scholarly journals Effects of repeated long-term sodium hypochlorite disinfection treatment on surface hardness and roughness of self-polymerizing reline acrylic resins

2014 ◽  
Vol 2 (1) ◽  
pp. 91
Author(s):  
Luciana Rezende Pinto ◽  
Dayane Rubim ◽  
Paulo Maurício Batista Silva ◽  
Vinícius Carvalho Porto
Keyword(s):  
Sodium Hypochlorite ◽  
Surface Hardness ◽  
Knoop Hardness ◽  
Control Group ◽  
Predisposing Factor ◽  
Denture Stomatitis ◽  
Tukey Test ◽  
Acrylic Resins ◽  
Chemical Disinfectant

Denture stomatitis is the most common alteration on the palate of denture wearers and deficient denture hygiene is an important predisposing factor, because it facilitates both the presence of Candida albicans and bacteria in saliva and their colonization on the oral mucosa and denture surfaces. Sodium hypochlorite is an efficient chemical disinfectant to eliminate denture biofilm, but the effect of long-term disinfection on reline acrylic resins was not studied. Purpose: This study investigated the hardness and roughness of three self-polymerizing reline resins after repeated long-term sodium hypochlorite disinfections. Material and methods: Forty round specimens (30 x 6mm) were made from each material: Jet, Kooliner and Tokuyama Rebase II Fast, and divided in 4 groups (n=10). The control group was stored in water and the others were disinfected with 1%, 2%, 5.25% sodium hypochlorite, respectively. The specimens were tested for knoop hardness (KHN) and roughness (Ra) before disinfection and after 30, 90 and 180 disinfection cycles. Data were analyzed by analysis of variance followed by the Tukey test at 5%. Results: The hardness of Jet resin varied from 18.74 ± 0.47 to 13.75 ± 0.95 KHN, Kooliner varied from 14.09 ± 1.63 to 7.52 ± 0.88 KHN, and Tokuyama Rebase II Fast from 12.57 ± 0.94 to 8.28 ± 0.39 KHN. Statistically significant decrease in hardness of the three reline acrylic resins was observed early after the first 30 disinfection cycles. Conclusion: The hardness of the tested materials decreased after immersion in water and after repeated long-term chemical disinfections

scholarly journals Effects of long-term repeated chemical disinfection treatment on the surface hardness self-polymerizing reline resins

2013 ◽  
Vol 1 (1) ◽  
pp. 55
Author(s):  
Luciana de Rezende Pinto ◽  
Paulo Maurício Batista Silva ◽  
Vinicius Carvalho Porto
Keyword(s):  
Surface Hardness ◽  
Knoop Hardness ◽  
Control Group ◽  
Tukey Test ◽  
Acrylic Resins ◽  
Biofilm Removal ◽  
Chemical Solutions ◽  
1960S And 1970S ◽  
The 1960S

Denture hygiene techniques and procedures were developed in the 1960s and 1970s and most studies indicate the importance of mechanical biofilm removal by denture brushing associated with disinfection with chemical solutions. Studies in the literature show many chemical procedures that may be used for denture biofilm control. When the immersion procedure is used, the disinfectant should be selected with regard to its effectiveness in inactivating microorganisms without any adverse effects on the denture materials. PURPOSE: This study investigated the hardness of three self-polymerizing reline resins after long-term repeated chemical disinfections. MATERIAL AND METHODS: Sixty round specimens (30 x 6mm) were made from each material: Jet, Kooliner and Tokuyama Rebase II Fast, and divided in 6 groups (n=10). The control group was stored in water and the others were disinfected with 1%, 2%, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate, respectively. The specimens were tested for knoop hardness (KHN) before disinfection and after 30, 90 and 180 disinfection cycles. Data were analyzed by analysis of variance followed by the Tukey test at 5%. RESULTS: The hardness of Jet resin varied from 18.74 ± 0.47 to 13.75 ± 0.95 KHN, Kooliner varied from 14.09 ± 1.63 to 7.52 ± 0.88 KHN, and Tokuyama Rebase II Fast from 12.57 ± 0.94 to 8.28 ± 0.39 KHN. Statistically significant decrease in hardness of the three reline acrylic resins was observed early after the first 30 disinfection cycles. CONCLUSION: The hardness of the tested materials decreased after immersion in water and after long-term repeated chemical disinfections.

