scholarly journals Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins

2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 32-37
Author(s):  
Muhammet Fidan ◽  
Hakan Yasin Gönder
Keyword(s):  
Vickers Microhardness ◽  
Composite Resin ◽  
Native Speakers ◽  
Composite Resins ◽  
The Other ◽  
Control Group ◽  
Application Techniques ◽  
Native Speakers Of English

Aim: The aim of this study was to investigate the effect of different application techniques on microhardness in one universal resin material and three different bulk-fill composite resin materials. Materials and Methods: In this study, one universal composite resin (Universal Restorative 200 [U], 3M-ESPE, USA) and three different bulk-fill composite resins (Filtek-One Bulk-Fill Restorative [F]; 3M-ESPE, USA: Tetric Evo-Ceram Bulk-Fill [E]; and Ivoclar-Vivadent, Liechtenstein; Tetric N-Ceram Bulk-Fill [N], Ivoclar-Vivadent, Liechtenstein) materials were used. A total of 60 disk-shaped samples, including 20 samples from each bulk-fill composite resin group, were prepared. The polymerization of the bulk-fill composite resins in one group was completed using a 2 mm (40 sec) + 2 mm (40 sec) incremental technique, and in the other group, it was completed using a 4 mm bulk technique (40 sec). The U composite resin (control group) polymerization was completed using a 2 mm + 2 mm (40 sec) incremental technique (n = 10). The Vickers microhardness (VHN) values ​​of the samples were calculated. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (p < 0.05). Results: Higher VHN values ​​were found in the U composite resin compared to those in the bulk-fill composite resins (p < 0.05). In the bulk technique, a lower VHN value ​​was observed in the N bulk-fill composite resin than in the control group (p < 0.05), while there was no difference between the N and E composite resin groups (p > 0.05). A lower N bulk-fill composite resin was observed in the groups in which the incremental technique was applied than in the control group (p < 0.05). When the techniques applied to the bulk-fill composite resins were evaluated within themselves, higher VHN values ​​were observed in the E composite resin in the group in which the incremental technique was applied but not in the group in which the bulk was applied. Conclusion: It was observed that the content differences of composite resins were effective at different VHN values. The U composite resin (control) group showed higher VHN values than all the bulk-fill composite groups.   How to cite this article: Fidan M, Gönder HY. Investigation of the effect of different application techniques on microhardness in bulk-fill composite resins. Int Dent Res 2021;11(Suppl.1):32-7. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.6   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Comparative evaluation of the color stability of universal composites

2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 234-237
Author(s):  
Merve Gürses ◽  
Nevin Çobanoğlu ◽  
Omar Faez Abdulateef
Keyword(s):  
Comparative Evaluation ◽  
Color Change ◽  
Native Speakers ◽  
Color Stability ◽  
Composite Resins ◽  
Control Group ◽  
Distilled Water ◽  
Color Changes ◽  
Before And After ◽  
Native Speakers Of English

Aim: The aim of this study is to compare the color stability of different universal composites and to evaluate the effects of keeping them in water for 1 week before coloring. Methodology: Filtek Ultimate (FU), Estelite Ʃ Quick (EQ), and Ceram X One (CX) composites were used. The specimens were kept in the dark, dry environment for 24 hours, then polished, and each composite group was divided into 3 groups: the control, the group that was kept in water for 1 week before coloring and coloring (n=7). The samples in the control group were kept in distilled water for 3 weeks. Samples in the coloring group were colored with coffee for 2 weeks (C), and the samples in the last group were kept in water for 1 week and then stained with coffee for 2 weeks (W+C) (n=7). Color measurements for all samples were taken twice, once before and once after the coloring period. The color changes of the samples were measured using the ∆E* parameter, which was calculated with before and after measurements.  Results: For all composite resins, the ΔE values of the samples in the W+C and C groups were significantly higher than those in the control group. When the composites were compared with each other, the differences between the ΔE values of the composites in the control, W+C, and C groups were not statistically significant. For FU and ESQ, at the end of the coloration period, there were no statistically significant differences between the W+C and C groups. However, for CX, the color change of the samples in the W+C group was significantly higher than that in  the C group. Conclusion: Storage in distilled water for 1 week before staining did not reduce the color change values of the samples. Thus, after composite restorations are performed, there is no need to advise patients to avoid staining foods, especially in the first week after restoration.   How to cite this article: Abdulateef OF, Çobanoğlu N, Gürses M. Comparative evaluation of the color stability of universal composites. Int Dent Res 2021;11(Suppl.1):234-7. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.34   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

