JOURNAL OF ISLAMIC DENTAL ASSOCIATION OF IRAN (MAJALLAH-I-DANDANPIZISHKI)
Year:2012 | Volume:24 | Issue:3 (84)|Papers Count:13

Background and Aim: Many attempts have been done to improvethe quality, properties and composition of dental materials to decrease the microleakage and its consequences. The objective of this invitro study was to compare microleakage of light cure resin modified glass ionomer cement and a hydroxyapatite containing base.Materials and Methods: In this experimental study 40 intact human premolars were divided into 4 groups. On the buccal surface of each tooth, around cavity was prepared with 3 mm in diameter and at least 1 mmdeep into dentin. Teeth were restored using L.C resin modified glass ionomer lining cement, L.C resin modified glass ionomer restorative cement, Lime-Lite with bonding agent, and Lime – Lite without bonding agent. After thermocycling the specimens were immersed in AgNO3 solution for 2 hours.After sectioning the specimens, dye leakage wad evaluated by a stereomicroscope. Microleakage was graded according to ISO 11 405 in occlusal and gingival cavity margins. Obtaineddata were statisticallyanalysed by Kruskal-Wallis, Wilcoxon and Mann-Whitney tests.Results: Most of the samples in group 3 (lime – lite with bonding agent) demonstrated zeromicroleakage grades in gingival and occlusal cavity margins and in group 4 (Lime – Lite – without bonding agant) the majority of samples showedgrade 3 microleakagein both margins. These findings is both margins were significantly higher than those of other groups (p<0.05), but there were not significant differences among glass ionomer groups in marginal microleakage (p>0.05).Conclusion: Hydroxyapatite containing base showed more microleakage compared with glass ionomer cement, but application of a bonding agent prior to its placement was effective in reducing its microleakage.

Background and Aim: Contrary to the theory of planned behavior (TPB), intention alone is not sufficient to predict behavior. The aim of the study was application of annex tended model of planned behavior in predicting dental brushing behavior among a sample of adolescents in Qazvin.Materials and Methods: A number of 383 adolescents participated in this cross-sectional study. Attitude, subjective norm, perceived behavior control, action and coping scales and a self-report questionnaire regarding dental brushing behavior was completed by the adolescents. Data were analyzed by a confirmatory factor analysis (CFA) on an original six-factor structure (attitude, subjective norms, perceived behavior control, intention, action plan and coping plan) and also a hierarchical linear regression analysis.Results: The mean age of the adolescents was 15.41 years. The most of the student were male (50.2). The CFA for the original six-factor structure showed a good fit index ( l2=645.25, degrees of freedom df=309, goodness-of-fit index (GFI) =90, root mean squared error of approximation (RMSEA) =0.054). Action- and coping planning aggregately accounted for 11.1% of the variance associated with dental brushing behavior.Conclusion: Results obtained form CFA analysis approved the six-factor structure including intention, action plan and coping plan. Action plan and coping plan can reduce intention-behavior gap.

Background and Aim: Current self-adhesive resin cements have become popular for esthetic restorations. The purpose of this study was to compare the microleakage of 2 self-adhesive resin cements and 2 etch and rinse versions of the same brands.Materials and Methods: Forty human third molars were randomly assigned to 4 experimental groups: 1-Rely X Unicem, 2- Rely X ARC+ Acid etch 37% + Single Bond, 3- Nexus 3 Acid etch 37% + Optibond Solo, and 4- Maxcem Elite. Microleakages of the specimens were then measured with a four point scoring system at both the cervical & occlusal areas, with the aid of a stereomicroscope. Microleakage scores were compared using Kruskul-Wallis analysis, followed by relative Dunn test.Results: The microleakage of Rely X Unicem and Nexus 3 were significantly less in the occlusal region (P<0.05), whereas in the cervical area there was no significant difference in microleakage between Rely X Unicem and Rely X ARC (P= 0.0087). The microleakage of Nexus 3 was significantly less than that of Rely X Unicem. Maxcem Elite showed the highestlevel of microleakage (P<0.05).Conclusion: Microleakage of both cements using etch & rinse adhesive systems were significantly lower in comparison with their self- etch counterparts both at the cervical & occlusal areas. (P<0.05).