The Effect of Bleach Liquid and Household Cleaner on Surface Hardness and Roughness of Acrylic Base of Orthodontic Appliances

2021 ◽  
Author(s):  
Saeed Noorollahian ◽  
Farinaz Shirban ◽  
Vahid Mojiri
Keyword(s):  
Surface Roughness ◽  
Hydrochloric Acid ◽  
Sodium Hypochlorite ◽  
Surface Hardness ◽  
Acrylic Resin ◽  
Liquid Sodium ◽  
P Value ◽  
Orthodontic Appliances ◽  
Acrylic Resins ◽  
Significant Difference

Introduction: The daily use of orthodontic removable plates can interfere with the self-cleansing function of the mouth. Although various techniques have been proposed for cleaning removable orthodontic appliances, there is no consensus on the use of a safe method that preserves the physical properties of the appliance. This study aimed to investigate the effect of using hydrochloric acid (10%, for removal of mineral deposits) and sodium hypochlorite (5.25%, to remove organic matter and discolorations) on surface hardness and roughness of self-cure orthodontic acrylic resins. Materials & Methods: This cross-sectional laboratory study was conducted in the fall of 2017 at Isfahan University of Medical science and Isfahan University of Technology. In this study two orthodontic acrylic resins (Orthocryl® and Acropars®) were used. Eighty samples (12×10×3 mm) from each one were fabricated and divided into four groups (n = 20). Group 1: 15 minutes immersion in household cleaner liquid (Hydrochloric acid, 10%) followed by15 minutes immersion in household bleach liquid (Sodium Hypochlorite, 5.25%). In group 2, immersions were repeated just like group two times and in group 3, were done three times. Group 4 was as control and had no immersion. The surface hardness and roughness of samples were measured. Data were analyzed with Two Way ANOVA and the significance level was set at 0.05. Results: The number of immersion procedures did not significantly affect the surface hardness (p value = 0.958) and surface roughness (p value = 0.657) in the different study groups. There was no significant difference in the surface hardness between the two acrylic resin brands (p value = 0.077); however, Acropars acrylic resin samples exhibited significantly higher surface roughness compared to the Orthocryl acrylic resin samples(p value < 0.001). Conclusion: 15 minutes of immersion in 10% HCl, followed by 15 minutes of immersion in 5.25% NaOCl and repetition of the procedure three times did not significantly affect the surface hardness and roughness of self-cured acrylic resins.

scholarly journals Effect of repeated cycles of chemical disinfection in microhardness of acrylic resins of complete denture base

2017 ◽  
Vol 65 (3) ◽  
pp. 196-201
Author(s):  
Elisa das Graças MARTINS ◽  
Rafael Tobias MORETTI NETO
Keyword(s):  
Sodium Hypochlorite ◽  
Knoop Hardness ◽  
Sodium Hypochlorite Solution ◽  
Chlorhexidine Digluconate ◽  
Water Control ◽  
Denture Base ◽  
Acrylic Resins ◽  
Hardness Tests ◽  
Before And After ◽  
Edentulous Patients

ABSTRACT Objective: To evaluate the microhardness of specimens of acrylic resins VipiCril® (thermally polymerized resin) and Bosworth New Truliner® (self-polymerized resin), before and after immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control), testing the null hypothesis that the mouthwashes and chemicals used to disinfect complete dentures do not interfere with the superficial microhardness, and can therefore be used as adjuncts to oral hygiene of edentulous patients. Methods: Sixty specimens of resin VipiCril®(thermally polymerized resin) and 60 specimens of resin Bosworth New Truliner® (self-polymerized resin) measuring 16 mm of diameter and 6 mm of height were prepared, which were randomly divided into four groups of 15 specimens each, undergoing Knoop hardness tests (KHN) both before and after cycles of immersion in solutions of 0.12% chlorhexidine digluconate, 1% sodium hypochlorite, Corega Tabs® and water (control). Results: The specimens of resins VipiCril and Bosworth immersed in solutions of 0.12% chlorhexidine, Corega Tabs® and water showed decreased microhardness. Conclusion: The 1% sodium hypochlorite solution caused least damage to the denture structure, not leading to decrease of the superficial microhardness.

Effect of Nd:YAG Laser Irradiation Pretreatment on the Long-Term Bond Strength of Etch-and-Rinse Adhesive to Dentin

2017 ◽  
Vol 42 (1) ◽  
pp. 62-72 ◽  
Author(s):  
J Gan ◽  
S Liu ◽  
L Zhou ◽  
Y Wang ◽  
J Guo ◽  
...  
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Nd:Yag Laser ◽  
Knoop Hardness ◽  
Control Group ◽  
In Vitro Test ◽  
Dentin Surface ◽  
Etch And Rinse ◽  
Significant Difference

