مجله تحقیق در علوم دندانپزشکی
سال شانزدهم شماره 1 (پیاپی 59، بهار 1398)

Allografts are a group of binding materials with various applications in restoration of osseous tissues. These materials are in two types: DFDBAs and FDBAs which have been evaluated and different reports are available regarding their properties. So we decided to launch a study and compare 2 types of FDBA and DFDBA osseous powders manufactured by Hamanand Saz Baft Kish Company and their application in restoration of calvaria bone damages in rabbits. The research performed on randomized clinical trial on 12 white rabbits. It was made 4 full 8 millimeter defects in calvaria bones in all rabbits. Then in group 1 we used DFDBA and in second group we used FDBA and the other groups were the positive and negative control groups. Within the 2 consecutive months (2,4,6,and 8 weeks) we sacrificed 3 rabbits for histologic and Histomorphometric analysis. Data were analyzed using Friedman and Mann-Whitney. We utilized SPSS ver:20 software. There were no statistically significant differences between groups FDBA and DFDBA in the filling status of the defect, inflammation and amount of resorption. At the end of 6 weeks in both groups, Inflammation also decreased in both groups from week 6. Foreign body reaction and complete remodeling of bone was not observed in both groups during the study period. Both of FDBA and DFDBA groups are the same in the rate of bone formation, inflammation and foreign body reaction and absorption.

The gradual color change of the tooth shade guide is due to the use of an autoclave is one of the clinical problems for correct color reproduction. The purpose of this research was study the effect of autoclave on dental shade guide. This experimental experiment was experimental and done on 20 dental paints guide (vitaA3). Subsequently, they were divided into 2 groups color guide by randomly. First, all specimens were washed Before placing in the autoclave Distilled for 3 minutes and they were dry with a tissue and they went on to the autoclave, of course The first group is at 121 °C for 40 minutes and the second group was kept at 134 °C for 10 minutes. These specimens were placed in an autoclave with 180 cycles and3 times a day, 5 days a week (equivalent to 3 months). At each stage set the Spectrophotometer color Indicators (abl) and Guide the color of the teeth. Statistical analysis was performed in SPSS software and in the way of Mann-Whitney. Mean in the group with a temperature of 121 degrees was 3.79 ± 0.63 and in the group with a temperature of 134 degrees, it was 3.55 ± 1.04 which are not significant. According to the statistical test, there is a difference (P <0.3). About b and c index, difference were minor and no significant difference was observed in the case of other measured indicators, L, a, H in the two groups.(P<0.2). The color change was more than 3.3 for both method and not acceptable related to clinical subjects. (3.55 and 3.79) In this study, it was observed that sterilization process by autoclave, can lead to change the color properties of the classic VITA color guide.

Candidiasis is a common fungal disease in the mouth. An appropriate treatment for candidiasis is the use of antifungal drugs. Due to drug resistance and known side effects of drugs, the tendency to use medicinal herbs is increasing. Garlic is identified as a strong antibacterial. Therefore, in this study, the effect of aqueous garlic extract and nystatin on Candida albicans was investigated. An experimental study was carried out. For each control and case group, one standard strain and 10 clinical strains were studied. The standard strain of Candida albicans was obtained from the Iranian Research Institute of Industrial Research and clinical strains from different patients. Garlic was prepared from the north of the country and was extracted by soaking method. Control groups containing nystatin suspension of 10,000 units / ml were prepared from Sigma, and finally, the diameter of the inhibition zone and MIC by Micro Broth Dialution method were studied. The results were analyzed by T test. MIC of nystatin and the MIC and MBC of garlic show that Nystatin MIC was 3.49 ± 4.96 μg / ml and micronutrient was 1.42 ± 2.22 mg / ml and nystatin variation coefficient was 28% and garlic 15% as well as MBC of garlic equal to 58 /. ± 59.1 mg / ml with a coefficient of variation of 36%. In the meantime, mic is for standard samples of 78. 0 mg / ml and nystatin 0.5 μg / ml. The amount of non-growth halo in nystatin was 29.1 ± 1.72 and in the garlic group was 20.1 ± 1.5, which was 9.1% or 31% higher in the nystatin group and the T test showed that this difference was statistically significant. (p <0/000) and the inferiority halo for standard sample 22 and nystatin 32.  The study showed that the aqueous extract of garlic was able to inhibit the growth of Candida albicans but its effect was less than nystatin.

