Psychophysically Based Physical Capability Limits For Right Angle Power Tool Operation

2020 ◽  
Vol 64 (1) ◽  
pp. 910-914
Author(s):  
Jonathan Valencia ◽  
Joel Cort
Keyword(s):  
Analysis Of Variance ◽  
The Other ◽  
Mixed Design ◽  
Joint Orientation ◽  
Physical Capability ◽  
Subject Variables ◽  
Group A ◽  
Repeated Analysis ◽  
Post Hoc

A psychophysical methodology was utilized to examine 40 non-skilled female participants performing right-angle power tool (RAPT) fastening tasks. A combination of two between subject variables were examined for a total of four between-subject groups: joint orientation (horizontal and vertical planes) and joint hardness (hard and soft joints). Participants were evenly distributed into one of four joint orientation- hardness groups. Within each group, a combination of three fastening strategies and three fastening frequencies were performed by each participant. The chosen target torque determined the physical capability limits (PCL). A mixed-design repeated analysis of variance with Tukey’ significance post hoc test were used to determine any significance with the measured variables ( p<0.05). Fastening strategy and frequency influenced the chosen torque magnitude. Participants chose significantly higher target torques with the Turbo Tight strategy in comparison to the other two strategies. Furthermore, participants chose to accept lower target torques and forces as fastening frequency increased.

scholarly journals Maxillary incisor retraction: evaluation of different mechanisms

2013 ◽  
Vol 18 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Antônio Carlos de Oliveira Ruellas ◽  
Matheus Melo Pithon ◽  
Rogério Lacerda dos Santos
Keyword(s):  
Stainless Steel ◽  
Heat Source ◽  
Analysis Of Variance ◽  
Steel Wire ◽  
The Other ◽  
Maxillary Incisor ◽  
Tukey Test ◽  
Group A ◽  
Incisor Retraction ◽  
Incisor Inclination

OBJECTIVE: To mechanically evaluate different systems used for incisors retraction. METHODS: Three different methods for incisors retraction using 0.019 x 0.025-in stainless steel wire were evaluated. The samples were divided into three groups: Group A (retraction arch with 7-mm high vertical hooks); Group G3 (elastic chain attached to the miniimplant and to the 3-mm stainless steel hook soldered to the retraction arch); Group G6 (elastic chain attached to the mini-implant and to the 6-mm stainless steel hook soldered to the retraction arch). A dental mannequin was used for evaluation in order to simulate the desired movements when the device was exposed to a heat source. The analysis of variance (ANOVA) and the Tukey test were used (p < 0.05). RESULTS: The results demonstrated that Groups G3 and G6 exhibited less extrusion and less incisor inclination during the retraction phase (p < 0.05). With regard to incisor extrusion, statistically significant differences were observed between Groups A and G3, and between Groups A and G6 (p < 0.05). Regarding incisor inclination, statistically significant differences were observed between the three systems evaluated (p < 0.05). CONCLUSIONS: Arches with 6-mm vertical hooks allow the force to be applied on the center of resistance of the incisors, thus improving mechanical control when compared with the other two systems.

scholarly journals Fluoride kinetics in saliva after the use of a fluoride-containing chewing gum

2005 ◽  
Vol 19 (4) ◽  
pp. 256-260 ◽  
Author(s):  
Maria Francisca Thereza Borro Bijella ◽  
Fernanda Lourenção Brighenti ◽  
Maria Fernanda Borro Bijella ◽  
Marília Afonso Rabelo Buzalaf
Keyword(s):  
Dental Caries ◽  
Acid Hydrolysis ◽  
Analysis Of Variance ◽  
Dental Fluorosis ◽  
The Other ◽  
Chewing Gum ◽  
Other Hand ◽  
High Fluoride ◽  
The Mean ◽  
Post Hoc

