scholarly journals Influence of Thermal Cycles Number on Bond Strength of Metallic Brackets to Ceramic

2017 ◽  
Vol 28 (2) ◽  
pp. 206-209 ◽  
Author(s):  
José Eliú Pereira Jurubeba ◽  
Ana Rosa Costa ◽  
Lourenço Correr-Sobrinho ◽  
Carlos Alberto Malanconi Tubel ◽  
Américo Bortolazzo Correr ◽  
...  
Keyword(s):  
Bond Strength ◽  
Thermal Cycling ◽  
Control Group ◽  
Thermal Cycles ◽  
Group 4 ◽  
Group Data ◽  
Group 5 ◽  
Group 2 ◽  
Ceramic Restorations

Abstract The aim of this study was to evaluate the effect of different number of thermal cycles on the shear bond strength (SBS) of metallic orthodontic brackets bonded to feldspathic ceramic by a composite resin. Twenty-five ceramic cylinders were etched with 10% hydrofluoric acid for 60 s and received two layers of silane. Brackets were bonded to the cylinders using Transbond XT and assigned to 5 groups (n=5): Group 1 - Control group (without thermal cycling); Group 2 - 500 thermal cycles; Group 3 - 5,000 thermal cycles; Group 4 - 7,000 thermal cycles and Group 5 - 10,000 thermal cycles. Light-activation was carried out by Radii Plus LED. SBS testing was carried out after 24 h of storage in deionized water and thermal cycling (5/55 oC and 30 s dwell time). Five brackets were bonded to each cylinder, totalizing 25 brackets for each group. Data were submitted to one-way ANOVA and Tukey’s test (α=0.05). The Adhesive Remnant Index (ARI) was evaluated at 8× magnification. The SBS (MPa) of control group (9.3±0.8), 500 (9.0±0.7) and 5,000 (8.4±0.9) thermal cycles were significantly higher than those after 7,000 (6.8±0.6) and 10,000 (4.9±1.0) thermal cycles (p<0.05). The ARI showed a predominance of Scores 0 (adhesive failure) prevailed in all groups, as shown by the ARI, with increased scores 1 and 2 (mixed failures) for control group and 500 thermal cycles. In conclusion, thermal fatigue may compromise the bonding integration between metallic brackets and ceramic restorations. For in vitro testing, use of at least 7,000 cycles is advised to result in significant fatigue on the bonding interface.

scholarly journals Effect of the superficial treatment in the repair of silorane-based composite aged artificially

2015 ◽  
Vol 63 (4) ◽  
pp. 376-382
Author(s):  
Chaiane Emilia DALAZEN ◽  
Mario Alexandre Coelho SINHORETI ◽  
Margareth COUTINHO
Keyword(s):  
Bond Strength ◽  
Aluminum Oxide ◽  
Thermal Cycling ◽  
Surface Treatments ◽  
Control Group ◽  
Group 4 ◽  
Diamond Bur ◽  
Composite Methods ◽  
Group 3 ◽  
Group 2

Objective: To evaluate the effects of different surface treatments, in repair bond strength of an aged silorane-based composite. Methods: Specimens were made of a silorane-based composite (P90, 3M/ESPE), aged with thermal-cycling (10,000 cycles; 5-55ºC) and randomly submitted to different surface treatments (each group n = 24): control group (no repair); group 1 (only application of P90 adhesive); group 2 (diamond bur asperization + P90 adhesive); group 3 (aluminum oxide sandblasting + P90 adhesive) and group 4 (asperization + sandblasting + P90 adhesive). Then, the specimens were repaired with the same silorane-based composite and each group randomly subdivided into 2 subgroups: stored in distilled water at 37 °C for 7 days or submitted to thermal-cycling (5,000 cycles). After aging, the tensile test was carried out. The data was submitted to 2-way analysis of variance (2-way ANOVA). Results: The repaired groups aged with oven storage for 7 days did not statistically differ (p>0.05) from the corresponding groups aged with thermal-cycling. The bond strength of the specimens was significantly influenced by the superficial treatment (p<0.01). The highest values of tensile bond strength were found in groups 3 (20.76 ± 4.51 MPa) and 4 (20.67± 3.96 MPa), regardless of aging and repair. Conclusion: The repair of silorane-based composite showed to be stable after aging, and the superficial treatment with aluminum oxide sandblasting was the most effective.

scholarly journals Effect of the number of thermocycles on microleakage of resin composite restorations

2003 ◽  
Vol 17 (4) ◽  
pp. 337-341 ◽  
Author(s):  
Flávia Bittencourt Pazinatto ◽  
Bruno Barbosa Campos ◽  
Leonardo César Costa ◽  
Maria Teresa Atta
Keyword(s):  
Resin Composite ◽  
Control Group ◽  
Group 4 ◽  
Thermal Changes ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Number Of Cycles ◽  
Group 1

Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width) were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE) and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group), and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5º-55º ± 2ºC, 15 s dwell time). The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05). The averages of microleakage values in millimeters were: group 1 (3.92); group 2 (3.13); group 3 (4.48); group 4 (4.33) and group 5 (3.42). Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.

scholarly journals Effectiveness of medical treatment in overcoming the ureteral double-J stent related symptoms

2012 ◽  
Vol 6 (6) ◽  
pp. 234 ◽  
Author(s):  
Ugur Kuyumcuoglu ◽  
Bilal Eryildirim ◽  
Murat Tuncer ◽  
Gokhan Faydaci ◽  
Fatih Tarhan ◽  
...  
Keyword(s):  
The Body ◽  
Control Group ◽  
Group 4 ◽  
Double J Stent ◽  
Urinary Tract Symptoms ◽  
Stone Treatment ◽  
Group 3 ◽  
Group 5 ◽  
Group 2

Background: We investigated whether the frequency of lower urinary tract symptoms (LUTS) increased in patients in whom double-J stents were applied. We also evaluated several medical therapy protocols to treat symptoms related with ureteral stents.Materials and Methods: A total of 108 patients, in whom unilateral double-j stent was applied during ureteral stone treatment, were included. Before the double-J stent was applied, all patients completed storage components of the “International Prostate Symptom Score” (IPSSs), quality of life components of the IPSS (IPSS-QOL) and “Overactive Bladder Questionnaire” (OABq) forms and scores were calculated. After the procedure, cases were randomized into 5 groups, an antiinflammatory was given to Group 1, spasmolytic to Group 2, anticholinergic to Group 3 and α-blocker to Group 4. No additional drug was given to Group 5 as this control group. During the fourth week of the procedure, IPSSs, IPSS-QOL and OABq forms were again completed and scores were compared with the previous ones.Results: When all the cases were evaluated, the IPSSs, IPSS-QOLand OABq scores of patients in whom the double-J stent was applied were statistically significantly higher the procedure. Compared to the control group, the cases where the double-J stent was applied showed a higher IPSSs, IPSS-QOL and OABq scores and none of the medical therapies could prevent this increase.Interpretation: The frequency of LUTS increased in cases where the ureteral stent was applied and discomfort continued as long as the stent stayed in the body.

scholarly journals Zingerone Ameliorates Hepatotoxicity

2020 ◽  
Vol 11 (1) ◽  
pp. 280-284 ◽  
Author(s):  
Julietpoornamathy J ◽  
Parameswari C.S.
Keyword(s):  
The Body ◽  
Control Group ◽  
Medical Sciences ◽  
Toxic Compounds ◽  
Group 4 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Insight Into ◽  
Group 1

In medical sciences, toxicity is an area wherein extensive studies have been carried to improve the diseases as well as to prevent. So, there is a high requirement for novel and improved alternative therapeutic strategies to manage diseases. The liver is the largest gland in the body, which executes several important mechanisms; it stores minerals and vitamins and releases them in periods of need. The main aim of this study was to give a closer insight into potent non- toxic compounds that is capable of modifying the responses. Animals were divided into five equal groups viz control (Group 1), administered with food and water ad libitum, (Group 2) administered with olive oil, (Group 3) administered with zingerone, (Group 4) administered with concanavalin A, (Group 5) administered with cyclosporine A followed by zingerone. Our results revealed significant changes in liver marker enzymes and liver histology of zingerone treated rats when compared to control rats.  A corollary, zingerone has no toxic effect on hepatocytes and was found to be safe at a dose of 10mg/kg b wt and also ameliorates hepatotoxicity.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Testing Machine ◽  
Resin Cement ◽  
Control Group ◽  
Sem Images ◽  
Group 4 ◽  
Modes Of Failure ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

scholarly journals HBX-6, Standardized Cornus officinalis and Psoralea corylifolia L. Extracts, Suppresses Benign Prostate Hyperplasia by Attenuating E2F1 Activation

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1719 ◽  
Author(s):  
Bo-Ram Jin ◽  
Hyo-Jung Kim ◽  
Jong-Hwan Seo ◽  
Myoung-Seok Kim ◽  
Kwang-Ho Lee ◽  
...  
Keyword(s):  
Therapeutic Effects ◽  
Herbal Formula ◽  
Psoralea Corylifolia ◽  
Prostate Hyperplasia ◽  
Cornus Officinalis ◽  
Group 4 ◽  
Group 5 ◽  
Group 2 ◽  
Related Proteins

