamel surfaces with adhesive was measured after rinsing with acetone and water. The SBS values in total‐etch mode were significantly higher than those in self‐etch mode. In total‐etch mode, significantly lower SBS values were observed with active application compared with inactive application; in contrast, in self‐etch mode there were no significant differences in SBS between active and inactive applications. A reduction in total SFE was observed for active application compared with inactive application. The interaction between etching mode and application method was statistically significant, and the application method significantly affected enamel bond strength in total‐etch mode.     

Relationship between mechanical properties and bond durability of short fiber‐reinforced resin composite with universal adhesive

The purpose of this study was to determine the relationship between mechanical properties and bond durability of short fiber‐reinforced resin composite with universal adhesive. As controls, micro‐hybrid and nano‐hybrid resin composites were tested. The universal adhesives used were Scotchbond Universal, Adhese Universal, and G‐Premio Bond. The fracture toughness and flexural properties of resin composites, and shear bond strength and shear fatigue strength of universal adhesive with resin composite using both total‐etch and self‐etch modes were determined. In the results, short fiber‐reinforced resin composite showed significantly higher fracture toughness than did micro‐hybrid and nano‐hybrid resin composites. The flexural strength and modulus of short fiber‐reinforced and nano‐hybrid resin composites were significantly lower than were those of micro‐hybrid resin composites. Regardless of etching mode, the shear bond strength of universal adhesives with short fiber‐reinforced resin composite did not show any significant differences from micro‐hybrid and nano‐hybrid resin composites. The shear fatigue strength of universal adhesives with short fiber‐reinforced resin composite and micro‐hybrid resin composites were significantly higher than that of nano‐hybrid resin composites. The results of this study suggest that the mechanical properties of short fiber‐reinforced resin composite improve their bond durability with universal adhesive.     

通用型粘接剂对牙体组织粘接效果影响因素的研究进展

近年来,通用型粘接剂因其操作简单、适用范围广等优点而被广泛运用于口腔治疗中。在实际临床操作中,酸蚀模式、涂布方法、粘接前预处理等因素可能影响其对牙体组织的粘接性能。本文归纳和分析可能影响通用型粘接剂粘接性能的因素,并以此为基础阐述如何进一步改善通用型粘接剂的粘接效果,以期为临床工作提供参考。现阶段研究表明,对于牙釉质粘接,通用型粘接剂的全酸蚀模式可取得更好的粘接效果;而对于牙本质粘接,全酸蚀和自酸蚀的粘接效果相近。延长粘接剂的涂布时间、双层涂布粘接剂、粘接前用水或乙醇润湿可提升粘接强度。0.2%氯己定和金属纳米粒子可有效抑制基质金属蛋白酶(matrix metallo?proteinases,MMPs)的激活,提高长期粘接效果。通用型粘接剂具有良好的稳定性和抗唾液污染能力,但抗血液污染能力不佳。酸蚀模式、涂布方法、粘接前预处理等因素均可影响粘接效果,临床操作中医师应注意以上因素。目前,通用型粘接剂仍存在对牙釉质自酸蚀粘接强度不佳、对龋病周围脱矿的牙体组织粘接能力下降等问题,仍有待进一步研究改进。     

Immediate enamel bond strength of universal adhesives to unground and ground surfaces in different etching modes

The purpose of this study was to determine the immediate bond effectiveness of universal adhesives to unground and ground enamel surfaces in different etching modes, through shear bond strength (SBS) tests and scanning electron microscopy observations. Three universal adhesives, a conventional two‐step self‐etch adhesive, and a conventional single‐step self‐etch adhesive were compared. Human enamel specimens from lower anterior teeth were divided into four groups and subjected to the following treatments: (i) unground enamel in self‐etch mode; (ii) ground enamel in self‐etch mode; (iii) unground enamel in etch‐&‐rinse mode; and (iv) ground enamel in etch‐&‐rinse mode. Bonded assemblies were subjected to SBS testing. All the adhesives showed significantly higher SBS values in etch‐&‐rinse mode than in self‐etch mode, regardless of whether enamel was unground or ground. The influence of the enamel surface condition on SBS was different in different etching modes. Without pre‐etching, all tested materials showed lower SBS values in unground enamel than in ground enamel. In etch‐&‐rinse mode, no significant differences in SBS values were observed between unground enamel and ground enamel for any of the adhesives tested. Phosphoric acid pre‐etching before application of self‐etch adhesives to an unground enamel surface is essential to enhance initial enamel bond effectiveness.     

