scholarly journals Variable Smear Layer and Adhesive Application: The Pursuit of Clinical Relevance in Bond Strength Testing

2019 ◽  
Vol 20 (21) ◽  
pp. 5381 ◽  
Author(s):  
Abu Faem Mohammad Almas Chowdhury ◽  
Rafiqul Islam ◽  
Arefin Alam ◽  
Mariko Matsumoto ◽  
Monica Yamauti ◽  
...  

The removal or modification of smear layers that cover the dentin is critical to allow the penetration of adhesive molecules and to ensure a strong bond between resin and dentin. Aiming to establish a model for clinically-relevant dentin-bond testing, we evaluated the effects of smear layers created by abrasives having similar coarseness (180-grit SiC paper; fine-grit diamond bur) and application modes (single application; double application) on the microtensile bond strengths (µTBS) of two currently available universal adhesives (G-Premio Bond; Scotchbond Universal Adhesive) and a two-step self-etch adhesive (Clearfil Megabond 2). Sixty extracted human third molars were used for the μTBS test. Data were analyzed by three-way ANOVA and Tukey’s test (α = 0.05). Fracture modes were determined using stereomicroscopy. An additional 24 third molars were prepared for observation of the resin–dentin interface by TEM and adhesive-smear layer interaction by SEM. μTBS was significantly affected by the adhesives and their application modes (p < 0.001), implying that the double application of universal adhesives should be recommended to improve their performance. The effect of smear layers was not significant (p > 0.05), indicating that 180-grit SiC papers could be used to prepare dentin as a substitute for fine-grit diamond burs for dentin-bond testing in laboratory settings.

2020 ◽  
Vol 45 (2) ◽  
pp. 183-195 ◽  
Author(s):  
T Saito ◽  
T Takamizawa ◽  
R Ishii ◽  
A Tsujimoto ◽  
E Hirokane ◽  
...  

SUMMARY We attempted to determine the effect of universal adhesive application time on dentin bond performance in different etching modes based on shear bond strength (SBS) tests and surface free energy (SFE) measurements. The five universal adhesives used were Adhese Universal (AU), Clearfil Universal Bond Quick (CQ), G-Premio Bond (GP), Scotchbond Universal (SU), and Tokuyama Universal Bond (TU). Bovine dentin specimens were divided into four groups of 10 for each adhesive. SBS and SFE were determined after applying the following surface treatments: 1) self-etch (SE) mode with immediate air blowing after adhesive application (IA treatment), 2) SE mode with prolonged application time (PA treatment), 3) etch-and-rinse (ER) mode with IA treatment, and 4) ER mode with PA treatment. Bonded specimens were subjected to SBS testing. The SFE of adhesive-treated dentin surfaces was measured after rinsing with acetone and water. Three-way analysis of variance revealed that dentin SBS values (p&lt;0.001) were significantly influenced by the factors of adhesive type and application duration, but the factor of pre-etching was not significant (p=0.985). The manufacturer's instructions require longer application times for AU and SU, which showed significantly lower SBS values in IA than in PA treatment in both etching modes. However, the difference in the other adhesives was not significant between the IA and PA treatments in either etching mode. The total SFE (γS) was dependent on the adhesive and etching mode. The γS value of the initial group (SiC paper ground group) at baseline was 69.5 (mN·m−1) and that of the pre-etching group at baseline was 30.6 (mN·m−1). For all the adhesives, γS in SE mode showed significantly higher values than in ER mode, regardless of the application time. In SE mode, almost all universal adhesives tested showed lower γS values in PA treatment than in IA treatment. For ER mode, all the adhesives showed significantly higher γS values than those of the pre-etching baseline, regardless of the application time. Most adhesives did not show any significant differences in γS values between IA and PA treatments, regardless of etching mode.


