The Use of Composite Layering Technique to Mask a Discolored Background: Color Analysis of Masking Ability After Aging—Part II

2019 ◽  
Vol 44 (5) ◽  
pp. 488-498
Author(s):  
BG Perez ◽  
LL Miotti ◽  
AH Susin ◽  
LB Durand
Keyword(s):  
Resin Composite ◽  
Water Immersion ◽  
Background Color ◽  
Color Analysis ◽  
Mean Values ◽  
Time Points ◽  
Color Measurements ◽  
Color Background ◽  
One Year ◽  
Post Hoc

SUMMARY The aim of this study was to evaluate the effectiveness of the layering technique to mask a discolored background (C4) after one year of water aging. The technique was used with three resin composite restorative systems (IPS Empress Direct, Charisma Diamond, and Filtek Z350XT). Ninety 1.5-mm-thick specimens were divided into groups and subgroups according to the restorative system and resin composite shade combination used in the layering technique (enamel, body, and dentin). The color measurements were made by reflection spectrophotometer (SP60, EX-Rite) over the C4 substrate at two time points: after 24-hour water immersion (T0) and after one-year water aging (T1). The masking ability was evaluated by calculating the ΔE between an inherent color background and a C4 background at T0 and T1. CIELAB and CIEDE2000 formulas were used for comparative analysis between T0 and T1 color measurements. Analysis of variance and Turkey's post hoc test (a=0.05) were performed to analyze ΔEab and ΔE00 mean values. The Z350XT restorative system presented adequate masking ability in the combinations of 0.5 mm body + 1.0 mm dentin, 0.5 mm enamel + 1.0 mm dentin, and 1.5 mm dentin after 24-hour water immersion. The masking ability was affected negatively by water aging in most of the combinations. The IPS Empress Direct was the only system that remained stable after aging in the combinations of 0.5 mm enamel + 1.0 mm dentin and + 1.5 mm dentin (p=0.05 and p=0.47 for CIELAB; p=0.15 and p=0.51 for CIEDE2000), although it did not present adequate masking ability in both time points. None of the combinations of any system presented adequate masking ability after prolonged water aging.

The Use of Resin Composite Layering Technique to Mask Discolored Background: A CIELAB/CIEDE2000 Analysis

2017 ◽  
Vol 42 (2) ◽  
pp. 165-174 ◽  
Author(s):  
LL Miotti ◽  
IS Santos ◽  
GF Nicoloso ◽  
RT Pozzobon ◽  
AH Susin ◽  
...  
Keyword(s):  
Linear Models ◽  
Resin Composite ◽  
Color Difference ◽  
Tooth Surface ◽  
Color Measurements ◽  
The Mean ◽  
Color Background ◽  
Post Hoc ◽  
Total Color Difference ◽  
Composite Restoration

SUMMARY The purpose of this study was to evaluate the ability of three resin composite systems to mask a severely discolored background by the application of a layering technique through CIELAB and CIEDE2000 analysis. Ninety 1.5-mm-thick disc specimens were produced from three different resin composite restoration systems: IPS Empress Direct (Ivoclar Vivadent), Charisma Diamond (Heraeus Kulzer), and Filtek Z350 XT (3M-ESPE). The specimens were divided into groups according to the restoration system and the resin composite shade combination used for the layering technique (enamel, body, and dentin shades). Color measurements were performed by a reflectance spectrophotometer (SP60, EX-Rite) against a C4 shade background and an inherent color background, which simulates a severely discolored background and a tooth surface with no discoloration, respectively. The total color difference between both color measurements was calculated by CIELAB (ΔE*ab) and CIEDE2000 (ΔE00) formulas. The mean ΔEab* and ΔE00 values were analyzed by analysis of variance (general linear models) and Tukey's post hoc tests (α=0.05). Three groups presented clinically acceptable color difference values (ΔE*≦3.46 and ΔE00≦2.25): 1.5 mm dentin, 1.0 mm dentin/0.5 mm body, and 1.0 mm dentin/0.5 mm enamel; ie, all the groups from the Z350 XT restoration system. The resin composite layering technique is an effective way to mask severely discolored backgrounds. The Filtek Z350 XT system was the only restoration system capable of masking the C4 background.

