Search results for "Study groups"
showing 10 items of 22 documents
Reparability of giomer using different mechanical surface treatments
2016
Background In the repair process achieving high bond strength between the new and old resin based materials is necessary for clinical longevity. This study compared the effect of three different mechanical surface treatments (air abrasion, Nd:YAG laser and diamond bur) on the repair bond strength of giomer. Material and Methods In this in vitrostudy, 125 cylindrical giomer samples were used. The giomer samples were randomly assigned to 5 groups (n=25). In group 1, the samples did not undergo any surface treatment. In groups 2 to 4, the samples underwent surface treatments with air abrasion, Nd:YAG laser and a diamond bur. The samples in group 5 were prepared to measure giomer cohesive stren…
Effects of Different Percentages of Microhydroxyapatite on Microhardness of Resin-modified Glass-ionomer and Zirconomer
2016
Background Hydroxyapatite (HA) is the main mineral component of the tooth structure, which exhibits considerable biological behavior and its incorporation might improve microhardness of dental materials. Microhardness of restorative materials, like glass-ionomer, is critical for the clinical longevity of restorations. The aim of this study was to evaluate the microhardness of two glass-ionomers types by incorporating different percentages of microhydroxyapatite. Material and Methods In this study, 80 disc-shaped experimental specimens (6 mm in diameter, 2 mm in height) were prepared in 8 groups, including resin-modified glass-ionomer (RMGI, GC, Gold Label, Japan), zirconia-reinforced glass-…
2-Engel relations between subgroups
2016
Abstract In this paper we study groups G generated by two subgroups A and B such that 〈 a , b 〉 is nilpotent of class at most 2 for all a ∈ A and b ∈ B . A detailed description of the structure of such groups is obtained, generalizing the classical result of Hopkins and Levi on 2-Engel groups.
Comparative Analysis of Periodontal Pain According to the Type of Precision Orthodontic Appliances: Vestibular, Lingual and Aligners. A Prospective C…
2021
The objective of this prospective clinical study was to analyze the pain (intensity, location and type) that patients presented after the placement of different types of orthodontic appliances: conventional, low friction, lingual and aligners. The sample consisted of 120 patients divided into four groups: conventional (CON), low friction (LF), lingual (LO) and aligners (INV). The participants were given the Short-Form McGill Pain Questionnaire (Ortho-SF-MPQ), where they had to record the pain intensity (no pain, mild, moderate or intense) and the periodontal location at different time points, from the first 4 h to 7 days after the start of treatment. In all the study groups, the most freque…
Technique of CT Examination
1981
The three study groups used the same CT systems during the investigation period : the EMI Mark I head scanner from 1975 until June 1977 and the EMI CT 1010 head scanner from the middle of 1977, with the Diagnostic Enhancement Package since March 1980. Special studies of the base of the skull were performed with an EMI CT 5005 body scanner (Department of Radiology, Klinikum Steglitz, Free Universityof Berlin).
The staining effect of different mouthwashes containing nanoparticles on dental enamel
2015
Background: This study aimed to evaluate the effects of several mouthwashes containing nanoparticles on discoloration of dental enamel, and compare the results with that of 0.2% chlorhexidine (CHX). Material and Methods: Sixty intact premolars were randomly assigned to six groups. A spectrophotometer was used to measure the color of the teeth (T1) according to the CIELAB system. The specimens in groups 1 to 4 were then immersed in colloidal solutions containing nanoTiO2 (Group 1), nanoZnO (Group 2), nanoAg (Group 3) and nanoCuO (Group 4). In groups 5 and 6, a 0.2% CHX mouthwash and distilled water were used as positive and negative controls, respectively. After 24 hours of immersion, color …
Bleaching in vital teeth : combined treatment vs in-office treatment
2019
Background The aim of this study was to verify that there will be greater whitening in teeth treated with combined bleaching than in those that have been applied a clinical one and to evaluate the efficiency of the clinical treatment, those cases in which it is not able, or it is not wanted, to carry out the home phase. Material and Methods They were used 66 extracted anterior human teeth, which were divided into two study groups. On the one hand, the clinical group (ClG) consisted of 33 teeth, which were treated with a clinical guideline using 37.5% hydrogen peroxide in a single session of 4 applications of 8 minutes. On the other hand, the combinate group (CoG) consisted of 33 teeth, whic…
The Development of the Dealing with Challenging Interaction (DCI) Method to Evaluate Teachers’ Social Interaction Skills
2012
The Dealing with Challenging Interaction (DCI) method was developed to measure social interaction skills of teacher study groups. The participants were 70 teachers from three schools. The inter-rater agreement, Cohen’s kappa, varied between 0.57- 1.00. The discriminant validity was supported by a cluster analysis differentiating between the skilful and less skilful teachers. The results of the supplementary instrument were equivalent to the cluster analysis maintaining criterion oriented validity of the method developed. The DCI appeared to be a reliable and valid tool for measuring teachers’ social interaction skills. Peer reviewed
Safety of sublingual immunotherapy started during the pollen season
2009
Sublingual immunotherapy (SLIT) is safer than subcutaneous immunotherapy (SCIT) and this has lead to the reconsideration of the use of ultra-rush schedules for SLIT. The aim of this study was to assess the safety of ultra-rush SLIT in pollen-allergic children according to different timing of administration in relation to the pollen season.In total, 34 children with pollen-induced rhinitis and 36 with pollen-induced asthma and rhinitis, were enrolled and assigned to three study groups: group 1 (n = 17 patients): conventional pre-seasonal-SLIT treatment; group 2 (n = 23 patients), seasonal SLIT ended before the pollen seasonal peak; group 3 (n = 30 patients), SLIT began after the pollen seaso…
Accuracy of Computer-Aided Dynamic Navigation Compared to Computer-Aided Static Procedure for Endodontic Access Cavities: An In Vitro Study
2020
: Purpose: To analyze the accuracy of two computer-aided navigation techniques to guide the performance of endodontic access cavities compared with the conventional access procedure. Materials and Methods: A total of 30 single-rooted anterior teeth were selected, which were randomly distributed into three study groups: Group A&mdash