Enzymatic degradation of adhesive–dentin interfaces produced by mild self‐etch adhesives

De Munck J, Mine A, Van den Steen PE, Van Landuyt KL, Poitevin A, Opdenakker G, Van Meerbeek B. Enzymatic degradation of adhesive–dentin interfaces produced by mild self‐etch adhesives.
Eur J Oral Sci 2010; 118: 494–501. © 2010 Eur J Oral Sci Endogenous matrix metalloproteinases (MMPs) released by adhesive procedures may degrade collagen in the hybrid layer and so compromise the bonding effectiveness of etch‐and‐rinse adhesives. In this study, endogenous enzymatic degradation was evaluated for several simplified self‐etch adhesives. In addition, primers were modified by adding two MMP inhibitors: chlorhexidine, a commonly used disinfectant, but also a non‐specific MMP inhibitor; and SB‐3CT, a specific inhibitor of MMP‐2 and MMP‐9. Gelatin zymography of fresh human dentin powder was used to identify the enzymes released by the adhesives. Micro‐tensile bond strength (μTBS) testing was used to assess the mechanical properties of resin–dentin interfaces over time. In none of the experimental groups treated with the mild self‐etch adhesives was MMP‐2 and/or MMP‐9 identified. Also, no difference in the μTBS was measured for the inhibitor‐modified and the control inhibitor‐free adhesives after 6 months of water storage. It is concluded that in contrast to etch‐and‐rinse adhesives, the involvement of endogenous MMP‐2 and MMP‐9 in the bond‐degradation process is minimal for mild self‐etch adhesives.     

Influence of different smear layers on bond durability of self-etch adhesives

Objective

The purpose of this study was to determine the influence of different smear layers on enamel and dentin bond durability of various types of self-etch adhesives.

Effects of increased exposure times of simplified etch‐and‐rinse adhesives on the degradation of resin–dentin bonds and quality of the polymer network

Reis A, Ferreira SQ, Costa TRF, Klein‐Júnior CA, Meier MM, Loguercio AD. Effects of increased exposure times of simplified etch‐and‐rinse adhesives on the degradation of resin–dentin bonds and quality of the polymer network.
Eur J Oral Sci 2010; 118: 502–509. © 2010 Eur J Oral Sci One of the reasons for resin–dentin degradation is poor polymerization of the adhesive layer. This study evaluated the effect of prolonged polymerization times on the immediate and 6‐month resin–dentin bond strengths, silver nitrate uptake, and polymer quality of etch‐and‐rinse adhesives. Thirty extracted teeth were obtained, and a flat dentin surface was exposed on each tooth. Adhesives (Adper Single Bond 2 and One Step Plus) were applied to the dentin surface of these teeth and light‐cured for 10, 20, or 40 s at 600 mW cm^?2. Bonded sticks (0.6 mm²) were tested in tension (0.5 mm min^?1) and analyzed, after immersion in 50% silver nitrate, using scanning electron microscopy. The polymer quality of adhesive films was evaluated using thermogravimetric analysis. Statistically higher bond strengths were observed for both adhesives when light‐cured for 40 s. Degradation of dentin bonds occurred under all experimental conditions but it was less pronounced for adhesives light‐cured for 40 s. Longer exposure times reduced silver nitrate uptake for Adper Single Bond 2. Solvent retention and the amount of residual monomer were statistically lower when both adhesives were light‐cured for 40 s. Although longer exposure times than those recommended cannot prevent degradation of the dentin bonds, they can increase bond strength, probably because of the removal of an increased amount of solvent and the presence of a lower amount of residual monomer.     

Influence of an oxygen‐inhibited layer on enamel bonding of dental adhesive systems: surface free‐energy perspectives

The influence of an oxygen‐inhibited layer (OIL) on the shear bond strength (SBS) to enamel and surface free‐energy (SFE) of adhesive systems was investigated. The adhesive systems tested were Scotchbond Multipurpose (SM), Clearfil SE Bond (CS), and Scotchbond Universal (SU). Resin composite was bonded to bovine enamel surfaces to determine the SBS, with and without an OIL, of adhesives. The SFE of cured adhesives with and without an OIL were determined by measuring the contact angles of three test liquids. There were no significant differences in the mean SBS of SM and CS specimens with or without an OIL; however, the mean SBS of SU specimens with an OIL was significantly higher than that of SU specimens without an OIL. For all three systems, the mean total SFE (γ_S), polarity force (), and hydrogen bonding force () values of cured adhesives with an OIL were significantly higher than those of cured adhesives without an OIL. The results of this study indicate that the presence of an OIL promotes higher SBS of a single‐step self‐etch adhesive system, but not of a three‐step or a two‐step self‐etch primer system. The SFE values of cured adhesives with an OIL were significantly higher than those without an OIL. The SFE characteristics of the OIL of adhesives differed depending on the type of adhesive.     

