Journal of Dental Medicine

Background and Aims: By measure of scientific publications, it is possible to present a real picture of scientific activities of a country. In this regard, based on joint work to achieve specific objectives that typically produce knowledge and scientific information, scientific and research cooperations are defined. Therefore, the purpose of this study was to analyze the scientific collaborations in Iranian dentistry articles in Scopus during 2010‐2014.
Materials and Methods: The population was Iranian dental articles which were indexed in Scopus during 2010‐2014. Finally, the results were presented in the format of tables and diagrams.
Results: The findings showed that scientific cooperations were increased in the field of dentistry during 2014-2010 in the Scopus. Tehran University of Medical Sciences had the most publications. The rate of index, degree and coefficient of collaboration during 2010-2014, were 4.23, 0.97 and 0.71, respectively with relatively high values. Most of the articles during the 2010-2014 were four, three, and five authored articles were the first, second and finally the third position of occurrence rate. Our data suggested that the lowest number of articles were related to articles with 9 authors or more.
Conclusion: According to the results of this study, it can be concluded that the Iranian prosperity of scientific publication in the field of Dentistry is growing. Furthermore, the results showed that the Iranian authors and researchers have tendency to scientific collaboration with other researchers in groups.
 

Background and Aims: Headache is among the most common complaints in patients suffering from temporomandibular joint disorders (TMD). Thus, it seems that evaluation of patients with headache in terms of temporomandibular joint (TMJ) disorders is necessary. In people with TMD, parafunctional activities play an important etiologic role. Considering the high prevalence of bruxism and TMDs in patients with headache, assessment the accuracy and severity of this association can play a key role in diagnosis and treatment of these two phenomena. The purpose of this study was to investigate the relationship between bruxism, TMD and headache, also assessment the efficacy of TMD conservative therapy with a special approach to self-management in treating patients with headache.
Materials and Methods: Motor searches of Cochrane, Medline and EMbase databases, PubMed, Google Scholar, Uptodate, BMJ clinical Evidence, MD consult and science direct by using of relevant key words were searched for article published between 2000 and 2015. A total of English language abstracts were reviewed, 80 full articles were obtained and among them, 30 relevant articles were reviewed in this study. Because of the high number of studies in this field, we divided the data into four group, bruxism and TMD, TMD and headache, bruxism, TMD and headache, treatment.
Conclusion: Bruxism and temporomandibular disorders are the two main contributing factors in initiation and perpetuation of headache. Treatment of these two phenomena would be effective in the treatment of headache.

Background and Aims: Microhardness, sorption, and solubility are useful predictors of a resin composite’s clinical success. This study aimed to evaluate the effect of 60 days of water storage on the microhardness, sorption, and solubility of 3 commercial nanohybrid resin composites.
Materials and Methods: Three nanohybrid composites were evaluated: GC Kalore (GC), Aura (SDI), and G-ænial Universal Flo Universal Flo (GC). Ten disc-shaped samples were prepared for each material. After baseline weight measurement, the specimens were stored in distilled water for a period of 60 days, and then in desiccators for another 60 days. Specimens were weighed at 24 hours, 7 and 60 days of water storage and desiccation. For the microhardness test, 24 were prepared for each material and divided into 6 groups based on storage media (dry and wet) and storage time (24 hours, 7 days, and 60 days). Specimens were tested by a digital Vickers microhardness tester after storage and data were analyzed using SPSS software.
Results: G-ænial Universal Flo Universal Flo showed the highest sorption and solubility and the lowest microhardness after 60 days of water storage. GC Kalore showed lower sorption and solubility compared to Aura. Also GC Kalore had higher microhardness than Aura after 60 days of storage in water, while Aura had higher microhardness in dry storage.
Conclusion: Composites with lower sorption and solubility showed higher microhardnss in wet conditions. Flowable composite resin showed the lowest microhardness and the highest sorption and solubility values. Therefore, the negative effect of water sorption and solubility on Surface microhardness should be considered in clinical decisions.

