Triacrylamide-Based Adhesives Stabilize Bonds in Physiologic Conditions

2022 ◽  
pp. 002203452110617
Author(s):  
F.S. de Lucena ◽  
S.H. Lewis ◽  
A.P.P. Fugolin ◽  
A.Y. Furuse ◽  
J.L. Ferracane ◽  
...  
Keyword(s):  
Bond Strength ◽  
Cross Sections ◽  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Bond Stability ◽  
Occlusal Surfaces ◽  
Before And After

In this study, an acrylamide-based adhesive was combined with a thiourethane-based composite to improve bond stability and reduce polymerization stress, respectively, of simulated composite restorations. The stability testing was conducted under physiologic conditions, combining mechanical and bacterial challenges. Urethane dimethacrylate was combined with a newly synthesized triacrylamide (TMAAEA) or HEMA (2-hydroxyethyl-methacrylate; control) to produce a 2-step total-etch adhesive system. Methacrylate-based composites (70 wt% silanized filler) were formulated, containing thiourethane oligomers at 0 (control) or 20 wt%. Standardized preparations in human third molars were restored; then, epoxy replicas were obtained from the occlusal surfaces before and after 7-d storage in water or with Streptococcus mutans biofilm, which was tested after storage in an incubator (static) or the bioreactor (mechanical challenge). Images were obtained from the replicas (scanning electron microscopy) and cross sections of the samples (confocal laser scanning microscopy) and then analyzed to obtain measurements of gap, bacterial infiltration, and demineralization. Microtensile bond strength of specimens stored in water or biofilm was assessed in 1-mm2 stick specimens. Data were analyzed with analysis of variance and Tukey’s test (α = 0.05). HEMA-based materials had greater initial gap measurements, indicating more efficient bonding for the acrylamide materials. When tested in water, the triacrylamide-based adhesive had smaller gaps in the incubator or bioreactor. In the presence of biofilm, there was less difference among materials, but the acrylamide/thiourethane combination led to statistically lower gap formation in the bioreactor. HEMA and TMAAEA-based adhesives produced statistically similar microtensile bond strengths after being stored in water for 7 d, but after the same period with biofilm-challenged specimens, the TMAAEA-based adhesives were the only ones to retain the initial bond strength values. The use of a stable multiacrylamide-based adhesive led to the preservation of the resin-dentin bonded interface after a physiologically relevant challenge. Future studies will include a multispecies biofilm model.

scholarly journals The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
T. A. Bakhsh ◽  
A. Turkistani
Keyword(s):  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Swept Source ◽  
Before And After ◽  
One Step ◽  
Self Etch ◽  
Filled Composite

Objective. The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM). Materials and Methods. Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth ( 1.5   mm   depth × 3.5   mm   diameter ) and divided randomly into two groups: TS and SN, according to the adhesive system ( n = 10 ). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers’ instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5–55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation. Results. B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC ( p < 0.001 ). Conclusions. An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.

scholarly journals Evaluation of Degree of Conversion, Resin-Dentin Bond Strength, and Durability of Polydopamine Incorporated Total Etch Adhesive System

2021 ◽  
Author(s):  
Vandana James ◽  
Manavalan Madhana Madhubala ◽  
Shari S Devarajan ◽  
Sekar Mahalaxmi ◽  
Shanmugasundaram Sathyakumar
Keyword(s):  
Bond Strength ◽  
Laser Scanning ◽  
Testing Machine ◽  
Adhesive System ◽  
Degree Of Conversion ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Occlusal Surfaces ◽  
Bonferroni Test ◽  
Strength And Durability