Glutaraldehyde collagen cross‐linking stabilizes resin–dentin interfaces and reduces bond degradation

This study evaluated the stability of resin–dentin interfaces treated with glutaraldehyde‐containing agents, and assessed collagen degradation in dentin matrices treated with Gluma. Microtensile bond strength (μTBS) was evaluated 24 h and 6 months after treatment with three desensitizers (Gluma Desensitizer, Gluma Desensitizer Power Gel, and MicroPrime G) and two etch‐and‐rinse adhesives (Comfort Bond & Desensitizer and iBond TE). Demineralized beams of human dentin were treated with water or Gluma, and the degradation of collagen in these beams was assessed by quantification of the dry mass loss and of the amount of hydroxyproline released from hydrolyzed specimens after 1 or 4 wk. All groups demonstrated significant reduction in μTBS after 6 months, except for Gluma Desensitizer and iBond TE groups, which showed decreases of 7.2% and 10.8%, respectively. The most prevalent failure mode was ‘mixed’. Significantly less hydroxyproline was released from Gluma‐treated beams than from control beams after 4 wk. Beams treated with Gluma yielded significantly less dry mass loss than did beams in the control group. Collagen cross‐linking with glutaraldehyde‐containing agents may assist in the stabilization of resin–dentin bonds by reducing the amount of collagen solubilized from dental matrices in the hybrid layer. In turn, this may contribute to the preservation of adhesive interfaces.     

Bond strength of different adhesive systems to dental hard tissues

This study compared the shear bond strengths of different adhesive systems to enamel and dentin of different depths. The adhesive systems used were: Single Bond one-bottle total-etch; AQ Bond one-step self-etching, Clearfil SE Bond two-step self-etching and Tyrian SPE/One-step Plus two-step self-etching. Eighty extracted non-carious human mandibular molars were mounted in self-curing resin and the occlusal surfaces were ground with a mechanical grinder to obtain flat occlusal enamel surfaces. After applying the adhesive systems, a plastic tube was attached to the enamel surfaces. The tube was filled with a universal hybrid resin composite, which was then polymerized. The specimens were stored in water at 37 degrees C for 24 hours. Shear bond testing was carried out using an Instron Universal testing machine with a crosshead speed of 1 mm/minute. The occlusal enamel of the 80 teeth was removed to determine the bond strengths of the adhesives to superficial dentin. To obtain deep dentin, the same teeth were ground deep towards the pulp, with the remaining dentin thickness approximately 0.7 mm. The adhesives and restorative material were then applied to the prepared dentin surfaces following the methodology described above. For occlusal enamel surfaces, the bond strength of Single Bond was significantly higher than the other adhesives. Single Bond, Clearfil SE Bond and Tyrian SPE/One-step Plus performed equally when bonded to superficial dentin; the lowest bond strength was obtained with AQ Bond. On deep dentin, the highest bond strengths were obtained with Clearfil SE Bond. For each adhesive system, shear bond strength to enamel was statistically higher than it was to either superficial or deep dentin. There were no significant differences between shear bond strengths to superficial versus deep dentin, regardless of adhesive.     

Dental adhesion: mechanism, techniques and durability

Contemporary dental adhesives show favorable immediate results in terms of bonding effectiveness. However, the durability of resin-dentin bonds is their major problem. It appears that simplification of adhesive techniques is rather detrimental to the long-term stability of resin-tooth interface. The hydrostatic pulpal pressure, the dentinal fluid flow and the increased dentinal wetness in vital dentin can affect the intimate interaction of certain dentin adhesives with dentinal tissue. Bond degradation occurs via water sorption, hydrolysis of ester linkages of methacrylate resins, and activation of endogenous dentin matrix metalloproteinases. The three-step etch-and-rinse adhesives still remain the gold standard in terms of durability. This review discusses the fundamental process of adhesion to enamel and dentin with different adhesive techniques, factors affecting the long-term bonding performance of modern adhesives and addresses the current perspectives for improving bond durability.     