FTIR spectroscopic imaging is a chemical imaging method that can be employed to a broad range of applications. This powerful technique is suitable for determining the functional groups and chemical structures of the samples. The advantage of infra-red spectroscopy is that it can be used for various modes of physical samples. The aim of the current paper was to review the recent advances and the potential uses of Fourier Transform Infra-red Spectroscopy in dentistry via exploring related literature during 1960 till 2017 in Science Direct and PubMed databases. One of the most popular applications of infrared spectroscopy is to calculate the degree of conversion in the resin based dental materials. It has also been used to investigate the chemical structure of the teeth and bones, synthesis calcium phosphate, the diagnosis of microorganisms, and pathological conditions. In this paper, we mentioned the principles of this technique and recommend this method as a simple and fast way to determine the structure of the materials and their alteration.

Background and Aims: A suitable restorative material must have acceptable mechanical properties. The aim of this study was to evaluate the effect of conventional acidic drinks on the micro-hardness of two dental resins.
Materials and Methods: 48 samples of each of P60 and G-aenial composites were prepared and randomly divided into six groups: Coca-Cola, Fanta, yoghurt drinks, soft beer, Sprites and control groups. The study was in 3 steps: after one day in distilled water and after one day and one week of immersion in beverages per day
(6 hours). The Vickers micro-hardness was then evaluated. Finally, data were analyzed by, t-tests, ANOVA and Tukey tests.
Resultes: Comparing the results between the two groups, a significant difference between the two composite was found. After one day in the water, the average micro-hardness for P60 was of 27.12 (kgf/mm²) and 16.51 (kgf/mm²) for G-aenial amount and these differences were found statistically significant (P=0.0001). For the
6-hour maintenance interval, the average micro-hardness between P60 and G-aenial was statistically significant (P=0.0001). For 42 hours, the average micro-hardness ranged between P60 and G-aenial that were statistically significant (P=0.0004). The stiffness of the P60 composite after 42 hours’ storage in soft beer significantly decreased compared with the control group (P=0.03). G-aenial composite hardness after 42 hours of soaking in the Coca-Cola was reduced significantly compared to yogurt drinks (P=0.02).
Conclusion: As a result, the hardness of P60 composite was higher than that of G-aenial. The hardness of both composites reduced in acidic drinks after one week.

Background and Aims: While there are a lot of information about an illness risk factors, there are still some gaps in understanding factors influencing the progression of disease. Given the important role of psychological factors in physical conditions, the purpose of this study was to compare the cognitive emotion regulation, stress, depression, anxiety, and stress related to life events in people with and without periodontal disease.
Materials and Methods: The type of this study was causal comparative. Research society was all clients referred to dental clinics in Lamerd and Mehr cities, then 50 people with and 50 people without periodontal disease (male and female, 15-49 years old) were selected using purposive sampling. The group without periodontal disease was matched with patient group in terms of demographic characteristics. Both groups completed cognitive emotion regulation questionnaire (CERQ), Depression Anxiety Stress Scale (DASS), and life events questionnaire. Data analysis was conducted with SPSS version 17 using multivariate analysis of variance (MANOVA).
Resultes: Data analysis showed that people with periodontal disease had more stress, depression, anxiety, and stress related to life events than matched control group. The groups had significant differences in the components of self-blame, rumination, positive attention to evaluation and catastrophizing (P<0.05). People with periodontal disease had higher scores in self-blame, rumination and catastrophizing and lower scores in positive attention to evaluating compared with matched control group.
Conclusion: The results showed people who were vulnerable to stressfull situations, depression, and anxiety during their lives, and also use maladaptive emotion regulation strategies, were more susceptible to periodontal disease.