2017 ◽  
Vol 42 (3) ◽  
pp. 284-296 ◽  
Author(s):  
EC Martini ◽  
SO Parreiras ◽  
MF Gutierrez ◽  
AD Loguercio ◽  
A Reis

SUMMARY Objectives: The aim of this study was to investigate the effect of different protocols of 17% ethylene diamine tetra-acetic acid (EDTA) conditioning on the etching pattern and immediate bond strength of universal adhesives to enamel and sclerotic dentin. Methods and Materials: Forty bovine teeth with sclerotic dentin and 20 human third molars were randomly divided into eight groups resulting from the combination of the main factors surface treatment (none, two-minute EDTA conditioning manual application, 30-second EDTA manual application, 30-second EDTA sonic application) and adhesives systems (Scotchbond Universal Adhesive [SBU] and Prime & Bond Elect [PBE]). Resin-dentin and enamel-dentin bond specimens were prepared and tested under the microtensile bond strength (μTBS) and microshear bond strength (μSBS) tests, respectively. The etching pattern produced on the unground enamel and the sclerotic dentin surfaces under the different protocols and adhesive systems was evaluated under scanning electron microscopy. Results: For enamel, only the main factor adhesive was significant (p&lt;0.0001), with SBU showing the highest μSBS. In sclerotic dentin, the lowest mean was observed for the group without EDTA application and the highest mean in the group with EDTA application with the sonic device for 30 seconds. Regardless of the EDTA protocol, the highest means of μTBS were observed for SBU (p&lt;0.05). Conclusions: EDTA conditioning improves the bonding performance of universal adhesives in the self-etch mode on sclerotic dentin, mainly when applied for 30 seconds with the aid of a sonic device. EDTA pretreatment also improves the retentive etching pattern of enamel, but it does not result in higher enamel bond strength.


Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 461 ◽  
Author(s):  
Joana Vasconcelos e Cruz ◽  
Mário Polido ◽  
José Brito ◽  
Luisa L. Gonçalves

Due to their polymerization characteristics, hyper-branched dendrimers have lately shown to be promising candidates for use in dental materials. In this study, a new dental adhesive system was prepared, using a dendrimer derived from 2-isocyanatoethyl methacrylate (G-IEMA), and its adhesive properties were investigated. The exposed dentin was treated with four universal adhesives (UAs): SBU (Scotchbond Universal™), FUT (Futurabond M+™), AE1 (experimental adhesive with Bis-GMA) and AE2 (experimental adhesive with G-IEMA), using Etch & Rinse (ER) or Self Etch (SE) protocols. Composite build-ups were prepared and stored for 24 h at 37 °C in distilled water. Composite/dentin beams were prepared with cross-sectional areas of 1 ± 0.3 mm2 and µTBS (Micro-tensile bond strength) test was performed at 0.5 mm/min. Failures modes were evaluated by stereomicroscopy, and bonding interfaces were observed by scanning electron microscopy (SEM). Statistical analysis of µTBS data was performed using General Linear (GLM) and Linear Mixed Models (LMM). The effect of adhesive type on µTBS was significant (p = 0.010), with AE1 presenting significantly higher µTBS than SBU (p = 0.019). No other differences between adhesives were observed. ER showed significantly better results than SE (p = 0.019), and no significant interactions between the adhesives and protocols were determined. Results obtained so far pinpoint the emergence of a new paradigm in the dental materials field, as G-IEMA can be used successfully as an alternative to Bis-GMA.


2021 ◽  
Author(s):  
JMMS Cruz ◽  
ALGBM Silva ◽  
RMRF Eira ◽  
BMPR Sousa ◽  
MMN Lopes ◽  
...  

