behnaz esmaeili

Titanium abutments are the gold standard of implant treatments. However, they may not create sufficient color matching to the natural teeth due to the gray color showing through under the ceramic crown. The present study aimed to determine the masking ability of computer‑aided design and manufacturing () bleach shade ceramics in different thicknesses on titanium abutments.

In this laboratory study, a total of 90 specimens of bleach shade ceramics Celtra Duo (CD), Vita Suprinity (VS), and zirconia Luxen were prepared in thicknesses of 1, 1.5, and 2 mm (n = 10). Background specimens of G‑aenial composite in A3 color and titanium were used. The ceramic specimens were placed on titanium and composite backgrounds and L*a*b* color parameters and color difference (ΔE) were measured with the VITA Easyshade spectrophotometer. Data were analyzed using three‑way and one‑way analysis of variance tests. Pairwise comparisons of groups were also performed with Tukey’s test. P <0.05 was considered statistically significant and ΔE <2.7 was considered clinically acceptable criteria.

The effects of thickness, ceramic type, and their interaction effects on the ΔE were statistically significant (all three: P <0.001). The difference in ΔE values of bleach shade ceramics on titanium and composite backgrounds was estimated to be statistically significant in the thicknesses of 1 mm (P = 0.01), 1.5 mm (P < 0.001), and 2 mm (P = 0.001). Zirconia had a better performance for masking ability in thicknesses of 1.5 mm (P < 0.001) and 1 mm (P = 0.01), while VS ceramic showed the best masking ability in thicknesses of 2 mm (P = 0.001). The masking ability of ceramics was improved by increasing the thickness.

Except for VS ceramic in thickness of 1 mm, the rest of the bleach shade ceramics in all three thicknesses of 1, 1.5, and 2 mm have adequate ability to mask the titanium background and their use in line with the masking ability of titanium background has brought acceptable esthetic results.

This study aimed to measure light transmittance (LT) through various thicknesses of computer‑aided design/computer‑aided manufacturing bleach shade ceramics and to assess the Vickers microhardness (VMH) of underlying light‑cured resin cement.

In this in vitro study, a total of 90 ceramic discs (VITA Mark II [VM], VITA Suprinity, and CELTRA Duo) were prepared in 0.5, 1, and 1.5 mm thicknesses. To measure LT, the Valo light‑curing unit was placed in direct contact with the ceramics on the radiometer. The average LT was recorded after three measurements. In addition, 90 specimens of light‑cured resin cement (Allcem Veneer) were cured in Teflon molds (0.5 mm in depth) beneath ceramic pieces. Ten specimens of resin cement were also cured without the presence of ceramic as a control group. VMH of the cement specimens was reported. The data were analyzed by one‑way analysis of variance and multiple comparison tests (α =0.05) in SPSS version 17.

In each ceramic group, LT was negatively related to ceramic thickness (P < 0.05). At a thickness of 1.5 mm among all ceramic types, the VMH of resin cement was significantly decreased (P < 0.05). In all thicknesses, theVMH of resin cement was lower significantly than the control group, except for the thickness of 0.5 mm of VM.

According to the results of this study, light‑cured cement is not a suitable option for cementing the studied bleach shade ceramics. Furthermore, the thickness of the ceramic has a significant effect on LT (P < 0.05), unlike VMH.

This study aimed to assess the effect of polishing versus glazing of computer‑aided design‑computer‑aided manufacturing (CAD‑CAM) ceramics on depth of wear and surface roughness of opposing composite resin.

This in vitro study was conducted on 40 Z250 composite and 40 CAD‑CAM ceramic specimens including Celtra Duo, Vita Mark II, e.max CAD, and Vita Suprinity ceramics. All ceramic specimens were roughened by a fine‑grit bur after primary glazing to simulate an adjusted surface in the clinical setting. They were then randomly assigned to two subgroups and underwent reglazing or polishing. All composite and ceramic specimens underwent profilometry after surface treatment and prior to the wear test, and the results were recorded quantitatively. Composite specimens were then subjected to 120,000 wear cycles against ceramic specimens in a chewing simulator, and the depth of wear was measured by a scanner. Data were statistically analyzed by repeated measures two‑way analysis of variance (ANOVA) and one‑way ANOVA (α = 0.05).