Background and Aims: Loss of retention is one of the main reasons of failure in teeth restored with post and core. Several factors, including the type of cement can influence the retention of the posts. As zinc phosphate cement is considered as the standard for comparison this study performed to review articles evaluating the retention of cast posts cemented with zinc phosphate.
Materials and Methods: This systematic review was performed based on the PRISMA (Transparent Reporting of Systematic Reviews and Meta-analyses) guide. The question of this study was that how much is the amount of retention of cast posts cemented with zinc phosphate. Hence, a literature search was done in PubMed and Medline databases as well as Google scholar search engine using relevant keywords until 2016 limited to the English language. Articles were selected based on the inclusion and exclusion criteria, and were evaluated qualitatively.
Resultes: Internet search resulted in 1141 articles. Following the application of inclusion and exclusion criteria, 6 studies were included in this systematic review. The most common post material was nickel-chromium alloy. Retention of casting posts cemented by zinc phosphate was from 8.76 to 34.2 Kg and from 91 to 192.2 N.
Conclusion: Our review showed that the retention of cast posts cemented with zinc phosphate in controlled condition is moderate and factors including post material and length could influence the retention of the post.

Background and Aims: Fracture and color change are among the most common causes of clinical failure of resin composite restorations. Therefore, this study aimed to examine the fracture toughness and color changes of 3 Nano-hybrid resin composites in dry and wet conditions.
Materials and Methods: Three resin composites were studied. A total of 36 rectangular specimens were prepared for each material, randomly divided into 2 groups, and stored at 37°C dry or soaked in distilled water. In each group, the specimens were subdivided into three groups (n=6) and stored for 1, 7, and 60 days. After each time interval, the specimens were tested for the fracture toughness and loaded at a cross-head speed of 0.5mm/min using a universal testing machine. The baseline and final color measurement was recorded for each specimen using a spectrophotometer. The collected data was analyzed using ANOVA and Kruskal-Wallis tests.
Results: After 60 days, the mean value of fracture toughness was lower in the wet condition compared to that of dry condition. However, it was not significantly different except for aura Bulkfil (P=0.001). Color change was significantly different for Tetric Evoceram and aura with a greater value in the wet condition compared to that of dry (P=0.004). The greatest color stability was found for aura and the least for Tetric Evoceram.
Conclusion: In this study, most of the materials stored in a dry condition showed a greater fracture toughness and color change.

Background and Aims: Microorganisms are the main cause of pulpal and periapical diseases. The most important failure factor is the lack of proper seals for the canal, resulting in microbial leakage. Therefore, the purpose of this study was to evaluate the sealing ability of ProRoot MTA and Bio MTA in canal obturation using fluid infiltration.
Materials and Methods: In this experimental study, 46 extracted mandibular premolar single canal teeth were used. After preparing and disinfecting the teeth with 3% sodium hypochlorite, their crowns were cut off from the cement-enamel junction. The teeth were then randomly divided into four groups: Group 1 (n=20) Bio MTA, Group 2 MTA ProRoot (n=20), negative and positive control groups, each of them contained 3 teeth. The preparation of teeth was performed using the step back method. The filled teeth were then evaluated by fluid filtration for leakage prevention. Data were analyzed by Mann-Whitney test and Tukey test (α=0.05).
Results: The results of statistical analysis showed that there was no significant difference between the MTA ProRoot and Bio MTA in sealing ability (P>0.05). That micro leakage is less in the Bio MTA group than in the ProRoot MTA group, but the difference was not significant.
Conclusion: This study showed that MTA ProRoot and Bio MTA can be used as appropriate canal filling materials.

Background and Aims: Functional therapy locates the mandible in a more anterior and inferior position. Tongue posture and oropharynx space have a considerable relationship with mandibular posture. The aim of the present study was to determine the changes of tongue posture and oropharynx space following treatment with Twin block appliance in adolescent patients with class II division 1 ma1occlusion.
Materials and Methods: Twenty two patients (14 girls mean age:11.5, 8 boys mean age:12.5 years) who were treated with twin-block appliance were enrolled. Cephalograms were used to assess the linear measurements. Graber pattern and McNamara parameter were used to evaluate the tongue posture and oropharynx space, respectively. Data analysis was performed by paired t-test.
Results: The findings of the present study showed a significant increase in anterior position of tongue (P=0.06). Oropharynx space was increased significantly (P<0.001). There was a significant correlation between the decrease of ANB and anteroposterior increase of oropharynx space.
Conclusion: Twin-block appliance caused considerable forward movement of tongue and significant increase of oropharynx space in the sagittal plan.

