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.

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

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>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>0.05); however, long-term MTBS differed between the groups (p>0.05). Furthermore, the laser-treated group showed less silver deposition than the control group after aging (p<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 Preliminary Revision of the Palynological Collection of Professor Blanka Pacltová – A Significant Collection of Cenomanian Microflora Housed at the National Museum, Prague

2019 ◽  
Vol 75 (2) ◽  
pp. 141-152
Author(s):  
Eduardo Barrón ◽  
Jiří Kvaček ◽  
Jiřina Dašková
Keyword(s):  
Czech Republic ◽  
National Museum ◽  
The Czech Republic ◽  
Pollen Types ◽  
1960S And 1970S ◽  
Bohemian Cretaceous Basin ◽  
The 1960S ◽  
Angiosperm Pollen ◽  
Long Term Preservation

A preliminary revision of the palynological collection of Professor Blanka Pacltová was carried out considering samples from the middle Cenomanian of the Peruc-Korycany Formation, the basal most member of the Bohemian Cretaceous Basin (the Czech Republic). This collection is mainly composed of slides with palynological residues for light microscope study, which were mounted in the 1960s and 1970s. This work presents an evaluation of the state of preservation of this collection, taking into account the presence of ancient angiosperm pollen types. High percentage of preparations is affected by degradation of glycerine jelly and their remounting is necessary. The present study additionally suggests a methodology for curation of this collection with the objective of long-term preservation.

The Improbable Permanence of a Commitment: America's Troop Presence in Europe during the Cold War

2009 ◽  
Vol 11 (1) ◽  
pp. 3-27 ◽  
Author(s):  
Hubert Zimmermann
Keyword(s):  
Cold War ◽  
The United States ◽  
West Germany ◽  
Fundamental Feature ◽  
Global Policy ◽  
Long Time ◽  
1960S And 1970S ◽  
The 1960S ◽  
The Cold War

This article elucidates a fundamental feature of transatlantic relations during the Cold War: the presence of more than 250,000 U.S. troops in Europe, mainly in West Germany, from 1952 through 1990. The article explains why this unprecedented commitment was extended for such a long time, despite intense domestic debates in the United States in the 1960s and 1970s. Opposition to the troop commitment was particularly strong in Congress. The article shows that the long-term stationing of U.S. troops in Europe was more precarious than often assumed. The article also shows that the debates in the 1960s and 1970s were instrumental in establishing the acceptance of long-term military commitments abroad as a feature of U.S. global policy.

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.

Industrial Parks as Industrial Renewal

2020 ◽  
pp. 159-181
Author(s):  
Robert Lewis
Keyword(s):  
The Other ◽  
Public Private Partnerships ◽  
Industrial Park ◽  
Industrial Parks ◽  
Ordered Space ◽  
Term Basis ◽  
1960S And 1970S ◽  
The 1960S ◽  
Industrial Center

This chapter looks at the other main industrial redevelopment strategy that emerged in the 1960s. It mentions the building of industrial parks in the 1960s and 1970s, such as the Ashland Industrial Center in the deindustrialized Stockyards, that became a failure despite the allocation of significant funds by public–private partnerships. It emphasizes how the institutional fix of the industrial park could not solve the Chicago's manufacturing decline. The chapter refers to industrial areas that consist of many lots managed on a long-term basis by industrial and nonindustrial promoters. It outlines two principles that shaped the development of the industrial park in postwar Chicago: First was modern planning ideas that emerged after 1890 and second was the search for ordered space paralleled by the search for property profits.

Music, the Fête de l’Humanité, and Demographic Change in Post-War France

Red Strains ◽  
2013 ◽  
Author(s):  
Eric Drott
Keyword(s):  
Working Class ◽  
Demographic Change ◽  
Public Outreach ◽  
1960S And 1970S ◽  
Post War ◽  
The 1960S

This chapter examines music's role in the Fête de l'Humanité, an annual festival organized by L'Humanité, the French Communist Party's principal organ. Beyond generating revenue and mobilizing support for the Party, the Fête has long served an important ritual function, fostering a sense of camaraderie among participants. Music has proven particularly effective in this regard, offering a medium through which one's membership in an imagined (communist) community could be experienced. The chapter focuses on the Fête's transformation during the 1960s and 1970s, a period that saw the Party struggle to broaden its electoral appeal beyond its working-class base. By expanding the range of musics featured at the event, its organizers sought to address an increasingly diverse electorate. Yet the Party's reliance on the Fête as an instrument of public outreach proved problematic, given that the image of inclusiveness it projected masked rather than resolved the Party's long-term demographic difficulties.

scholarly journals Aleksei Petersoni roll vepslaste ja udmurtide rahvuslikus taassünnis (1980.–1990. aastad)