Background and Aim: Excessive heat produced while curing of light-activated dental restorations may cause irreversible damage to dental pulp. The Aims of this study wereto measure the temperature rise(TR) induced by two different light curing units and to evaluate the relathionship between the measured TR in dentin discs of different thicknesses and different distances of light guide tips from dentin disc.Materials and Methods: In this experimental study, Quartz-Tungsten-Halogen (QTH) (400 mw/cm2) and Light-Emitting Diode (LED) systems (1500 mw/cm2) were used as the curing units. Dentin discs of 0.5, 1.0 and 1.5 mm thicknesses were prepared. Distances of 1, 2 and 3 mm from the tip of the light guide and dentin discs were set. Temperatures were recorded using a digital laser thermometer. Data were statistically analyzed using two-way ANOVA, Duncan and T-test.Results: Results showed that both dentin thickness and distance between tip of curing units and dentin disks had significant effects on temperature rise in both curing units (P<0.001 ).Conclusion: LED produced the highest and the QTH the lowest TR for all tested conditions. Reduced thermal insults were related to increased dentin thickness, increased distance between the light guide tip and dentin, and decreased energy emitted from the light-curing unit.

Background and Aim: Recurrent aphthous stomatitis (RAS) is the most common oral mucosal inflammatory disease, with unknown etiology. Antioxidants are able to preserve molecules from damage and also can delay the start of RAS. The aim of this study was to determine serum level of vitamin A as an antioxidant in RAS patients compared with normal subjects.Materials and Methods: The total 38 subjects were divided into two groups of 19. One group consisted of aphthous patients and the other comprised of healthy subjects. The groups were matched by sex and age. Serum levels of vitamin A were measured in both groups. Finally data were analyzed with T tests.Results: The mean and standard deviation of serum vitamin A was 13.63±2.3 mg/ml in RAS group and 23.9±4.5 mg/ml in control group. There was a significant difference between the two groups (p<0.05).Conclusion: It was shown that serum levels of vitamin A in RAS patients were lower than that of normal individuals.

Background and Aim: Dynamic and static activities in dentistry, cause musculoskeletal disorders but dentists do not have enough awareness about effects of ergonomic factors on their health. T he aims of this study were to assess ergonomic conditions in dental workstation in Faculty of Dentistry, Qazvin University of Medical Sciences, using REBA method, to investigate the relationship between REBA scores and musculoskeletal disorders and finally, to present corrective solutions.Materials and Methods: In this cross-sectional study posture assessment of 63 participants were implemented by the REBA method. In order to investigate incidence of musculoskeletal disorders, the standard Nordic questionnaire was used. Data were processed using regression and chi-square tests and the significance level was determinate at P<0.05.Results: The results indicated that 30.2% of participants obtained from11 to 15 scores (very high risk level). Results of the Nordic questionnaire indicated that the highest musculoskeletal disorder report was related to neck region with 50.8%.Conclusion: The results showed that 30.2% from the final REBA scores had very high risk level and 51.7% high risk level means that essential corrective and urgent corrective measures are required respectively.

Background and Aim: Regarding chemical methods of plaque control, use mouthrinses are more frequent than other methods. The objective of this research is making a comparison between the antibacterial effect of Nanosil and chlorhexidine mouthwashes.Materials and Methods: In this experimental study samples were taken from supragingival and subgingival plaques of 15 patients and transferred to aerobic and anaerobic liquid culture environments. The numbers of the bacteria in both aerobic and anaerobic liquid environments were determined by spectrophotometer. Then, the samples were transferred from the liquid culture environment to the considered solid culture environment as a mixture of nanosil and chlorhexidine mouthwashes and placebo and the numbers of the growth colonies in the solid culture environment were counted in each group and compared with each other by t test.Results: In both aerobic and anaerobic conditions, the number of the growth colonies, was depicted in ascending order the groups of chlorhexidine, nanosil, and placebo. Concerning chlorhexidine, there was no significant difference between the growth colonies in the two aerobic and anaerobic environments indicating the absolute antibacterial effect of this mouthwash.Nanosil mouthwash had a significant statistical superiority in comparison with the placebo in both aerobic and anaerobic environments. Nanosil had a significant effect on anaerobic environment; meanwhile, the placebo indicated a superior effect in anaerobic environment.Conclusion: Nanosil mouthwash can be applied as an effective antibacterial substance especially in an anaerobic environment, though chlorhexidine as a standard mouthwash has still the strongest effect in this field.