Effect of desensitizing agents on the microtensile bond strength of two‐step etch‐and‐rinse adhesives to dentin

Desensitizers can be used to control postoperative sensitivity in adhesive restorations. The aim of this study was to evaluate the effect of desensitizing agents on the bond strength of two‐step etch‐and‐rinse adhesive systems to dentin. Forty‐two human molars were sectioned to obtain 3‐mm‐thick dentin discs. The discs were divided into three groups (n = 14 in each) – no‐treatment control group (CT), and oxalic acid [BisBlock (BB)] and calcium phosphate [Desensibilize Nano‐P (NP)] desensitizers – before the application of two adhesive systems [Adper Single Bond Plus (SB) and One‐Step Plus (OSP)]. A nanoparticle composite resin was used to create a 3‐mm‐thick build‐up. The specimens were stored in distilled water for 24 h before a microtensile bond‐strength test was performed. The failure modes were determined using a stereomicroscope at 100 × magnification. Specimens were sectioned perpendicular to the interface for scanning electron microscopy analyses. The CT‐SB group exhibited the highest bond strength, differing significantly from BB‐SB and BB‐OSP groups. Mixed failures were prevalent for all groups. Scanning electron microscopy revealed a continuous hybrid layer and resin tags in all groups. Dentin bond strength of etch‐and‐rinse adhesive systems was reduced by an oxalic acid desensitizer but was not affected by a calcium phosphate‐containing desensitizer.     

Effect of a functional monomer (MDP) on the enamel bond durability of single‐step self‐etch adhesives

The present study aimed to determine the effect of the functional monomer, 10‐methacryloxydecyl dihydrogen phosphate (MDP), on the enamel bond durability of single‐step self‐etch adhesives through integrating fatigue testing and long‐term water storage. An MDP‐containing self‐etch adhesive, Clearfil Bond SE ONE (SE), and an experimental adhesive, MDP‐free (MF), which comprised the same ingredients as SE apart from MDP, were used. Shear bond strength (SBS) and shear fatigue strength (SFS) were measured with or without phosphoric acid pre‐etching. The specimens were stored in distilled water for 24 h, 6 months, or 1 yr. Although similar SBS and SFS values were obtained for SE with pre‐etching and for MF after 24 h of storage in distilled water, SE with pre‐etching showed higher SBS and SFS values than MF after storage in water for 6 months or 1 yr. Regardless of the pre‐etching procedure, SE showed higher SBS and SFS values after 6 months of storage in distilled water than after 24 h or 1 yr. To conclude, MDP might play an important role in enhancing not only bond strength but also bond durability with respect to repeated subcritical loading after long‐term water storage.     

SEM observation of novel characteristic of the dentin bond interfaces of universal adhesives

ObjectiveThe aim of this study was to observe the resin/dentin interfaces of universal adhesives by using scanning electron microscopy (SEM), and to compare their morphologies with conventional etch & rinse (ER) and self-etch (SE) adhesive systems.MethodsTwo three-step and one two-step ER adhesives and two two-step and two single-step SE adhesives were used for comparison with seven universal adhesives in ER mode and SE mode, respectively. Bonded surfaces with bovine teeth were longitudinally sectioned and mirror-polished. Half of the samples were treated with HCl and NaOCl solutions. The interfaces were subjected to argon ion beam etching and then observed by scanning electron microscopy.ResultsThe thickness of the adhesive layer (AL) of most of the seven universal adhesives and single-step SE adhesives was similar. Universal adhesives in SE mode formed a hybrid smear layer as a high-density zone between the AL and dentin. The thickness of the hybrid layer (HL) of the universal adhesives in ER mode was ∼1–2 μm, with a high-density zone (reaction layer [RL]) below the HL.ConclusionThe morphological features of most universal adhesives in SE mode and single-step SE adhesives are similar. Although resin–dentin interfaces of universal adhesives in ER mode resemble those of ER adhesives, universal adhesives have a distinctive feature, an RL.SignificanceThe RL might be a sign of chemical bonding even when using universal adhesives in ER mode.     

