scholarly journals The influence of different working lengths on apically extruded debris

2021 ◽  
Vol 10 (4) ◽  
pp. e55410414554
Author(s):  
Karla Garcia ◽  
Ana Grasiela da Silva Limoeiro ◽  
Wayne Martins Nascimento ◽  
Eduardo Mansur Kadi ◽  
Sandra Radaic ◽  
...  
Keyword(s):  
Average Weight ◽  
Agar Gel ◽  
Mean Values ◽  
Root Canals ◽  
Average Value ◽  
Working Length ◽  
Coronal Section ◽  
The Difference ◽  
The One ◽  
Post Hoc

Aim: To evaluate the influence of three different working lengths on the amount of apically extruded debris. Methodology: Thirty lower premolars with single roots and straight root canals were standardized at 17 mm. Then, they were inserted into Eppendorf tubes, and the 1.5% agar gel was introduced into the tubes surrounding the roots. The coronal section of the roots was kept visible. The set of tubes and agar gel was weighed 3 times and the average value was recorded. Then, the specimens were randomly distributed in 3 different groups according to the working length (CT) used for the instrumentation: Group (CT -1) - the working length 1 mm below the major foramen (MF); Group (CT 00) - the length was determined at the MF, and Group (CT +1) - the CT was determined 1 mm beyond the MF. Instrumentation was performed with Reciproc Blue R25 (VDW, Munich, Germany) under irrigation with 0.9% saline. After preparation, samples were removed from Eppendorf tubes and weighed 3 times again. The difference between the mean values ​​of the initial and final weight was recorded. The one-way ANOVA test (post-hoc Bonferroni) was used with P> 0.05. Results: The average weight of the extruded waste was 0.0134 ± 0.0157 for CT -1, 0.0075 ± 0.0062 for CT 00 and 0.0075 ± 0.0068 for CT +1, with no statistically significant differences between groups. Conclusion: There was no impact of the different CTs on the amount of extruded debris beyond the apex.

scholarly journals Fracture resistance of immature teeth filled with mineral trioxide aggregate, bioaggregate, and biodentine

2016 ◽  
Vol 10 (02) ◽  
pp. 220-224 ◽  
Author(s):  
Emre Bayram ◽  
Huda Melike Bayram
Keyword(s):  
Fracture Resistance ◽  
Mineral Trioxide Aggregate ◽  
Mean Values ◽  
Root Canals ◽  
Immature Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Post Hoc ◽  
Group 1

ABSTRACT Objective: The purpose of this study was to evaluate fracture resistance of teeth with immature apices treated with coronal placement of mineral trioxide aggregate (MTA), bioaggregate (BA), and Biodentine. Materials and Methods: Forty-one freshly extracted, single-rooted human premolar teeth were used for the study. At first, the root length was standardized to 9 mm. The crown-down technique was used for the preparation of the root canals using the rotary ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) of F3 (30). Peeso reamer no. 6 was stepped out from the apex to simulate an incompletely formed root. The prepared roots were randomly assigned to one control (n = 5) and three experimental (n = 12) groups, as described below. Group 1: White MTA (Angelus, Londrina, Brazil) was prepared as per the manufacturer's instructions and compacted into the root canal using MAP system (Dentsply Maillefer, Ballaigues, Switzerland) and condensed by pluggers (Angelus, Londrina, Brazil). Group 2: The canals were filled with DiaRoot-BA (DiaDent Group International, Canada). Group 3: Biodentine (Septodont, Saint Maur des Fosses, France) solution was mixed with the capsule powder and condensed using pluggers. Instron was used to determine the maximum horizontal load to fracture the tooth, placing the tip 3 mm incisal to the cementoenamel junction. Mean values of the fracture strength were compared by ANOVA followed by a post hoc test. P < 0.05 was considered statistically significant. Results: No significant difference was observed among the MTA, BA, and biodentine experimental groups. Conclusion: All the three materials tested, may be used as effective strengthening agents for immature teeth.

scholarly journals Retinomotor movements in the Antarctic fish Trematomus newnesi Boulenger submitted to different environmental light conditions