SUMMARY Purpose: To investigate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation pretreatment on the long-term bond strength of an etch-and-rinse adhesive to dentin. Methods: Fifty molars were sectioned parallel to the occlusal plane and randomly divided into two groups (n=25 per group): control group (no treatment) and laser group (dentin surfaces were treated with Nd:YAG laser at a setting of 100 mJ/10 Hz). Afterward, resin was bonded to the dentin surface using a two-step etch-and-rinse adhesive (Adper SingleBond 2), and then 150 beams of each group were produced. Each group was divided into three subgroups (n=50 each group): 24 hours of water storage, thermocycling, and NaOCl storage. The microtensile bond strength (MTBS), failure modes, nanoleakage expression, and Masson's trichrome staining were evaluated. An additional 20 molars were sectioned to obtain 2-mm-thick flat dentin slices. These slices were randomly divided into control and laser-treated groups as mentioned previously. Then slices of each group were examined by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and the Knoop hardness test. Results: The results of ATR-FTIR and Masson's trichrome verified that laser irradiation partly removed collagen fibers from the dentin surface; however, no significant difference was found in the Knoop hardness (p&gt;0.05). The XRD result showed similar crystalline structure regardless of laser pretreatment. There is no significant difference in short-term MTBS between control and laser-treated groups (p&gt;0.05); however, long-term MTBS differed between the groups (p&gt;0.05). Furthermore, the laser-treated group showed less silver deposition than the control group after aging (p&lt;0.05). Conclusion: Pretreatment by Nd:YAG laser irradiation appeared to have a positive effect on the adhesive-dentin bonding in vitro test, and the bonding effectiveness could be preserved after aging.

scholarly journals Effect of Incorporation of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone: An in vitro Study

2017 ◽  
Vol 7 (3) ◽  
pp. 86-91
Author(s):  
Anubhuti Bakshi ◽  
Rajat Dang
Keyword(s):  
Sodium Hypochlorite ◽  
Testing Machine ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Control Group ◽  
Time Interval ◽  
Type Iv ◽  
Post Hoc

ABSTRACT Aim To evaluate surface hardness and dimensional accuracy of type IV dental stone after incorporation of disinfectants. Materials and methods A total of 100 specimens, 50 (40 mm⨯ 10 mm) disk shaped and 50 frustum cone shaped, were fab- ricated from type IV dental stone after incorporation of various disinfectants, namely glutaraldehyde (2%), iodophor (1.76%), chlorhexidine (2%), and sodium hypochlorite (1%), for evaluation of surface hardness and dimensional accuracy. Surface hardness was tested after 1- and 24-hour time interval using Rockwell hard- ness testing machine. Dimensional accuracy was measured using traveling microscope. Data obtained were compiled and analyzed statistically by using analysis of variance and post hoc test. Results Results showed significant decrease in surface hard- ness of samples incorporated with disinfectants at 1 hour as compared with control (distilled water). Surface hardness of all the samples increased with time and was almost equal to control group at 24-hour interval, with iodophor showing the maximum value in comparison with the other disinfectants used. When dimensional accuracy of all the groups was compared, iodophor and sodium hypochlorite were found to cause negative alterations. Conclusion Within the limitations of this in vitro study, it was concluded that incorporation of disinfectants in die stone during mixing did not affect the hardness value at 24-hour interval. Dimensional accuracy was altered by iodophor and sodium hypochlorite, but remained unaffected by chlorhexidine and glutaraldehyde. How to cite this article Bakshi A, Dang R. Effect of Incorpo- ration of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone An in vitro Study. Int J Prosthodont Restor Dent 2017;7(3):86-91.

scholarly journals Acute response of refeeding in tambaqui submitted to long-term fasting

2021 ◽  
Vol 22 ◽  
Author(s):  
Renata Franco dos SANTOS ◽  
Shamila Évellem Magalhães da SILVA ◽  
Monique Ferreira BRANDÃO ◽  
Maria Vitória Marialva da Silva LÔBO ◽  
Deborah Jacob Freire da PAZ ◽  
...  
Keyword(s):  
Serum Protein ◽  
Statistical Significance ◽  
Experimental Period ◽  
Control Group ◽  
Blood Collection ◽  
Hepatic Glycogen ◽  
Tukey Test ◽  
Acute Response ◽  
Mesenteric Fat

ABSTRACT This study aimed evaluate energetic mobilization in tambaqui submitted to fasting, after a one-day refeeding. 120 tambaqui juveniles were distributed in 12 310L polyethylene boxes. Three treatments were evaluated: Control (14 days of feeding); Fasting for 14 days; and Refeeding (13 days fasting and one day of feedback). After the experimental period, the fish were anesthetized with eugenol for blood collection and serum and plasma were used to measure glucose, triglycerides, cholesterol and serum protein. Subsequently, fish were euthanized to remove liver and mesenteric fat and were used to determine hepatic glycogen and lipid and mesenteric fat index. The results were submitted to ANOVA and the means compared by Tukey test when statistical significance was observed (P <0.05). Glucose, triglycerides and serum protein decreased after fasting, differing statistically with the control. Refeeding resulted in the recovery of three blood indicators. Liver analysis shows glycogen was consumed intensely during fasting and partially recovered after refeeding, when compared to control group. The results obtained in this study suggest that the 14-day fast was not harmful to the fish and the tambaqui are able to quickly adjust their metabolism according to their nutritional status.