Background and Aim: Nowadays the most significant indicator for scientific production is the number of scientific articles that are indexed in certificated databases. Evaluation of the scientific production has become so significant as an important aspect of research and scientific production, in the way that today production and consumption of information in different communities is one of the growth and development indicators. The aim of this article is to investigate 10-years of scientific production of Iranian dentistry community in the ISI.Materials and Methods: In this article ten years of scientific production in dentistry in ISI database was investigated using bibliometric method. Therefore, our search was limited to Iran and dentistry during 2000-2009, and the retrieved items were analyzed.Results: It was shown that a total of 383 documents have been produced and published in this time period, among which 350 (91.4%) was authored by dental professionals in 10 Iranian universities. In this regard, Tehran University of medical sciences researchers has authored 30.8% of all productions. The most international cooperation of the Iranian dentistry researchers has been with the researchers of USA with 28 articles followed by Australia, England and Finland. Concerning journals publishing the research of the Iranian dental community, the Journal of Endodontics, has published 34 documents of all productions in this realm.Conclusion: Our search showed that the scientific productivity of Iranian dentists has been ascending in these years. The growth reached the top in 2009, and became doubled compared with the previous year and ten times more than those in 2000.

Background and Aim: Evidence-based dentistry is an approach to oral health that requires a reasonable combination of scientific evidence with the dentists’ diagnostic and clinical practice as well as patients’ needs and treatment priorities. The aim of this study was evaluation of awareness, attitudes and self- assessed knowledge of dentistry students about EBD in governmental universities in Tehran.Materials and Methods: Subjects included junior students of dentistry studying in Tehran and Shahid Beheshti Universities of Medical Sciences. Sixty-five subjects were evaluated, among which 85% answered the questionnaire. Questionnaires were distributed to the students before and after their courses to evaluate student’s awareness, attitude and self- assessment knowledge. Chi- square and T- test were used to analyze the results.Results: Totally 80% of students had a fair or poor awareness about EBD. Almost, all the students had a correct attitude about EBD and 80% had a correct attitude about the steps. The mean male student’s knowledge was significantly higher than that of female counterparts. Also, there was a significantly positive correlation between student’s knowledge score and self- assessed knowledge about EBD.Conclusion: Despite good attitudes about EBD, there is a deficiency in student’s knowledge, so an appropriate plan is suggested to resolve this problem.

Background and Aim: Tooth discoloration of anterior teeth is an important esthetic problem for both the patient and dentist. One of the causative factors in this regard is placing intracanal medicaments. The aim of this study was to compare discoloration potential of calcium hydroxide vs. triantibiotic paste when being placed into the pulp chamber space.Materials and Methods: Forty extracted upper human central incisors, with no caries or crack were selected for this study. Digital photographs were taken from the buccal aspect of all specimens under a standard situation. RGB/HSB variables were recorded, using Photoshop software,. Then access cavities were prepared and canals enlarged using #1, #2, and #3 gates glidden drills and peeso reamers. The teeth were randomly divided into two experimental groups. In group A calcium hydroxide and in group B triantibiotic compound was placed in pulp chamber space. Then access cavities were sealed with a self-curing glass ionomer cement. After incubation of the samples for four months digital photographs were taken in the same standard situation and RGB/HSB variables were recorded. Pre- and post-treatment data were compared and analyzed using paired-t and independent t-tests.Results: Both experimental groups showed a significant discoloration after four months in their labial surfaces. (p<0.05) Discoloration changes in calcium hydroxide group was much more than that of triantibiotic group but the difference was not significant (p>0.05).Conclusion: Tooth discoloration was indicated following use of both calcium hydroxide and triantibiotic dressing within the pulp chamber space, but the difference between two groups was not statistically significant.(p>0.05 ).