2021 ◽  
Vol 63 (1) ◽  
pp. 45-66
Author(s):  
Indrek Jääts ◽  
Svetlana Karm
Keyword(s):  
National Identity ◽  
Mother Tongue ◽  
Folk Culture ◽  
The Press ◽  
High Regard ◽  
1960S And 1970S ◽  
The 1960S ◽  
Almost All ◽  
Relationship Of

Estonian ethnographers have always taken a keen interest in Finno-Ugric peoples, their linguistic kin. The golden age of Finno-Ugric studies in Estonian ethnography began in the 1960s and lasted until the early 1990s. The State Ethnographic Museum of the Estonian SSR in Tartu (the current Estonian National Museum) emerged as the center of Finno-Ugric research with its long-term director Aleksei Peterson at the helm of the enterprise. Estonian ethnographers visited almost all Finno-Ugric peoples, with the major focus given to the Veps in the 1960s and 1970s, and to the Udmurts, in the 1980s. The museum acquired an awe-inspiring number of ethnographic objects, descriptions, photographs, drawings and films. Did all this benefit the peoples visited? What was the relationship of Estonian ethnographers with the subjects of their research? Did their plight affect Estonian scholars? The Estonian ethnographers had a high regard for the ethnic particularities, languages and traditional folk cultures of the kindred peoples and resisted their disappearance. Their views contradicted the Soviet nationalities policy which until the mid-1980s, emphasized the convergence and assimilation of nations. The interaction between the Estonian ethnographers and the Veps and Udmurts during the long series of expeditions helped to stimulate the suppressed and weak ethnic self-esteem of the latter. The mid-1980s marked the beginning of the era of Gorbachev’s glasnost and perestroika. As a result, national issues could be discussed openly, and it was at that time that the national revival of the Veps and Udmurts began. Estonian ethnologists embraced the process and actively contributed to it. This is especially true of Peterson, who was quite well known in Vepsia and Udmurtia and had a certain authority there. In his speeches at various events and in the press, Peterson encouraged the use of Veps and Udmurt in public life, including the schools. He emphasized the need to place a greater emphasis on traditional folk culture, which he considered to be critical to the national identity of small nations. His ideas influenced the creation of the open-air museum of the Udmurts. He supported the territorial autonomy of the Veps. He could speak as a messenger of perestroika whose word had weight. Thus Veps and Udmurt activists and nationally-minded ordinary people received inspiration and moral support from Peterson (and other Estonian ethnographers) for the preservation of their mother tongue, national identity and cultural heritage.

Racism Is Not Enough: Minority Coalition Building in San Francisco, Seattle, and Vancouver

2020 ◽  
Vol 34 (2) ◽  
pp. 195-215 ◽  
Author(s):  
Jae Yeon Kim
Keyword(s):  
United States ◽  
San Francisco ◽  
Minority Groups ◽  
Historical Analysis ◽  
The United States ◽  
Coalition Building ◽  
Exogenous Shocks ◽  
1960S And 1970S ◽  
The 1960S

Scholars have long argued that the marginalized racial status shared by ethnic minority groups is a strong incentive for mobilization and coalition building in the United States. However, despite their members’ shared racial status as “Orientals,” different types of housing coalitions were formed in the Chinatowns of San Francisco, Seattle, and Vancouver during the 1960s and 1970s. Asian race-based coalitions appeared in San Francisco and Seattle, but not in Vancouver, where a cross-racial coalition was built between the Chinese and southern and eastern Europeans. Drawing on exogenous shocks and process tracing, this article explains how historical legacies—specifically, the political geography of settlement—shaped this divergence. These findings demonstrate how long-term historical analysis offers new insights into the study of minority coalition formation in the United States.

Cultural revolution

The Athenaeum ◽  
2020 ◽  
pp. 270-295
Author(s):  
Michael Wheeler
Keyword(s):  
Cultural Revolution ◽  
Public Discourse ◽  
Financial Difficulties ◽  
The 1950S ◽  
1960S And 1970S ◽  
The 1960S ◽  
The Cultural Revolution

This chapter examines the Athenæum during the period from the mid-1950s to the mid-1980s. While enjoying affectionate teasing by cartoonists, the club tended to stand upon its dignity in the 1950s. Although some aspects of the 'cultural revolution' that so disturbed Richard Cowell at the time created divisions among the membership, others suited the club in the long term, allowing it not only to survive but also to position itself for the process of reinvention that was to take place in later decades. During the 1960s and 1970s, life at the club carried on much as before, in spite of recurrent financial difficulties. The decorous tradition of 'lunch at the Athenæum' had become proverbial in public discourse, as published novels, memoirs, and diaries recorded conversations there in which bonds of friendship were strengthened, or matters of state and church quietly arranged in private.

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