There is a relationship between the use of fluoride, the reduction of dental caries and the increase of dental fluorosis. The purpose of this study was to analyze the fluoride kinetics in saliva after using the HappydentTM chewing gum, which contains 3.38 mg of fluoride as monofluorophosphate. Fifteen 7-9-year-old volunteers were instructed to chew the gum TridentTM (control) and HappydentTM on different days. Total saliva was collected for 3 minutes, at 0, 3, 6, 9, 15, 30 and 45 minutes after starting chewing. Salivary fluoride was analyzed with a fluoride-specific electrode (Orion 96-09) after acid hydrolysis. The data were analyzed by two-way analysis of variance and by Tukey’s post hoc test (p < 0.05). The mean amounts ± sd (mg) of fluoride released in saliva were 0.276 ± 0.126 and 0.024 ± 0.014 for HappydentTM and TridentTM respectively. The fluoride amount in the saliva samples after the use of Happydent was significantly higher than after the use of TridentTM in all experimental periods, except after 30 and 45 minutes. The high fluoride presence in saliva after the use of Happydent may be significant to prevent dental caries and this should be evaluated in clinical researches. On the other hand, children at an age of risk for dental fluorosis should avoid the use of HappydentTM.

scholarly journals Influência da polimerização adicional na microdureza de compósitos diretos para uso indireto: estudo in vitro

2020 ◽  
Vol 42 ◽  
pp. e35
Author(s):  
Carlos Henrique Camilo Marcehsan ◽  
Angela Isabel dos Santos Dullius ◽  
Angela Pellegrin Ansuj ◽  
Vinícius Pinheiro Nunes ◽  
Gislaine Rosa Biachi
Keyword(s):  
Analysis Of Variance ◽  
Composite Resin ◽  
The Other ◽  
Distilled Water ◽  
Led Light ◽  
Post Hoc

The aim of this study was to verify the effect of additional polymerization with microwave and autoclave on the microhardness of 3 different commercial brands of composite resin compared to the ceromere. Cylindrical specimens (6mm x 3mm) were made with a split matrix divided into 10 groups of 13 bodies, with: Photoactivation (LED light on the top surface-40s; photoactivation LED + microwave (500W per 3min) immersed in 100ml distilled water and Photoactivation LED + autoclave (full cycle). The Ceromere group was activated according to the manufacturer's recommendation. The specimens went through a finishing and polishing sequence being stored with a cotton moistened in distilled water for 24h. They were taken to the microhardness meter (three dentations, 50g/15s load). The analysis of variance (ANOVA) was performed with post hoc Games Howell at a level of 5%. It was verified that the ceromere did not differ from the groups Z250 photo and microwave, but was inferior to the Z250 group with autoclave, and the microhardness of this was higher than the other groups. The Tetric group was inferior to all other groups. It was concluded that the additional polymerization methods promoted an increase of the superficial microhardness of the Z250 resin and this did not present a difference of microhardness when compared to the Ceromere

scholarly journals Relative Translucency of a Multilayered Ultratranslucent Zirconia Material

2017 ◽  
Vol 18 (12) ◽  
pp. 1099-1106 ◽  
Author(s):  
Loubna Shamseddine ◽  
Zeina Majzoub
Keyword(s):  
Clinical Significance ◽  
Analysis Of Variance ◽  
Digital Images ◽  
Multiple Comparisons ◽  
The Other ◽  
International Commission ◽  
Transitional Layer ◽  
Post Hoc ◽  
Cie Lab ◽  
Enamel Layer

ABSTRACT Aim The aim of this study was to compare the translucency parameter (TP) of ultratranslucent multilayered (UTML) zirconia according to thickness and layer level. Materials and methods Rectangles of UTML zirconia with four layers [dentin layer (DEL), first transitional layer (FTL), second transitional layer (STL), and enamel layer (ENL)] and four different thicknesses (0.4, 0.6, 0.8, and 1 mm) were milled from blanks. Digital images were taken in a dark studio against white and black backgrounds under simulated daylight illumination and international commission on illumination (CIE) Lab* color values recorded using Photoshop Creative Cloud software. The TP was computed and compared according to thickness and layer level using analysis of variance (ANOVA) followed by Bonferroni post hoc analysis for multiple comparisons. Significance was set at p < 0.05. Results In each thickness, TP values were similar between any two layers. The significant effect of thickness on the TP was observed only in the first two layers. In the DEL, translucency was significantly greater at 0.4 mm than all other thicknesses. In the FTL, differences were significant between 0.4 and 0.8 mm and between 0.4 and 1 mm. Conclusion The investigated zirconia does not seem to show gradational changes in relative translucency from dentin to enamel levels regardless of the thickness used. Thickness affected the TP only in the first two layers with better translucency at 0.4 mm. Clinical significance Since relative translucency does not seem to be significantly different between layers, clinicians can modify the apicocoronal positioning of the UTML layers within the restoration according to the desired Chroma without any implications on the clinically perceived translucency. While the thickness of 0.4 mm may be suggested for anterior esthetic veneers because of its higher translucency, the other thicknesses of 0.6 to 1 mm can be used to mask colored abutments in full contour restorations. How to cite this article Shamseddine L, Majzoub Z. Relative Translucency of a Multilayered Ultratranslucent Zirconia Material. J Contemp Dent Pract 2017;18(12):1099-1106.