scholarly journals Probing rhythmic patterns in english-L2

2017 ◽  
Vol 6 (1) ◽  
pp. 47-58
Author(s):  
Ronaldo Mangueira Lima Junior ◽  
Guilherme Duarte Garcia
Keyword(s):  
Second Language ◽  
Native Speakers ◽  
Brazilian Portuguese ◽  
The Other ◽  
Production Data ◽  
Control Group ◽  
Advanced Learners ◽  
Other Hand ◽  
Native Speakers Of English ◽  
Categorical Classification

Languages are traditionally classified as mora-timed, syllable-timed or stress-timed in relation to their rhythmic patterns. The distinction between syllable-timed and stress-timed languages, however, lacks solid evidence in the literature. Syllable-timed languages typically have similar duration across unstressed and stressed syllables, whereas stress-timed languages tend to have similar inter-stress intervals, and unstressed syllables are shorter than stressed syllables. According to this categorical classification, English is a stress-timed language, thus having more reduction in unstressed vowels. Brazilian Portuguese, on the other hand, is typically classified as syllable-timed, and thus has little reduction of unstressed vowels. If these categorical rhythmic differences are correct, then acquiring the rhythmic patterns of English should be a challenging task to Brazilian learners, who are not expected to produce unstressed vowels with as much reduction as English native speakers. However, recent studies have found that the typology of rhythm is best understood as not categorical, but rather gradient, and that Brazilian Portuguese has a mixed classification, with more stress timing than would be expected from a traditional and categorical perspective. We therefore hypothesize that Brazilian learners of English should not have major difficulties reducing unstressed vowels, even when exposed to the second language later in life. To test this hypothesis, we analyze production data of native speakers of English (control group) and of Brazilian advanced learners of English. 

scholarly journals Pre-Heating Effect on the Microhardness and Depth of Cure of Bulk-Fill Composite Resins

2021 ◽  
pp. 270-283
Author(s):  
Alperen Değirmenci ◽  
Dilber Bilgili Can
Keyword(s):  
Room Temperature ◽  
Vickers Microhardness ◽  
Composite Resin ◽  
Multiple Comparisons ◽  
Composite Resins ◽  
Control Group ◽  
Heating Process ◽  
Distilled Water ◽  
Depth Of Cure ◽  
Heating Device

OBJECTIVE: The aim of this study was to investigate the effect of preheating three bulk-fill and one conventional composite resin on the Vickers microhardness and depth of cure of these composites. METHODS: In this study, three bulk-fill composites-SDR Plus (SDR), Estelite BULK FILL Flow (EST), Admira® Fusion x-tra (AFX), and one conventional composite resin G-ænial POSTERIOR (GP) were used as the control group. The samples were obtained at room temperature (24°C) and at 55°C in T2 mode after being placed in a heating device for 10 minutes. The samples were divided into eight groups (n=10) according to the type of material and heating process that was utilized (preheated and nonheated). All samples were tested with a Vickers microhardness (VHN) tester on the bottom and top surfaces. The first measurements were obtained at baseline; the second set of measurements was performed after the samples were stored in distilled water at 37°C for 24 hours. The depth of cure was calculated using a bottom/top hardness ratio of measurements. Statistical analysis was performed utilizing the SPSS V23 and Shapiro-Wilk tests. Lastly, the Duncan test was used for multiple comparisons (p<0.05). RESULTS: While the VHN increased after the preheating procedure in bulk-fill composites, it decreased in GP. There was no difference between the baseline and the 24-hour VHN values in SDR and GP. After 24 hours, while the VHN of EST increased, the VHN of AFX decreased. There was no difference between the hardness ratios of the AFX and EST samples (p<0.001) and hardness ratios were greater than GP and SDR. CONCLUSION: When comparing the baseline and the 24-hour values, the VHN depended on the type of materials. Sufficient curing depth was obtained in all groups with a thickness of 2mm.

scholarly journals Intuitions of adult L2-Leamer and translation students as a guide to analysis in teaching