scholarly journals Effect of Storage Time on Bond Strength and Nanoleakage Expression of Universal Adhesives Bonded to Dentin and Etched Enamel

2016 ◽  
Vol 41 (3) ◽  
pp. 305-317 ◽  
Author(s):  
P Makishi ◽  
CB André ◽  
APA Ayres ◽  
AL Martins ◽  
M Giannini
Keyword(s):  
Bond Strength ◽  
Resin Composite ◽  
Nitrate Solution ◽  
Storage Period ◽  
Silver Nitrate Solution ◽  
Silver Particles ◽  
Flat Surfaces ◽  
Universal Adhesives ◽  
One Year ◽  
Post Hoc

SUMMARY Purpose: To investigate bond strength and nanoleakage expression of universal adhesives (UA) bonded to dentin and etched enamel. Methods: Extracted human third molars were sectioned and ground to obtain flat surfaces of dentin (n = 36) and enamel (n = 48). Dentin and etched enamel surfaces were bonded with one of two UAs, All-Bond Universal (ABU) or Scotchbond Universal (SBU); or a two-step self-etching adhesive, Clearfil SE Bond (CSEB). A hydrophobic bonding resin, Adper Scotchbond Multi-Purpose Bond (ASMP Bond) was applied only on etched enamel. Following each bonding procedure, resin composite blocks were built up incrementally. The specimens were sectioned and subjected to microtensile bond strength (MTBS) testing after 24 hours or one year water storage, or immersed into ammoniacal silver nitrate solution after aging with 10,000 thermocycles and observed using scanning electron microscopy. The percentage distribution of silver particles at the adhesive/tooth interface was calculated using digital image-analysis software. Results: The MTBS (CSEB = SBU > ABU, for dentin; and CSEB > ABU = SBU = ASMP Bond, for etched enamel) differed significantly between the adhesives after 24 hours. After one year, MTBS values were reduced significantly within the same adhesive for both substrates (analysis of variance, Bonferroni post hoc, p<0.05), and no significant differences were found among the adhesives for etched enamel. Silver particles could be detected within the adhesive/dentin interface of all specimens tested. Kruskal-Wallis mean ranks for nanoleakage in ABU, SBU, and CSEB were 16.9, 18.5 and 11, respectively (p>0.05). Conclusions: In the short term, MTBS values were material and dental-substrate dependent. After aging, a decrease in bonding effectiveness was observed in all materials, with nanoleakage at the adhesive/dentin interface. The bonding of the UAs was equal or inferior to that of the conventional restorative systems when applied to either substrate and after either storage period.

scholarly journals Discoloration of new nanohybrid composites into two different solutions  (an invitro study)

2020 ◽  
Author(s):  
mohammad ali wannous ◽  
souad ali abboud
Keyword(s):  
Resin Composite ◽  
Study Time ◽  
The Other ◽  
Time Points ◽  
Color Measurements ◽  
Time Period ◽  
Group A ◽  
Nanohybrid Composite

Abstract Objective: this study aimed to evaluate discoloration of two inorganic nanohybrid composite and an organic modified ceramic resin composite (ormocer) into two solution at different periods of time.Methods: 60 discs of (admira fusion voco, tetric evoceram vivadet ivoclar , tetric N-ceram vivadent ivoclar) were prepared with dimentions of (2mm x 5mm) and devided into three group (A ,B, C) Each group of 20 specimens were randomized into two subgroups, one of them were immersed in coffee and the other in cola for 1, 7, and 28 days of immersion. Color measurements were recorded every time period using Vita Easy shade compact according to the CIE L*a*b* system and results were saved for comparing .The ΔE values between the study time points were calculated. Results: Admira Fusion x-tra showed the lowest ΔE variations (P < 0.01) at all periods of time comparing with Tetric evoceram and Tetric N-ceram at both solution. Coffee caused higher discoloration at all periods of time.Conclusion: Staining beverages caused significant discolorations for all the materials tested. Coffee caused higher discoloration comparing with cola. Nanohybrid ormocer composite reported the lowest color variations.

scholarly journals Adaptational changes in clear aligner fit with time:

2021 ◽  
Author(s):  
Amal I. Linjawi ◽  
Amal M. Abushal
Keyword(s):  
San Jose ◽  
Lower Incisor ◽  
Mean Values ◽  
Significance Level ◽  
Time Points ◽  
Post Hoc ◽  
Clear Aligner ◽  
Gap Width ◽  
Labial Surface ◽  
Different Levels