Clinical Relevance Universal adhesives do not seem to have the ability to effectively seal dentin, regardless of the mode of application. SUMMARY Purpose: This study evaluates the reduction in dentin permeability (P) and the expression of nanoleakage in resin-dentin interfaces made with universal adhesives, comparing the self-etch mode of application with the etch-and-rinse mode of application. Methods and Materials: To measure dentin P at the baseline and after adhesive polymerization, 80 extracted noncarious human third molars (N=80) were sectioned to obtain 0.7-mm-thick midcoronal dentin disks. The specimens were randomly assigned to 8 groups according to the different adhesive systems and application modes used: Scotchbond Universal (SBU; etch-and-rinse [ER] mode vs self-etch [SE] mode), OptiBond XTR (OPT; etch-and-rinse mode vs self-etch mode), Clearfil Universal Bond Quick (CL; etch-and-rinse mode vs self-etch mode), and Adhese Universal (ADH; etch-and-rinse mode vs self-etch mode). A two-way analysis of variance with interaction was used to evaluate the P reduction differences among the groups (α=0.05). Sixteen additional 0.7-mm-thick dentin disks were similarly prepared and treated, immersed in 50 wt% ammoniacal silver nitrate, and then processed according to conventional methods for analysis under transmission electron microscopy. Results: The differences in P reduction among the adhesives were significant (p=0.029). For OPT and ADH (p=0.0304 and p=0.0120, respectively), the P reduction was higher in the ER mode than in the SE mode. For CL and SBU, no differences in P reduction was observed between the two application modes (p&gt;0.05). All the groups showed some pattern of nanoleakage. Conclusions: No adhesive system completely reduced dentin P. Dentin sealing was higher for OPT and ADH in the ER mode, while for SBU and CL, there was no difference between the two modes. All the adhesive systems showed nanoleakage.


2016 ◽  
Vol 41 (5) ◽  
pp. 481-490 ◽  
Author(s):  
AM Cardenas ◽  
F Siqueira ◽  
J Rocha ◽  
AL Szesz ◽  
M Anwar ◽  
...  

SUMMARY Objectives: To evaluate the effect of application protocol in resin–enamel microshear bond strength (μSBS), in situ degree of conversion, and etching pattern of three universal adhesive systems. Methods and Materials: Sixty-three extracted third molars were sectioned in four parts (buccal, lingual, and proximals) and divided into nine groups, according to the combination of the main factors—Adhesive (Clearfil Universal, Kuraray Noritake Dental Inc, Tokyo, Japan; Futurabond U, VOCO, Cuxhaven, Germany; and Scotchbond Universal Adhesive, 3M ESPE, St Paul, MN, USA)—and enamel treatment/application time (etch-and-rinse mode [ER], self-etch [SE] application for 20 seconds [SE20], and SE application for 40 seconds [SE40]). Specimens were stored in water (37°C/24 h) and tested at 1.0 mm/min (μSBS). The degree of conversion of the adhesives at the resin–enamel interfaces was evaluated using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data were analyzed with two-way analysis of variance and Tukey test (α=0.05). Results: In general, the application of the universal adhesives in the SE40 produced μSBS and degree of conversion that were higher than in the SE20 (p&lt;0.01) and similar to the ER mode. The deepest enamel-etching pattern was obtained in the ER mode, followed by the SE40. Conclusions: The active and prolonged application of universal adhesives in the SE mode may be a viable alternative to increase the degree of conversion, etching pattern, and resin–enamel bond strength.


2015 ◽  
Vol 40 (3) ◽  
pp. 282-292 ◽  
Author(s):  
MA Muñoz ◽  
I Luque-Martinez ◽  
P Malaquias ◽  
V Hass ◽  
A Reis ◽  
...  

SUMMARY Purpose To evaluate the immediate and 6-month resin-dentin bond strength (μTBS) and nanoleakage (NL) of universal adhesives that contain or do not contain methacryloyloxydecyl dihydrogen phosphate (MDP) and are used in the etch-and-rinse and self-etch strategies. Methods and Materials Forty caries-free extracted third molars were divided into eight groups for μTBS (n=5). The groups were bonded with the Clearfil SE Bond (CSE) and Adper Single Bond 2 (SB) as controls; Peak Universal, self-etch (PkSe) and etch-and rinse (PkEr); Scotchbond Universal Adhesive, self-etch (ScSe) and etch-and-rinse (ScEr); and All Bond Universal, self-etch (AlSe) and etch-and-rinse (AlEr). After composite restorations, specimens were longitudinally sectioned to obtain resin-dentin bonded sticks (0.8 mm2). The μTBS of the specimens was tested immediately (IM) or after 6 months of water storage (6M) at 0.5 mm/min. Some sticks at each storage period were immersed in silver nitrate and photo developed, and the NL was evaluated with scanning electron microscopy. Data were analyzed with two-way repeated-measures analysis of variance and Tukey test (α=0.05). Results At the IM period, PkSe and PkEr showed μTBS similar to the control adhesives (p&gt;0.05) but increased NL pattern and lower μTBS after 6M (p&lt;0.05). ScSe and ScEr showed intermediary μTBS values at the IM period but remained stable after 6 months (p&gt;0.05). AlSe showed the lowest μTBS (p&lt;0.05), but μTBS and NL remained stable after 6M (p&gt;0.05). AlEr showed higher IM μTBS but showed higher degradation after 6M (p&lt;0.05). Conclusions Universal adhesives that contain MDP showed higher and more stable μTBS with reduced NL at the interfaces after 6 months of water storage.