Selflessness in Anorexia Nervosa as Reflected in the Rorschach Comprehensive System

2012 ◽  
Vol 33 (1) ◽  
pp. 78-93 ◽  
Author(s):  
Gili Curiel-Levy ◽  
Laura Canetti ◽  
Esti Galili-Weisstub ◽  
Myrna Milun ◽  
Eitan Gur ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Anorexia Nervosa ◽  
Analysis Of Variance ◽  
Clinical Observation ◽  
Comparison Group ◽  
Comprehensive System ◽  
Multivariate Analysis Of Variance ◽  
Rorschach Comprehensive System ◽  
Group A

This study examines the expression of selflessness – the tendency to ignore one’s own needs and serve others’ needs – in Rorschach protocols of women suffering from anorexia nervosa. The protocols of 35 women suffering from anorexia nervosa were compared to 30 protocols of a psychiatric comparison group. A multivariate analysis of variance over five variables (AG, PER, PHR, COP, and GHR) was significant: Anorexic patients showed higher characteristics of selflessness compared to the psychiatric comparison group. These findings contribute to the validation of the Rorschach technique and to the clinical observation of selflessness in anorexic patients, and they emphasize specific characteristics in the treatment of anorexia nervosa patients.

Tonsillar Inflammation, a Rare Cause of Bradycardia and Hypotension

2018 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Streptococcus Pyogenes ◽  
Fusobacterium Necrophorum ◽  
Outpatient Setting ◽  
Peritonsillar Abscess ◽  
The Other ◽  
Streptococcus Group ◽  
Other Hand ◽  
Group A

Tonsillitis is a frequently encountered pathology in the outpatient setting, usually caused by viruses [1]. When bacterial, the most common causatory microbe is streptococcus group A [1]. Tonsillar and peritonsillar abscess (PTA) on the other hand are never viral, and are usually caused by streptococcus pyogenes, Streptococcus melleri, fusobacterium necrophorum and staphylococci [1,2]. The overall incidence of PTA is suggested to be 37/100,000 patients, with the highest incidence between ages 14-21 at 124/100,000 [3].

scholarly journals Effect of Photofunctionalization with 6 W or 85 W UVC on the Degree of Wettability of RBM Titanium in Relation to the Irradiation Time

2021 ◽  
Vol 11 (12) ◽  
pp. 5427
Author(s):  
Arturo Sanchez-Perez ◽  
Nuria Cano-Millá ◽  
María José Moya Villaescusa ◽  
José María Montoya Carralero ◽  
Carlos Navarro Cuellar
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Irradiation Time ◽  
Contact Angles ◽  
The Other ◽  
Control Group ◽  
Hydrophilic Surface ◽  
Biological Ageing ◽  
Ultraviolet C ◽  
Group A

Photoactivation with ultraviolet C light can reverse the effects derived from biological ageing by restoring a hydrophilic surface. Ten titanium discs were randomly divided into three groups: a control group, a 6 W group, and an 85 W group. A drop of double-distilled, deionized, and sterile 10 µL water was applied to each of the discs. Each disc was immediately photographed in a standardized and perpendicular manner. Measurements were taken based on the irradiation time (15, 30, 60, and 120 min). UVC irradiation improved the control values in both groups. There was no difference in its effect between the 6 W group and the other groups during the first 30 min. However, after 60 min and up to 120 min, 85 W had a significantly stronger effect. The contact angles with the 85 W ultraviolet light source at 60 and 120 min were 19.43° and 31.41°, respectively, whereas the contact angles for the 6 W UVC source were 73.8° and 61.45°. Power proved to be the most important factor, and the best hydrophilicity result was obtained with a power of 85 W for 60 min at a wavelength of 254 nm.

