scholarly journals Influence of gamma radiation on microshear bond strength and nanoleakage of nanofilled restoratives in Er, Cr:YSGG laser-prepared cavities

2018 ◽  
Vol 12 (03) ◽  
pp. 338-343
Author(s):  
Engy Fahmy Abaza ◽  
Ahmed Abbas Zaki ◽  
Haytham Samir Moharram ◽  
Amal Alaa El Din El Batouti ◽  
Asmaa Aly Yassen
Keyword(s):  
Bond Strength ◽  
Gamma Radiation ◽  
Artificial Saliva ◽  
Strength Test ◽  
The Other ◽  
Class V ◽  
Gamma Irradiated ◽  
Microshear Bond Strength ◽  
Ammoniacal Silver ◽  
Scanning Electron

ABSTRACT Objective: To evaluate the effect of gamma radiation on microshear bond strength and nanoleakage of nanofilled restoratives in laser-prepared cavities. Materials and Methods: Twenty-eight flat buccal dentin surfaces were prepared for microshear bond strength test. Er, Cr:YSGG laser was used to prepare another 28 Class V cavities on the buccal surfaces of the molars. All teeth were divided into four groups; 1st group: Application of Filtek Z350 nanocomposite material, 2nd group: As the 1st group and then exposure to gamma radiation, 3rd group: Application of Ketac N100 nanoglass ionomer, and the 4th group: As the 3rd group and then gamma irradiated. The bond strength test was performed after storage in artificial saliva for 24 h. For the nanoleakage test, teeth were submerged in a solution of ammoniacal silver nitrate, sectioned, and then examined under a scanning electron microscope. The collected data were statistically analyzed. Results: Nanocomposite showed higher bond strength values than nanoglass ionomer. Despite the fact that gamma radiation did not decrease nanocomposite bond strength, it decreased nanoglass ionomer bond strength. Nanoglass ionomer-restored cavities showed higher silver ion penetration than nanocomposite in both control and gamma-irradiated groups. Conclusion: Gamma radiation has no effect on bond strength and nanoleakage of nanocomposite so that it can be placed before radiotherapy. On the other hand, the bond strength of nanoglass ionomer was adversely affected by gamma radiation.

scholarly journals The Influence of Blade Type and Feeding Force during Resin Bonded Dentin Specimen Preparation on the Microtensile Bond Strength Test

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 450
Author(s):  
Apinya Limvisitsakul ◽  
Suppason Thitthaweerat ◽  
Pisol Senawongse
Keyword(s):  
Bond Strength ◽  
Surface Integrity ◽  
Strength Test ◽  
Specimen Preparation ◽  
Sectional Area ◽  
Microtensile Bond Strength ◽  
Cross Sectional ◽  
Microtensile Testing ◽  
Feeding Force ◽  
Scanning Electron

This paper presents the effect of blade type and feeding force during resin-bonded dentin specimen preparation on the microtensile bond strength (μTBS) test. Forty resin-bonded flat middle dentin specimens were divided into four groups. The specimens of each group were sectioned according to type of blade and feeding force as follows: fine grit/20 N, fine grit/40 N, medium grit/20 N, and medium grit/40 N to obtain resin-dentin sticks with a cross-sectional area of 1.0 mm2. Four sticks from the center of each tooth were subjected to the μTBS test. Five remaining sticks of each group were selected for surface topography observation under a scanning electron microscope (SEM). As a result, the bond strength of the medium-grit group was higher than that of the fine-grit group (p < 0.001), whereas the feeding force had no influence on bond strength values (p = 0.648). From the SEM, sticks prepared with the fine-grit blade showed a smoother surface integrity and fewer defects on the specimen edges in comparison with the sticks prepared with the medium-grit blade. The grit type of the blade is one of the considerable factors that may affect the bond strength and the surface integrity of resin-dentin specimens for microtensile testing.

scholarly journals Effect of topical fluoride on microshear bond strength of primary enamel to composite, microhardness of enamel and its surface morphology: An in vitro study

2019 ◽  
Vol 13 (4) ◽  
pp. 305-310
Author(s):  
Mina Biria ◽  
Sajedeh Namaei Ghasemi ◽  
Seyedeh Mahsa Sheikh-Al-Eslamian ◽  
Narges Panahandeh
Keyword(s):  
Bond Strength ◽  
Artificial Saliva ◽  
Morphological Characteristics ◽  
In Vitro Study ◽  
Vitro Study ◽  
Control Group ◽  
Modes Of Failure ◽  
Group 3 ◽  
Microshear Bond Strength

Background. This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene’s and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.