2018 ◽  
Vol 27 ◽  
pp. 35-51
Author(s):  
Connors K.
Keyword(s):  
Adult Learners ◽  
Native Speakers ◽  
The Other ◽  
Control Group ◽  
Syntactic Ambiguity ◽  
Garden Path ◽  
Linguistic Awareness ◽  
Grammaticality Judgments ◽  
Native Speakers Of English ◽  
The One

This paper deals with the pedagogical implications of a series of studies on linguistic awareness. Adult learners, native- and near-native speakers of English were studied for their knowledge of equivalence and contrast relations between reflexive and emphatic -self constructions, on the one hand, and the possible interpretations of French pronominal-verbal constructions, on the other. In the pilot study, adult Francophone learners of English and an Anglophone control group judged the grammaticality of sets of sentences, one of which presented -self constructions that were grammatical as reflexives, as emphatics, as both, or as neither. The original purpose of this combination was to study the relation between objective ambiguity and grammaticality judgments. The results suggested not that syntactic ambiguity led to incorrect grammaticality judgments, but that garden-path (or “hard-to-get”) readings of constructions which globally are asymmetrically ambiguous are associated with incorrect judgments of ungrammaticality. That is, the only reading on which a given sub-type of construction is grammatical can be unknown to learners and even undetected by native speakers.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
Control Group ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Tukey Test ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p&lt;0.05). Color changes were significant for different tested bleaching therapies (p&lt;0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p&lt;0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

Deferring to the Other

2021 ◽  
pp. 126-148
Author(s):  
Joseph Sung-Yul Park
Keyword(s):  
Multinational Corporations ◽  
Language Ideologies ◽  
Native Speakers ◽  
The Other ◽  
Language And Identity ◽  
Self Development ◽  
Native Speakers Of English ◽  
Linguistic Insecurity

This chapter discusses how the notion of linguistic insecurity can illuminate the processes by which essentialist conceptions of language and identity—in particular, the persistent colonial ideology of nativeness—contribute to the hegemonic status of English in neoliberalism. This chapter conceptualizes linguistic insecurity in terms of tensions that speakers experience between conflicting language ideologies. Focusing on the case of Korean mid-level managers working in non-Korean multinational corporations abroad, the chapter argues that the notion of linguistic insecurity allows us to explore how conflicting ideologies about English in neoliberalism—one in which English is valorized as a commodifiable resource available to anyone through projects of self-development, and one in which who counts as a legitimate speaker of English is defined in ethnonational terms—can jointly create a sense of insecurity in those who are traditionally considered non-native speakers of English, and rationalize the inequalities they are subjected to in neoliberalism.

scholarly journals Does the temperature of beverages affect the surface roughness, hardness, and color stability of a composite resin?

2013 ◽  
Vol 07 (02) ◽  
pp. 165-171 ◽  
Author(s):  
Duygu Tuncer ◽  
Emel Karaman ◽  
Esra Firat
Keyword(s):  
Surface Roughness ◽  
Composite Resin ◽  
Color Change ◽  
Artificial Saliva ◽  
Color Stability ◽  
The Other ◽  
Control Group ◽  
Baseline Values ◽  
Hardness Values ◽  
Properties Of Composites

ABSTRACT Objective: To investigate the effect of beverages′ temperature on the surface roughness, hardness, and color stability of a composite resin. Materials and Methods: Fifty specimens of the Filtek Z250 composite (3M ESPE, Dental Products, St.Paul, MN, USA) were prepared and initial roughness, microhardness, and color were measured. Then the specimens were randomly divided into five groups of 10 specimens each: Coffee at 70°C, coffee at 37°C, cola at 10°C, cola at 37°C, and artificial saliva (control). After the samples were subjected to 15 min × 3 cycles per day of exposure to the solutions for 30 days, the final measurements were recorded. Results: After immersion in beverages, the artificial saliva group showed hardness values higher than those of the other groups (P < 0.001) and the microhardness values were significantly different from the initial values in all groups except for the control group. Both cola groups showed roughness values higher than the baseline values (P < 0.05), while the other groups showed values similar to the baseline measurements. When ΔE measurements were examined, the 70°C coffee group showed the highest color change among all the groups (P < 0.05). Conclusion: High-temperature solutions caused alterations in certain properties of composites, such as increased color change, although they did not affect the hardness or roughness of the composite resin material tested.