Background and Aims: The dentistry profession is one of the most injuring professions that causes most pains and hurts for dentists because of their lack of knowledge about the ergonomic position through the work. The purpose of this study was to assess the ergonomic position of dentists with RULA method in dentists of Bojnord.
Materials and Methods: In this cross-sectional study, all of the Bojnord’s county dentists were selected. RULA method and Nowerdik questionnaire were used for investigating the agronomical position, and muscular-skeleton position, respectively. The analysis was done by SPSS22 using regression and chi-square test. A P-value of less than 0.005 was assumed as significant.
Results: The most muscle-skeleton reports were 55.6% (35 persons) related to back, 54% (34 persons) related to shoulders, 50.8% (32 persons) related to waist, and 47.6% (30 persons) related to neck aches. In the last 12 months, 90.5% of dentists reported pains from at least one of organs of their bodies and 27% were supposed to leave their works which the sex (P=0.84), length (P=0.75), and weight (P=0.38) were not significantly related to this case.
Conclusion: According to the results of this study educational interventions is essential to prevent the musculoskeletal disorders in dentistry.

Background and Aims: Despite their ascribed intellectual ability and achieved academic pursuits, the dental student’s academic achievement is influenced by learning motivation. This study in an Endeavour aimed to examine the learning motivation factors of dental students of Rafsanjan University of Medical Sciences.
Materials and Methods: In this descriptive-cross sectional study, 120 dental students completed the questionnaire which comprised of 33 questions regarding intrinsic and exogenic motivational factors. Demographic factors (gender, marital and native status, employment year of study) were examined. Data were analyzed by SPSS17 software. Descriptive and analytical statistical methods (t-test, Pearson correlation and ANOVA statistical tests) were used.
Results: The mean of the achieved scores in the domains of learning motivation was 2.98±0.32 out of 5,which was considered as moderate level. Comparing the means of the intrinsic (3.16±0.48) and exogenic
(2.82±0.44) domains showed significant differences (P<0.05). Correlation between the intrinsic motivation domain and elements of exogenic motivation domain with academic achievement were not significant (P=0.62). Total score of Intrinsic and exogenic motivation is higher in male and non-native students.
Conclusion: Educational motivation of Rafsanjan dental students was moderate. In learning, intrinsic motivational factor was more than exogenic factors in male students.

Background and Aims: Cancer is the 3rd cause of death after heart disease and injuries in Iran. Radiotherapy and chemotherapy are the most effective procedures in cancer therapy, but their side effects are still unknown for many patients. The main goal of this study was to evaluate the patients’ knowledge with head and neck cancer regarding the complications of radiotherapy and chemotherapy.
Materials and Methods: This descriptive-analytical research was based on the information extracted from personal questionnaires and files of cancer patients who referred to the centers of Kerman University of Medical Sciences during a 6 months period in 2017. The data were analyzed by chi-square test at the significance level of 0.05.
Results: Our findings showed that most of the patients (76.48%) had low information level. There was no statistically significant association between the knowledge with demographic variables (P>0.05). However, patients with chronic disease had higher level of information. Only 10% of patients had received information by their physicians.
Conclusion: It seems there is not effective education regarding the rated radiotherapy and chemotherapy complications, because their knowledge was not in acceptable level. Considering the importance of this issue, it is necessary to perform educational program to improve patients' ability and skills to cope whit the chemotherapy and radiotherapy complications and their side effects.

Background and Aims: The dentist's attire and appearance affects his/her relationships with the patients. It is also essential to sync the professional attire in dentistry with the habits and Islamic culture of Islamic Republic of Iran, meet the patients' desires, and pay attention to the infection-control-requirements as well.The objective of the present study was to determine the patients' viewpoints about the professional appearance of the dentists at Tehran University of Medical Sciences, Dental School in 1395-96.
Materials and Methods: In this descriptive cross-sectional study, 103 patients (54 females and 49 males) were studied. (=α0.05 and standard variation=4.5). The questionnaire were included color photographies of a female dentist and a male dentist dressed in different attires. The patients were asked to select the cleanest, and the most trustable, competent, and experienced dentist according to the 4 different attires. The frequencies and percentages of the participants’ answers to the questionaire were descriptively reported.
Results: All patients preferred dentists to use white coat during their treatment. For the male dentists, most patients (45.6%) favored simple hair model. For the female dentists, most patients (35.9%) considered veil as the more acceptable Hejaband, and 54.4% of them preferred light makeup.
Conclusion: All patients preferred their dentists to dress in the professional attire with a white coat. They believed that wearing formal-professional-dressing by the dentists may show them look cleaner, and more trustable, more competent, and experienced.