Influence of 38% silver diamine fluoride application on bond stability to enamel and dentin using universal adhesives in self-etch mode

In order to evaluate the influence of 38% silver diamine fluoride (SDF) application on enamel and dentin bond stability of universal adhesives in self-etch mode, a 38% SDF and three universal adhesives were used in this study. Initial shear bond strength (ISBS), fatigue bond strength (FBS), and shear bond strength of survivors (SBSS) to enamel and dentin of universal adhesives in self-etch mode, with and without SDF application, were determined. SDF was applied to the polished enamel or dentin surface for 1 min, water-rinsed and air-dried for comparison with controls. The universal adhesives were applied to the prepared samples and composite resin was bonded using a mold-enclosed method. Enamel bond stability of universal adhesives with SDF (ISBS: 14.7–20.4 MPa; FBS: 5.5–7.4 MPa and SBSS: 14.4–21.5 MPa) was significantly weaker than those without SDF (ISBS: 28.0–29.2 MPa; FBS: 12.1–15.6 MPa and SBSS: 28.4–34.4 MPa). Dentin bond stability with SDF (ISBS: 14.8–20.9 MPa; FBS: 7.1–8.2 MPa and SBSS: 17.3–21.8 MPa) was also significantly weaker than without SDF (ISBS: 19.3–36.1 MPa; FBS: 11.0–13.7 MPa and SBSS: 22.2–34.6 MPa). The results suggest that SDF application on enamel and dentin reduces the bond stability of universal adhesives in self-etch mode.     

评价新型粘接剂在不同粘接模式下的牙本质粘接性能

目的评价1种新型单瓶型多模式粘接剂在不同粘接模式下与牙本质的粘接强度和粘接耐久性。方法制作3组牙本质/复合树脂粘接试件,其中每组牙本质在粘接前接受不同的表面调节。包括不处理(空白对照),Singlebond Universal粘接剂自酸蚀模式下调节牙本质,Singlebond Universal粘接剂在酸蚀冲洗模式下调节牙本质。测量各组粘接试件水储24 h和180 d的微拉伸粘接强度值并进行统计分析。以扫描电子显微镜观察各组试件的粘接界面。结果不论老化前还是老化后,3组间的粘接强度均存在显著性差异,其中空白组的粘接强度值最低,另两组间则无显著性差异。人工老化使空白组的粘接强度值显著下降,而对另两组则并无显著影响。结论 Singlebond Universal粘接剂在自酸蚀粘接模式和酸蚀冲洗粘接模式下均能够形成与牙本质良好的粘接。     

Bonding characteristics of self-etching adhesives to intact versus prepared enamel

Purpose: This study tested the null hypothesis that the preparation of the enamel surface would not affect the enamel microtensile bond strengths of self‐etching adhesive materials. Materials and Methods: Ten bovine incisors were trimmed with a diamond saw to obtain a squared enamel surface with an area of 8 × 8 mm. The specimens were randomly assigned to five adhesives: (1) ABF (Kuraray), an experimental two‐bottle self‐etching adhesive; (2) Clearfil SE Bond (Kuraray), a two‐bottle self‐etching adhesive; (3) One‐Up Bond F (Tokuyama), an all‐in‐one adhesive; (4) Prompt L‐Pop (3M ESPE), an all‐in‐one adhesive; and (5) Single Bond (3M ESPE), a two‐bottle total‐etch adhesive used as positive control. For each specimen, one half was roughened with a diamond bur for 5 seconds under water spray, whereas the other half was left unprepared. The adhesives were applied as per manufacturers' directions. A universal hybrid composite resin (Filtek Z250, 3M ESPE) was inserted in three layers of 1.5 mm each and light‐cured. Specimens were sectioned in X and Y directions to obtain bonded sticks with a cross‐sectional area of 0.8 ± 0.2 mm². Sticks were tested in tension in an Instron at a cross‐speed of 1 mm per minute. Statistical analysis was carried out with two‐way analysis of variance and Duncan's test at p <. 05. Ten extra specimens were processed for observation under a field‐emission scanning electron microscope. Results: Single Bond, the total‐etch adhesive, resulted in statistically higher microtensile bond strength than any of the other adhesives regardless of the enamel preparation (unprepared = 31.5 MPa; prepared = 34.9 MPa, not statistically different at p < 05). All the self‐etching adhesives resulted in higher microtensile bond strength when enamel was roughened than when enamel was left unprepared. However, for ABF and for Clearfil SE Bond this difference was not statistically significant at p > 05. When applied to ground enamel, mean bond strengths of Prompt L‐Pop were not statistically different from those of Clearfil SE Bond and ABF. One‐Up Bond F did not bond to unprepared enamel. Commercial self‐etching adhesives performed better on prepared enamel than on unprepared enamel. The field‐emission scanning electron microscope revealed a deep interprismatic etching pattern for the total‐etch adhesive, whereas the self‐etching systems resulted in an etching pattern ranging from absent to moderate. CLINICAL SIGNIFICANCE For the recently introduced all‐in‐one self‐etching dental adhesives, instrumentation of enamel may be critical for their ability to optimally bond to enamel.