Objectives: This study aimed to evaluate the degree of conversion (DC%), shear bond strength (SBS), bond durability, and the resin-dentin interface of polydopamine (PDA) incorporated total-etch adhesive system. Materials and Methods: Five percentage by weight (wt%) concentration of PDA incorporated adhesive was prepared and its polymerization was evaluated using Fourier-transform infrared spectroscopy. The results were compared with the DC% of conventional total-etch adhesive (Adper Single Bond 2) using independent t-test. Occlusal surfaces of 80 freshly extracted human premolars were sectioned to expose the dentin, which was acid-etched. The samples were divided into two groups (n=40) of total-etch adhesive and total-etch adhesive+PDA. Composite resin blocks were built up over the bonded surface and cured. Each group was subdivided into two subgroups (n=20) of immediate and post-aging evaluation. Samples were immersed in 10% sodium hypochlorite for five hours, and then, the SBS was evaluated using a universal testing machine at a crosshead speed of 1 mm/minute. The resin-dentin interface was evaluated using confocal laser scanning microscopy. Data were analyzed using two-way analysis of variance and post-hoc Bonferroni test. Results: DC% was not affected by the addition of 5% PDA to the adhesive (group 2). The SBS of group 2A was significantly higher than that of group 1A. There was no significant reduction of SBS in group 2B. The hybrid layer was less degraded after aging in group 2B compared to group 2A. Conclusions: PDA incorporated adhesive increased the immediate bond strength and durability without changing the DC%.

scholarly journals Micromorphological analysis and bond strength comparison of two adhesives for different degrees of dental fluorosis

2020 ◽  
Author(s):  
Shuangfeng Liu ◽  
Yanxia Zhu ◽  
Tana Gegen
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Bonding Strength ◽  
Laser Scanning ◽  
Dental Fluorosis ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cohesive Failure ◽  
Bonding System ◽  
Significant Difference

Abstract The objective of this study was to analyze morphologically the all-etching bonding system and self-etching bonding system for enamel with different degrees of fluorosis and evaluate the bond strength of each system. Teeth that were indicated for extraction owing to orthodontic or periodontal problems were selected. According to Dean’s index and the Thylstrup-Fejerskov index, 180 extracted teeth were divided into three groups of mild, moderate, and severe dental fluorosis (DF), with 60 teeth in each group. The teeth in each group were randomly divided into two subgroups (n = 30), which were then subjected to the all-etching bonding system (Prime & Bond NT) and self-etching bonding system (SE-Bond). Each group of adhesives was used to bond Z350 universal resin (3M) to the etched dental enamel. Tensile and shear tests were conducted to determine the bond strength. Subsequently, the fractured specimens were investigated using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The Prime & Bond NT was statistically significant for the tensile and shear strength of enamel with mild fluorosis (P < 0.05) but did not exhibit a significant difference for moderate and severe DF (P > 0.05). The SE-Bond was not statistically significant for the tensile and shear strength of mild, moderate, or severe DF (P > 0.05). The SEM and CLSM results reveal that the mild fluorosis enamel crystals were relatively dense, and a small amount of resin remained. The moderate fluorosis enamel crystals were loosely arranged, and the gaps were widened. The severe fluorosis enamel crystals were irregularly arranged. The disorder was aggravated, and the dentinal orifice was exposed by partial enamel exfoliation. The bonding strength of mild fluorosis enamel with the Prime & Bond NT was better than that with the SE-Bond, and cohesive failure was the most common mode of failure. Because there was no difference in the bonding strength of the SE-Bond for different degrees of DF, we recommend the use of the all-etching adhesive system in the clinical treatment of teeth with mild fluorosis.

scholarly journals Analysis of Shear Bond Strength and Morphology of Er:YAG Laser-Recycled Ceramic Orthodontic Brackets

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ruo-qiao Han ◽  
Kai Yang ◽  
Ling-fei Ji ◽  
Chen Ling
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Laser Scanning ◽  
Er:Yag Laser ◽  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Test Machine ◽  
Ceramic Brackets