scholarly journals Effect of Household Denture Cleansers on Color Stability and Tensile Bond Strength of Two Different Heat Polymerized Acrylic Resins

2015 ◽  
Vol 5 (4) ◽  
pp. 95-100
Author(s):  
Ramesh Nadiger ◽  
Anupama Suresh Patankar ◽  
Paulami Bagchi
Keyword(s):  
Tensile Strength ◽  
Bond Strength ◽  
Sodium Hypochlorite ◽  
Testing Machine ◽  
Color Stability ◽  
Tensile Bond Strength ◽  
Control Group ◽  
Acrylic Resins ◽  
Heat Cure ◽  
Denture Cleansers

ABSTRACT Aim Denture cleansers are used not only to clean dentures but also for disinfection of dentures. Among household denture cleansers, bleach (which contains sodium hypochlorite) and vinegar (which contains acetic acid) have been found to be powerful disinfecting agents. The objectives of this in vitro study were to evaluate and compare the color stability and tensile bond strength of Trevalon and Lucitone 199 heat-cured resins after immersing in household denture cleansers like 1% household bleach and 50% vinegar. Methodology A total of 48 Trevalon and Lucitone 199 heat- cure resin samples respectively were fabricated. The samples were divided into three groups of 16 samples each. They were immersed in 1% bleach, 50% vinegar and water (control) respectively. The samples were alternatively immersed in cleanser and water for 8 hours for 20 days simulating 30 days of use. At the end of 20 days, color stability and tensile strength were assessed with the help of spectro-guide and Instron universal testing machine respectively. Results Sodium hypochlorite and vinegar affected the color stability of Lucitone 199 heat-cure acrylic resin. The color of Trevalon heat-cure resin remained unaltered after immersion in both the cleansers. The change in tensile strength of both the resins was not significant after immersion in both the cleansers as compared with water which was used as control group. Conclusion This study concludes that for disinfection and cleansing of denture, sodium hypochlorite can be considered as long as the acrylic used is cross linked. How to cite this article Patankar AS, Meshramkar R, Nadiger R, Bagchi P. Effect of Household Denture Cleansers on Color Stability and Tensile Bond Strength of Two Different Heat Polymerized Acrylic Resins. Int J Prosthodont Restor Dent 2015;5(4):95-100.

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.

Acute and Chronic Changes in Platelet Volume and Count After Cardiopulmonary Bypass Induced Thrombocytopenia in Man

1987 ◽  
Vol 57 (01) ◽  
pp. 55-58 ◽  
Author(s):  
J F Martin ◽  
T D Daniel ◽  
E A Trowbridge
Keyword(s):  
Platelet Count ◽  
Mean Platelet Volume ◽  
Artery Bypass ◽  
Bypass Graft ◽  
Control Group ◽  
Artery Bypass Graft ◽  
Platelet Volume ◽  
Young Males ◽  
The Mean

SummaryPatients undergoing surgery for coronary artery bypass graft or heart valve replacement had their platelet count and mean volume measured pre-operatively, immediately post-operatively and serially for up to 48 days after the surgical procedure. The mean pre-operative platelet count of 1.95 ± 0.11 × 1011/1 (n = 26) fell significantly to 1.35 ± 0.09 × 1011/1 immediately post-operatively (p <0.001) (n = 22), without a significant alteration in the mean platelet volume. The average platelet count rose to a maximum of 5.07 ± 0.66 × 1011/1 between days 14 and 17 after surgery while the average mean platelet volume fell from preparative and post-operative values of 7.25 ± 0.14 and 7.20 ± 0.14 fl respectively to a minimum of 6.16 ± 0.16 fl by day 20. Seven patients were followed for 32 days or longer after the operation. By this time they had achieved steady state thrombopoiesis and their average platelet count was 2.44 ± 0.33 × 1011/1, significantly higher than the pre-operative value (p <0.05), while their average mean platelet volume was 6.63 ± 0.21 fl, significantly lower than before surgery (p <0.001). The pre-operative values for the platelet volume and counts of these patients were significantly different from a control group of 32 young males, while the chronic post-operative values were not. These long term changes in platelet volume and count may reflect changes in the thrombopoietic control system secondary to the corrective surgery.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

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