Effect of Chlorhexidine Pretreatment on Bond Strength Durability of Caries–affected Dentin Over 2-Year Aging in Artificial Saliva and Under Simulated Intrapulpal Pressure

2011 ◽  
Vol 36 (6) ◽  
pp. 649-660 ◽  
Author(s):  
EH Mobarak
Keyword(s):  
Bond Strength ◽  
Failure Modes ◽  
Artificial Saliva ◽  
Water Control ◽  
Control Groups ◽  
Silver Precipitation ◽  
The Difference ◽  
Microshear Bond Strength ◽  
And Control ◽  
Composite Cylinders

SUMMARY Objective To evaluate the influence of 2% and 5% chlorhexidine (CHX) pretreatment on bond durability of a self-etching adhesive to normal (ND) and caries-affected (AD) dentin after 2-years of aging in artificial saliva and under simulated intrapulpal pressure (IPP). Methods One hundred twenty freshly extracted carious teeth were ground to expose ND and AD. Specimens were distributed into three equal groups (n=40) according to whether the dentin substrates were pretreated with 2% or 5% CHX or with water (control). Clearfil SE Bond (Kuraray) was applied to both substrates and composite cylinders (0.9 mm diameter and 0.7 mm height) were formed. Pretreatment and bonding were done while the specimens were subjected to 15 mm Hg IPP. After curing, specimens were aged in artificial saliva at 37°C and under IPP at 20 mm Hg until being tested after 24 hours or 2 years (n=20/group). Microshear bond strength was evaluated. Failure modes were determined using a scanning electron microscope (SEM) at 400× magnification. Data were statistically analyzed using three-way analysis of variance (ANOVA); one-way ANOVA tests, and t-test (p&lt;0.05). Additional specimens (n=5/group) were prepared to evaluate interfacial silver precipitation. Results For the 24-hour groups, there were no significant differences among the ND groups and AD groups. For ND aged specimens, the 5% CHX group had the highest value followed by the 2% CHX and control groups, although the difference was statistically insignificant. For AD aged specimens, the 5% CHX group revealed statistically higher bond values compared to the 2% CHX and control groups. Fracture modes were predominately adhesive and mixed. Different interfacial silver depositions were recorded. Conclusions Two percent or 5% CHX pretreatment has no adverse effect on the 24-hour bonding to ND and AD. Five percent CHX was able to diminish the loss in bonding to AD after 2years of aging in artificial saliva and under simulated IPP.

scholarly journals Effects of CPP-ACP Paste on the Shear Bond Strength of Orthodontic Brackets

2009 ◽  
Vol 79 (5) ◽  
pp. 945-950 ◽  
Author(s):  
Ding Xiaojun ◽  
Lu Jing ◽  
Guo Xuehua ◽  
Ruan Hong ◽  
Yu Youcheng ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Failure Modes ◽  
Artificial Saliva ◽  
Orthodontic Brackets ◽  
Acid Etching ◽  
Bonding System ◽  
Significant Difference ◽  
Bond Strengths ◽  
Scanning Electron

Abstract Objective: To evaluate the effect of casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) paste on shear bond strength and debonding failure modes of orthodontic brackets. Materials and Methods: Freshly extracted premolars were randomly divided into four groups (n =18) as follows: in groups 1 and 3, the enamel was treated with a solution of CPP-ACP dissolved in artificial saliva; groups 2 and 4 served as controls, and the enamel was treated with artificial saliva. After conventional acid etching, in groups 1 and 2, brackets were bonded using a light-cured bonding system (Blugloo); while in groups 3 and 4, brackets were bonded using a conventional bonding system (Unite Bonding Adhesive). Bonded specimens were subjected to thermal cycling for 1000 cycles before debonding procedures. After debonding, teeth and brackets were examined under a stereomicroscope at 10× magnification to determine whether any adhesive remained, in accordance with the adhesive remnant index. The acid-etched enamel surfaces were also observed using scanning electron microscopy after treatment with and without CPP-ACP paste. Results: The shear bond strengths of group 1 were significantly higher than those seen in group 2 (P &lt; .01). There was no significant difference in the shear bond strengths of groups 3 and 4 (P &gt; .05). Scanning electron microscopic observation showed that the pretreated enamel surface was rougher than that of the control surface after acid etching. Conclusion: The use of CPP-ACP can be considered as an alternative prophylactic application in orthodontic practice since it did not compromise bracket bond strength.

