scholarly journals The flow rate of endodontic sealers in various consistencies

2020 ◽  
Vol 67 (1) ◽  
pp. 27-35
Author(s):  
Dragan Ilic ◽  
Renata Petrovic ◽  
Bojan Dzeletovic ◽  
Veljko Ilic

Introduction. The flow of endodontic sealer (ES) is the property that characterizes its velocity along the certain surface and depends on the friction force. The aim of this research was to measure the flow rate of three zinc oxide eugenol based ES?s in various consistencies exposed to the load of 2 kg. Material and methods. The experimental group included prepared samples of sealers protocoled by ADA specification No. 57 A) Endomethasone N in liquid:powder ratio of 1:5, 1:6, 1:7 (standard), 1:8 and 1:9 according to the manufacturer brochure depending on the clinical situation; B) Roth 801 as 1:7 (standard) and 1:8 mixtures C) Tubliseal EWT as standard preparation (base-catalyst 1:1). A volume of 0.05 ml sealer was spread on the glass plate and upon applying the load of 2 kg the diameter of sealer was measured. In the control group the sealer samples were loaded only by the weight of glass plate (0.1kg). Results. Based on measured diameters of sealers, all of them satisfied ADA requirements for the flow (d>20mm) (Endomethasone - 20.7-27.8 mm; Roth 801- 29.6-30.0 mm; Tubliseal -39.9 mm). The thin consistency of sealers (1:5, 1:6) showed significantly higher flow than standard mixture (1:7) (p < 0.05). Conclusion. Tubliseal EWT sealer showed the highest flow rate, significantly different than standard mixtures (1:7) of Endomethasone N and Roth 801.

2013 ◽  
Vol 70 (1) ◽  
pp. 21-25
Author(s):  
Dragan Ilic

Background/Aim. Endodontic sealers (ES) for obturation are usually prepared with a slight variation of their components both on purpose or unintentionally. Considering that fact, as well as a frequent use of compaction techniques with the applied force to gutta-percha and ES of 1-3 kg, the aim of this study was to investigate the flow of two zinc-oxide eugenol ES in regard to the applied force and a variation of sealer?s components. Methods. The experimental group samples of both ES were prepared according to the manufacturer?s instructions, applied between pair of glass slabs and loaded by weights of 1 and 2 kg, respectively (American National Standard, Specification No. 57). Some samples of one ES were prepared as thick consistency with 10% more powder and some as thin mixture with 10% less powder than the standard prescription. These semples had been exposed to the load of 2 kg. The control group included samples of both ES prepared as standard prescription but exposed to the weight of one glass slab only. The spread ES appeared as a regular circle 10 min upon mixing and weighting. Measuring of the circle diameter was done by an orthodontic ruler. The flow of the used ES was considered the function of its spread diameter. Results. Application of 1 vs 2 kg load for both regularly mixed sealers in the scope of disk diameter (flow) was statistically insignificant (p > 0.05). This means that the stated null hypothesis that there would be no significant difference in flow rate among the regularly mixed sealers at the level of ? = 0.05 is accepted. The findings about difference in the disk diameter in regard to mixing variation of Endomethasone indicate that the null hypothesis that there would be no significant difference in flow rate between the regular and thick mixed mass at the level of ? = 0.05 is accepted. In the comparison of regular and thin mix a significant difference was noted and the null hypotesis is rejected (p < 0.01). The control group results displayed Roth 801 as less viscous than Endomethasone sealer (p < 0.01). Conclusion. Application of 1 or 2 kg pressure on the samples of both exposed sealers does not significantly affect the flow values as well as comparison of the regular to thick consistency of Endomethasone while comparison of its regular to thin mass shows a significant difference.


2021 ◽  
Vol 19 ◽  
pp. 228080002098740
Author(s):  
Haiyun Liu ◽  
Yanfeng Li ◽  
Guangquan Chai ◽  
Yuan Lv ◽  
Changjian Li ◽  
...  