2007 ◽  
Vol 24 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Lucélia Donatti ◽  
Edith Fanta
Keyword(s):  
Pigment Epithelium ◽  
Antarctic Fish ◽  
Constant Darkness ◽  
Time Intervals ◽  
Mean Values ◽  
Environmental Light ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Antarctic

The Antarctic fish Trematomus newnesi (Boulenger, 1902) occurs from benthic to pelagic habitats, in seasonally and daily varied photic conditions that induce retinomotor movements. Fish were experimentally kept under constant darkness or light, and 12Light/12Dark for seven days. The retinomotor movement of the pigment epithelium was established through the pigment index, while that of the cones was calculated as the length of the myoid. The retinomotor movement of the pigment epithelium in T.newnesi,revealed that the adaptation to constant light occurred in the one hour of exposure, remaining constant for the next seven days. However, the adaptation to constant darkness, was slower. The difference between the mean values of the pigment indices in the time intervals of sampling was significant in the first hours of the experiment, and only after six hours they were not significant any more. The myoid of cones became elongated in darkness and contracted in light. In the experiments where T.newnesiwas exposed initially to 12 hours light followed by 12 hours darkness 12 was evidenced that the speed and intensity of the retinomotor movements was higher when darkness changed into light, than when light changed into darkness.

scholarly journals Evaluation of Apically Extruded Debris Using Positive and Negative Pressure Irrigation Systems in Association with Different Irrigants

2018 ◽  
Vol 29 (2) ◽  
pp. 184-188 ◽  
Author(s):  
Marlos Barbosa-Ribeiro ◽  
Rodrigo Arruda-Vasconcelos ◽  
Fabio L. Fabretti ◽  
Emmanuel J. N. L Silva ◽  
Gustavo De-Deus ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Saline Solution ◽  
Irrigation System ◽  
Average Weight ◽  
Irrigation Systems ◽  
Root Canals ◽  
Single Root ◽  
Mechanical Preparation ◽  
Post Hoc ◽  
Chlorhexidine Gel

Abstract This study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) using positive and negative pressure irrigation systems [Conventional irrigation (CI) and EndoVac (EV)] in association with different irrigants [6% Sodium Hypochlorite (NaOCl), 2% Chlorhexidine gel + saline solution (CHXg + SS), 2% Chlorhexidine solution (CHXs) or Saline solution (SS)]. Eighty mandibular premolars with single root canals were selected and randomly assigned into 8 groups (n = 10) according to the irrigation system and the irrigant used during CMP: G1 (EV + NaOCl), G2 (EV + CHXg + SS), G3 (EV + CHXs), G4 (EV + SS), G5 (CI + NaOCl), G6 (CI + CHXg + SS), G7 (CI + CHXs) and G8 (CI + SS). Reciproc® R25 files (25/.08) were used during the CMP and the extruded debris from each tooth was collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed using a microbalance, and the data were statistically analyzed using ANOVA and the post hoc Tukey’s test (a = 0.05). All groups were associated with debris extrusion. EV was the irrigation system with less extruded debris (p < 0.05). No differences were observed regarding the irrigant when EV was used. When CI was used, CHXg + SS were associated with lower debris extrusion (p < 0.05). It was concluded that no irrigation protocol succeeded in preventing debris extrusion. EV resulted in lower levels of debris extrusion than CI. The use of CHXg + SS resulted in lower debris extrusion.

scholarly journals Carbon monoxide protects Neural Stem Cells against iron overload by modulating the crosstalk between Nrf2 and NF-κB Signaling

2021 ◽  
Author(s):  
zhengxing Xie ◽  
Aiying Hu ◽  
qing Wang ◽  
Zengli Miao
Keyword(s):  
Iron Overload ◽  
Redox Homeostasis ◽  
Mean Values ◽  
Downstream Target ◽  
Stroke Models ◽  
Anti Oxidant ◽  
The Difference ◽  
Induced Apoptosis ◽  
Post Hoc ◽  
Survival Effect