Dirty Work and Dirtier Work: Differences in Countering Physical, Social, and Moral Stigma

2014 ◽  
Vol 10 (1) ◽  
pp. 81-108 ◽  
Author(s):  
Blake E. Ashforth ◽  
Glen E. Kreiner
Keyword(s):  
Distinct Group ◽  
The Other ◽  
Future Research ◽  
Identity Threat ◽  
Dirty Work ◽  
Exotic Dancers ◽  
Organization Level ◽  
Group A

The literature on dirty work has focused on what physically (e.g., garbage collectors), socially (e.g., addiction counsellors), and morally (e.g., exotic dancers) stigmatized occupations have in common, implying that dirty work is a relatively monolithic construct. In this article, we focus on thedifferencesbetween these three forms of dirty work and how occupational members collectively attempt to counter the particular stigma associated with each. We argue that the largest differences are between moral dirty work and the other two forms; if physical and social dirty work tend to be seen as more necessary than evil, then moral dirty work tends to be seen as more evil than necessary. Moral dirty work typically constitutes a graver identity threat to occupational members, fostering greater entitativity (a sense of being a distinct group), a greater reliance on members as social buffers, and a greater use of condemning condemners and organization-level defensive tactics. We develop a series of propositions to formalize our arguments and suggest how this more nuanced approach to studying dirty work can stimulate and inform future research.

scholarly journals Characteristics of anteroposterior curvatures of the spine in soccer and futsal players

2017 ◽  
Vol 18 (4) ◽  
Author(s):  
Krystyna Chromik ◽  
Anna Burdukiewicz ◽  
Jadwiga Pietraszewska ◽  
Aleksandra Stachoń ◽  
Paweł Wolański ◽  
...  
Keyword(s):  
College Students ◽  
Statistical Analysis ◽  
Injury Prevention ◽  
Analysis Of Variance ◽  
Statistical Significance ◽  
Body Posture ◽  
Soccer Players ◽  
Prevention Training ◽  
The Difference ◽  
Post Hoc

AbstractPurpose. The aim of the study was to determine differences in anteroposterior spine curvatures between futsal players, soccer players, and non-training students. The results may contribute to the development of present-day knowledge of posturometry, and its implementation in training can help reduce the risk of body posture disorders in athletes. Methods. The examined group consisted of 48 athletes and 38 non-training college students. Body posture parameters were measured with the use of Posturometr-S. The normality of distribution was checked with the Shapiro-Wilk test, and the differences between the groups were measured with ANOVA and the Bonferroni post-hoc test. The level of statistical significance was set at p < 0.05. Results. The analysis of angle values revealed the widest and most similar measurements in the group of futsal players and soccer players. The analysis of variance proved statistically significant differences between the soccer players and futsal players (p = 0.003). The difference between the soccer players and non-training students was statistically significant. The highest γ angular value was measured in non-training students, followed by futsal players and soccer players. The statistical analysis revealed significant differences between the non-training students and futsal players, as well as non-training students and soccer players (p < 0.001). Conclusions. A complex assessment of athletes’ body posture is crucial in injury prevention. Training overloads may often lead to disorders of the organ of locomotion and affect the correct body posture in athletes. This, in turn, may result in pains and injuries.

Interfacial Nanoleakage and Bonding of Self-Adhesive Systems Cured with a Modified-Layering Technique to Dentin of Weakened Roots

2013 ◽  
Vol 38 (5) ◽  
pp. E154-E165 ◽  
Author(s):  
E Mobarak ◽  
R Seyam
Keyword(s):  
Bond Strength ◽  
Repeated Measures ◽  
Adhesive Systems ◽  
Root Canals ◽  
Root Region ◽  
Modes Of Failure ◽  
Group A ◽  
Post Hoc ◽  
Vertise Flow ◽  
Self Etch

SUMMARY Objective The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots. Methods Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05). Results With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p&lt;0.001) but not for root region (p&lt;0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions. Conclusion All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self-adhering systems had higher bond strength than self-etch adhesives.

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