Background and Aims: The cell phone has played a significant role in the transmission of microbial contamination as a public tool. The present study was conducted to determine the degree of contamination of mobile phones of students and staff of the dental school of Isfahan University of Medical Sciences.
Materials and Methods: In a cross-sectional study, 60 samples were taken from 60 cell phones belonging to students, staff and faculty members of the Isfahan Dental School, the samples were cultured in the laboratory for microbial contamination of the phone. The behavioral characteristics of the subjects were also determined using a cell phone special questionnaire. Data were analyzed by SPSS version 24 using descriptive statistics, one-way AVONA, T-test and Chi square.
Results: Among the 60 cultured samples, 11 (18.3%) did not grow any bacteria. In 31 cases (51.7%), Staphylococcus epidermidis, 14 cases (23.3%) Staphylococcus aureus susceptible to methicillin and in 4 (6.7%) methicillin resistant staphylococcus aurous were grown. The mean of bacteria colonization was 18±12.2 and there was not any relation between the colonization and kind of bacteria (P=0.78) and studied groups (P=0.43). Also, there was a significant difference between the sanitary conditions and the type of bacteria grown in the culture medium (P=0.04).
Conclusion: According to the results of the study, the cell phones belonging to the students, lecturers and faculty staff were contaminated by harmful bacteria such as staph aurous. These bacteria are the most important of nosocomial infections and may be led to a wide areas of infections from simple to serious types.

Background and Aims: Color is the most important and complicated part of aesthetic dentistry. The tooth color matching of restorations is considered as one of the most difficult tasks in the restorative dentistry. The aim of this study to evaluate the effect of two training methods on the dental students’ ability in determining tooth color matching.
Materials and Methods: In this study, 40 dentistry students participated which randomly allocated into two groups. The first group consisted of students who learned teeth color matching methods practically. In the second group, training booklet was used for learning. Using Vita Classic shade guide series, 4 color samples were chosen and the students of each group were asked to determine samples’ color, before, after and one month after the training.
Results: Booklet learning group was more successful in determining fourth color sample. However, in no studied group and no used samples, the results of one month after learning were not better than that of before learning. Also generally, no significant relationship was found between the color matching accuracy, using glasses, and sex of participants.
Conclusion: The use of booklet learning was more effective than practical learning in color matching accuracy for dental students. Also, using glasses and sex were not effective on their color matching accuracy.

The Guided Bone Regeneration (GBR) treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. The use of membrane to exclude non-osteogenic cells, is a key principle of guided bone regeneration. A large number of membranes have been evaluated in clinical and experimental studies. The object of this study was to review the literature regarding guided bone regeneration and all types of membranes that were used in this technique. 72 articles between the years 1968 through the 2016 from PubMed, Medline and Google Scholar using the related keywords, were selected. Finally, we concluded that the modification of mechanical and physico-chemical properties of membranes could improve the process of new bone growth. However, determination of the exact role of membrane porosity in this process, still needs to be clarified. Optimization the chemical composition of membrane with the focus and attention to obstructive property and bioactivity, is an important point in this research field. Various factors such as flexibility, mechanical strength and degradation rate determine the type of membrane used for bone tissue regeneration.