Background: The aim of this study was to simplify and identify the contents of the herbal formula, HBX-5. This study was carried out to evaluate the therapeutic effects of HBX-6 in a mouse model of benign prostatic hyperplasia (BPH). Based on in vitro, we selected a candidate, reconstituted an experimental agent and investigated the effects on testosterone-induced BPH rats. Cell viability was determined by MTT assay in RWPE-1 and WPMY-1 cells. The expression of androgen receptor (AR) was measured in dihydrotestosterone-stimulated RWPE-1 and WPMY-1 cells. BPH was induced in mice by a subcutaneous injection of testosterone propionate for four weeks. Animals were divided into six groups: Group 1, control mice; Group 2, mice with BPH; Group 3, mice with BPH treated with finasteride; Group 4, mice with BPH treated with 200 mg/kg HBX-5; Group 5, mice with BPH treated with 100 mg/kg HBX-6; and Group 6, mice with BPH treated with 200 mg/kg HBX-6. Changes in prostate weight were measured after treatments, and the thickness of the epithelium was evaluated. The expression levels of proteins associated with prostatic cell proliferation and cell cycle-related proteins were determined. Based on previous reports and in vitro results, we selected Cornus officinalis and Psoralea corylifolia among HBX-5 components and reconstituted the experimental agent, and named it HBX-6. The result represented a new herbal formula, HBX-6 that suppressed the pathological alterations in BPH and showed a marked reduction in proliferation-related protein expression compared to mice with BPH. Our results indicate that HBX-6 has a better therapeutic effect in the BPH murine model than those of HBX-5 and finasteride, suggesting the role of HBX-6 as a new BPH remedial agent.

scholarly journals The Influence of Post Bleaching Treatments in Stain Absorption and Microhardness

2016 ◽  
Vol 10 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Horieh Moosavi ◽  
Fatemeh Darvishzadeh
Keyword(s):  
Color Change ◽  
Enamel Surface ◽  
Control Group ◽  
Surface Microhardness ◽  
Dental Bleaching ◽  
Tooth Color ◽  
Group 4 ◽  
Group 3 ◽  
Group 2

Objectives: This study investigated the effects of post bleaching treatments to prevent restaining and the change of enamel surface microhardness after dental bleaching in vitro. Methods: Sixty intact human incisor teeth were stained in tea solution and randomly assigned into four groups (n=15). Then samples were bleached for two weeks (8 hours daily) by 15% carbamide peroxide. Tooth color was determined both with a spectrophotometer and visually before bleaching (T1) and immediately after bleaching (T2). Next, it was applied in group 1 fluoride (Naf 2%) gel for 2 minutes, and in group 2 a fractional CO2 laser (10 mJ, 200 Hz, 10 s), and in group 3, nanohydroxyapatite gel for 2 minutes. The bleached teeth in group 4 remained untreated (control group). Then teeth placed in tea solution again. Color examinations were repeated after various post bleaching treatments (T3) and restaining with tea (T4) and color change values recorded. The microhardness was measured at the enamel surface of samples. Data was analyzed using ANOVA, Tukey HSD test and Dunnett T3 (α = 0.05). Results: Directly after bleaching (ΔE T3-T2), the treatment with nanohydroxyapatite showed significantly the least color lapse in colorimetric evaluation. In experimental groups, the color change between T3 and T4 stages (ΔE T4-T3) was significantly lower than control group (P < 0.05). Different methods of enamel treatment caused a significant increase in surface microhardness compared to control group (P < 0.05). Significance: Application of fluoride, fractional CO2 laser and nanohydroxyapatite as post bleaching treatments are suggested for prevention of stain absorption and increasing the hardening of bleached enamel.

scholarly journals Effect of Different Neutralizing Agents on Feldspathic Porcelain Etched by Hydrofluoric Acid

2019 ◽  
Vol 13 (01) ◽  
pp. 075-081 ◽  
Author(s):  
Tool Sriamporn ◽  
Ploypim Kraisintu ◽  
Lily Pachanin See ◽  
Somporn Swasdison ◽  
Awiruth Klaisiri ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Control Group ◽  
Sem Images ◽  
Carbonate Group ◽  
Aging Conditions ◽  
Feldspathic Porcelain ◽  
Group 5 ◽  
Group 2

Abstract Objective The aim of this study was to evaluate the effect of neutralizing agents on the shear bond strength of hydrofluoric (HF)–etched porcelain in nonaging and aging conditions. Subjects and Methods One hundred and twenty feldspathic porcelain specimens were prepared and divided into six groups to undergo different surface conditioning methods—group 1: control; group 2: HF; group 3: HF + calcium hydroxide; group 4: HF + calcium carbonate; group 5: HF + calcium gluconate; and group 6: HF + ultrasonic. All samples were immersed in 37°C distilled water for 24 h. Half of the samples were thermocycled in water for 5,000 cycles. The shear bond strength test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were statistically analyzed by two-way ANOVA and Tukey's multiple comparison test at a 95% confidence level. The surface micromorphology and surface elements were analyzed using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. Results The shear bond strengths of groups 2–6 were significantly higher than the control group in both aging and nonaging conditions (p < 0.05). There were no significant differences among all of the HF-etched porcelain groups (p > 0.05). SEM images of groups 2–6 illustrated similar patterns of irregularity on the specimen surfaces. Elemental analysis of EDX demonstrated identical elements on surfaces of specimens of groups 2–6. Conclusion Within the limitations of this study, shear bond strength values between HF-etched porcelain, HF-etching followed by application of neutralizing agents, and HF-etching followed by ultrasonic cleaning were not significantly different in both nonaging and aging conditions.