Abstract Background:It is well CO is an important gas transmitter. Although accumulating evidences have demonstrated pro-survival effects of CO against various insults, the precise mechanism explaining how neural stem cell is protected by CO also remains largely unknown. Methods: After NSCs were challenged by iron overload with or without CO pretreatment, apoptosis of NSCs was tested by Flow cytometry and the level of antioxidant protein was also detected. ROS of NSCs was demonstrated via the fluorescent probe. We applied siRNA to demonstrated role of the protective effect of CO. In invivo experiment, NSCs with or without CO pretreatment were implanted into intracranial hemorrhagic mouse and the survival of NSCs were detected. The significance of the difference among mean values was determined by the Student–Newman–Keuls test or two-way analysis of variance followed by the Bonferroni post hoc test. Results: CO effect on pro-survival was comparable to that obtained with pharmacological inhibitors of ROS. Its effect on pro-survival was accompanied by the inhibition of ROS and subsequent inhibition of NF-κB. Such effect is believed to be mediated through Nrf2, in that siRNA-mediated inhibition of Nrf2 revealed that Nrf2 is required for the pro-survival effect of CO. CO also activated NQO-1, a downstream target of Nrf2, which was inhibited by down-regulating Nrf2. CO-mediated precondition results in Nrf2 stimulation and NF-κB inhibition, suggesting that these two pathways act in an inverse manner to maintain redox homeostasis. The pro-survival effect of CO was also further endorsed by the evidences in mouse hemorrhagic stroke models. Conclusions: Results, by showing that CO attenuates iron overload induced apoptosis by suppressing the NF-κB signaling via Nrf2-mediated anti-oxidant effect, contribute to the understanding of essential cellular pathways. Our findings reveal CO preconditioning as a promising treatment strategy to improve efficacy of NSCs transplantation after HS.

scholarly journals Intensity of Soccer Players’ Training Load in Small-Sided Games with Different Number of Players

2020 ◽  
Vol 60 (1) ◽  
pp. 55-74
Author(s):  
Nikolas Nagy ◽  
Miroslav Holienka ◽  
Matej Babic ◽  
Jakub Michálek ◽  
Egon Kunzmann
Keyword(s):  
Heart Rate ◽  
Statistical Significance ◽  
Soccer Players ◽  
Special Software ◽  
Systematic Training ◽  
The Difference ◽  
The One ◽  
Post Hoc ◽  
Experimental Group ◽  
One Way Anova

SummaryThe main aim of this research was to compare differences in heart rate values (HR) of soccer players during small-sided games (SSGs) with different number of players. We assumed that the number of “neutral” player or players in small-sided games will significantly affect the intensity of SSGs and in this case the heart rate values of participating players. The experimental group consisted of older junior players from the FC DAC 1904 Dunajská Streda soccer club (n = 9). The heart rate values were evaluated on the basis of collected data, which we obtained using Polar sport testers and special software Polar Team2. In order to find out the statistical significance of the difference in heart rate was used the One-Way ANOVA and the Bonferroni post hoc test. The level of statistical significance we set at 5 %. We found out that with increasing number of “neutral” players’ the intensity of small-sided games gradually decreased. During SSG1 (3 vs. 3), we recorded the highest achieved average heart rate values of the monitored players, in average 171.33 ± 9.39 beats.min-1. This form of the SSGs was the most intense, but not statistically significant. Our recommendation is to employ SSGs in the systematic training process with different number of players, because we can adequately prepare the players for the match load itself. Attention need to be paid for the playing position requirements.

scholarly journals Intensity of Soccer Players’ Training Load in Small-Sided Games with Various Content Focus

2019 ◽  
Vol 59 (1) ◽  
pp. 44-68
Author(s):  
Nikolas Nagy ◽  
Miroslav Holienka ◽  
Matej Babic ◽  
Jakub Michálek ◽  
Egon Kunzmann
Keyword(s):  
Statistical Significance ◽  
Training Load ◽  
Soccer Players ◽  
Internal Reaction ◽  
Game Activity ◽  
Systematic Training ◽  
The Difference ◽  
The One ◽  
The Individual ◽  
Post Hoc