Objective: To evaluate the effect of synchronous water irrigation on the fatigue resistance of nickel-titanium instrument. Methods: A standardized cyclic fatigue test models were established, and five types of nickel-titanium instruments (PTU F1, WO, WOG, RE, and M3) were applied. Each instrument was randomly divided into two groups ( N = 12). There was synchronous water irrigation in the experimental group, and no water irrigation in the control group. Besides, ProTaper Universal F1 was randomly divided into 10 groups ( N = 20). In the static group, nickel-titanium instruments were divided into one control group (no irrigation, N = 20) and six experimental group (irrigation, N = 20) based on different flow rate, angle and position; while in the dynamic group, instruments were divided into one control group (no irrigation, N = 20) and two experimental group (irrigation, N = 20) based on different flow rate. The rotation time (Time to Failure, TtF) of instruments was recorded and analyzed. Results: According to the static experiments, the TtF of instruments in all experimental groups was significantly higher than that in the static control group. Besides, the dynamic tests of PTU F1 showed that the TtF in the experimental group was significantly higher than that in the dynamic control group. Compared with control group, the TtF in the experimental groups increased by at least about 30% and up to 160%. The static and dynamic tests of PTU F1 showed that the TtF of nickel-titanium instrument in all experimental groups was significantly higher than that in the control group. However, there was no significant difference between any two experimental groups. Conclusion: Regardless of dynamic or static model, TtF with irrigation was longer than that with non-irrigation, indicating that synchronous irrigation can increase the fatigue resistance of nickel-titanium instrument. However, different irrigation conditions may have the same effect on the fatigue resistance.


2002 ◽  
Vol 16 (2) ◽  
pp. 127-130 ◽  
Author(s):  
Jesus Djalma Pécora ◽  
Rodrigo Gonçalves Ribeiro ◽  
Danilo M. Zanello Guerisoli ◽  
João Vicente Baroni Barbizam ◽  
Melissa Andréia Marchesan

The objective of this research was to evaluate, in vitro, the importance of the correct manipulation of endodontic sealers, correlating it with flow rate and with the consequent obturation of root canals. Twenty-four human canines were prepared, 1 mm from the apex, with K-files up to size 50, by means of the step-back technique. Six lateral canals were then drilled in each tooth, with size 10 file fixed to a low-speed handpiece. The teeth were randomly divided into 4 groups, and root canals were obturated either with the Endométhasone<FONT FACE=Symbol>Ò</FONT> sealer or Grossman sealer, prepared at ideal or incorrect clinical consistency. After obturation by means of the lateral condensation technique, the teeth were radiographed and evaluated as to the number of sealed lateral canals. Statistical analysis revealed significant differences (p < 0.001) between the tested sealers, and indicated the higher capacity of the well-manipulated Grossman sealer to fill lateral canals. It can be concluded that the flow rate of a sealer and its correct manipulation are very important for the satisfactory obturation of lateral canals.


Author(s):  
D.C. Dominguez ◽  
J.T. Ellzey

Peroxisomes which participate in 1ipid metabolism have been shown to be altered in several metabolic disorders and toxic conditions. In alcoholic liver disease, the single lesion most frequently found is lipid accumu1ation in hepatocytes. However, the mechanisms for this 1ipid accumu1ation are not clear. The occurrence of modifications of liver peroxisomes due to excess alcohol consumption has not been subjected to a controlled study. We utilized a combination of cytochemica1 and morphometrictechniques to study the size and number of liver peroxisomes in rats fed an alcohol-supplemented diet compared to those of matched-paired control animals.Male Sprague-Daw1ey rats (400-500 g) received a liquid diet. The experimental group (N = 5/group) was fed a diet containing 30% ethanol-derived calories (EDC) and the control group was fed an isocaloric diet to 30% EDC. A pair feeding procedure was employed to control for caloric intake. Small pieces of liver randomly selected, were fixed in 2.3% -glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.2, incubated in a DAB medium and postfixed with. 2% aqueous osmium tetroxide. EM photographs were taken from sections of 3 tissue blocks from each sample (7,200X) with a Zeiss EM10-A (60 kV). With the use of a point counting method and a digital planimeter the volume density (Vv) and numerical density (Nv) were determined.