Comparison of the surface roughness of composite specimens before and after the wear test revealed significant differences in both glazed Suprinity (P = 0.048) and Vita Mark II (P = 0.026) ceramics groups. The change in surface roughness after the wear test (compared with baseline) was significant in glazed (P = 0.000) and polished (P = 0.013) Vita Mark II and polished Suprinity (P = 0.037) ceramics, but this change was not significant in other ceramics (P > 0.05). The depth of wear after the wear test was not significantly different among the ceramic and composite subgroups (P > 0.05).

Assessment of depth of wear and surface roughness of composite specimens showed that the polishing kits of CAD‑CAM ceramics can serve as a suitable alternative to reglazing.

Compromised fracture resistance of endodontically treated premolars, is one of the most common dental problems. The aim of the present study was to investigate the effect of using fiberglass with bulk fill composite on fracture resistance of premolars.

In this in vitro study, 60 healthy human premolar teeth were divided into 5 equal groups (n=12). The first group included healthy teeth without any cavity preparation. These teeth were considered as control group (negative control). In group 2, MOD cavity was prepared but not repaired and they were considered as positive control. Group 3, MOD cavity preparation was done similarly to group 2. The cavity was repaired with composite. Group 4: Preparation of the MOD cavity and etching and bonding steps were carried out in the same way as the previous group. A layer of composite was placed on the pulpal floor of the cavity and before curing, glass fiber was placed on the composite in the bucco-lingual direction and cured for 40 seconds. In group 5, cavity preparation and bonding were performed similar to the previous groups. Cavities were filled with composite up to a thickness of 4 mm. Then, glass fiber was extended on the composite and then the sample was cured for 40 seconds. The fracture resistance of the teeth was checked with a universal test device and finally the data was analyzed with SPSS software.

In the gingival fiber-reinforced group, the fracture toughness was significantly higher than the bulk composite-restored group (P=0.01), but this difference was not significant in the occlusal fiber group (P=0.870). No significant difference was observed between occlusal and gingival fiber groups. (P=0.38)

Restoring endodontically treated premolars with bulk fill composite increases their fracture resistances, equal to an intact tooth, and using glass fibers in the gingival area of the cavity enhances its effect.

Many studies have evaluated the possible utility of cycle threshold (Ct) values as a predictor of Coronavirus disease 2019 (COVID-19) severity and patient outcome. Given the inconsistent results, we aimed to evaluate the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Ct values and disease severity, inflammatory markers, and outcomes in Iranian patients with COVID-19. A retrospective study of 528 patients with COVID-19 hospitalized from September 2020 to October 2021 was conducted. Demographic, clinical, and laboratory data of patients were retrieved from electronic medical records. Ct values were analyzed as a continuous variable after subcategorizing into 3 groups: low (Ct values<20), medium (Ct values 20 to 30), and high (Ct values>30). Of the 528 patients (45.1% female) aged 13 to 97 years, 109 patients had low Ct values, 312 patients had medium, and 107 patients had high Ct values. Patients with low Ct values were more likely to present with critical COVID-19, require invasive mechanical ventilation and develop complications such as acute respiratory distress syndrome and pneumonia. Furthermore, patients with low or medium Ct values were more likely to die compared to patients with high Ct values. Multivariate analysis showed that patients with low or medium Ct values were more likely to have severe COVID-19 compared with patients with high Ct values. The multivariate analysis also showed a higher risk of mortality in patients with low Ct values compared to patients with high Ct values, although this was not statistically significant. Our findings revealed that Ct values were an independent predictor of COVID-19 severity. The risk of mortality was higher in patients with low Ct values. However, further investigation is needed to address the Many studies have evaluated the possible utility of cycle threshold (Ct) values as a predictor of Coronavirus disease 2019 (COVID-19) severity and patient outcome. Given the inconsistent results, we aimed to evaluate the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Ct values and disease severity, inflammatory markers, and outcomes in Iranian patients with COVID-19. A retrospective study of 528 patients with COVID-19 hospitalized from September 2020 to October 2021 was conducted. Demographic, clinical, and laboratory data of patients were retrieved from electronic medical records. Ct values were analyzed as a continuous variable after subcategorizing into 3 groups: low (Ct values<20), medium (Ct values 20 to 30), and high (Ct values>30). Of the 528 patients (45.1% female) aged 13 to 97 years, 109 patients had low Ct values, 312 patients had medium, and 107 patients had high Ct values. Patients with low Ct values were more likely to present with critical COVID-19, require invasive mechanical ventilation and develop complications such as acute respiratory distress syndrome and pneumonia. Furthermore, patients with low or medium Ct values were more likely to die compared to patients with high Ct values. Multivariate analysis showed that patients with low or medium Ct values were more likely to have severe COVID-19 compared with patients with high Ct values. The multivariate analysis also showed a higher risk of mortality in patients with low Ct values compared to patients with high Ct values, although this was not statistically significant. Our findings revealed that Ct values were an independent predictor of COVID-19 severity. The risk of mortality was higher in patients with low Ct values. However, further investigation is needed to address the correlation between Ct values and inflammatory factors.correlation between Ct values and inflammatory factors.