Background and Aims: Glass ionomer cements are among direct restorative materials which are used in an environment saturated with moisture. Therefore, having the ability to prevent water contamination is crucial. The aim of this study was to determine the water sorption and solubility of five glass ionomer restoratives with and without two nanofilled resin coating agents.
Materials and Methods: Five glass ionomer cements (Fuji BULK/GC, EQUIA Forte Fil/GC, Fuji II LC/GC, riva self cure/SDI, riva light cure/SDI) and two resin-based coating (G-COAT PLUS/GC and EQUIA Forte Coat/GC) were used in this study. Water sorption and solubility were measured in accordance with the ISO 4049's. For each material, 15 disc-shaped specimens were prepared using a polyethelyn mould. The specimens of each material were randomly divided into two groups: 10 coated and 5 uncoated. For the coated groups of each material, 5 specimens were coated with G-COAT PLUS, and 5 with EQUIA Forte Coat. Data were analyzed using SPSS software version 18 (SPSS Inc., Chicago, IL, USA). Two-way ANOVA was applied to investigate if there were any interactions between materials and coatings. One-way ANOVA was used to compare different variables between the materials, and post-hoc Tukey’s test was performed to show significant differences in subgroup comparisons.
Results: A significant interaction effect was obsevred between materials and coatings (P<0.05) using two-way ANOVA. The uncoated groups showed higher mean sorption and solubility values compared to the coated groups, and the groups coated by G-COAT PLUS showed less mean sorption and solubility values than that of EQUIA Forte Coat. In general, the lowest mean sorption and solubility values among glass ionomer cements belonged to Fuji BULK.
Conclusion: The water sorption and solubility values of glass ionomer cements could be reduced by the use of a protective coating.

Background and Aims: Despite the increasing application of intra-oral scanners, the effect of finish line position on gingival margins adaptation is still discussed. The purpose of this clinical study was to evaluate the fitness of cobalt-chromium copings obtained from intraoral scanning in two depth of finish lines.
Materials and Methods: Thirty teeth prepared for single premolar metal-ceramic crowns were included. Fifteen teeth had supragingival and fifteen had sub-gingival finish lines. Digital impressions were made using an intraoral scanner (Trios-3shape). Computer-aided design and computer-aided manufacture (CAD/CAM) cobalt-chromium copings were fabricated from the scan files. The copings were evaluated intraorally and after adjustments, the internal and marginal discrepancy were measured using silicone replicas and a stereomicroscopy. Internal and marginal discrepancies were analyzed using the Multivariate test (P<0.05).
Results: The mean internal and marginal gap were 52.1 and 56.27μ, for supragingival group and 49.72 and 62.98μ for subgingival group, respectively. The evaluation of finish line position showed no significant effect on obtained results (P>0.05).
Conclusion: CAD/CAM chrome-cobalt copings fabricated by digital impressions provided acceptable marginal and internal precision. However, the finish line position had no significant effect on the internal and marginal adaptation.

Background and Aims: Methicillin-resistant Staphylococcus Aureus (MRSA) is an important infection source in dentistry for different disinfectants to be used to prevent its transmission. Furthermore, a variety of chemical disinfectants are developed to remove bacterial infections from the dental care workers' hands and claims are made regarding their superiority in infection control, although all requires scientific investigations. The aim of present study was to compare the effects of chemical hand-disinfectants Micro Zed HD, Aseptoman and Decosept on MRSA (methicillin resistant staphylococcus aureus) in different periods of time.
Materials and Methods: In this experimental study, the antibacterial efficacy of three hand-disinfectants on standard strain of MRSA (USA300: ATCC® BAA-1717™) was evaluated according to European standard of evaluating antiseptics (EN 1040:2005 CSN EN). First we prepared a 0.5 Mc Farland (108 CFU/ml) suspension of MRSA, and exposed to three disinfectants for 15, 30, 60 and 90 seconds. Then, they were transferred to separate plates of Mueller-Hinton medium and incubated in 37^◦C for 24 hours. The plates were compared then with control plate to evaluate the efficacy of materials on bacteria by calculating the CFU/ml of plates.
Results: Three hand-disinfectants evaluated in this study had the maximum anticabterial effect on MRSA in the minimum time of exposure (15 seconds), and we found no trace of growth in any plates.
Conclusion: The three hand-disinfectans (MicroZed HD, Aseptoman and Decosept) in the concentration suggested by their companies, showed no difference in efficacy to remove MRSA from hands.