Due to the importance of polymerization of resin cements on the longevity of indirect restorations, this study aimed to evaluate the effect of various thicknesses of IPS e.max Press porcelain on the amount of polymerization of light cured choice 2 resin cement by FTIR method.  In this experimental study, 40 porcelain disks (IPS e.max Press, (Ivacolar Vivadent, Liechtenstein) with a diameter of 10 and thicknesses of, 0.5, 1, And 1.5 mm (n = 10) were prepared using wax removal method. Resin cement Choice 2 (Bisco Inc, USA) with A2 color once before curing and wants after curing with LED (LEDemetronll, Ker, USA) mv / cm2 1200 the samples were placed in an FTIR machine and the polymerization percentage was recorded. Data were analyzed using ANOVA. The light cured Choice 2 resin cement polymerization in four groups showed that the highest polymerization was related to 1.5 mm thickness (72.5% ± 0.41% ) and the least of them was for 0.5 mm thickness ( 68.7% ± 0.88%) ANOVA test showed that this difference between groups were not statistically significant (p <0.2). Selective thicknesses of porcelain IPS e.max Press in this study did not have affect on polymerization of choice2 cement.

Microgap found in implant-abutment connection is still one of the main problems that may lead to mechanical and biological failure and inflammation around implants. This study aimed to evaluate the effect of GapSeal on microgap and microleakage between fixture and abutment in internal hex connections. The experiment was performed using 12 implants to check the efficacy of sealing agent at the IAI. The implants were divided into 2 groups of 6 implants each: a group that used no sealing agent at the IAI and a group that used GapSeal at the IAI. Each sample mounted in the acrylic polymerized resin. GapSeal was applied between the fixture and abutment then abutments were assembled using a torque of 30N by digital torque meter. Then cyclic load was applied with the force of 80N and frequency of 1 Hz on the longitudinal axis of each sample. After 500000 cycles, for assessment of microleakage methylene blue solution was used. All set of fixture-abutment (case and control) immersed in the solution and all samples were placed in the incubator (37◦c) for 24 hour. Then the implant-abutments were cross sectioned longitudinally with cutting machine (figure 2) then micro-leakage and microgap were measured by Scanning electron microscope (×200) in the 3 points in each half circle. Finally data was evaluated by t-test. The mean microgap was 0.99±0.39 for GapSeal group that was significantly lower (P<0.000) than that of control group (3.04±0.54).
Also, results showed microleakage in all samples of control group whereas none of the samples of Gapseal group had microleakage. GapSeal caused less microgap and microleakage in implant-abutment interface.

Periodontal infections are one of the most common diseases of the gum and connective tissue around the teeth and are the main cause of the loss of teeth after decay. The purpose of this study was to identify and sequencing of the periodontal-causing bacteria and its relation with interleukin-6 gene polymorphism by Tetra-Arms-PCR method. In this case-control study, 100 samples (50 periodontal infections and 50 healthy people) were collected under the supervision of a dentist. After genomic DNA extraction using the sinaclon Company Kit, identification of bacterial strains was performed using 16S rRNA gene amplification. Also, after extraction of cellular DNA from blood samples taken, the polymorphism of the genome encoding IL-6 was performed using the Tetra-Arms-PCR method. The sequencing was carried out by the Sanger method and by Bioneer Company, and finally, the MEGA 7 software was scanned to determine the genetic affinity of the phylogeny tree strains. In the present study, bacteria of Staphylococcus, Lactobacillus, Streptococcus, Acroombocator, Granulicatla Adiasens, Gordonia and Kocuria rhizophila were found in periodontal patients. Also, there was a significant relationship between G/G genotype in -174G/C in periodontal patients compared to control group. Polymorphism -174G / C in IL-6 revealed a significant relationship between G allele and GG genotype with chronic periodontal disease. It also showed a variety of germs in periodontal disease, which indicates the complex role of microbial infections in the periodontal infection.