Objective. The aim of this study was to compare the recycling of deboned ceramic brackets via an Er:YAG laser or via the traditional chairside processing methods of flaming and sandblasting; shear bond strength and morphological changes were evaluated in recycled brackets versus new brackets.Materials and Methods. 3M Clarity Self-Ligating Ceramic Brackets with a microcrystalline base were divided into groups subjected to flaming, sandblasting, or exposure to an Er:YAG laser. New ceramic brackets served as a control group. Shear bond strengths were determined with an Electroforce test machine and tested for statistical significance through analysis of variance. Morphological examinations of the recycled ceramic bracket bases were conducted with scanning electron microscopy and confocal laser scanning microscopy. Residue on the bracket base was analyzed with Raman spectroscopy.Results. Faded, dark adhesive was left on recycled bracket bases processed via flaming. Adhesive was thoroughly removed by both sandblasting and exposure to an Er:YAG laser. Compared with new brackets, shear bond strength was lower after sandblasting (p<0.05), but not after exposure to an Er:YAG laser. The Er:YAG laser caused no damage to the bracket.Conclusion. Er:YAG lasers effectively remove adhesive from the bases of ceramic brackets without damaging them; thus, this method may be preferred over other recycling methods.

Effect of Calcium-phosphate Desensitizers on Staining Susceptibility of Acid-eroded Enamel

2019 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
KY Kyaw ◽  
M Otsuki ◽  
MS Segarra ◽  
N Hiraishi ◽  
J Tagami
Keyword(s):  
Surface Roughness ◽  
Calcium Phosphate ◽  
Repeated Measures ◽  
Laser Scanning ◽  
Artificial Saliva ◽  
Color Difference ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Before And After

SUMMARY Objective: To investigate the effect of calcium-phosphate–based desensitizers, Teethmate AP paste (TMAP) and Teethmate Desensitizer (TMD) (Kuraray Noritake Dental, Tokyo, Japan), on the prevention of staining on acid-eroded enamel. Methods and Materials: Forty polished enamel samples (4×4×1 mm) from bovine incisors were randomly divided into five groups (n=8). After immersion in 50 mL of 0.5% citric acid (pH 2.5) for 15 minutes to form acid-eroded surfaces, the surfaces were subjected to different treatments with TMAP, TMD, and NaF (0.21% means 950 ppm) for five minutes. Another eroded group was not treated with desensitizer. For the control group, the samples were not eroded or treated. All the samples were stored in artificial saliva (AS) at pH 7.2 for 24 hours at 37°C. The TMAP, TMD, or NaF was reapplied at eight and 16 hours during the 24 hours of storage time. The surface roughness (Sa) was evaluated following ISO 25178 for surface texture using confocal laser scanning microscopy (VK-X 150 series, Keyence, Osaka, Japan) before acid erosion, after acid erosion, and after 24 hours of incubation in AS. Afterward, the color difference was measured with a dental colorimeter (Shade Eye NCC, Shofu, Kyoto, Japan) before and after staining with tea solution. Results: One-way repeated measures analysis of variance showed that acid erosion significantly increased Sa (p&lt;0.001). TMAP- and TMD-treated groups exhibited lower Sa values than the NaF group and the no-desensitizer treatment group. The greatest staining was observed in the NaF group and the no-desensitizer group, while the TMAP and TMD groups significantly decreased the formation of stains. Conclusions: Acid-eroded enamel increased surface roughness and tended to absorb more stains. However, the application of TMAP and TMD moderated the roughness and thus prevented the formation of extrinsic stains.

scholarly journals Effect of Etching Procedures on the Adhesion of Biofilm-Coated Dentin

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2762
Author(s):  
Bo-Kyung Jeon ◽  
Chang-Ha Lee ◽  
A Reum Kim ◽  
Seung Hyun Han ◽  
Hyun-Jung Kim ◽  
...  
Keyword(s):  
Bond Strength ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Failure Modes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Acid Etching ◽  
Dentin Surface ◽  
Biofilm Removal ◽  
Oral Biofilms