The durability of composite restorations is directly affected by the mechanical properties of the composite. The aim of this study was to evaluate the hardness and wear resistance of self-adhesive flowable composite (SAF) in comparison with conventional flowable composites.

In this in vitro study, 50 composite specimens were prepared in brass molds with 10mm ×10mm ×2mm and divided into five groups (n=10). Specimens included three conventional flowable composites (Grandio flow, Filtek flow and Admira fusion flow), one self-adhering flowable composite (SAF, Vertise flow) and a microhybrid composite (filtek z250). After polishing, the micro-hardness of the specimens was measured in a Vickers hardness device, and the specimens were then subjected to 5000, 10000, 20000, 40000, 80000 and 120000 wear cycles in a wear tester. One-way ANOVA/Games-Howell, Kruskal Wallis, and Friedman tests were used for statistical analysis. The significance level was set at P<0.05.

The surface micro-hardness of the SAF was significantly lower than that of the microhybrid composite (P=0.01). There was no significant difference between the surface hardness of the different tested flowable composites (P>0.05). Also, the wear resistance of the studied composites was not significantly different in various cycles (P>0.05).

Based on our results, SAF would not be an ideal substitute for conventional flowable composites in high-stress areas.

This study aimed to assess the microtensile bond strength (µTBS) of etch-and-rinse (E&R), self-etch (SE), and universal adhesives to superficial and deep dentin.

In this in vitro study, 40 sound third molars were randomly divided into two main groups of superficial and deep dentin. Based on our classification, superficial dentin was right beneath the deepest occlusal groove, and deep dentin was 2mm beneath the deepest occlusal groove. Each group was divided into 4 subgroups (n=20) for application of Adper Single Bond 2 (ASB), Clearfil SE Bond (CSE), and Scotchbond Universal (SBU) in E&R and SE modes along with Charisma Smart composite resin on dentin. The specimens were incubated in distilled water at 37°C for 24 hours and their µTBS was then measured. The mode of failure was determined under a stereomicroscope at ×40 magnification. Data were analyzed by one-way ANOVA (alpha=0.05).

The highest µTBS belonged to the superficial dentin/SBU/E&R group. The µTBS was significantly higher in superficial dentin than deep dentin for all adhesives (P=0.005). There was no significant difference in mode of failure among the groups.

Based on the results obtained in the present study, type of bonding agent and application mode affected µTBS. In use of universal adhesive, E&R mode can improve µTBS.

Considering the studies on the effects of bleaching materials on properties of dental materials, The aims of this in vitro study were to evaluate the effects of two different concentrations of bleaching agents on flexural strength and microhardness of VITA ENAMIC.

In this experimental in vitro study, 30 rectangular‑shaped specimens(2 mm width × 2 mm height × 12 mm length) for flexural strength and 30 specimens (5 mm width × 5 mm length × 2 mm height) for microhardness tests were prepared from VITA ENAMIC blocks 12 × 14 × 18 mm. The specimens were polished using silicon‑carbide sandpapers 400, 600, 800, 1200, 2000 under flow of water for 60 s each. The prepared samples for flexural strength and microhardness were divided into 3 subgroups (n = 10): control group (C), samples bleached using Opalescence PF 15% (B15), and samples bleached with Opalescence Xtra Boost 40% (B40). Flexural strength measurement was done using a universal testing machine, and microhardness test was done using Vickers. Data were analyzed using analysis of variance and post hoc tests and P < 0.05 was considered significant.

The mean microhardness values of C, B15, and B40 groups were 255.46 ± 3.02, 249.86 ± 4.18, and 235.53 ± 4.61 kgf/mm2 . Opalescence PF 15% and Opalescence Xtra Boost 40% affected microhardness of ENAMIC significantly (P < 0.05). The mean flexural strength values of C, B15, and B40 groups were 155.26 ± 16.13, 142.14 ± 11.52, and 133.39 ± 16.13 MPa. A significant decrease in flexural strength was found between the C and B40 groups (P = 0.007). However, the difference between flexural strength of the C and B15 groups was not significant (P > 0.05).

