Caspian Journal of Dental Research

15-22

Authors: Effat Khodadadi , Nafiseh Ghasemi, Mehdi Pouramir* , Ali Bijani

Introduction: The antioxidant properties of chocolate and other flavored additives besides the sugar added to milk raises the question about the acidogenecity of flavored milk. This study was conducted to measure the pH changes of dental plaque and saliva after the consumption of flavored milk and evaluate the antioxidant property of them. Methods: This study was performed on 42 samples of dental plaque and 42 samples of saliva in 6-11 year old school going children. Milk with flavors of strawberry, chocolate, banana, honey and slim milk were evaluated, all from the same manufacturer with a similar production date. At the beginning of the study on the first day, children were given thorough oral propHylaxis and they were instructed to avoid any method of oral hygiene for 48 hours to permit enough plaque deposition. On the third day the children were divided into 7 groups, 6 children in each group. The supra-gingival plaque was collected through the help of an excavator #3 which was pulled twice with the same force on the tooth surface. The saliva was collected using spitting technique. Each child swished 10 cc of milk for 1 minute in his/her mouth. Fresh plaque samples after 5, 10, 20 and 30 minutes and saliva samples immediately, after 5, 10, 20 and 30 minutes were collected. The pH of the samples were recorded by a pH testing apparatus (Basic 20+, Crisom). To evaluate the antioxidant property of studied milk, Frap test was performed. The collected readings were reported as mean±SD and analyzed by ANOVA repeated measures, Post hoc Tukey and Paired T-test. In this study, p≤0.05 was considered as significant. Results: After 30 minutes, honey milk caused the least drop 0.74±0.30 and banana milk caused the highest drop 1.38 0.25 in plaque pH (p≤0.05). After 30 minutes, the pH of saliva showed no significant difference compared to the initial pH. Chocolate milk contained the highest (1000 micromol/liter) and banana milk the lowest (706.25 micromol/liter) antioxidant concentration. Conclusions: Because of the highest antioxidant properties and reduction of dental plaque PH to a lesser extent, milk with honey, chocolate and coffee is more recommended for children.

29-35

Authors: Mehdi Ravadgar , Valiollah Arash , Hamid Pachenari*

Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs) were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at comparing shear bond strengths of the stainless steel metallic brackets bonded by three bonding systems. Methods: In this experimental in vitro study, 60 extracted human maxillary premolar teeth were randomly divided into three equal groups: in the first group, Transbond XT (TBXT) light cured composite was bonded with Transbond plus self-etching primer (TPSEP); in the second group, TBXT composite was bonded with the conventional method of acid etching; and in the third group, the self cured composite Unite TM bonding adhesive was bonded with the conventional method of acid etching. In all the groups, Standard edgewise-022 metallic brackets (American Orthodontics, Sheboygan, USA) were used. Twenty-four hours after the completion of thermocycling, shear bond strength of brackets was measured by Universal Testing Machine (Zwick). In order to compare the shear bond strengths of the groups, the variance analysis test (ANOVA) was adopted and p≤0.05 was considered as a significant level. Results: Based on megapascal, the average shear bond strength for the first, second, and third groups was 8.27±1.9, 9.78±2, and 8.92±2.5, respectively. There was no significant difference in the shear bond strength of the groups. Conclusions: Since TPSEP shear bond strength is approximately at the level of the conventional method of acid etching and within the desirable range for orthodontic brackets shear bond strength, applying TPSEP can serve as a substitute for the conventional method of etch and bond, particularly in orthodontic operations.

42-47

Authors: Ali Nozari , Tahere Esmaeilpour , Soleiman Fijan* , Mahin Salmannejad

Introduction: Tooth avulsion is defined as the complete displacement of the tooth from its alveolar socket which causes damage to the periodontal ligament structure, cementum, alveolar bone, gingiva, and dental pulp. The purpose of this study was to determine the ability of long-shelf life honey milk to serve as a temporary storage medium for the maintenance of periodontal ligament (PDL) cell viability on avulsed teeth. Methods: PDL cells were obtained from premolars extracted for orthodontic purposes which were clinically healthy and had healthy gingiva (i.e. not inflamed).Then, 8×10³ cells were seeded in each well of 96-well plate. and Afterwards treated with long-shelf life milk and honey milk, Hank’s Balanced Salt Solution (HBSS) and fresh milk. Different incubation periods were 1, 3, 6, and 9 hours. Dulbecco’s Modified Eagle Medium (DMEM) and dry medium were considered as positive and negative control media, respectively. Cell viability was determined by using the MTT (Thiazolyl Blue Tetrazolium Bromide) assay. Data were statistically analyzed with one-way anova, two-way anova and post hoc Scheffe tests. A level of p≤0.05 was accepted as statistically significant Results: The results indicate that all media performed significantly better in maintaining PDL cell viability than the negative control at all time periods. (p≤0.001) After 9 hours, Percentage of viable PDL cells in long-shelf life honey milk, long-shelf life milk and HBSS were 82±0.82, 75±8.13 and 87±2.78 respectively. Furthermore cells' viability in both long-shelf life honey milk and HBSS was significantly better than fresh milk medium (p=0.003). Moreover, the results of One-way ANOVA showed long-shelf life honey milk were more effective in preserving the PDL cell viability as well as HBSS after 9 hours. Conclusions: According to the study results, long-shelf life honey milk considered as appropriate storage media which are comparable to HBSS. These media are not only able to keep more cells viability after 9h compared to the expensive commercial solutions, but are also be easily accessible.