Oral biofilms coat all surfaces in the oral cavity including the exposed dentin surface. This study aimed to investigate biofilm removal by acid etching procedures and the effects of the residual biofilm on dentin surfaces on composite–dentin adhesion. Dentin discs were assigned to five groups: no biofilm formation (C); biofilm formation and no surface treatment (BF); biofilm formation and acid etching (BF-E); biofilm formation and acid etching followed by chlorhexidine soaking (BF-EC); and biofilm formation and rubbing with pumice, followed by acid etching (BF-RE). Biofilms were formed on saliva-precoated dentin discs by soaking the discs in Streptococcus mutans (S. mutans) suspension. Biofilm removal from the dentin surface was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and scanning electron microscopy, respectively. To compare the bond strength of the biofilm-coated dentin discs with the surface treatments, specimens were assigned to four groups: no biofilm formation and acid etching (C-E); BF-E; BF-EC; and BF-RE. Assessments of the micro-shear bond strength and subsequent failure modes were performed. BF-E and BF-EC did not remove the biofilm, whereas BF-RE partially removed the biofilm attached to the dentin (p < 0.05). The bond strength of BF-RE was significantly higher than those of BF-E and BF-EC, but lower than that of C-E (p < 0.05). In conclusion, mechanical biofilm removal is recommended before etching procedures to enhance adhesion to the biofilm-coated dentin.

scholarly journals Correlation between Bond Strength to Dentin and Sealers Penetration by Push-Out Test and CLSM Analysis

2019 ◽  
Vol 30 (6) ◽  
pp. 555-562
Author(s):  
Maybell Tedesco ◽  
Marcelo Carvalho Chain ◽  
Wilson Tadeu Felippe ◽  
Ana Maria Hecke Alves ◽  
Lucas da Fonseca Roberti Garcia ◽  
...  
Keyword(s):  
Bond Strength ◽  
Laser Scanning ◽  
Regional Analysis ◽  
Kendall Test ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dentinal Tubules ◽  
Significant Difference ◽  
Ah Plus ◽  
Push Out

Abstract This study correlated the bond strength (BS) and dentin penetration of different sealers by push-out test and Confocal Laser Scanning Microscopy (CLSM) analysis. Forty-five root canals were prepared according to the crown-down technique and filled with gutta-percha associated to the following sealers (n=15): Endofill, AH Plus and MTA Fillapex. Five canals of each group were filled with the sealers added with 0.1% Rhodamine B dye. Next, the specimens were transversely sectioned and submitted to the push-out test (n=10) and CLSM analysis (n=5). The BS data showed the following means (MPa) and standard deviation: AH Plus (4.17±1.86); MTA Fillapex (3.13±1.96) and Endofill (2.10±1.03). Statistical analysis (two-way ANOVA, α=0.05) showed significant difference among sealers (p<0.001) and root canal thirds (p<0.001). The BS results of Endofill and MTA Fillapex were statistically similar (p>0.05), however, they were statistically different from AH Plus (p<0.001). The regional analysis of BS showed similarity between middle and apical thirds (p>0.05), and both were different from coronal portion (p<0.001). CLSM analysis verified tags formation in all groups and higher penetration of the specimens filled with AH Plus (p<0.05). The Kendall test (correlation between BS to dentin and sealer penetration into dentinal tubules) and the Pearson test (between failures pattern and sealer penetration into dentinal tubules) did not show correlation between the variables evaluated for all the tested sealers (p>0.05). AH Plus group had higher BS to dentin, and deeper tags formation than the other sealers. There was no significant correlation between BS and intratubular penetration of the tested sealers.

