Links between global and local shape perception, coloured backgrounds, colour discrimination, and non-verbal IQ

This study explored associations between local and global shape perception on coloured backgrounds, colour discrimination, and non-verbal IQ (NVIQ). Five background colours were chosen for the local and global shape tasks that were tailored for the coneopponent pathways early in the visual system (cardinal colour directions: L-M, loosely, reddish-greenish; and S-(L+M), or tritan colours, loosely, blueish-yellowish; where L, M and S refer to the long, middle and short wavelength sensitive cones). Participants also completed the Farnsworth-Munsell 100-hue test (FM100) to determine whether performance on the local and global shape tasks correlated with colour discrimination overall, or with performance on the L-M and tritan subsets of the FM100 test. Overall performance on the local and global shape tasks did correlate with scores on the FM100 tests, despite the colour of the background being irrelevant to the shape tasks. There were also significantly larger associations between scores for the L-M subset of the FM100 test, compared to the tritan subset, and accuracy on some of the shape tasks on the reddish, greenish and neutral backgrounds. Participants also completed the nonverbal components of the WAIS and the SPM+ version of Raven’s progressive matrices, to determine whether performance on the FM100 test, and on the local and global shape tasks, correlated with NVIQ. FM100 scores correlated significantly with both WAIS and SPM+ scores. These results extend previous work that has indicated FM100 performance is not purely a measure of colour discrimination, but also involves aspects of each participant’s NVIQ, such as the ability to attend to local and global aspects of the test, part-whole relationships, perceptual organisation and good visuomotor skills. Overall performance on the local and global shape tasks correlated only with the WAIS scores, not the SPM+. These results indicate that those aspects of NVIQ that engage spatial comprehension of local-global relationships and manual manipulation (WAIS), rather than more abstract reasoning (SPM+), are related to performance on the local and global shape tasks. Links are presented between various measures of NVIQ and performance on visual tasks, but they are currently seldom addressed in studies of either shape or colour perception. Further studies to explore these issues are recommended

Effects of Sodium Hypochlorite and Chlorhexidine Solutions on Resilon (Synthetic Polymer Based Root Canal Filling Material) Cones: An Atomic Force Microscopy Study

PubMedID: 16982275The aim of the present study is to evaluate the effects of 2% chlorhexidine and 5.25% sodium hypochlorite on the surface properties of Resilon cones with the atomic force microscopy. The Resilon cones were immersed in disinfecting agents (5.25% sodium hypochlorite and 2% chlorhexidine) at 1 and 5 min time intervals. Atomic force microscopy was used to evaluate topographical deviations of Resilon cones. Root mean square (RMS) parameters for topographic amplitudes were calculated. The cones exhibited statistically significant low RMS values at 5-min immersion in sodium hypochlorite and chlorhexidine groups compared to the all other groups (p 0.05). In conclusion, sodium hypochlorite and chlorhexidine solutions used for disinfection significantly decreased (p < 0.05) the RMS values of Resilon cones at 5-min applications. © 2006 American Association of Endodontists

Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin

PubMedID: 27191739This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p < 0.001). TAP removal from root canals with the Vibringe irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation

Post-obturation pain following the use of carrier-based system with AH Plus or iRoot SP sealers: a randomized controlled clinical trial

PubMedID: 30397735Objectives: The aim of this study was to compare the postoperative pain after root canal treatment using a carrier-based obturation system and two different sealers. Materials and methods: In this prospective randomized clinical trial, 160 patients were selected. Patients with vital and devital teeth were randomized into four groups using a randomized block design with block sizes of 10 patients each. The groups were devital/vital teeth treated with iRoot SP sealer and devital/vital teeth treated with AH Plus sealer. Patients were prescribed ibuprofen, a 200-mg analgesic, if needed, and postoperative pain was recorded by visual analogue scale at 6, 12, 24, and 72 h after obturation. Pain score and frequency of tablet intake were recorded and statistically analyzed. Results: Results showed that there was no significant difference between groups in the incidence of postoperative pain; however, iRoot SP sealer was associated with less analgesic intake compared to AH Plus sealer. Conclusion: The use of different sealers did not significantly affect pain levels. Clinical relevance: iRoot SP sealer was associated with less analgesic intake compared to AH Plus sealer. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.Funding The work was supported by Scientific Research Projects Coordination Center of Cukurova University (Project no. TDH-2015-4949), Adana, Turkey