10.2341/05-19 ◽  
2006 ◽  
Vol 31 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Y. Chiba ◽  
K. Yamaguchi ◽  
M. Miyazaki ◽  
K. Tsubota ◽  
T. Takamizawa ◽  
...  

Clinical Relevance The air-drying time of single-step self-etch adhesives was a significant factor influencing dentin bond strengths.


2021 ◽  
Vol 11 (16) ◽  
pp. 7675
Author(s):  
Toshiki Takamizawa ◽  
Munenori Yokoyama ◽  
Keiichi Sai ◽  
Sho Shibasaki ◽  
Wayne W. Barkmeier ◽  
...  

This study aimed to evaluate the effect of the adhesive application method on the durability of the enamel bond and the thickness of the adhesive layer. A new-generation two-step universal adhesive system, G2-Bond Universal, and two conventional two-step adhesive systems were utilized. The shear bond strength to bovine enamel was measured after thermal cycling in both etch-and-rinse and self-etch modes. Fifteen specimens were divided into three groups as follows: Group I, wherein a strong air stream was applied over the bonding agent for 5 s; Group II, wherein a gentle air stream was applied over the bonding agent for 5 s; and Group III, which was prepared as in Group II, followed by the application of a second layer of the bonding agent and a gentle air stream for 5 s. The durability of the enamel bond and thickness of the tested adhesives were influenced by the application method in both etching modes. The application method used in Group II appeared to be most suitable in terms of the bonding of the adhesives to the enamel. The new-generation two-step self-etch adhesive, comprising a universal adhesive-derived primer and a hydrophobic bonding agent, showed superior bond performance to the conventional two-step adhesive systems.


2016 ◽  
Vol 19 (2) ◽  
pp. 104
Author(s):  
Cristina Gre ◽  
MAuro Amaral Caldeira de Andrada ◽  
Sylvio Monteiro Junior

<p><strong>Objective</strong>: This study evaluated the microtensile bond strength of a universal adhesive system applied to deep dentin under different bonding strategies. <strong>Material</strong> <strong>and Methods</strong>: Fifteen human third molars had the coronal portion removed exposing deep dentin and were assigned into 3 groups according to the adhesive system: G1(control): 2-steps totaletch (Adper Single Bond 2, 3M ESPE); G2: 1-step self-etch universal adhesive (Scotchbond Universal, 3M ESPE); G3:2 steps total-etch universal adhesive (Scotchbond Universal, 3M ESPE). Composite buildups were performed on the dentin surfaces and after water storage for 24 h, teeth were sectioned to obtain 40 bonded beams per group with sectional area of 0.9 mm2 . The specimens were submitted to the microtensile bond strength (µTBS) test until failure. Statistical analyses were computed using one-way ANOVA (p = 0.05). <strong>Results</strong>: The mean µTBS (in MPa) were G1 = 22.27, G2 = 22.85 and G3 = 20.3. After statistical analysis, no significant differences were observed among the groups. <strong>Conclusions</strong>: Universal adhesive system performed similarly to the total-etch adhesive and was not affected by the adhesion strategy.</p><p> </p><p><strong>KEYWORDS </strong></p><p>Microtensile; Adhesive system; Dentin.</p>


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