Our study showed that both concentrations of bleaching agents can affect microhardness of ENAMIC. Moreover, hydrogen peroxide 40% has a negative effect on the flexural strength of ENAMIC

Autoimmune neutropenia is a type of immune-mediated neutropenia, caused by antibody-induced neutrophil destruction. Here, we report two cases (a 3-year-old boy and a 9-year-old girl) with suspected autoimmune neutropenia. The presence of neutrophil antibodies in the sera of these two patients was investigated; using standard neutrophil antibody screening tests such as granulocyte immunofluorescence test (GIFT), granulocyte agglutination test (GAT), and lymphocyte immunofluorescence test (LIFT). A positive reactivity with two-panel cells was found in GIFT. No reactivities with panel cells were observed in GAT and LIFT. To the best of our knowledge, this is the first report for detecting the neutrophil reactive antibodies; using genotyped neutrophils in patients with autoimmune neutropenia in Iran. The final diagnosis of our patients was primary autoimmune neutropenia for the boy and autoimmune neutropenia associated with familial Mediterranean fever for the girl.

T-cell receptor excision circles (TREC)/Kappa-deleting recombination excision circles (KREC) assay has been recently recognized for detecting patients with primary (T- and/or B-cell) immunodeficiency (PID). We aimed to investigate the alterations of these biomarkers in some combined immunodeficiency patients compared to the healthy controls in different age groups.TREC and KREC were assessed in a total of 82 PID patients, most of them with exact genetic diagnosis (3 months to 42 years); using quantitative real-time-polymerase chain reaction (PCR). Patients had a final diagnosis of common variable immunodeficiency (n=23), ataxia-telangiectasia (AT) (n=17), hyper-IgE syndrome (HIES) (7 with DOCK8 deficiency, 4 with signal transducer and activator of transcription 3 (STAT3) deficiency, and 8 children with unknown genetic defects), Wiskott-Aldrich syndrome (WAS) (n=20), purine nucleoside phosphorylase (PNP)deficiency(n=1), dedicator of cytokinesis2 (DOCK2) deficiency (n=1), recombinase activating gene1 (RAG1) deficiency (n=1).Very low to zero amounts of TREC and/or KREC were detected in 14 out of 23 cases of common variable immunodeficiency (CVID), 14 out of 17 cases of AT, 8 out of 20 cases of WAS, 6 out of 7 cases of DOCK8-deficiency patients, 4 out of 8 cases of HIES with unknown genetic defects and all patients with defects in DOCK2, PNP, and RAG1. STAT3-deficient patients were normal for both biomarkers. All patients showed a significant difference in both markers compared to age-matched healthy controls.
Our findings highlight that apart from severe types of T/B cell defects, this assay can also be used for early diagnosis the patients with late-onset of disease and even PIDs without a positive family history.

This study aims to investigate the role of prenatal diagnosis (PND) in Iranian couples with a previous history of primary immunodeficiency disorders (PIDD) in their family. All referred couples with a family history of PIDD and a tendency for PND were included in this project. Based on gestational age, chorionic villus sampling (CVS) was performed to analyze the molecular defect of the fetus according to the previous gene defect of the affected case in the family. Postnatal confirmation was performed by immunological screening tests. In a total of 100 cases, CVS was not evaluated in 19 patients due to unwillingness (n=5), late prenatal referral (n=7), miscarriage before CVS (n=3), and female fetus with x-linked diseases in previous children (n=4). In the remaining 81 patients, heterozygous and homozygous mutations were found in 33 and 23 cases, respectively. The hemizygous mutation was obtained in 6 and no pathogenic mutations were found in 19 individuals. Postnatal evaluations revealed that a total of 65 babies were healthy, 32 fetuses were aborted (3 cases before CVS, 2 spontaneous abortions of a healthy and as affected fetus in the CVS subgroup, and 27 cases were aborted due to therapeutic causes). One fetus from the heterozygous subgroup was spontaneously aborted with severe combined immunodeficiency (SCID) and one fetus from the homozygous subgroup that was supposed to be healthy was affected by the autosomal dominant-chronic granulomatous disease (AR-CGD). The diagnostic error was 1.2%. PND is highly recommended in families with a history of PID in their previous child to prevent an affected baby being born and to reduce the government, family, and personal burden of these diseases.

Glass ionomers are often used as a base under composite restorations in deep cavities by sandwich technique. The aim of this study was to compare the shear bond strength of composite to resin modified and conventional glass ionomer using total etch , self-etch and universal bonding systems.