scholarly journals AN INVITRO COMPARATIVE EVALUATION OF FRACTURE RESISTANCE OF ENDODONTICALLY TREATED TEETH OBTURATED WITH RESILON AND GUTTA-PERCHA

2014 ◽  
Vol 04 (03) ◽  
pp. 075-079
Author(s):  
Kiran Halkai ◽  
Rahul Halkai ◽  
Mithra N. Hegde ◽  
Vijay Kumar ◽  
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Control Group ◽  
Endodontically Treated Teeth ◽  
Group 4 ◽  
Anterior Teeth ◽  
Ah Plus ◽  
Group 3 ◽  
Group 2

Abstract Aim: To compare and evaluate in-vitro the fracture resistance of endodontically treated teeth obturated with resilon & epiphany sealer and guttapercha using different sealers. Epoxy resin based sealer AH-plus and zinc oxide eugenol based sealer-TubliSeal (EWT). Methodology: sixty four human single rooted maxillary anterior teeth, cleaned stored in 0.9% saline. All the teeth were decoronated to root length 14mm and bucco-lingual diameter of 5-7mm, After access openings teeth were instrumented using K3.06 up to final apical size 30/.06 and randomly allocated into 4 experimental groups (n=16 per group). Group 1(Control group): teeth were instrumented but not obturated, Group 2: Resilon cones and epiphany SE-sealer. Group 3: guttapercha cones and epoxy based sealer AH plus. Group 4: guttapercha and Tubli seal EWT. Coronal seal was done using IRM cement. Each of the specimens were tested for fracture resistance by instron universal testing machine. Results: Higher fracture resistance values were observed for group 2 (Resilon & Epiphany SE sealer) followed by group 3(Guttapercha & AH Plus sealer) and group 4(Guttapercha & TubliSeal EWT) when compared to group1 (control-instrumented but not obturated). Conclusion: filling the root canals with contemporary polymer based root canal obturating system- Resilon increased the in vitro fracture resistance of endodontically treated teeth.

Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights

2007 ◽  
Vol 8 (5) ◽  
pp. 34-42 ◽  
Author(s):  
Yonca Korkmaz ◽  
Nuray Attar
Keyword(s):  
Bond Strength ◽  
Testing Machine ◽  
Significance Level ◽  
Group 4 ◽  
Group 6 ◽  
Group 3 ◽  
Curing Light ◽  
Group 5 ◽  
Group 2 ◽  
Self Etch

Abstract Aim The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with halogen LCUs on the shear bond strength (SBS) of one nanofill composite (Filtek Supreme) and one microhibrid composite (Artemis) with self-etch adhesives. Methods and Materials The buccal surfaces of 60 non-carious extracted human molars were flattened to expose dentin and, subsequently, polished for 60 seconds with 600-grit wet silicon carbide abrasive paper. Specimens were assigned into six groups (n=10) according to composite material, self-etch adhesive, and curing light used as follows: Group 1: Adper Prompt L-Pop (AP) and Filtek Supreme (FS) using an Elipar Free Light (EFL); Group 2: AP and FS using an Elipar Free Light 2 (EFL2); Group 3: AP and FS using a Hilux Expert (HE) light, Group 4: AdheSE (AS)+Artemis (AR) using an EFL; Group 5: AS+AR using an EFL2; and Group 6: AS+AR using a HE light. The specimens were thermocycled for 500 cycles (5°C–55°C) and then loaded to failure in a Zwick universal testing machine at a crosshead speed of 5 mm/minute. SBS values were calculated as megapascals (MPa) and statistically analyzed using the one-way analysis of variance (ANOVA) test at a significance level of 0.05. Results Mean SBS (± standard deviations) values were as follows: Group1: 15.99±5.18; Group 2: 18.76±6.71; Group 3: 17.70±5.04; Group 4: 16.93±3.99; Group 5: 18.01±5.19, and Group 6: 17.46±5.40. There were no statistically significant differences for SBS to dentin among the groups tested. Conclusion The LED curing lights used in the study seem to be comparable with the halogen curing light for nanofill and microhybrid composites used in conjunction with self-etching systems in dentin. The EFL2 reduces curing time, which can be considered as an advantage. Citation Korkmaz Y, Attar N. Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights. J Contemp Dent Pract 2007 July;(8)5:034-042.

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