جستجوی مقالات مرتبط با کلیدواژه « رنگ پذیری » در نشریات گروه « پزشکی »

The Color stability of composite resin materials is important for satisfactory restorative results. Discoloration of composite restorations can bring about patient dissatisfaction as well as long term failure of the restoration. The purpose of this study was to evaluate the effect of tea solution on color stability of 3 nanocomposites. In this experimental study 30 composite disks 8. 5 mm in diameter and 2mm in thickness were made from the following composite materials: Grandio، Z350XT and Herculite XRV Ultra. The samples were assigned to 3 groups of 10 based on the composite material they were made of Half of the samples in each group (5 disks) were immersed in tea solution and the other half (5 disks) were submerged in pure water. Specimens were treated in selected solutions for 72 hours. Calorimetric assessment was done with a spectrophotometer before and after immersion in designated solutions.. Statistical analysis of the results were done using two-way ANOVA test. Measured discolorations for tested composites Z350XT، Grandio، and Herculite XRV were 1. 62 ± 0. 59، 2. 46 ± 0. 74، and 2. 92 ± 0. 72 respectively. The discoloration (ΔE) of all three composites after immersion in tea was significant (P=0. 03) compared to initial colors However، it was within the clinically acceptable range (ΔE < 3. 3). The Color change after immersion in pure water was not significant (P=0. 1). The highest level of discoloration belonged to Z350XT composite، and the lowest discoloration belonged to Herculite XRV Ultra

Background and Chlorhexidine (CHX) is still considered the gold standard anti-plaque agent. The main disadvantage of chlorhexidine is its taste، and staining. Improvements of these disadvantages are time consume. This study was to determine if polyvinylpyrrolidone (PVP) could be added to chlorhexidine rinses to maintain efficacy and reduce staining. This study divided to in vivo and in vitro. The in vivo was randomized، double blind study، and 40 patients with moderate to severe inflammation enrolled to study. The patients undergone dental polishing before the study. In case study and control used e Chlorhexidine + polyvinylpyrrolidone Chlorhexidine mouth wash for 2 weeks respectively. Plaque index (PI) and gingival index (GI)، bleeding index (BI)، and stain index were assessed before and after the intervention. The glass block and spectrophotometry was used to examine the staining intensity of each mouthwash in In vitro study. The data in SPSS and statistical methods were analyzed by Wilcoxon Signed Ranks Test. PI، GI، BI، stain index difference between base line of Chlorhexidine + polyvinyl pyrrolidone and Chlorhexidine mouthwash group was not significant، But the amount of interference between the two groups was significant difference (P=0. 006، 0. 007، 0. 042 respectively). Final severity of body and gingiva between base line of Chlorhexidine + polyvinylpyrrolidone and Chlorhexidine mouthwash group was significant (P<0. 05). Final extent of body and gingiva between base line of two groups was significant (P<0. 05). 0. 2% concentration of Chlorhexidine and 5% PVP concentration in clinical practice to decrease side effect of Chlorhexidine but maintain Chlorhexidine effect

Introduction & The present study evaluated staining as a result of the chlorhexidine use and the role of sodium perborate in removing stains; in addition, the amount of decreases in plaque and gingival inflammation and the role of sodium perborate in chlorhexidine efficacy in removing plaque and decreasing gingival inflammation were evaluated. In the present randomized clinical trial 40 patients (20-30 years old) referring to the Department of Periodontics, who had mild-to-moderate gingivitis were randomly divided into two groups with a parallel study design and were evaluated in a double-blind scheme. At baseline the patients underwent scaling, root planning and polishing procedures and brushed their teeth daily for two weeks. After two weeks, plaque indexes (PI), gingival indexes (GI) and bleeding indexes (BI) were determined and recorded. In the control group 0.2% chlorhexidine gluconate mouthwash and in the experimental group 0.2% chlorhexidine gluconate mouthwash containing 0.2% sodium perborate were used for 30 seconds. The subjects refrained from tooth brushing during this period. After 14 days the above-mentioned indexes were again determined and recorded, along with staining indexes.Also staining potential of mouthwash and chlorhexidine mouthwash containing sodium perborate was analysed with spectrophotometric devices. Data was analyzed by t-test. There were no statistically significant differences in PI, BI and GI between the control and experimental groups, although there were more decreases in PI, GI and BI in the experimental group compared to the control group. Regarding the intensity of staining, there was a significant decrease in the intensity and extent of staining on tooth surfaces and gingivitis in the experimental group compared to the control group (P=0.001). The use of chlorhexidine mouthwash containing sodium perborate significantly decreases the amount and extent of stains but has no inhibitory effect on chlorhexidine potential to reduce plaque and gingivitis.

The success rate of composite restorative materials depends very much on their color stability in the oral cavity. The purpose of this study was to investigate the color changes of four different brands of dental composite resin materials by using four staining solutions. A total of 128 disk-shaped specimens of 152 mm were prepared out of 4 composite resin materials. Two nanocomposites: Filtek supreme, Tetric Evoceram and two micro hybrid composites: Filtek Z250 and Tetric ceram, were prepared. The specimens were then divided into 4 groups of 8 specimens each and they were immersed in 4 staining solutions (Coffee, Tea, Cola, and Artificial Saliva) for 3 hours daily over a 24 day testing period. The color of specimens was measured with a spectrophotometer using CIELab color space relative to illuminant D65 at baseline and after staining. The color differences (E) were calculated. The E=3.3 was used as an acceptable value in subjective visual evaluations. Data was analyzed using ANOVA and Post-hoc test at significance level of 0.05. All tested materials showed unacceptable color change in coffee and tea groups (E>3.3). The greatest color change was observed in Filtek supreme in coffee. The specimens in cola and artificial saliva didnt cause a notable color change clinically. Coffee and tea can significantly influence the discoloration of dental resin composite materials under investigation. The nanocomposite Filtek supreme color change was significantly more than other composites when exposed to coffee. Therefore, color stability of composite restorative materials depends very much on dietary habits.

Leukoplakia is one of the most common premalignant or potentially malignant lesions of the oral mucosa. It’s potential for malignant transformation is unpredictable.The aim of present study was to evaluate the expression of p53 and proliferation status of ki67 antigen in normal, homogeneous and non-homogeneous leukoplakia. The standard immunohistochemistry staining method (Biotin Streptavidin peroxidase) was used to study the expression of p53 and ki67 on formalin fixed, paraffin embedded blocks of 7 cases of homogeneous leukoplakia, 10 cases of non-homogeneous leukoplakia and 9 cases of normal oral epithelium. Data were analyzed using ANOVA, MC Nemar and Fisher’s exact tests. No relationship was detected between p53 protein and Ki67 expression and clinical features of leukoplakia. The distribution patterns of p53 and ki67 were mainly localized in the basal layer of normal oral mucosa, while the expression of p53 and Ki67 were extended into suprabasal cell layer in leukoplakia lesions. Ki67 expression in dysplastic lesions was higher than non-dysplastic lesions. This study showed significant relationship between Ki67 and p53 protein. These findings showed that the expression of p53 and Ki67 in suprabasal cell layers in leukoplakia may be correlated with poor clinical outcome and alterations of p53 lead to increased cell proliferation.