Ninety glass-ionomer samples were prepared for this research: Fuji II (F II), IonoStar Plus (IS) and Fuji II LC (F II LC).Then the specimens were divided into 9 groups (n=10). The surface of the specimens were prepared with three types of bonding: Adper single bond2 (SB), Clearfil SE bond (SE) and Single bond Universal (SU).Then Z250 composite resin was applied on the glass ionomers. The specimens were incubated in distilled water for 24 hours at 37 ° C and then were tested for shear bond strength. The type of failure was determined by a ×40 stereomicroscope and the results of the study were analyzed by nonparametric statistical analysis and Kruskal Wallis test. P≤0.05 was considered significant.

The highest shear bond strength was observed in the Fuji II LC + Single bond2 group. There was a statistically significant difference in the shear bond strength of the composite to the two glass ionomers F II and F II LC using SB and SU bonding systems (P=0.033 and P=0.040, respectively).There was no significant difference between the groups regarding the type of failure.

Unlike the Fuji II LC and IonoStar Plus glass ionomers, the shear bond strength of the composite to the Fuji II conventional glass ionomer is affected by the type of bonding system. Total-etch and self-etch bonding systems can be used effectively in sandwich technique. Using a resin modified glass ionomer with total etch bonding can improve the shear bond strength of the composite to the glass ionomer.

Silane promotes bonding between ceramic and resin cement. Silane function could be improved by heat treatment and adding 4-Methacryloxyethyl trimellitate anhydride (4-META). The aim of this study was to assess the effect of heat treatment and adding 4‑META to silanes on the microtensile bond strength of IPS e.max CAD ceramic and resin cement.

In this in vitro study, 32 IPS e.max CAD blocks (6 mm × 6 mm × 4 mm) were randomly divided into 8 groups of 4. The ceramic surfaces were etched by 10% hydrofluoric (HF) for 20 s, and Clearfil Ceramic Primer Plus, Clearfil Porcelain Bond Activator (CPA) +4‑META, CPA + Clearfil SE Bond (CPA + SE), and Bis‑Silane with and without Oven drying at 100°C for 5 min were applied on the ceramic surfaces as silanes, and then, the ceramics were bonded to composite disks by dual‑cured resin cements. Ultimately, a total of 120 sticks ( 1 mm × 1 mm × 8 mm) were subjected to microtensile bond strength test (15 sticks from each group) and the failure types were assessed by stereomicroscope at 40x. Data were analyzed by two‑sided analysis of variance test and Student’s t‑test the P values were considered to be < 0.05.

The Bis Silane group (two bottles) showed maximum bond strength (P = 0.009). Heat treatment significantly reduced the bond strength in Bis Silane (P = 0.0001); but, in other groups, it did not show significant effect on the bond strength. Adding 4‑META to CPA did not significantly affect the microtensile bond strength of IPS e.max CAD ceramic to resin cement, and there was no difference in mode of failure between groups.

The effect of silane type was significant on the microtensile bond strength of the ceramic to resin cement. The effect of 4‑META on the bond strength was not significant. The interaction between silane type and heat treatment on the bond strength of ceramic to resin cement was also significant.

Memory regulatory T cells (Tregs) has been demonstrated to produce IL-17 in Psoriasis. Forkhead box P3 (Foxp3) has been demonstrated not to be reliable marker to evaluate Treg cells. Effector CD4+T cells also express Foxp3 after activation. Human T helper-17 cells (Th-17) express high level of surface CD26, while regulatory T cells are CD26 negative or low and this phenotype is stable even after activation of Treg cells. In this study, we aimed to analyze IL-17 producing Treg cells using CD26. Memory T cells were isolated from 10 patients with psoriasis and 10 controls. Ex vivo stimulated IL-17 producing regulatory (Forkhead Box P3 (Foxp3)+CD25+CD26-/low) and effector (Foxp3+CD25+CD26hi) memory T cells were analyzed by flow cytometry. IL-23, IL-6, TNFα, TGFβ and IL-17 cytokine levels were also evaluated. No significant difference in IL-17+memory regulatory T cells was seen between patients and controls (p=0.19). A significant decrease in the percentage of IL-17 producing CD26hi effector memory T cells was observed in patients (p=0.04). However, the percentage of these cells was not different between patients with mild or severe form of psoriasis compared to controls (p=0.13). We could not find any significant difference regarding IL-23, IL-6, TNFα, TGFβ and IL-17 cytokine levels in plasma and cell culture supernatant samples between patients and controls. Taken together, our results showed a reduced IL-17 producing effector memory CD26hi T cells in patients with psoriasis compared to controls. However, IL-17 producing memory regulatory CD4+T cells of patients showed no significant difference from that of controls

