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.

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 Long-Term Stability of a RAFT-Modified Bulk-Fill Resin-Composite under Clinically Relevant versus ISO-Curing Conditions

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5350
Author(s):  
Niklas Graf ◽  
Nicoleta Ilie
Keyword(s):  
Fracture Mechanism ◽  
Resin Composite ◽  
Bending Test ◽  
Depth Sensing ◽  
Matrix Formulation ◽  
Curing Conditions ◽  
Term Stability ◽  
Long Term Stability

The addition of RAFT (reversible addition-fragmentation chain transfer) agents to the matrix formulation of a bulk-fill resin composite can significantly decrease the required curing time down to a minimum of 3 s. Evaluating the long term-stability of this resin composite in relation to varied curing conditions in an in-vitro environment was this study’s goal. Specimens were produced according to either an ISO or one of two clinical curing protocols and underwent a maximum of three successive aging procedures. After each one of the aging procedures, 30 specimens for each curing condition were extracted for a three-point bending test. Fragments were then stereo-microscopically characterized according to their fracture mechanism. Weibull analysis was used to quantify the reliability of each aging and curing combination. Selected fragments (n = 12) underwent further testing via depth-sensing indentation. Mechanical values for either standardized or clinical curing were mostly comparable. However, changes in fracture mechanism and Weibull modulus were observed after each aging procedure. The final procedure exposed significant differences in the mechanical values due to curing conditions. Curing conditions with increased radiant exposure seemingly result in a higher crosslink in the polymer-matrix, thus increasing resistance to aging. Yet, the clinical curing conditions still resulted in acceptable mechanical values, proving the effectiveness of RAFT-polymerization.

Effect of Deep Margin Elevation on Interfacial Gap Development of CAD/CAM Inlays after Thermomechanical Cycling

2021 ◽  
Author(s):  
W Moon ◽  
SH Chung ◽  
J Chang
Keyword(s):  
Nitrate Solution ◽  
Lithium Disilicate ◽  
Rank Test ◽  
Control Group ◽  
Gap Formation ◽  
Thermomechanical Cycling ◽  
Computer Aided ◽  
Before And After ◽  
Cad Cam ◽  
Interfacial Gap

SUMMARY The aim of this study was to evaluate interfacial gap formation of CAD/CAM lithium disilicate inlay margins before and after thermomechanical loading. Methods and Materials: Mesio-occlusal-distal cavities were prepared on 12 extracted mandibular molars. The gingival margin of one proximal box was elevated with resin modified glass ionomer (RMGI) by a height of 2 mm (Group E [elevation]), and the margin of the other side served as a control (Group NE [no elevation]). Lithium disilicate computer-aided design and computer-aided manufacturing (CAD/CAM) inlays were fabricated and bonded with a self-adhesive resin cement. An aging process was simulated on the specimens under thermomechanical cycling by using a chewing simulator. Marginal integration was evaluated under scanning electron miscroscopy (SEM) using epoxy resin replicas before and after cycling. Marginal areas were stained with silver nitrate solution, and the volumetric gap was measured at the bonded interfaces using microcomputed tomography (CT) before and after cycling. Statistical analyses were performed using paired t-tests, the Wilcoxon signed rank test, and the Mann–Whitney test (a&lt;0.05). Results: SEM showed marginal discontinuities in Group NE that increased after thermomechanical cycling. Micro-computed tomography exhibited three-dimensional dye-penetrating patterns at the interfaces before and after cycling. Interfacial disintegration was larger in Group NE before cycling (p&lt;0.05). Thermomechanical cycling increased the gaps in both Groups NE and E (p&lt;0.05). The gap increment from thermomechanical cycling was larger in Group NE (p&lt;0.05). Conclusions: Thermomechanical cycling induced interfacial disintegration at the lithium disilicate CAD/CAM inlays, with deep proximal margins. Margin elevation with RMGI placement reduced the extent of the interfacial gap formation before and after the aging simulation.