18-24

Authors: Homayoun Alaghehmand , Maryam Seyedmajidi *, Behzad Amiri-Andi, Neda Babaee

Introduction: Previous researches showed that neutral soaps significantly increased bond strength and decreased microleakage of dentin bonding agents. The aim of this study was histopathological evaluation of the effect of sodium sulfonate application as neutral soap on the cat's dental pulp after an ideal composite restorative treatment. Methods: Ten adult cats with 40 caries-free canine teeth were selected for the study. Class V cavities were prepared in the buccal surfaces of all the teeth. The teeth of the right quadrants were treated with composite, whereas the teeth of the left quadrants were primarily etched, after using of sodium sulfonate solution, they treated with composite. The first five cats were killed after one week and the other five cats after one month. The teeth were fixed, decalcified and after being sliced, paraffined blocks were made and microscopic slides were prepared and histologically evaluated. Results: The results of the histological evaluation showed that there were no statistically significant differences between the intensity of inflammation in the pulp of the teeth in the right and left quadrants after one week (p=1.000) and one month (p=0.773). However, there was significant difference after one week regarding predentin formation (p=0.017) and in the teeth of the left quadrants, the formation of predentin was more that the right quadrants, but no meaningful difference was observed after one month (p=0.203). Conclusions: It seems that the sodium sulfonate in composite restorative treatments without fear of damage to the pulp can be used.

32-38

Authors: Marzieh Rohaninasab *, Mandana Sattari , Horrieh Abedi , Nafise Zarenejad

Introduction: Cytokines are the important factors in the progression of periodontal diseases. The aim of this study was to find out the effect of the first phase of the periodontal therapy on the amount of existing IL-17 and IL-23 in gingival crevicular fluid in patients with severe periodontitis and in the control group. Methods: In this clinical trial intervention study,after purifying the parts which were under consideration in 22 patients with severe periodontitis, gingival crevicular fluid was gathered using periopaper located within the gingival sulcus, Then, the first phase of periodontal therapy was carried out and sample taking from the same parts was conducted after 4 weeks. The same phase was carried out on 24 healthy patients (control group). All patients were selected from the Department of Periodontology, Tehran Islamic Azad University Dental Branch. Since the data did not have a normal distribution, therefore, nonparametric tests were used for comparing the groups (Mann-Whitney U Test). A p≤0.05 is considered as significant. Results: The results showed that there was a meaningful and significant difference between the IL-17 viscosity before (p<0005) and after (p<005) the therapy and IL-23 viscosity before (p<0001) and after (p<001) the therapy between the two groups. Conclusions: According to the results of the present study, we can conclude that IL-17 and IL-23 have a significant role in the pathogeneses of periodontal disease.

46-52

Authors: Abdolhamid Alhavaz *, HomayounAlaghemand , Arash Poorsattar-Bejehmir, Yashar Vakili, Mashhad Odak , Amir Rastar

Introduction: The selection of porcelain is based on high biocompatibility, endurance, superficial texture and aesthetics. Nevertheless, the innate fracture charateritics of porcelain is the main cause of the intra oral fractures. Electing a suitable porcelain restorative system in terms of stability of color is important. For this reason, this study aimed to examine the color changes of common porcelain repair materials. Methods: Using a silicon mold, 30 pieces of feldspathic porcelain in A3 color, 10mm of diameter and 2 mm of thickness were prepared. The samples were randomly distributed into three groups: Group 1: Porcelain-Silane-Bonding-Composite Group 2: Porcelain-Silane-Bonding-Panavia F 2.0-Bonding-Silane-Porcelain Group 3: Porcelain-Silane-Bonding-Choice 2 -Bonding-Silane-Porcelain The aging process was accomplished with thermocyling (3000 cycles, 5/55 degree), incubation in 37° and 100° humidity. Thereafter, discoloration was assessed In CIE system via designation of color transforming matrix in MATLAB environment . Results: The average quantitative amount of discoloration at day 0, 90 and 180 were 76.8±0.57, 79.15±0.52, 80.13±0.6 for Choice, 78.03±0.9, 79.42±0.82, 80.17±0.51 for Panavia, and 78.41±1.53, 79.59±0.77, 81.03±0.63 for Composite, respectively. The color changes by the time were significant for the all three groups (p<001).Calculating day 0-180 color changes, mean color differences for Choice, Panavia and Composite groups were 3.33±0.83 , 2.13±1.23, and 2.61±1.6, respectively. The color changes did not differ in the studied groups (p<0.133). Conclusions: Post-aging color changes were significant, although all samples had color changes less than 3.5. Considering the clinical significance of color changes of more than 3.5, these results were acceptable and all three restorative materials could reliably be applied in the daily clinical use.