Increased consumption of energy drinks has raised concerns about their effects on dental restorations. This study assessed the effects of two energy drinks on the surface microhardness of methacrylate and silorane-based composites after 1-week and 1-month periods.
In this in-vitro study, 90 cubic samples were prepared from Filtek P90, Filtek Z250 and Filtek Z350 XT composite resins. Vickers hardness test was performed to measure the baseline surface microhardness for each specimen. Ten randomly selected samples from each composite material were then immersed in one of the two sports drinks (Red Bull and Hype) or artificial saliva (control). Surface microhardness was re-evaluated after 1 week and 1 month of immersion. The data were evaluated using ANOVA via post-hoc Tukey tests and repeated measure test (α=0.05).
Surface microhardness of all composites were significantly decreased in energy drinks in both evaluation periods (P Hype and Red Bull energy drinks can affect the surface hardness of composite resins depending on their characteristics and exposure time.

Since trauma is the leading cause of death, hospitalization, and disability among children under 15, this study aimed to evaluate the epidemiology and patterns of trauma in children.

All trauma patients under 15 years of age who were hospitalized for trauma from 1999 to 2011 were enrolled in this crosssectional study. After obtaining informed consent, demographic information, locations of the events, seasons of occurrence, times of arrival at the hospital, the transfer methods of the patients, types of trauma, anatomical locations of the trauma, hospitalization durations, and distances and times of the accidents before getting to a hospital were collected on a checklist. Then, SPSS software version 20 with a chi-squared test was used for statistical analysis.

The study population consisted of 1,686 children with trauma injuries, 71.9% of whom were male, and 28.1% of whom were female. There was a significant correlation between age, sex, and duration of hospitalization among those patients presenting with certain mechanisms of trauma. The most injuries, with 620 (63.8%) cases, were reported in the lower extremities. After examining the relationships between the ages of the injured patients and the location of the upper extremities, multiple traumas, and abdominal injuries, significant correlations were found.

The results of the present study suggested that boys over 10 years of age were more susceptible to trauma and falling and other accidents are the most important causes of trauma identified among the children. The upper and lower extremities were also the most affected areas.

Fluoride varnish as an extrinsic factor may cause discoloration in tooth-colored restorative materials. This research compared the impact of different fluoride varnishes on color change of a composite restorative material.
This laboratory experimental study was conducted on 40 specimens of flowable composite resin were divided into four groups based on the brand of applied varnishes (Durashield, Nupro, Fluorilaque, and Profluoride varnishes) (n = 10). Color measuring (ΔE) was performed using the easy shade device and according to Commission Internationale de l’Eclairage (CIE) L*a*b* system at three times: 24 hours after immersing in artificial salvia (baseline), 24 hours after fluoride varnishes application and after brushing. The amount of color changes was calculated for all of the specimens as follows: ΔE1 (difference between fluoride application-base line), ΔE2 (difference between brushing-fluoride application), and ΔE3 (difference between brushing-base line). P The maximum and minimum color changes after applying varnishes were observed by Nupro and Profluoride, respectively. A significant difference was observed between ΔE 1 values of all types of studied varnishes (P Trends of color change after using all studied varnishes were clinically acceptable (ΔE

Microleakage is a major factor affecting the longevity of adhesive restorations. Colored compomer is a new restorative material that was specifically designed for the restoration of primary molars in different colors, but their microleakage is unknown. This study was carried out to compare the microleakage of a colored compomer (Twinky star) and a conventional compomer (F2000) with a microhybride composite (Z250).
In this in vitro study, class V cavities were prepared on buccal surfaces of 30 caries free extracted primary molars with gingival margins 1 mm below the Cemento Enamel Junction. The teeth were filled as follow: Group I: single bond2(3M, ESPE, USA) composite (Z250, 3M); Group II: Solobond M (VOCO, Germany) colored compomer (Twinky star, VOCO); Group III: single bond2 compomer (F2000, 3M).After polishing the restorations, all specimens were stored in distilled water for 6 days. Then, the samples were thermocycled for 500 cycles and placed in 0.5% fuchsine solution for 48 hours. The samples were sectioned longitudinally and evaluated for microleakage under a stereomicroscope (MoticMicro Optic, industrial group Co, LTD, Japan) at 40x magnification. Dye penetration was scored on a 0–4 ordinal scale. Data were analyzed using SPSS 14, Kruskal-Wallis, and Mann Whitney ranks tests. The level of significance was set at P There was no significant difference in the gingival microleakage of Twinky star and Z250 (P = 0.374), but the difference was significant between these two materials and F2000 compomer (P According to this study, due to their relatively low microleakage, special glitter, attractiveness to children, and release of fluoride, colored compomers might be an appropriate restorative material for restoration of primary teeth.