ABSTRACT Objectives To analyze adaptational changes in clear aligner fit after intraoral usage at different sets of time. Materials and Methods Eight Invisalign appliances (Align Technology, San Jose, California, USA) were collected after intraoral usage. Acrylic imprints of the lower incisor region were constructed for each appliance at T0 (unused appliance). Two appliances were then used intra-orally for each of the following defined periods of time: 3 days, 7 days, 10 days, or 15 days. Used aligners were adapted on its T0 imprint and both were sectioned buccolingually from the distal surfaces of each incisor at the attachment area. Eight surfaces were collected for each set of time (n = 32 surfaces). Microphotographs of obtained sections and micrometric measurements of aligner fit were recorded at five different levels using scanning electron microscopy (SEM). Mean values of the fit changes (gap width) and group comparisons were statistically analyzed using analysis of variance and Tukey's post hoc tests. Significance level was set at P &lt; .05. Results Highly significant differences in aligner fit were found at the different time points assessed (P &lt; .001) with the least mean gap width at 15 days (176 ± 98 μm) and the highest at 7 days (269 ± 145 μm). Significant differences in aligner fit at different attachment levels were also found (P &lt; .01) with the least mean gap width at the middle of the labial surface of the attachment (187 ± 118 μm). Conclusions The 15-day period of intraoral aligner wear might still be recommended as it showed the best adaptation and least gap width between the aligner and the attachment.

scholarly journals Effect of eggshell powder application on the shear bond strength of bulk-fill resin composite to bleached enamel

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Lamiaa M. Moharam ◽  
Shahinaz N. Hassan
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Control Group ◽  
Mean Values ◽  
Anterior Teeth ◽  
Mi Paste Plus ◽  
Mi Paste ◽  
Post Hoc ◽  
Self Etch

Abstract Objective To investigate experimental eggshell powder (ESP) solution application effect on shear bond strength (SBS) test timing of bulk-fill resin composite to bleached enamel. Methods Eighty bovine-extracted anterior teeth were alienated to eight groups (n = 10), representing shear bond strength test timing periods (immediate or delayed) and the remineralizing agents investigated (MI paste Plus and ESP solution). Enamel surfaces were bleached using in-office chemical bleaching agent and the two remineralizing agents were applied then self-etch adhesive and bulk-fill resin composite were performed at 24 h and 14 d before SBS test was done. One-way ANOVA followed by Tukey post hoc test was performed for statistical analysis. Results The control groups showed the highest mean values, while the bleached enamel groups recorded the least mean values. ESP bleached enamel group recorded a significantly higher mean SBS values than MI paste Plus bleached group. Delayed SBS groups showed higher mean values than immediate SBS groups except for control group. Conclusions ESP had a positive and significant effect on SBS of bulk-fill resin composite to bleached enamel surface. Delaying the bonding procedure and restoration of the bleached teeth using resin composite restorations results in a better bond durability.

scholarly journals Durability of the adhesive cementation to the dentin substract

2016 ◽  
Vol 64 (2) ◽  
pp. 132-139
Author(s):  
Rodivan BRAZ ◽  
Márcia de Almeida DURÃO ◽  
Gabriela Luna Santana GOMES ◽  
Fabio Barbosa DE SOUZA ◽  
Eliane Alves LIMA
Keyword(s):  
Resin Composite ◽  
Microtensile Bond Strength ◽  
Resin Cements ◽  
Adhesive Resin ◽  
Mean Values ◽  
Adhesive Cementation ◽  
Pre Treatment ◽  
One Year ◽  
The One

