scholarly journals Effects of Dentine Pretreatment Solutions Containing Flavonoids on the Resin Polymer-Dentine Interface Created Using a Modern Universal Adhesive

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1145
Author(s):  
Andrés Dávila-Sánchez ◽  
Mario Felipe Gutierrez ◽  
Jorge Pailover Bermudez ◽  
Luján Méndez-Bauer ◽  
Camilo Pulido ◽  
...  

The aim of the present study was to evaluate the influence of several experimental pretreatment crosslinker solutions on the resin polymer–dentine interface created using a representative universal adhesive system, by means of microtensile bond strength testing (μTBS), nanomechanical properties and ultramorphology confocal laser scanning microscopy (CLSM). Five experimental solutions containing different flavonoids were applied as dentine pretreatment after acid etching. A control pretreatment group containing no flavonoid was also employed. A representative modern universal adhesive was then applied, followed by a 3 mm thick composite built up. Specimens were sectioned into sticks and submitted to a μTBS test or nanoindentation analysis along the interface (24 h or 25,000 thermocycles). The ultramorphology of the polymer–resin interface was also evaluated using CLSM. The results were analyzed using two-way ANOVA and Bonferroni’s post hoc test (α = 0.05). All flavonoids improved short- and long-term μTBS values (p < 0.01), while only some specific such solutions improved the nanomechanical properties (p < 0.05) and preserved the structural morphology of the interface after aging. Pretreatment of acid-etched dentine using specific flavonoid-containing solutions may be a promising approach to improve both the nanomechanical properties and the durability of modern universal adhesive systems.

2018 ◽  
Vol 43 (6) ◽  
pp. 602-612 ◽  
Author(s):  
C Yao ◽  
H Yang ◽  
J Yu ◽  
L Zhang ◽  
Y Zhu ◽  
...  

SUMMARY Objective: This study aimed to investigate the long-term effectiveness of ceramic–resin bonding with universal adhesives in non–silane-pretreated and silane-pretreated modes after 10,000 cycles of thermal aging. Methods and Materials: All Bond Universal, Adhese Universal, Clearfil Universal Bond, and Single Bond Universal were selected. Etched lithium disilicate glass ceramics were prepared, randomly assigned to groups, and pretreated with or without ceramic primer containing silane coupling agent prior to the application of universal adhesive (ie, silane-pretreated or non–silane-pretreated mode). The shear bond strength (SBS), microleakage, and field-emission scanning electron microscopy images of the ceramic–resin interfaces were examined after 24 hours of water storage or 10,000 thermal cycles. Light microscopy and confocal laser scanning microscopy (CLSM) were performed to analyze marginal sealing ability. Results: SBS and microleakage percentage were significantly affected by bonding procedure (non–silane-pretreated or silane-pretreated mode) and aging (24 hours or 10,000 thermal cycles). After the universal adhesives in the non–silane-pretreated mode were aged, SBS significantly decreased and microleakage percentage increased. By contrast, the SBS of Adhese Universal, Clearfil Universal Bond, and Single Bond Universal decreased, and the microleakage percentage of all of the adhesives increased in the silane-pretreated mode. However, after aging, the SBS of the silane-pretreated groups were higher and their microleakage percentages lower than those of the non–pretreated groups. In the non–silane-pretreated mode, adhesive failure was dominant and gaps between composite resin and the adhesive layer were significant when observed with CLSM. Conclusions: The simplified procedure reduced the ceramic–resin bonding effectiveness of universal adhesives after aging, and additional silane pretreatment helped improve the long-term durability.


2022 ◽  
pp. 002203452110617
Author(s):  
F.S. de Lucena ◽  
S.H. Lewis ◽  
A.P.P. Fugolin ◽  
A.Y. Furuse ◽  
J.L. Ferracane ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
T. A. Bakhsh ◽  
A. Turkistani

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Dong Bo ◽  
Cecilia Marcellino Kayombo

Aim. To assess the effectiveness of nanosilver gel (NSG) in comparison to chlorhexidine gluconate (CHX) and camphorated phenol (CP) against Enterococcus faecalis (E.f) biofilm. Methods and Materials. Two tests were done, methyl thiazolyl tetrazolium (MTT) assay and confocal laser scanning microscopy (CLSM) analysis, to determine the effectiveness of NSG, CHX, and CP on E.f biofilm. Polystyrene microtiter 96- and 6-well plates were used for MTT and CLSM, respectively. Nanosilver gel was in three concentrations (0.05%, 0.1%, and 0.2%), chlorhexidine gluconate used was 2%, and camphorated phenol and normal saline were as control. Analysis was done using one-way ANOVA; the post hoc test was run for multiple comparisons. The level of statistical significance was set at P<0.05. Results. One-way ANOVA showed significant differences among groups (0.05% NSG and CP, 0.1% NSG and CP, 0.2% NSG and CP, 0.1% NSG and 2% CHX, 0.2% and NSG and 2% CHX) (P<0.001) and also showed significant difference between groups (P<0.001), f-ratio 87.823. A post hoc Tukey’s test revealed no significant difference between chlorhexidine gluconate and 0.05% nanosilver gel (P>0.05). Conclusions. 0.1% and 0.2% nanosilver gel is more effective on Enterococcus faecalis biofilm as compared to chlorhexidine gluconate and camphorated phenol.


2018 ◽  
Vol 19 (3) ◽  
pp. 248-252 ◽  
Author(s):  
Celso A Klein ◽  
Douglas da Silva ◽  
Eduardo G Reston ◽  
Diana LB Borghetti ◽  
Roberto Zimmer

ABSTRACT Aim The aim of this study is to assess marginal microleakage of cervical cavities restored with composite resins and two different adhesive techniques subjected to at-home and in-office bleaching. Materials and methods In this randomized, blind laboratory experiment, 60 bovine teeth recently extracted were collected and divided into six groups (n = 10 each group). The teeth received cervical cavity preparations (2 mm × 3 mm × 1 mm) with enamel margins. Two different adhesive systems were used (Single Bond 2 and Clearfil SE Bond), in addition to composite resin (Z250). Restored teeth received two different bleaching gels (Opalescence PF and Opalescence Boost). Teeth were thermocycled and analyzed under confocal laser scanning microscopy. Results No significant differences were observed (p > 0.05) in microleakage scores between the two groups not subjected to bleaching nor between the four groups that received bleaching treatment (p > 0.05), regardless of the gel and adhesive system employed. However, when comparing nonbleached with bleached teeth, those not subjected to bleaching showed statistically lower marginal microleakage scores (p < 0.05). Data were statistically analyzed using the Kruskal–Wallis test followed by Student–Newman–Keuls post hoc test, with significance set at 5%. Conclusion Marginal microleakage in composite resin restorations is influenced by the action of bleaching agents used both at-home and in-office, regardless of the adhesive system employed (total-etch or self-etch). Clinical significance Both at-home and in-office bleaching agents have an influence on the adhesive interface of resin restorations, producing changes and inducing marginal leakage. How to cite this article Klein Jr CA, da Silva D, Reston EG, Borghetti DLB, Zimmer R. Effect of At-home and In-office Bleaching on Marginal Microleakage in Composite Resin Restorations using Two Adhesive Systems. J Contemp Dent Pract 2018;19(3):248-252.


Author(s):  
Vandana James ◽  
Manavalan Madhana Madhubala ◽  
Shari S Devarajan ◽  
Sekar Mahalaxmi ◽  
Shanmugasundaram Sathyakumar

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%.


Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.


Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.


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