Influence of Gamma Irradiation to Magneto-Impedance Ratio in the Electrodeposited [NiFe/Cu]4 Multilayer

2020 ◽  
Vol 855 ◽  
pp. 202-207
Author(s):  
Ismail ◽  
Bangun Pribadi ◽  
Vina Oktaria ◽  
Artono Dwijo Sutomo ◽  
Utari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Magnetic Property ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Morphological Structure ◽  
Impedance Ratio ◽  
Gamma Irradiated ◽  
Scanning Electron

Influence of gamma irradiation to the magneto-impedance ratio of the electrodeposited [NiFe/Cu]4 multilayer on meander-shape PCB substrate has been studied. The magneto-impedance ratios were measured for both un-irradiated and irradiated by gamma radiation of Co-60 with a total dose of 40 Gy. The morphological structure were done by using scanning electron microscopy (SEM). The decrease in grain size of the samples after Gamma irradiated is observed. The magnetic property modifies as consequence of the change in the microstructure samples. Within result, the magneto-impedance ratio decreases around 34.9% for irradiated sample.

scholarly journals Bonding of contemporary glass ionomer cements to different tooth substrates; microshear bond strength and scanning electron microscope study

2015 ◽  
Vol 09 (02) ◽  
pp. 176-182 ◽  
Author(s):  
Aliaa Mohamed El Wakeel ◽  
Dina Wafik Elkassas ◽  
Mai Mahmoud Yousry
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Bond Strength ◽  
Nano Particles ◽  
Glass Ionomer ◽  
Scanning Electron Microscope Study ◽  
Modes Of Failure ◽  
Occlusal Surfaces ◽  
Microshear Bond Strength ◽  
Scanning Electron

ABSTRACT Objective: This study was conducted to evaluate the microshear bond strength (μSBS) and ultramorphological characterization of glass ionomer (GI) cements; conventional GI cement (Fuji IX, CGI), resin modified GI (Fuji II LC, RMGI) and nano-ionomer (Ketac N100, NI) to enamel, dentin and cementum substrates. Materials and Methods: Forty-five lower molars were sectioned above the cemento-enamel junction. The occlusal surfaces were ground flat to obtain enamel and dentin substrates, meanwhile the cervical one-third of the root portion were utilized to evaluate the bonding efficacy to cementum substrate. Each substrate received microcylinders from the three tested materials; which were applied according to manufacturer instructions. μSBS was assessed using a universal testing machine. The data were analyzed using two-way analysis of variance (ANOVA) and Tukey’s post-hoc test. Modes of failure were examined using stereomicroscope at ×25 magnification. Interfacial analysis of the bonded specimens was carried out using environmental field emission scanning electron microscope. Results: Two-way ANOVA revealed that materials, substrates and their interaction had a statistically significant effect on the mean μSBS values at P values; <0.0001, 0.0108 and 0.0037 respectively. RMGI showed statistically significant the highest μSBS values to all examined tooth substrates. CGI and RMGI show substrate independent bonding efficiency, meanwhile; NI showed higher μSBS values to dentin and cementum compared to enamel. Conclusion: Despite technological development of GI materials, mainly the nano-particles use, better results have not been achieved for both investigations, when compared to RMGI, independent of tooth substrate.

Influence of matrix type on microshear bond strength test

Dental Cadmos ◽  
2016 ◽  
Vol 84 (5) ◽  
pp. 314-318 ◽  
Author(s):  
H. Heringer Vieira ◽  
A. Catelan ◽  
D. Alves Nunes Leite Lima ◽  
F.H. Baggio Aguiar ◽  
M.C. Caldas Giorgi ◽  
...  
Keyword(s):  
Bond Strength ◽  
Strength Test ◽  
Matrix Type ◽  
Microshear Bond Strength

Shear Bond Strength and Tooth-Composite Interaction With Self-Adhering Flowable Composites

2017 ◽  
Vol 42 (1) ◽  
pp. 90-100 ◽  
Author(s):  
C Brueckner ◽  
H Schneider ◽  
R Haak
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Failure Modes ◽  
Clinical Use ◽  
Use Of Self ◽  
Class V ◽  
Interface Length ◽  
Flowable Composites ◽  
Vertise Flow ◽  
Scanning Electron