This study aimed to assess the effects of two energy drinks on color change (∆E) of two methacrylate-based and a silorane-based composite resin after one week and one month.
Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ∆E values were calculated. The data were analyzed using the Kruskal Wallis and Mann–Whitney U tests.
Filtek Z250 composite showed the highest ∆E irrespective of the solutions at both time points. After seven days and one month, the lowest ∆E values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ∆E values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points.
Prolonged immersion time in all three solutions increased ∆E values of all composites. However, the ∆E values were within the clinically acceptable range (

This study aimed to evaluate the effects of chlorhexidine mouthrinses on color stability of nanofilled and micro-hybrid resin-based composites.
In this in-vitro study, 160 disc-shaped specimens (7x2mm) were fabricated of Filtek Z250 and Filtek Z350XT Enamel (A2 shade). The samples of each group were randomly divided into eight subgroups (n=10). The specimens were incubated in artificial saliva at 37˚C for 24 hours. The baseline color values (L*, a*, b*) of each specimen were measured according to CIE LAB system using a reflection spectrophotometer. After baseline color measurements, the control samples were immersed in saliva and the test groups were immersed in Kin (Cosmodent), Vi-One (Rozhin), Epimax (Emad), Hexodine (Donyaye Behdasht), Chlorhexidine (Shahrdaru), Najo (Najo) and Behsa (Behsa) mouthrinses once a day for two minutes. The specimens were then immersed again in saliva. This process was repeated for two weeks. Color measurements were made on days seven and 14. Two-way and one-way ANOVA and Tukey’s post hoc test, t-test and paired t-test were used to analyze data at a significance level of 0.05.
All specimens displayed color change after immersion in the mouthrinses. Significant interactions were found between the effects of materials and mouthrinses on color change.
All composite resins tested showed acceptable color change after immersion in different mouthrinses. Filtek Z350XT showed less color change than Filtek Z250. Mouthrinses containing alcohol (Behsa and Najo) and citric acid (Vi-One) caused greater discoloration of composites.

Background. Repairing aged composite resin is a challenging process. Many surface treatment options have been proposed to this end. This study evaluated the effect of different surface treatments on the shear bond strength (SBS) of nanofilled composite resin repairs.
Methods. Seventy-five cylindrical specimens of a Filtek Z350XT composite resin were fabricated and stored in 37°C distilled water for 24 hours. After thermocycling, the specimens were divided into 5 groups according to the following surface treatments: no treatment (group 1); air abrasion with 50-µm aluminum oxide particles (group 2); irradiation with Er:YAG laser beams (group 3); roughening with coarse-grit diamond bur 35% phosphoric acid (group 4); and etching with 9% hydrofluoric acid for 120 s (group 5). Another group of Filtek Z350XT composite resin samples (4×6 mm) was fabricated for the measurement of cohesive strength (group 6). A silane coupling agent and an adhesive system were applied after each surface treatment. The specimens were restored with the same composite resin and thermocycled again. A shearing force was applied to the interface in a universal testing machine. Data were analyzed using one-way ANOVA and post hoc Tukey tests (P Results. One-way ANOVA indicated significant differences between the groups (P Conclusion. All the surface treatments used in this study improved the shear bond strength of nanofilled composite resin used.

The aim of this study was to compare the discoloration potential of calcium-enriched mixture (CEM) cement, white mineral trioxide aggregate (WMTA) and calcium hydroxide (CH), after placement in pulp chamber. Methods and Materials: Access cavities were prepared in 40 intact maxillary central incisors. Then, a 2×2 mm box was prepared on the middle third of the inner surface on the buccal wall of the access cavity. The specimens were randomly assigned into four groups; the boxes in the control group were left empty, in groups 1 to 3, the boxes were filled with CH, WMTA and CEM cement, respectively. The access cavities and the apical openings were sealed using resin modified glass ionomer (RMGI). The color measurement was performed with a spectrophotometer at the following intervals: before (T0), immediately after placement of the filling material (T1), one week (T2), 1 month (T3), 3 months (T4) and 5 months (T5) after filling of the box and finally immediately after removing the material from the boxes (T6). Color change (ΔE) values were calculated using the sample Kolmogorov-Smirnov test to determine the normal distribution of data, followed by ANOVA, repeated measured ANOVA and post-hoc Tukey’s tests. All materials led to clinically perceptible crown discoloration after 1 week. The highest ΔE value belonged to WMTA group. Discoloration induced by CEM cement was not significantly different from CH or the control group (P>0.05). CEM cement may be the material of choice in the esthetic region, specifically pertaining to its lower color changing potential compared to WMTA.