Summary The aim of this research was to make reference to the difference in heart rate values (HR) of soccer players in small-sided games (SSG) with various content focus. We assumed that the aim at the content in small-sided games would significantly affect the HR values of participating soccer players. The research group was comprised of players (n = 6) of the soccer club FK DAC 1904 Dunajská Streda (U15) at the age of 14 ± 0.7 years. The HR values were evaluated on the basis of collected data, which we obtained using sport testers and special software POLAR TEAM2. In order to find out the statistical significance of the difference in HR was used the One-Way ANOVA and the Bonferroni post hoc test. The level of statistical significance was set at 5 %. We found out that by the change of the small-sided game’s content focus, the internal reaction of players’ organism to training load was at different level. In the SSG3, with the emphasis on the improvement of individual’s final offensive game activity – shooting, was recorded the highest achieved HRavg value of the monitored players (181.83 ±7.11 beats.min−1). This form of the SSG was the most intense. However, there were no significant differences in HR values among the individual forms of the SSG. Our recommendation is to employ in the systematic training process small forms of small-sided games with various content focus, because by the means of it we can adequately prepare the players for the match load itself.

scholarly journals Comparative skills to communicate science students using group investigation learning model genuine object and non genuine objects in science subject

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Alvy Nur Latifah Sari
Keyword(s):  
Communication Skills ◽  
Science Communication ◽  
Learning Model ◽  
Science Students ◽  
Learning Models ◽  
Average Value ◽  
Object Based ◽  
The Difference ◽  
The Times ◽  
The One

Along with the times, humans are required to master the skills of communication, collaboration, critical thinking, and creativity. Communication skills become one of the important skills that must be mastered by someone. In this case the world of education plays a role in being able to train students to have communication skills. One of them is by applying the Group Investigation learning model assisted by Genuine Object, because with direct learning supported by real object media, students will easily make observations, and communicate everything they get. The objectives of this study are: 1) Knowing the difference in students' science communication skills with the Genuine Object and Non-Genuine Group Investigation learning models The sample used was grade VII student of SMP Negeri 2 Ponorogo. Data used collecteddescriptive analysis were analyzed through descriptively quantitative and inferential statistics. The results showed that students 'science communication skills using Genuine Object Assisted Group Investigation learning models had an average value of 65.7 while students' communication communication skills using Group Investigation Non Genuine Objects had average values an average of 41.6. Communication skills of students using the Group Investigation learning model assisted by Genuine Object are better than Non Genuine Object. Based on the one tailed t test, the value obtained is - 3,27748. Based on the results of the study it can be concluded that the learning model of Group Investigation assisted by Genuine Object can improve students' science communication skills.

scholarly journals Effective Establishment of Glide-Path to Reduce Torsional Stress during Nickel-Titanium Rotary Instrumentation

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 493 ◽  
Author(s):  
Ibrahim H Abu Tahun ◽  
Sang Won Kwak ◽  
Jung-Hong Ha ◽  
Asgeir Sigurdsson ◽  
Mehmet Baybora Kayahan ◽  
...  
Keyword(s):  
Nickel Titanium ◽  
Stress Generation ◽  
Total Stress ◽  
Significance Level ◽  
Glide Path ◽  
Working Length ◽  
Canal Shaping ◽  
The One ◽  
Data Acquisition Module ◽  
Post Hoc

This study compared the torque generation during canal shaping with a nickel-titanium endodontic instrument according to the extent of glide-path establishment. Seventy-five simulated S-shaped canal blocks were divided into five groups (n = 15) according to the number of repetitive insertions to the working length using a One G glide-path instrument: groups with 5, 10, 15, and 20 insertions as well as group Z without glide-path establishment. When the tip of the One G file reached the working length, the file was moved back and forth repetitively at the working length for the designated number of times for each group. The instrumentation procedure with HyFlex EDM had 15 pecking strokes. During instrumentation, the generated torque was transmitted to a customized data acquisition module and collected using customized software. Data were computed to determine the maximum torque and total stress. The maximum screw-in forces were statistically analyzed using one-way analysis of variance and Tukey’s post hoc comparison test with a significance level of 95%. While the maximum stress did not have significant differences among the five groups (p > 0.05), groups with more than 10 repetitive insertions generated lower total stress during instrumentation than did the group with 5 insertions and group Z (p < 0.05). Under the limitations of this study, repetitive insertions of glide-path establishment files at the working length reduced stress generation during the shaping using nickel-titanium instruments.