ABSTRACT Objective The aim of this study was to evaluate, in vitro, the union stability of resin cements to the dental substract through microtensile bond strength (µTBS) analysis and scanning electron microscopy (SEM). Methods Fifty-four third human molars, stored in water for a short (24 hours) and long period of time (1 year) presented a flat oclusal superficial dentin. The teeth were distributed in six different groups: G1- Panavia F2.0/Kuraray; G2- RelyXUnicem/3M ESPE; G3- G-Cem/GC; G4- Biscem/ Bisco; G5- Panavia F2.0/Kuraray without pre-treatment and G6- Multilink Sprint/Ivoclar-Vivadent which were adhered to its respective indirect resin composite restoration, (G1- Clearfil AP-X/Kuraray; G2- Filtek Z350/3M ESPE; G3- Gradia Direct X(tm)/GC; G4- Aelite(tm)/ Bisco; G5- Clearfil AP-X/Kuraray; G6- Tetric Ceram/ Ivoclar-Vivadent). The resin blocks were cemented and the sticks were obtained by tooth, with an area of adhesive interface of 0,8mm² (±0,2). Results The mean values, submitted to Mann-Whitney and Kruskal-Wallis tests (α = 5%) were in MPa after 24 hours: G1 = 9.66 (A), G2 = 13.37 (A); G3 = 15.89 (A); G5 = 4.18 (B); G6 = 11.01 (A) and after 1 year: G1 = 9.75 (A), G2 = 11.73 (A); G3 = 20.10 (B); G5 = 6.80 (A); G6 = 21.09 (B). All G4 group presented pretest failures. Conclusion During the one year period, with the exception of BisCem, the self-adhesive resin cements were a favorable alternative for the adhesive cementation, standing out among these, the G-Cem and Multilink Sprint.

scholarly journals Longitudinal Associations between Internalizing Symptoms, Dispositional Mindfulness, Rumination and Impulsivity in Adolescents

2021 ◽  
Author(s):  
Estíbaliz Royuela-Colomer ◽  
Liria Fernández-González ◽  
Izaskun Orue
Keyword(s):  
Mental Health ◽  
Depressive Symptoms ◽  
Internalizing Symptoms ◽  
Protective Factor ◽  
Negative Association ◽  
Dispositional Mindfulness ◽  
Vulnerability Factors ◽  
Time Points ◽  
Longitudinal Associations ◽  
One Year

AbstractMindfulness has been associated with fewer negative mental health symptoms during adolescence, but fewer studies have examined longitudinal associations between mindfulness and symptoms in conjunction with two vulnerability factors for psychopathology with mindfulness: rumination and impulsivity. This study examined longitudinal associations between internalizing symptoms (depression, anxiety, stress), mindfulness, rumination, and impulsivity over a one-year period among 352 Spanish adolescents (57.4% girls; M = 14.47, SD = 1.34). Participants completed self-reported measures of symptoms, mindfulness, rumination, and impulsivity at two time points. Mindfulness negatively predicted stress and depressive symptoms, and a bidirectional negative association was found between mindfulness and impulsivity. Impulsivity positively predicted stress, and anxiety positively predicted depressive symptoms, stress, and rumination. This study highlights the importance of mindfulness as a protective factor and impulsivity and anxiety as risk factors for internalizing symptoms throughout adolescence. These findings build on previous studies that examined longitudinal associations between mindfulness and symptoms by including rumination and impulsivity’s roles.

scholarly journals The Influence of Cement Layer Thickness on the Stress State of Metal Inlay Restorations—Photoelastic Analysis

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 599
Author(s):  
Grzegorz Sokolowski ◽  
Michal Krasowski ◽  
Agata Szczesio-Wlodarczyk ◽  
Bartlomiej Konieczny ◽  
Jerzy Sokolowski ◽  
...  
Keyword(s):  
Stress State ◽  
Layer Thickness ◽  
Resin Composite ◽  
Water Immersion ◽  
Cylindrical Sample ◽  
Resin Cement ◽  
Adhesive Resin ◽  
Cement Layer ◽  
Contraction Stress ◽  
Photoelastic Analysis

The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.

scholarly journals Dose-dependent effects of insoluble fibre on glucose metabolism: a stratified post hoc analysis of the Optimal Fibre Trial (OptiFiT)

2021 ◽  
Author(s):  
Stefan Kabisch ◽  
Caroline Honsek ◽  
Margrit Kemper ◽  
Christiana Gerbracht ◽  
Ayman M. Arafat ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Dose Effect ◽  
Oral Glucose ◽  
Oat Hulls ◽  
Post Hoc Analysis ◽  
Fibre Intake ◽  
Glucose Levels ◽  
Insoluble Fibre ◽  
One Year ◽  
Post Hoc

