Real-Time Imaging of Gap Progress during and after Composite Polymerization

2017 ◽  
Vol 96 (9) ◽  
pp. 992-998 ◽  
Author(s):  
J. Hayashi ◽  
Y. Shimada ◽  
J. Tagami ◽  
Y. Sumi ◽  
A. Sadr
Keyword(s):  
Real Time ◽  
3D Visualization ◽  
Adhesive System ◽  
Gap Formation ◽  
Universal Adhesive ◽  
Swept Source ◽  
Real Time Imaging ◽  
Light Curing ◽  
Time Observation ◽  
Interfacial Gap

The aims of this study were to observe the behavior of composite and formation of gaps during and immediately after light polymerization using swept source optical coherence tomography (OCT) and to compare the interfacial integrity of adhesives in cavities through 3-dimensional (3D) image analysis. Forty tapered cylindrical cavities (4-mm diameter, 2-mm depth) were prepared in bovine incisors and restored using Bond Force (BF), Scotchbond Universal Adhesive (SBU), OptiBond XTR (XTR), or Clearfil SE Bond 2 (SE2), followed by Estelite Flow Quick flowable composite. Real-time imaging was performed at the center of restoration by the OCT system (laser center wavelength: 1,330 nm; frequency: 30 KHz) during and up to 10 min after light curing. The 3D scanning was performed 0, 1, 3, 5, and 10 min after light curing. The percentages of sealed enamel and dentin interface area (E%, D%) were calculated using Amira software. In real-time videos, the initial gaps appeared as a bright scattered area mainly on dentin floor and rapidly progressed along the cavity floor. The timing, rate, and extent of gap formation were different among the specimens. From 3D visualization, gap progress could be seen on both enamel and dentin even after irradiation; furthermore, typical toroidal gap patterns appeared at the dentin floor of BF and SBU. XTR and SE2 showed nearly perfect sealing performance on the dentin floor up to the 10 min that images were recorded. From quantitative analysis, SE2 and XTR showed significantly higher E% and D% than other groups. SBU showed the smallest E% and BF showed a significantly smaller D% than other groups ( P < 0.05). In conclusion, real-time observation of composite placement and 3D quantification of interfacial gaps were implemented within the experimental limitations. Interfacial gap formation during polymerization of the composite depended on the adhesive system used. The formed gaps continued to propagate after composite light curing finished.

scholarly journals Influence of Silane Pretreatment and Warm Air-Drying on Long-Term Composite Adaptation to Lithium Disilicate Ceramic

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 86
Author(s):  
Pa Pa Kay Khine ◽  
Antonin Tichy ◽  
Ahmed Abdou ◽  
Keiichi Hosaka ◽  
Yasunori Sumi ◽  
...  
Keyword(s):  
Resin Composite ◽  
Lithium Disilicate ◽  
Drying Methods ◽  
Gap Formation ◽  
Universal Adhesive ◽  
Air Drying ◽  
Swept Source ◽  
Long Term Stability ◽  
Interfacial Gap

Background: Repair bonding to lithium disilicate ceramic (LDS) remains an issue. This study examined whether the adaptation of a resin composite to LDS can be improved by a silane pretreatment and warm air-drying. Methods: LDS blocks (IPS e.max CAD) with prefabricated tapered cavities were bonded using a silane-containing universal adhesive (Clearfil Universal Bond Quick ER; UBQ) or the bonding agent of a two-step self-etch adhesive (Clearfil SE Bond 2), with and without a silane pretreatment (Clearfil Ceramic Primer; CP). CP and the adhesives were air-dried with normal air (23 ± 1 °C) or warm air (60 ± 5 °C), light-cured, and the cavities were filled with a flowable composite. Interfacial gap formation was evaluated using swept-source optical coherence tomography immediately after filling, after 24 h, 5000 and 10,000 thermal cycles, and an additional 1 year of water storage. Results: Without the silane pretreatment, all specimens soon detached from the cavities. Warm air-drying significantly decreased gap formation compared to normal air-dried groups (p < 0.001) and improved long-term stability (p < 0.001). The lowest gap formation was observed with UBQ when the silane pretreatment was combined with warm air-drying. Conclusions: Composite adaptation to LDS was insufficient without silanization, but it was stable in the long term if the silane pretreatment and warm air-drying were combined.

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.

Comparative bonding ability to dentin of a universal adhesive system and monomer conversion as functions of extended light curing times and storage

2017 ◽  
Vol 75 ◽  
pp. 41-49 ◽  
Author(s):  
Paula Costa Pinheiro Sampaio ◽  
Paula de Castro Kruly ◽  
Clara Cabral Ribeiro ◽  
Leandro Augusto Hilgert ◽  
Patrícia Nóbrega Rodrigues Pereira ◽  
...  
Keyword(s):  
Monomer Conversion ◽  
Adhesive System ◽  
Universal Adhesive ◽  
Light Curing ◽  
And Storage

scholarly journals Bond strength and marginal microleakage in restorations photopolymerized with LED and halogen light associated with three application modes of a universal adhesive system: in vitro study

2019 ◽  
Vol 67 ◽  
Author(s):  
Felipe de Brum RICARDI ◽  
Mauro Carlos Agner BUSATO ◽  
Priscilla do Monte Ribeiro BUSATO ◽  
Márcio José MENDONÇA ◽  
Saulo Vinicius da ROSA ◽  
...  
Keyword(s):  
Bond Strength ◽  
Adhesive System ◽  
Third Molars ◽  
Universal Adhesive ◽  
Healthy Human ◽  
Halogen Light ◽  
Etch And Rinse ◽  
Application Techniques ◽  
Light Curing