scholarly journals Working Length Transfer in the Endodontic Clinical Practice: A Comparative Study

2020 ◽  
Vol 10 (17) ◽  
pp. 5824
Author(s):  
Mario Alovisi ◽  
Mario Dioguardi ◽  
Massimo Carossa ◽  
Giuseppe Troiano ◽  
Maria Chiara Domini ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Comparative Study ◽  
Traditional Method ◽  
Nickel Titanium ◽  
Permanent Teeth ◽  
Root Canals ◽  
Working Length ◽  
Two Measures ◽  
The Difference ◽  
Transfer Method

The present paper evaluated the accuracy of two different methods for transferring working length (WL) between manual endodontic instruments and nickel–titanium (NiTi) shaping files. Thirty root canals of extracted permanent teeth were used. Root canals were divided according to canal length (CL) and canal curvature (CC). The reference cusp and the root end were flattened to provide reproducible and accurate measurements. During shaping, the WL measurements were obtained with manual k-files (KF) and transferred to WaveOne (W1) NiTi reciprocating files using the traditional method with the endodontic ruler (method I) and an alternative clinical procedure based on the comparison of the instruments side by side from tip to shank (method II). For each file and each tested method, two measures were taken by two examiners using Rhino (ver. 4.0, McNeel, Seattle, WA, USA) software for a total of 360 (30 × 3 × 2 × 2) measures. Analysis of variance was performed by taking the difference in length (Delta WL, DWL) between files used for the same canal. The difference between methods I and II for WL transfer was found to be statistically significant (df = 1; F = 71.52; p < 0.001). The DWL absolute values obtained with method II were found to be closer to 0 mm (i.e., same length as corresponding KF) than those obtained with method I. Both CL (df = 2; F = 1.27; p = 0.300) and CC (df = 1; F = 2.22; p = 0.149) did not significantly influence WL measurements. With respect to WL transfer, method II seemed to better preserve the correct WL transfer between instruments during the clinical endodontic procedures.

scholarly journals Adaptation of the single-cone in prepared long oval-shaped canals: a micro-computed tomography study

2021 ◽  
Vol 10 (15) ◽  
pp. e444101523301
Author(s):  
Christianne Velozo ◽  
Hugo Dantas ◽  
Basílio Rodrigues Vieira ◽  
Frederico Barbosa de Sousa ◽  
Victor Felipe Farias do Prado ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Root Canal ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Mean Values ◽  
Root Canals ◽  
Gutta Percha ◽  
Working Length ◽  
Single Cone ◽  
Student’S T

The present study aimed to evaluate adaptation of the single gutta-percha cone on root canal walls prepared with the two systems, the XP-endo Shaper (XPS; FKG Dentaire, La Chaux-de-Fonds, Switzerland) and ProTaper Next systems (PTN; Dentsply Sirona, Ballaigues, Switzerland) by using micro-computed tomography (micro-CT) technology. Twenty long oval-shaped canals in mandibular incisors were scanned by micro-CT (Skyscan 1172; Bruker microCT, Kontich, Belgium). Two groups were divided into (n = 10) according to the canal preparation protocol: XPS group with an extra 45 s of instrumentation and PTN group. A gutta percha cone, with respect to the protocol used for each group (size 40, .04 taper, XPS and size 40, .06 taper, PTN) was adapted to the canal at the working length of all the samples, and all root canals were filled, using the single-cone technique. The mean values for volume of voids and percentage relative to the mentioned space were correspondingly higher in XPS group than they were PTN group, mean values for volume of voids (3.61 mm3 - 1.92 mm3) and for percentage of voids (39.25% - 23.28%), respectively, significant differences were recorded (p < 0.05) between the two groups (XPS and PTN, Student’s-t test for homogenous variances and Mann–Whitney test). The canals prepared with XPS, in the procedure performed with an extra 45 s of instrumentation, showed a higher volume of voids than those prepared with the PTN system, in obturation of the root canal with the single cone technique.

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