How native and non-native English speakers adapt to humor in intercultural interaction

2007 ◽  
Vol 20 (1) ◽  
Author(s):  
Nancy D Bell
Keyword(s):  
Second Language ◽  
Intercultural Communication ◽  
Native Speakers ◽  
Native English Speakers ◽  
The Other ◽  
English Speakers ◽  
Intercultural Interaction ◽  
Second Language Speakers ◽  
Negative Message ◽  
Native Speakers Of English

AbstractHumor can often carry an implicit negative message and thus be potentially dangerous to use. In addition, it is culturally and linguistically complex and sophisticated. Because of these things, it poses a challenge for L2 (second language) speakers and we might expect to see attempts at humor failing and causing offense in intercultural interaction. This paper reports on a study that examined humor in interaction between native and non-native speakers of English and found that humor did not seem to be a cause of conflict because of adjustments speakers made to their speech and their situated interpretations of meaning. In general, taboo topics and potentially dangerous forms of humor were avoided and humor was carefully contextualized. Native speakers reported being careful about the vocabulary they used in creating humor and both sides appeared to approach humor in intercultural communication prepared to accommodate the other and with an attitude of leniency.

Effect of Tooth-Whitening Procedures on Stained Composite Resins

2019 ◽  
Vol 44 (1) ◽  
pp. 65-75 ◽  
Author(s):  
JW Reinhardt ◽  
MM Balbierz ◽  
CM Schultz ◽  
B Simetich ◽  
MW Beatty
Keyword(s):  
Red Wine ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
The Other ◽  
Time Interval ◽  
Distilled Water ◽  
Water Control ◽  
Tooth Whitening ◽  
Final Composite

SUMMARY In this laboratory study, a composite resin was stained to a visibly discernible level using both coffee and red wine over 14 days (change was considered clinically noticeable and significant when ΔEab*≥2.7). Color change was measured at one, three, seven, and 14 days of staining. Although the nature of color change was different for the two staining solutions, the overall degree of staining (ΔEab*) rendered by either coffee or wine at each time interval was not significantly different (p≥0.05). Four whitening protocols were applied to stained composites. Treatment included applications of distilled water (control), Crest Pro-Health [HD] toothpaste, Crest Whitestrips, Opalescence PF bleach (15%), and application of a fine pumice polishing (Preppies). HD toothpaste and Whitestrips were applied daily for 21 days, Opalescence was applied daily for 10 days, and polishing was applied once. Each of the whitening products, applied in a manner simulating at-home or in-office treatment, was effective in producing color improvements (lightening) over controls (p&lt;0.05), but none of the four treatments produced lightening that was significantly different from the other treatments (p≥0.05). A comparison of final composite color with that measured at baseline showed that Opalescence returned composite color to an acceptable level following exposure to both staining solutions (ΔEab*&lt;2.7), Whitestrips returned color close to baseline for wine-stained composites, and HD paste and polishing permitted residual stain to remain (ΔEab*≥2.7).

Lexical and discourse factors in the second language acquisition of Spanish word order

2003 ◽  
Vol 19 (4) ◽  
pp. 273-304 ◽  
Author(s):  
Tammy Jandrey Hertel
Keyword(s):  
Second Language Acquisition ◽  
Word Order ◽  
Native Speakers ◽  
Native Speaker ◽  
Control Group ◽  
Order Effects ◽  
Advanced Learners ◽  
Spanish Word ◽  
Native Speakers Of English ◽  
Beginning Learners

This study investigates the acquisition of Spanish word order by native speakers of English. Specifically, it considers the development of sensitivity to the distinct interpretations of subject-verb (SV) vs. verb-subject (VS) order, as determined by lexical verb class (unaccusative and unergative verbs) and discourse structure.Participants included a native speaker control group and learners at four proficiency levels. Results from a contextualized production task indicate that beginning learners transferred the SV order of English for all structures. Intermediate learners showed a gradual increase in the production of lexically and discourse-determined inversion, although their data was also characterized by indeterminacy and variability. The advanced learners demonstrated a sensitivity to the word order effects of unaccusativity and discourse factors, but also tended to overgeneralize inversion to unergative verbs in a neutral discourse context.

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