ABSTRACT Objective: This study aimed to assess the bond strength and marginal microleakage in composite resin restorations, using the Single Bond Universal adhesive system associated with Ultralux (halogen) and Bluephase (LED) light curing units. Methods: For bond strength, 80 healthy human third molars were divided into halogen light (n=40) and LED (n=40), and subdivided according to the following application techniques for the adhesive system: etch-and-rinse (enamel), self-etching (enamel), etch-and-rinse (dentin), and self-etching (dentin). The teeth were subjected to the microtensile test and the fracture pattern was observed under an optical microscope at 40X magnification; they were analyzed by ANOVA, and Fisher and Tukey’s tests (5%). For the marginal microleakage test, 120 class II cavities were prepared in 60 healthy human third molars that were randomly divided into halogen light (n=30) and LED (n=30), and subdivided according to the following application techniques for the adhesive system: etch-and-rinse, selective etching, and self-etching. The teeth were thermocycled 2000 times (±5/55°C), stained in 5% basic fuchsin and sectioned for qualitative and quantitative assessments; they were analyzed by Kruskall-Wallis and Dunn tests (5%). Results: For the bond strength of enamel and dentin, the adhesive application with prior acid etching was better than self-etching (p<0.0001), regardless of the type of light curing unit (p<0.05). Etch-and-rinse showed the lowest microleakage values (p<0.0001). Conclusion: Etch-and-rinse obtained the best results relative to the other application techniques for the adhesive system in both tests, regardless of the type of light curing unit.

External Marginal Gap Evaluation of Different Resin-filling Techniques for Class II Restorations—A Micro-CT and SEM Analysis

2020 ◽  
Vol 45 (4) ◽  
pp. E167-E175 ◽  
Author(s):  
CS Sampaio ◽  
GA Garcés ◽  
N Kolakarnprasert ◽  
PJ Atria ◽  
M Giannini ◽  
...  
Keyword(s):  
Class Ii ◽  
Sem Analysis ◽  
Micro Ct ◽  
Gap Formation ◽  
Scanning Electronic Microscopy ◽  
Marginal Gap ◽  
Universal Adhesive ◽  
Similar Images ◽  
Light Curing ◽  
Post Hoc

Clinical Relevance Secondary caries are the main reason for the failure of restorations, class II being the most affected. Techniques that promote less gap percentage are important. Flowable bulk fill composites used at such locations have been shown to decrease gap formation while being a faster procedure than an incremental technique. SUMMARY Purpose: To evaluate gap formation of class II restorations, resin-filling techniques using microcomputed tomography (μCT) and scanning electronic microscopy (SEM) are discussed. Methods and Materials: Class II cavities were prepared in 30 third molars and analyzed in distal and mesial views. Prime&Bond Universal adhesive was applied in all teeth and divided into five groups (n=6): G1, SS+HIT (Spectra Smart+Horizontal Incremental Technique); G2, SS+OBL (Oblique Incremental Technique); G3, SDR+BFT (Surefil SDR+Bulk Fill Technique); G4, SDR+SS (SDR placed on cervical floors from mesial and distal boxes (not light cured), followed by incremental layering with SS and light curing incrementally with the horizontal technique); and G5, BEZ+BFT (Bulk EZ+BFT). All light-curing procedures were performed with high-mode/1200 mW/cm2, Bluephase Style 20i. Teeth were scanned twice (first scan, empty tooth; second scan, filled tooth after light curing) by μCT. Acquired μCT data were evaluated with software looking for gaps at the external mesial and distal margins and submitted to statistical analysis (one-way analysis of variance and least significant differences post hoc test). Validation of the μCT analysis was performed by SEM. Results: G5 showed the lowest gap formation percentage, similar to G4 (p=0.20). G4 also showed statistical similarities to G1 and G3 (p&gt;0.05). G2 showed the highest percentages, similar to G1 (p=0.10) but different from the rest of the groups (p&lt;0.05). SEM validated the μCT technique by showing qualitative similar images regarding external marginal gap. Conclusions: The dual-cure composite and the use of flowable nonpolymerized plus horizontal filling technique showed the best marginal adaptations. The μCT technique was validated for visualization of gap formation after being compared to the SEM technique.

Real-time observation of vortex lattices in a superconductor

1993 ◽  
Vol 51 ◽  
pp. 1050-1051
Author(s):  
K. Harada ◽  
T. Matsuda ◽  
J.E. Bonevich ◽  
M. Igarashi ◽  
S. Kondo ◽  
...  
Keyword(s):  
Real Time ◽  
Flux Line ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Vortex Lattices ◽  
Flux Lines ◽  
Magnetic Flux Lines ◽  
Time Observation ◽  
Thin Superconductor ◽  
Real Time Observation

Previous observations of magnetic flux-lines (vortex lattices) in superconductors, such as the field distribution of a flux-line, and flux-line dynamics activated by heat and current, have employed the high spatial resolution and magnetic sensitivity of electron holography. And recently, the 2-D static distribution of vortices was also observed by this technique. However, real-time observations of the vortex lattice, in spite of scientific and technological interest, have not been possible due to experimental difficulties. Here, we report the real-time observation of vortex lattices in a thin superconductor, by means of Lorentz microscopy using a 300 kV field emission electron microscope. This technique allows us to observe the dynamic motion of individual vortices and record the events on a VTR system.The experimental arrangement is shown in Fig. 1. A Nb thin film for transmission observation was prepared by chemical etching. The grain size of the film was increased by annealing, and single crystals were observed with a thickness of 50∼90 nm.

Sign in / Sign up

Export Citation Format

Share Document