microleakge is one of the most common cause of failure in restorative dentistry in this study the microleakge of filtek p90 , filtek p60 was evaluated and compared . In this experimental study, on 48 premolar teeth standardized class II MOD preparations were made cervical margin of mesial preparation were 1mm above the CEJ and 1 mm and the distal preparation were 1 mm below the CEJ Samples divided in to 3 groups of sixteen teeth. A group: teeth were filled with filtek silorane (3M ESPE , USA) and silorane system adhesive self-etch primer and bond. B: teeth were filled with filtek silorane and Adper single bond plus. C: sixteen teeth were filled with filtek p60 and Adper single bond plus. After AgNO3 dye opplicaiton microleakage were evaluated by stereomicroscope.data were statistically analyzed by kurskal-wallis and Wilcoxon. the level of 0.05 considered significant. The most enamel microleakage was related to C and lowest enamel microleakge was shown in A group. The most dentin microleakage was related to B and the lowest dentin microleakge was shown in A group. Microleakage was significantly different between A, with B and C (P‹0.05) dentin microleakage was not significant difference between B and C. Type of composite and bonding effect to microleakage, the lowest microleakage was gingival margine irrespective of the location of the margine related to group A.

The level of anxiety in 3-6 year old children when receiving dental care, is effective in compliance of the patients and the quality of the received care. The behavior and level of anxiety of children may be associated with their mothers’ psychological status. In this study, the relationship between the mothers’ emotional maturation and the anxiety and behavior of 3-6-year-old children during routine dental treatments was investigated. The current investigation was a cross section-descriptive study. Seventy patients aged 3-6 years old referring to pediatric dentistry ward of Tabriz dental school in 2015 were studied. In selection of the children, the age and lack of previous dental encounter was considered. The patients’ anxiety during dental treatment was assessed by evaluating the child’s behavior by venham scale utilizing frankel index.
Before initiation of dental treatment, questionnaires regarding emotional maturation and PTSD was filled by the mothers. At the end, the relationship between mothers’ emotional maturation and the child’s behavior and anxiety was analyzed by Pearson correlation coefficient test with 0.05 significance level under SPSS 16 software. The current study revealed two main findings. Firstly, the mothers’ emotional maturity did not have a statistically significant relationship with child’s behavior in dental environment. Also the mother’s emotional maturation did not have a statistically significant relationship with child’s anxiety in dental environment. The emotional maturation of mothers was generally at normal level and there does not seem to be a direct relationship between mothers’ level of emotional maturity and child’s behavior and anxiety in the dental environment.

Recognition of learning and study strategies is a fundamental step for educational interventions, especially in the field of medical sciences. This study aimed to determine the relationship between learning and study strategies with Academic performance of dental students of Babol University of Medical Sciences. This descriptive cross-sectional study was carried out on 85 dental students were randomly studied. The second edition of the Learning and Study Strategies Inventory (LASSI) was completed by students after the confirmation of its validity and reliability. For ten area of motivation, attitude, time management, anxiety, concentration, study guide, self-examination, study strategies, main idea choose, time management, data were analyzed using independent t-test and variance and Pearson correlation test. Among the mean scores gained by students, the highest one obtained from ten areas (27.65 ± 5.39) was related to the main idea and the least one (14.88 ± 4.35) was related to the level of anxiety. There was no statistically significant difference between sex and study strategies. (P=0.05) There was positive and strong correlation between study strategies and learning with academic performance. (r=0.52) It seems, post graduate dentistry students need to be guided in some study strategies areas. Particularly, in anxiety area, which has positive and significant correlation.