Search results for "Negative control"
showing 7 items of 7 documents
Recentrifuge: Robust comparative analysis and contamination removal for metagenomics
2017
Metagenomic sequencing is becoming widespread in biomedical and environmental research, and the pace is increasing even more thanks to nanopore sequencing. With a rising number of samples and data per sample, the challenge of efficiently comparing results within a specimen and between specimens arises. Reagents, laboratory, and host related contaminants complicate such analysis. Contamination is particularly critical in low microbial biomass body sites and environments, where it can comprise most of a sample if not all. Recentrifuge implements a robust method for the removal of negative-control and crossover taxa from the rest of samples. With Recentrifuge, researchers can analyze results f…
Smear layer removal evaluation of different protocol of Bio Race file and XP- endo Finisher file in corporation with EDTA 17% and NaOCl.
2017
Background The aim of the present study was to compare the amount of the smear layer remaining in prepared root canals with different protocols of Bio RaCe files and XP-endo Finisher file (XPF) in association with 17% EDTA and sodium hypochlorite solution. Material and Methods A total of 68 extracted single-rooted teeth were randomly divided into 4 experimental groups (n=14) and two control groups (n=6). The root canals were prepared with Bio RaCe files (FKG Dentaire, Switzerland) using the crown-down technique based on manufacturer's instructions and irrigated according to the following irrigation techniques: Group 1: XPF with 2 mL of 2.5% NaOCl for 1 minute. Group 2:, XPF with 1 mL of 17%…
Victimization at school: relationship of parenting and functional-dysfunctional developmental variables
2015
El presente estudio tiene como principal objetivo analizar elpapel diferencial de la crianza (apoyo y comunicación versus control), devariables funcionales del desarrollo (empatía y mecanismos de afrontamientofuncionales) y las variables disfuncionales (inestabilidad emocional yafrontamiento improductivo) en la victimización ocurrida en el entorno escolar,o por el contrario, con el apego entre pares. Participaron en el estudio418 alumnos, 224 chicas y 194 chicos adolescentes, entre 13 y 14 años,escolarizados en los niveles de 3º y 4º curso de Educación SecundariaObligatoria. Para analizar estas relaciones se llevó a cabo un modelo deecuaciones estructurales EQS. Los resultados obtenidos mue…
Efficacy of preheated chelating agents on calcium ion removal from instrumented root canals
2021
Background The heating of chelating agents such as EDTA increases dentin wettability by decreasing surface tension. However, the calcium ion release effect of preheated chelating agents in instrumented root canals has not yet been mentioned. In this study, it was aimed to evaluate the number of calcium ions removed by the pre-heated chelating agents from the root canals. Material and Methods After 51 bovine teeth were instrumented, three of them were separated as negative controls and the remaining teeth were divided into six groups according to the temperature of the solution (at 22 or 37ºC): EDTA-22, CITRIC-22, QMix-22, EDTA-37, CITRIC-37 and QMix-37. Following irrigation, calcium ion lev…
Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations
2016
Background: Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods: Sixty intact extracted premolar teeth were randomly divided into 6 groups (G1-G6) of 10 teeth. G1; consisted of intact teeth and G2; consisted of teeth with MOD preparations were assigned as the positive and negative control groups respectively. Other exper…
The XP-Endo Finisher for the removal of calcium hydroxide paste from root canals and from the apical third
2017
Background The aim was to compare the efficacy of the passive ultrasonic irrigation PUI and the Xp-endo Finisher (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland) in removing the calcium hydroxide paste from root canals and from the apical third. Material and methods Sixty-eight root canals of single-rooted teeth were shaped using the BT-Race files (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland). Ca(OH)2 was placed in all samples except for the negative control group (n=4). Remaining teeth were randomly divided into three groups: G1-Xp (n=30), G2-PUI (n=30) and the positive control group (n=4). Removal procedure consisted of three repeated one-minute-cycles. Samples were split longitudinally, p…
The use of three-dimensional oral mucosa cell cultures to assess the toxicity of soldered and welded wires
2007
The aim of the present study was to determine whether there is a difference in toxicity and loss of viability of three-dimensional (3D) reconstructed human oral epithelium (RHOE) cell cultures induced by point-welded (PW), laser-welded (LW), and silver-soldered (SiS) orthodontic wires. Three types of soldered stainless steel (SS) wires: PW, LW, and SiS were prepared ( n = 3) and subjected to multiple end-point analysis (MEA). Six pieces were cut from each wire. Each piece was placed on the triplicate cell cultures (RHOE model based on TR 146 cells). After 24 hours of topical exposure, the cell cultures were cut and stained with haematoxylin/eosin. Toxicity was assessed by evaluating the mor…