1999 ◽  
Vol 58 (4) ◽  
pp. 263-272
Author(s):  
Jörg Doll ◽  
Michael Dick

The studies reported here focus on similarities and dissimilarities between the terminal value hierarchies ( Rokeach, 1973 ) ascribed to different groups ( Schwartz & Struch, 1990 ). In Study 1, n = 65 East Germans and n = 110 West Germans mutually assess the respective ingroup and outgroup. In this intra-German comparison the West Germans, with a mean intraindividual correlation of rho = 0.609, perceive a significantly greater East-West similarity between the group-related value hierarchies than the East Germans, with a mean rho = 0.400. Study 2 gives East German subjects either a Swiss (n = 58) or Polish (n = 59) frame of reference in the comparison between the categories German and East German. Whereas the Swiss frame of reference should arouse a need for uniqueness, the Polish frame of reference should arouse a need for similarity. In accordance with expectations, the Swiss frame of reference significantly reduces the correlative similarity between German and East German from a mean rho = 0.703 in a control group (n = 59) to a mean rho = 0.518 in the experimental group. Contrary to expectations, the Polish frame of reference does not lead to an increase in perceived similarity (mean rho = 0.712).


Author(s):  
J. Santoantonio ◽  
L. Yazigi ◽  
E. I. Sato

The purpose of this study was to investigate the personality characteristics in adolescents with SLE. The research design is a case-control study by means of the Rorschach Method and the Wechsler Intelligence Scale. Study group: 30 female adolescents with lupus, 12–17 years of age. The SLE Disease Activity Index was administered during the period of psychological evaluation. Control group: 32 nonpatient adolescents were matched for age, sex, and socioeconomic level. In the Wechsler Intelligence Scale the mean IQ of the experimental group was significantly lower than that of the control group (77 and 98, respectively, p < .001). In the Rorschach, the lupus patients showed greater difficulty in interpersonal interactions, although they displayed the resources to process affect and to cope with stressful situations. A positive moderate correlation (p = .069) between the activity index of the disease and the affect constriction proportion of the Rorschach was observed: the higher the SLEDAI score, the lower the capacity to process affect. There is a negative correlation between the activity index of the disease and the IQ (p = .001): with a higher activity index of the disease, less intellectual resources are available.


Author(s):  
Leonard Reinecke ◽  
Sabine Trepte

Abstract. This quasi-experimental study examined the effects of exposure to a computer game on arousal and subsequent task performance. After inducing a state of low arousal, participants were assigned to experimental or control conditions via self-selection. Members of the experimental group played a computer game for five minutes; subjects in the control group spent the same amount of time awaiting further instructions. Participants who were exposed to the computer game showed significantly higher levels of arousal and performed significantly better on a subsequent cognitive task. The pattern of results was not influenced by the participants' prior experience with the game. The findings indicate that mood-management processes associated with personal media use at the workplace go beyond the alteration of arousal and affect subsequent cognitive performance.


Author(s):  
Laetitia Idier ◽  
Aurélie Untas ◽  
Nicole Rascle ◽  
Michèle Koleck ◽  
Maider Aguirrezabal ◽  
...  