A Comparison of Spray-Drying and Freeze-Drying for the Production of Stable Silybin Nanosuspensions

2020 ◽  
Vol 20 (6) ◽  
pp. 3598-3603 ◽  
Author(s):  
Yingying Ma ◽  
Jin Gao ◽  
Wankui Jia ◽  
Yangyang Liu ◽  
Lanying Zhang ◽  
...  
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Drying Methods ◽  
Dry Powders ◽  
Term Stability ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Spray Dried

Spray-drying and freeze-drying are effective approaches to improve the long-term stability of nanosuspensions. This research explored the effect of spray-drying and freeze-drying techniques on PVP K30-stabilized silybin nanosuspensions. The morphology was observed by scanning electron microscopy (SEM): The spray-dried sample was spherical, and the freeze-dried samples were rodlike with smooth surfaces. The redispersibility was studied via dynamic light scattering (DLS): The size, PDI, and zeta of the spray-dried sample were 133.27 nm, 0.214, and 24.37 mV, respectively; the size, PDI, and zeta of the freeze-dried sample were 298.70 nm, 0.114, and 20.98 mV, respectively. The in vitro dissolution was studied, and the two dry powders showed a significant increase compared to silybin. The two dried powders had better long-term stability than the liquid starting material. Overall, spray-drying and freeze-drying are appropriate drying methods for the preparation of silybin nanosuspensions with better stability and dissolution velocity.

scholarly journals One-year clinical performance of lithium disilicate versus resin composite CAD/CAM onlays

Odontology ◽  
2020 ◽  
Vol 109 (1) ◽  
pp. 259-270
Author(s):  
Joana Souza ◽  
Mª Victoria Fuentes ◽  
Eugenia Baena ◽  
Laura Ceballos
Keyword(s):  
Clinical Performance ◽  
Resin Composite ◽  
Oral Care ◽  
Lithium Disilicate ◽  
Biological Properties ◽  
Color Match ◽  
Posterior Teeth ◽  
Cad Cam ◽  
One Year

AbstractTo compare the 1-year clinical performance of lithium disilicate and resin composite CAD/CAM onlay restorations. Twenty patients that required two restorations in posterior teeth, with at least one cusp to be covered, received two onlays. One was made with IPS e.max CAD (Ivoclar-Vivadent) and the other with Lava Ultimate (3M Oral Care). Two blind observers evaluated the restorations at baseline and 1 year after the onlays were cemented, according to FDI criteria. At each recall, digital photographs, bite-wing radiographs and impressions of the restorations were taken for SEM evaluation of the interface. Results were analyzed by Mann–Whitney U and Wilcoxon tests (p < 0.05). At baseline and in the 1-year recall, both CAD/CAM materials exhibited excellent results in most criteria with similar esthetic, functional and biological properties (p > 0.05). However, deterioration in surface lustre (p = 0.020) and color match/translucency (p = 0.039) were detected for IPS e.max CAD onlays after 1-year. Under SEM evaluation, there were no statistically differences in micromorphological criteria at baseline nor after a year between IPS e.max CAD and Lava Ultimate onlays. Conclusion: After 1 year of clinical service IPS e.max CAD and Lava Ultimate onlays showed a similar clinical performance that needs to be confirmed in long-term evaluations.

scholarly journals Rapid Method for Isolation of Desiccation-Tolerant Strains and Xeroprotectants

2010 ◽  
Vol 76 (15) ◽  
pp. 5254-5262 ◽  
Author(s):  
J. J. Narv�ez-Reinaldo ◽  
I. Barba ◽  
J. Gonz�lez-L�pez ◽  
A. Tunnacliffe ◽  
M. Manzanera
Keyword(s):  
Compatible Solutes ◽  
Soil Samples ◽  
Environmental Implications ◽  
Air Drying ◽  
New Approach ◽  
Long Term Stability ◽  
Therapeutic Value ◽  
Natural Isolates ◽  
Incubation Method

ABSTRACT A novel biotechnological process has been developed for the isolation of desiccation-tolerant microorganisms and their xeroprotectants, i.e., compatible solutes involved in long-term stability of biomolecules in the dry state. Following exposure of soil samples to chloroform, we isolated a collection of desiccation-tolerant microorganisms. This collection was screened for the production of xeroprotectants by a variation of the bacterial milking (osmotic downshock) procedure and by a novel air-drying/rehydration (“dry milking”) incubation method. The resultant solutes were shown to protect both proteins and living cells against desiccation damage, thereby validating them as xeroprotectants. Nuclear magnetic resonance (NMR) analytical studies were performed to identify the xeroprotectants; synthetic mixtures of these compounds were shown to perform similarly to natural isolates in drying experiments with proteins and cells. This new approach has biotechnological and environmental implications for the identification of new xeroprotectants of commercial and therapeutic value.