Introdouction: Bleaching has become a common treatment for improving the appearance of natural teeth. However, the need to protect dental restorations from bleaching agent exposure is inevitable, as these agents may change the color of restorative materials by oxidation. Filtek P90 composite resin has recently been introduced with the aim of decreasing polymerization shrinkage. The purpose of this study was to compare the color changes of silorane- and methacrylate-based resin composites after exposure to various carbamideperoxide regimens. Sixty-four disk-shaped specimens (10 × 2 mm) of a microhybrid composite, Z250, and a siloranebased composite, P90, were prepared and divided into four subgroups (n = 8). An unbleached group was used as a control, while the remaining specimens in the three subgroups were bleached with 10%, 16%, and 22% carbamide peroxide for 14 days. The color was measured with a spectrophotometer using Commission International de I’Eclairage L*, a*, and b* color scale. The data were analyzed using ANOVA, the t-test, and Tukey’s HSD test. Color differences between bleaching and baseline values (&DeltaE) were <3.3 for all the groups. Z250 and P90 resin composites showed color changes after bleaching with 10%, 16%, and 22% carbamide peroxide, but the changes were insignificant (Z250: p = 0.323, P90: p = 0.136). The color changes were not clinically evident in the sample groups. For both the Z250 and P90 specimens, no statistically significant differences in color were noted.

In recent dentin adhesive systems etching of enamel/dentin are achieved simultaneously. The objective was to evaluate the microleakage of composite restorations using Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). Class V cavities were prepared on 45 extracted intact premolars with gingival margins at the cementoenamel junction and they were randomly divided into 3 groups (n=15) based on the type of adhesives: Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). After applying the adhesives, the cavities were filled with Z250 composite resin. The occlusal and gingival microleakage was evaluated using 2% basic fuchsin staining technique. Data were analyzed using Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. The mean rank of occlusal microleakage exhibited significant differences by comparison of G Bond, Clearfil S3 Bond and Single Bond2 (21.07, 30.67) and 17.27, respectively) (P=0.005). There was a significant difference in gingival microleakage of different bonding agents (34.40, 17.83 and 16.77 for G Bond, Clearfil S3 Bond and Single Bond2, respectively) (P<0.001). There was a significant difference in occlusal microleakage of Clearfil S3 Bond and Single Bond2 (P= 0.003), but no significant difference was found between Clearfil S3 Bond and G Bond (P=0.025). No significant difference was observed between occlusal microleakage by G Bond and Single Bond2 (P=0.238). The difference in gingival microleakage was significant by G Bond compare with Single Bond2 and Clearfil S3 Bond (P<0.001and P<0.001, respectively). The microleakage of class V composite restorations in permanent teeth using the Single Bond2 was lower than that with the use of G Bond in gingival margins. The sealing ability with Single Bond2 was superior to Clearfil S3 Bond in occlusal margin but they were equally effective at gingival margin.

One of the main disadvantages of composites is marginal microleakage; using flowable composites as a liner beneath composite restorations has been recommended to reduce microleakage. The aim of this study was to assess the microleakage of class II restorations with different flowable composites liners. 45 extracted premolars teeth with class II cavity preparation (90 cavities) were divided into five groups and filled as follows: 1.control group: hybrid composite(Z250) 2. Z250+surefil SDR flow 3.Z250+filtek supreme xt flow composite 4.Z250+Grandio flow 5.Z250+Tetric flow. Mesial and distal cavities were filled using snowplow and layering technique, respectively. After that, the samples were immersed in 0. 5% fuchsin solution and sectioned. Gingival microleakage was then graded. Data were analyzed using Kruskal Wallis and Mann Whitney U test. There was no significant difference between the snowplow and layering methods. Microleakage of Tetric flow and Grandio flow liners was significantly higher than the control group. Other flowable composites showed no significant difference in comparison with the control group. In the present study, the results indicated that the flowable composites were not effective on reducing gingival microleakage.