Introduction:Psychological impact of Therapeutic Patient Education (TPE) for dialysis patients is rarely evaluated since the focus of many studies is on medical variables (i.e., adherence).Objectives:The aims of this study were: 1) to estimate the impact of a TPE program on knowledge, depression and anxiety, 2) to examine change in knowledge as a mediator of the effects of a TPE program on mental health.Method:This study was conducted in three hemodialysis units and comprised two groups: an experimental group with education and a control group with routine care. The program was based of 5 educative sessions. Knowledge, depressive and anxious symptoms were assessed with self-reported outcomes measured before and 3 months after the program.Results:The sample comprised 125 patients. Knowledge about vascular access and nutrition (p < 0.01) and depressive symptoms increased in the experimental group (p < 0.01). Analysis of mediation showed that changes in knowledge about vascular access were a significant mediator of the effects of the program on depressive symptoms (F = 4.90;p = 0.01).Discussion:Knowledge acquired during an educational program could lead to an emotional change. Improving knowledge often leads to an awareness of the risks that can modify the psychological state of patients by reminding them of their vulnerability. This study shows that it is required to be attentive to the way of transmitting knowledge. It’s necessary adapting this transmission to the needs of patients and promoting the acquisition of psychosocial competence too.Conclusion:This study shows that knowledge acquired during an educational program can lead to an emotional change in the short term. A long-term follow-up of the population should be interesting to observe these emotional effects.


Author(s):  
E. L. Kuznetsova ◽  
L. A. Dultsev ◽  
E. V. Safin

Goal of research - the study aims to examine the osteopathic profi le of children with dysarthria and to develop recommendations for osteopathic correction of somatic dysfunctions in 2-3 year old children presenting this pathology.Materials and methods. 30 2-3 year old children with the symptoms of dysarthria took part in the research. All the children were divided into 2 groups: the control group of 15 children received standard treatment, and the experimental group of 15 children received both standard and osteopathic treatment. The dysarthria severity and the osteopathic profi le were evaluated with account of the number of somatic dysfunctions at global, regional, and local levels.Results. The osteopathic correction was shown to have a positive effect on dysarthria severity. The study established a correlation between the dysarthria severity in children and the number of somatic dysfunctions at the local level.Conclusion. The study suggests using osteopathic correction of somatic dysfunctions in the complex therapy of dysarthria in children.


2020 ◽  
pp. 15-18
Author(s):  
Inna R. Kilmetova ◽  
◽  
Igor A. Rodin ◽  
Nazira I. Khayrullina ◽  
Nikolay G. Fenchenko ◽  
...  

Summary. The disbalanced feeding and the uneven distribution of micro- and macroelements in the environment leads to a trace element, in particular hypomelanosis. To accelerate the growth and preservation of young farm animals include in the diet of various biological additives and drugs, which include selenium. For stimulation of weight gain in the livestock industry, as well as for the prevention and treatment of pathological processes in addition to micro - and macrouse amino acids, primarily methionine. The aim of this work was to study the influence of composition of DAFS-25+Polizon on morpho-biochemical parameters of blood and functional state of the liver in fattening bulls of black-motley breed in the conditions of the Republic of Bashkortostan. Experiments using were conducted on bull-calves of black-motley breed of the properties in the properties age from 6 to 15 months. The first experimental group during the experiment was additionally given the composition of DAFS-25+Polizon at a dose of 2 mg/kg, the animals of the control group received a standard diet. To assess the impact of the composition DAFS-25+Polizon on metabolism cattle studied morphological and biochemical indicators of blood and conducted histological examination of the liver. It is established that the use of the composition of DAFS-25+Polizon at a dose of 2 mg/kg increases the number of erythrocytes and hemoglobin in the experimental group and reduces the amount of white blood cells. The serum content of total protein, phosphorus and calcium increases in the group of experimental animals. Microscopic examination of the liver revealed no changes in the structure of the organ and hepatocytes in the experimental group, whereas in the control group hemodynamic disorders and dystrophic changes in liver cells were observed. Thus, the use of the composition DAFS-25+Polizon at a dose of 2 mg/kg of live weight in fattening bulls black-and-white breed contributes to the increase of redox processes in the body, stimulation of metabolism, prevent the development of liver disorders of cellular mechanisms of metabolism, optimizes the structure of the liver, which generally provides higher productivity.


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