Comparison of gutta percha and resilon by using two root canal obturation system (system-b and obtura ii) on capability to replicate intracanal depressions and void formation [Guta-perka ve resilonun iki farkli dolgu yöntemi (sistem b ve obtura ii) kullanarak kanal içi düzensizlikleri doldurma ve boşluk oluşumu özelliklerinin karşilaştirilmasi]

Purpose: The purpose of this study is to compare gutta percha and Resilon by using two root canal obturation systems (System-B and Obtura II) on capability to replicate intracanal depressions and void formation. Material and Methods: Two human maxillary central incisors were embedded in a clear acrylic resin blocks just below the cemento-enamel junction (CEJ). The root canals were enlarged by using crown-down technique same apical width but different taper. Split tooth models were sectioned parallel to the long axis in two parts with water cooled diamond coated saw. Four artificial defects were created on the dentin walls. Split tooth models were obturated with gutta-percha and Resilon by using System B and Obtura II techniques. Replication of defects and void formation were evaluated and the data were analyzed chi square and logistic regression tests. Results: No statistically significant differences were found between the gutta-percha and Resilon in void formation; however System B were created voids higher than Obtura II. Gutta-percha was showed better results than Resilon in defect replication, but no differences were found between the obturation techniques and wide and narrow taper. Conclusion: It was concluded that Resilon and gutta-percha has similar handling properties, and obturation technique is more significative on capability to replicate intracanal depressions and void formation in root canal treatment

Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An in Vitro Study

PubMedID: 27218106Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl)2; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl)2 with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p&lt;0.05). There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl)2 and NaOCl. Conclusion. The antimicrobial property of Ca(OCl)2 has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth. © 2016 Aysin Dumani et al

A Meta-analysis of Work–Family Conflict and Social Support

The relationship between social support and work–family conflict is well-established, but the notion that different forms, sources, and types of social support as well as contextual factors can alter this relationship has been relatively neglected. To address this limitation, the current study provides the most comprehensive and in-depth examination of the relationship between social support and work–family conflict to date. We conduct a meta-analysis based on 1021 effect sizes and 46 countries to dissect the social support and work–family conflict relationship. Using social support theory as a theoretical framework, we challenge the assumption that social support measures are interchangeable by comparing work/family support relationships with work–family conflict across different support forms (behavior, perceptions), sources (e.g., supervisor, coworker, spouse), types (instrumental, emotional), and national contexts (cultural values, economic factors). National context hypotheses use a strong inferences paradigm in which utility and value congruence theoretical perspectives are pitted against one another. Significant results concerning support source are in line with social support theory, indicating that broad sources of support are more strongly related to work–family conflict than are specific sources of support. In line with utility perspective from social support theory, culture and economic national context significantly moderate some of the relationships between work/family support and work interference with family, indicating that social support is most beneficial in contexts in which it is needed or perceived as useful. The results suggest that organizational support may be the most important source of support overall

Effects of seven different irrigation techniques on debris and the smear layer: A scanning electron microscopy study

PubMedID: 28256488Aim: Conventional manual irrigation with a syringe and needle remains widely accepted technique in the irrigation procedures. However, its flushing action has some limitations. Currently, several techniques and systems are available and reported to improve the insufficiency of syringe irrigation. The aim of this study was to evaluate the effectiveness of 7 different irrigation techniques compared to standard irrigation. Materials and Methods: Straight roots from 80 extracted human maxillary central incisors were collected, and root canals were instrumented with K-files up to apical size 50. The teeth were randomly divided into 8 groups (n = 10), and final irrigation procedures were performed with 17% ethylenediaminetetraacetic acid and 5.25% NaOCl solutions using following irrigation agitation techniques: RinsEndo, EndoVac, Canal CleanMax, sonic, Canal Brush, NaviTip FX, manual dynamic irrigation, and conventional irrigation. The presence of debris and smear layer (SL) at coronal, middle, and apical thirds was evaluated by using a 5-grade scoring system with ×200 and ×1000 magnification, respectively. Results: Concerning debris removal, the MM 1500 sonic group reduced apical debris significantly better than the other groups tested (P 0.05) related SL removal in all levels. Conclusions: MM 1500 scored best with debris removal; however, there was no significant reduction in the SL in apical third with any of the methods tested