scholarly journals Atıştırmalık Et Üretiminde Kurutma Yöntemleri ve Öneriler

2019 ◽  
Vol 7 (3) ◽  
pp. 523
Author(s):  
Anıl Bodruk ◽  
Özgün Köprüalan ◽  
Figen Kaymak-Ertekin
Keyword(s):  
Mineral Content ◽  
Meat Products ◽  
Drying Methods ◽  
Hot Air Drying ◽  
Air Drying ◽  
Long Term Storage ◽  
Hot Air ◽  
Review Study ◽  
Term Storage

Meat with high protein, vitamin and mineral content is processed in different ways because it cannot be consumed fresh. Drying is one of the oldest methods for long-term storage of meat. Dried meat products, called as Jerky are generally produced by drying of the meat after the application of various pretreatments (marination, salting, smoking, etc.). Common methods for drying of the meat are sun drying and conventional hot air drying, which is modelled as shade drying. However, the development of various drying methods to reduce the quality losses as textural, sensorial and physicochemical created by the traditional methods and the use of these techniques in meat drying are becoming widespread nowadays. This review study includes the studies on the drying of various meat groups with traditional and current methods and the recommendations regarding these methods.

scholarly journals Effect of Simplified Bonding on Shear Bond Strength between Ceramic Brackets and Dental Zirconia

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1640 ◽  
Author(s):  
Ga-Youn Ju ◽  
Soram Oh ◽  
Bum-Soon Lim ◽  
Hyun-Seung Lee ◽  
Shin Hye Chung
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dihydrogen Phosphate ◽  
Universal Adhesive ◽  
Significance Level ◽  
Long Term Stability ◽  
Ceramic Brackets ◽  
The Mean ◽  
Ceramic Bracket

The aim of this study was to evaluate the long term stability of shear bond strength (SBS) when 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) containing universal adhesive was used in the ceramic bracket bonding on dental zirconia. Twenty human maxillary incisors were collected. The ceramic bracket was bonded on the buccal enamel surface after the acid-etching and orthodontic primer application (Group CON). Sixty zirconia specimens were sintered, sandblasted and divided into three experimental groups; group CP—ceramic primer followed by an orthodontic primer; group U—universal adhesive; group CU—ceramic primer followed by a universal adhesive. For each specimen, the bracket was bonded onto the treated surface with composite resin (Transbond XT, 3M ESPE). The SBS tested before (CON0, CP0, U0, CU0) and after the artificial aging (CON1, CP1, U1, CU1). The data were statistically analyzed with the Kruskal–Wallis test at a significance level of 0.05. The mean SBS of CON0, CP0, U0 and CU0 were within the clinically acceptable range without significant differences. After the aging process, SBS decreased in all groups. Among the aged groups, CP1 showed the highest SBS. Based on the results, when bonding ceramic brackets to a dental zirconia surface, we can conclude that ceramic primer used with an orthodontic primer, rather than using a universal adhesive, is recommended.

The Effects of Drying Techniques on Clay-Rich Soil Texture

1974 ◽  
Vol 32 ◽  
pp. 466-467
Author(s):  
T. G. Naymik
Keyword(s):  
Critical Point ◽  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Drying Methods ◽  
Air Drying ◽  
Freeze Dried ◽  
Critical Point Drying ◽  
Set Up ◽  
The Relationship ◽  
Quartz Grains

Three techniques were incorporated for drying clay-rich specimens: air-drying, freeze-drying and critical point drying. In air-drying, the specimens were set out for several days to dry or were placed in an oven (80°F) for several hours. The freeze-dried specimens were frozen by immersion in liquid nitrogen or in isopentane at near liquid nitrogen temperature and then were immediately placed in the freeze-dry vacuum chamber. The critical point specimens were molded in agar immediately after sampling. When the agar had set up the dehydration series, water-alcohol-amyl acetate-CO2 was carried out. The objectives were to compare the fabric plasmas (clays and precipitates), fabricskeletons (quartz grains) and the relationship between them for each drying technique. The three drying methods are not only applicable to the study of treated soils, but can be incorporated into all SEM clay soil studies.

Sign in / Sign up

Export Citation Format

Share Document