Control of Thermal-Oxidative Degradation of Natural Rubber STR 5L by Using Cysteine Encapsulated with Alginate/Chitosan Microcapsules

2014 ◽  
Vol 1044-1045 ◽  
pp. 743-749 ◽  
Author(s):  
Narumol Kreua-Ongarjnukool ◽  
Surakit Tuampoemsab ◽  
Pensiri Rattanasupa
Keyword(s):  
Natural Rubber ◽  
Laser Scanning ◽  
Average Molecular Weight ◽  
Oxidative Degradation ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Thermal Oxidative Degradation ◽  
Rubber Sample ◽  
Aging Test ◽  
Before And After

This research was to study the efficiency of cysteine (Cys) acted as a natural antioxidant, which was encapsulated in alginate/chitosan (AG/CS) microcapsules to control the thermal oxidative degradation of natural rubber STR 5L. The microcapsules were prepared by a combined method based on ionic gelation and electrospraying techniques. The preparation of AG/CS microcapsules were executed to find the appropriate parameters such as applying voltage and concentration of alginate and chitosan. The applied voltage achieved for controlling the particle size as well as narrow size distribution of microcapsule. The AG/CS/Cys microcapsules were found to be a spherical shape and the average size was approximately 120 μm. The percentage of cysteine encapsulated within AG/CS microcapsules was increased with the increasing of chitosan concentration and encapsulation efficiency of cysteine in the microcapsules is about 81%. Core-shell structure of the microcapsule was confirmed by confocal laser scanning microscopy. After that, the natural rubber STR 5L mixed with AG/CS/Cys microcapsules was evaluated the oxidative resistance by Wallace plasticity. Thermal aging test according to standard ASTM D1349 at 70°C of the STR 5L mixed with AG/CS/Cys microcapsules were carried out. Weight-average molecular weight (w) of the rubber sample before and after aging test was also investigated by gel permeation chromatography. Thewof rubber sample before and after aging test presented clearly results depending on the aging time. Concisely, the AG/CS/Cys microcapsules have a potential to control release Cys and can be used to control the deterioration of raw STR 5L. The model of this encapsulation is expected to be applied with other applications.

The Effect of Peri-Bracket Excess Adhesive on Shear Bond Strength and Enamel–Adhesive Interface Morphology With Confocal Laser Scanning Microscopy: An In Vitro Comparative Study

2021 ◽  
pp. 232020682098739
Author(s):  
Banan Almashali ◽  
Nasser Alqahtani ◽  
Ahmed Almahdy
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Orthodontic Brackets ◽  
Confocal Laser ◽  
Adhesive Interface ◽  
Adhesive Remnant Index ◽  
Interface Characteristics ◽  
Group 1

Aim: To evaluate the effect of leaving excess adhesive around orthodontic brackets on the shear bond strength and on the enamel–adhesive interface characteristics. Materials and Methods: One hundred forty four human premolars were randomly divided into two groups according to the test performed. For the shear bond strength, 120 teeth were bonded with stainless steel orthodontic brackets using Transbond XT light cure adhesive composites. After positioning the bracket and before light curing, excess adhesive was removed according to the test group: group 1, all excess adhesive was removed (0 mm excess); group 2, 1 mm excess adhesive was left; group 3, 2 mm excess adhesive was left; shear bond strength was measured immediately and after three months of natural aging using a universal testing machine; and adhesive remnant index scores were also evaluated. For the enamel–adhesive interface characteristics, 24 teeth were bonded with stainless steel orthodontic brackets using Transbond XT light cure adhesive composites mixed with Rhodamine B fluorescent dye, excess adhesive was removed in the same manner according to the test groups, and teeth were evaluated using confocal laser scanning microscopy. Results: Time did not significantly affect the bond strength results ( P = .888) but the amount of excess adhesive significantly affected the results ( P < .05). Interaction terms were not significant ( P = .337). In both immediate and aged conditions, group 1 (0 mm excess) presented the highest bond strength results (MPa; P < .05). No significant difference was found in adhesive remnant index scores or enamel–adhesive interface characteristics. Conclusion: Excess adhesive around orthodontic bracket does not increase shear bond strength.

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