SUMMARY Purpose: To evaluate the tooth-composite interaction (A) and shear bond strength (SBS; B) of self-adhering flowables. Methods and Materials: (A) Thirty-two human molars with one Class V cavity were restored with Vertise Flow (VF), Fusio Liquid Dentin (FLD), an experimental self-adhering flowable (EF), or Adper Prompt-L-Pop/Filtek Supreme XT Flowable (PLP). Teeth were prepared according to laboratory standard and stored in water (24 hours, 37°C). Microleakage (ML; percentage interface length at enamel [E]/dentin [D]) and tooth-composite interaction were investigated. (B) The buccal surface of 160 embedded human molars was abraded to expose an enamel/dentin area of diameter ≥3 mm. Composite specimens were produced on enamel/dentin with VF, FLD, EF, or PLP. Prior to loading, 80 samples were water stored (24 hours, 37°C) and 80 thermocycled (5°C-55°C, 1500 cycles). The SBS was measured, and failure modes were classified by scanning electron microscopy. Statistics: Kruskal-Wallis, Mann-Whitney U, and Fisher exact tests were performed (α=0.05). Results: (A) At enamel margins, EF and VF showed significantly lower ML than did FLD and PLP (pi≤0.009; 81%-89%); in dentin, lower values resulted with FLD and VF compared with PLP and EF (pi≤0.01; 77%-94%). Adhesive tags at E were consistently verifiable with EF and VF but irregularly with FLD and PLP. At D, tags were detectable with all systems. (B) In all groups, SBS decreased by up to 97% after thermocycling. It was generally diminished with self-adhering flowables (E: 50%-98%, D: 59%-98%; pi&lt;0.02). More cohesive defects were observed with PLP (pi&lt;0.009). Conclusion: Tooth-composite morphology and bond strength indicate that the clinical use of self-adhering flowables must be pursued cautiously.

scholarly journals Antibacterial and Bonding Properties of Universal Adhesive Dental Polymers Doped with Pyrogallol

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1538
Author(s):  
Naji Kharouf ◽  
Ammar Eid ◽  
Louis Hardan ◽  
Rim Bourgi ◽  
Youri Arntz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antibacterial Activity ◽  
Bond Strength ◽  
The Other ◽  
Adhesive Systems ◽  
Universal Adhesive ◽  
Bonding Properties ◽  
Morphological Differences ◽  
Scanning Electron

This study investigated the antibacterial activity, bond strength to dentin (SBS), and ultra-morphology of the polymer–dentin interface of experimental adhesive systems doped with pyrogallol (PY), which is a ubiquitous phenolic moiety that is present in flavonoids and polyphenols. A universal adhesive containing 4-META and 10-MDP was used in this study. PY behaves as an antioxidant and anti-cancerogenic agent and it was incorporated into the adhesive at different concentrations (0.5 and 1 wt.%). The antibacterial activity and SBS were analyzed and the results were statistically analyzed. The ultra-morphology of the polymer–dentin interface was assessed using scanning electron microscopy (SEM). At 24 h, a lower antibacterial activity was observed for the control adhesive compared to those with 0.5% and 1% PY. No difference was seen in SBS between the three groups at 24 h. After 6 months, the SBS of the 0.5% PY adhesive was significantly lower than the other tested adhesives. The specimens created with 1% PY adhesive presented a higher bond strength at six months compared with that found at 24 h. No morphological differences were found at the polymer–dentin interfaces of the tested adhesives. Pyrogallol may be incorporated into modern universal adhesive systems to preserve the polymer–dentin bonding interface and confer a certain degree of antibacterial activity.

scholarly journals Hydrofluoric acid concentration and etching time on bond strength to lithium disilicate glass-ceramic

2021 ◽  
Vol 10 (17) ◽  
pp. e215101724776
Author(s):  
Roberta Pinto Pereira ◽  
Renan Dias Carvalho ◽  
Carolina Mayumi Cavalcanti Taguchi ◽  
Sylvio Monteiro Jr ◽  
Renata Gondo
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Morphology ◽  
Bond Strength ◽  
Hydrofluoric Acid ◽  
Resin Cement ◽  
Etching Time ◽  
Post Hoc ◽  
Microshear Bond Strength ◽  
Scanning Electron

The objective of this study to evaluate the effect of different HF concentrations and etching times on the microshear bond strength (μSBS) of LD to resin cement. Forty LD sections (8x8 mm) of 3-mm thickness were randomly distributed (n=10) in accordance with the HF concentration (5 or 10%) and surface etching time (20 or 60 sec). The specimens were silanized and received an air-thinned layer of a light-curable adhesive. Six translucent tubes (0.8-mm diameter and 1-mm height) were positioned over each LD section, filled with resin cement and light-cured. After 24 h of storage, the tubes were carefully removed and the specimens were submitted to the μSBS test. The results submitted to a two-way analysis of variance and Sidak post hoc test (α=.05). Representative HF-etched specimens and one non-etched LD specimen were observed under a field-emission scanning electron microscope. The interaction between the HF concentrations and etching times was not significant (p=0.075). No significant differences were observed regarding HF concentrations and etching times (p=0.06 and p=0.059, respectively). Surfaces of specimens etched with 10% HF for 60 sec were found with grooves and microcracks. The μSBS of LD to resin cement was not significantly influenced by different HF concentrations and etching times; however, the LD surface morphology was found considerably modified.

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