Abstract Aims As the first long-term RCT on insoluble cereal fibre, the optimal fibre trial demonstrated glycometabolic benefits, confirming cohort studies. The combined study intervention of lifestyle recommendations and supplementation with insoluble oat hulls fibre allows to clarify, which amount of fibre is required for a beneficial effect. Methods One hundred and eighty participants with impaired glucose tolerance underwent the one-year PREDIAS lifestyle programme and received a blinded, randomized fibre or placebo supplement for two years. We conducted a regression analyses and cut-off-based tertile comparisons in subjects with full data on dietary compliance (food records and accounted supplement; n = 120) after one year, investigating effects on fasting blood parameters, oral glucose tolerance test and anthropometry. Results We found a nonlinear inverse relation between fibre intake and change in postprandial 2-h glucose levels, showing a metabolic benefit beyond 14 g and a plateau beyond 25 g of total insoluble fibre per day. 2-h glucose levels improved significantly stronger in both upper tertiles (−0.9 [−1.6;−0.2] mmol/l, p = 0.047, and −0.6 [−1.6;0.3] mmol/l, p = 0.010) compared to the lowest tertile (0.1 [−1.2;1.1] mmol/l), also when adjusted for changes in bodyweight. Subjects with the highest fibre intake showed superior effects on fasting and postprandial insulin resistance, hepatic insulin clearance, leucocyte count and fatty liver index. Conclusions Extending the knowledge on the benefits of insoluble oat hulls fibre, our post hoc analysis demonstrates a dose effect for glycaemia and associated metabolic markers. Further research is needed in order to replicate our findings in larger trials.

scholarly journals Treatment benefit among migraine patients taking fremanezumab: results from a post hoc responder analysis of two placebo-controlled trials

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Stephen D. Silberstein ◽  
Joshua M. Cohen ◽  
Ronghua Yang ◽  
Sanjay K. Gandhi ◽  
Evelyn Du ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Medication Use ◽  
Two Phase ◽  
Double Blind ◽  
Treatment Benefit ◽  
Mean Values ◽  
Treatment Benefits ◽  
Acute Headache ◽  
Post Hoc ◽  
Insight Into

Abstract Background Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway, including the fully humanized monoclonal antibody (IgG2Δa) fremanezumab, have demonstrated safety and efficacy for migraine prevention. Clinical trials include responders and nonresponders; efficacy outcomes describe mean values across both groups and thus provide little insight into the clinical benefit in responders. Clinicians and their patients want to understand the extent of clinical improvement in patients who respond. This post hoc analysis of fremanezumab treatment attempts to answer this question: what is the benefit in subjects who responded to treatment during the two, phase 3 HALO clinical trials? Methods We included subjects with episodic migraine (EM) or chronic migraine (CM) who received fremanezumab quarterly (675 mg/placebo/placebo) or monthly (EM: 225 mg/225 mg/225 mg; CM: 675 mg/225 mg/225 mg) during the 12-week randomized, double-blind, placebo-controlled HALO EM and HALO CM clinical trials. EM and CM responders were defined as participants with a reduction of ≥ 2 or ≥ 4 monthly migraine days, respectively. Treatment benefits evaluated included reductions in monthly migraine days, acute headache medication use, and headache-related disability, and changes in health-related quality of life (HRQoL). Results Overall, 857 participants from the HALO trials were identified as responders (EM: 429 [73.8%]; CM: 428 [56.7%]). Reductions in the monthly average number of migraine days were greater among EM (quarterly: 5.4 days; monthly: 5.5 days) and CM (quarterly: 8.7 days; monthly: 9.1 days) responders compared with the overall population. The proportion of participants achieving ≥ 50% reduction in the average monthly number of migraine days was also greater in responders (EM: quarterly, 59.8%; monthly, 63.7%; CM: quarterly, 52.8%; monthly, 59.0%) than in the overall population. Greater reductions in the average number of days of acute headache medication use, greater reductions in headache-related disability scores, and larger improvements in HRQoL were observed among EM and CM responders compared with the overall populations. Conclusions Fremanezumab responders achieved clinically meaningful improvements in all outcomes. The magnitude of improvements with fremanezumab across efficacy outcomes was far greater in responders than in the overall trial population, providing insight into expected treatment benefits in participants who respond to fremanezumab in clinical practice. Trial registration ClinicalTrials.gov identifiers: NCT02629861 (HALO EM) and NCT02621931 (HALO CM).

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