Journal of Dental Medicine

Conclusion: According to the results of this study, it seems that dentists should pay more attention to the components of emotion regulation and emotions in order to prevent and reduce job burnout.

Background and Aims: Due to the review of general dental courses, it was necessary to assess the students' satisfaction with this curriculum. The aim of this study was the assessment level of students’satisfaction with the new educational curriculum of the Ministry of Health at the department of restorative dentistry of Tehran university of medical sciences in 2019-2020.
Materials and Methods: In this descriptive cross-sectional trial,72 sixth year dental students of Tehran University who passed the restorative dentistry courses based on the new curriculum were studied. A questionnaire was developed and for validity content assessment, it was presented to 5 professors and then revised. For reliability approval of the questionnaire, test-retest approach was used. The questionnaire was given to the 30 students of the main pilot group in one session and two-week later and agreement percentage and Kappa index were calculated.  After conducting the "test" process and re-testing, the "questions" were statistically analyzed using STATA software.
Results: The most level of satisfaction regarding to practicality of subjects was found for fundamental of restorative dentistry including principles of amalgam class I cavity preparations and restorations on the dentic (81.94% and 76.39% acceptable respectively) and the principles of amalgam classII cavity restorations on the dentic (72.22%). The least satisfaction levels were obsereved in the first and second theoretical restorative courses including tooth-colored restorations (47.22%), onlays and inlays (47.22%) and tooth-colored classII cavity preparations and restorations (48.61%). The amount (P-value or error of the first type) was reported in all questions>0.001.
Conclusion: Despite the limitation of this study, final-year dental students’ satisfaction of theoretical restorative dentistry courses was medium, while it was high for the fundamental and practical restorative courses of 2017 educational curriculum.

Background and Aims: The need to use a highly effective sealer in order to create a complete seal along the canal is essential for the basic treatment of tooth roots. Therefore, the aim of this study was to investigate the sealing ability of cold ceramic and gutta-percha with sealer by applying the bacterial leakage and electrochemical method.
Materials and Methods: In this in-vitro experimental study, fifty human single-rooted teeth were selected and their crowns were cut from the cervical region. The canals were prepared and washed with 17% EDTA. Then the teeth were randomly divided into four groups: group 1 gutta-percha with AH26 sealer (Dentsply Detrey, Germany) (n=20), group 2 cold ceramic (Yazd, Iran) (n=20), negative and positive control groups which each consisted of 5 teeth. Samples were kept in an incubator at 37° C for 48 hrs. Two coats of nail polish were used for covering the root, except for the last 2 mm, and microleakage in the fillings was measured by the bacterial leakage and electrochemical methods. The microleakage of the two groups was statistically analyzed in the electrochemical technique by Student's t-test, and in the bacterial leakage method by Fisher's exact test.
Results: In bacterial leakage method, in the first group (gutta-percha) 7 samples (35%) and in the second group (cold ceramic) 3 samples (15%) had bacterial leakage, but no significant difference was observed between the two groups on different days (P>0.05). The mean microleakage based on the electrochemical technique in gutta-percha was significantly higher than that of cold ceramic (P=0.0001).
Conclusion: According to the lower microleakage values in the use of cold ceramic compared to gutta-percha, cold ceramic  can be used to fill root canals to reduce microleakage, although further studies are needed.

Background and Aims: Finishing and polishing of composites is a critical step influencing the clinical service of restorations. The aim of this article was to evaluate and compare the effect of two liquid polishes on the polish retention of two nanocomposites.
Materials and Methods: Eighty standardized disk-shaped specimens (4×2 mm) were prepared from two nanocomposites (n=40), including one nano-filled composite (Filtek Z350 XT-3M ESPE, USA) and one nano-hybrid composite (Aelite Aesthetic Enamel-Bisco, Inc. Schaumburg, USA). The specimens were randomly divided into 4 subgroups (n=10) based on the method of finishing (F) and polishing (P) procedures: M: as control, polymerized under Mylar strip; S: finish and polish with a sequence of Sof-Lex discs (3M ESPE, USA); SP: finish and polish with Sof-Lex discs and use of Permaseal liquid polish (Ultradent products, Inc. USA); SB: finish and polish with Sof-Lex discs and use of Biscover liquid polish (Bisco, Inc. Schaumburg, USA). The specimens were undergone pH cycling and brushing machine and then, the average surface roughness (Ra) and average profile changes along the desired area (Rz) of the specimens were determined with profilometer instrument. Two-way and one-way analysis of variance (ANOVA) was used to compare the mean of surface roughness. Then, Tukey test was used to identify the groups responsible for the difference and t-test was used to compare the mean of surface roughness.
Results: The type of composite and the method of polishing procedure had no effect on the mean Ra (P=0.733) but it had significant effect on Rz1 factor (P=0.025).
Conclusion: Using liquid polish after polishing discs had no effect on the polish retention of nanocomposites.

Background and Aims: For dental students, communication skills are essential to effectively transfer the necessary information to the patient and meet the patient’s needs and expectations. Therefore, this study was conducted to determine the patient communication skills of dental students at Islamic Azad university of Isfahan in 2021.
Materials and Methods: In the present cross-sectional analytical study, an online standardized questionnaire DCCC (Dental consultation communication checklist) was provided to all clinical dental students applying a census sampling method. In total, from 248 clinical dental students, 230 students participated in the study (response rate=92.7%). The questionnaire included five dimensions of introduction, medical history, clinical examination, closure and patient. In order to determine the patient communication skills, its dimensions, and the association between patient communication skills and students’ demographic characteristics, friedman test, analysis of variance, independent t-test and a linear regression model were used for statistical analysis.
Results: The mean score of total communication skills of the students (117.16±15.6) was above average which was obtained from the maximum score of 155. There was a significant difference between the dimensions of communication skills (P<0.001). The highest scores were assigned to the clinical examination, patient, medical history, introduction and closure, respectively. No significant relationship existed between the score of students' communication skills with gender (P=0.08), age (P=0.17), marital status (P=0.19), and educational background in psychology (P=0.07). No significant relationship revealed between the total score of communication skills (P=0.92) and its dimensions (introduction P=0.79, medical history P=0.90, clinical examination P=0.77, closure P=0.35, and patient P=0.85) with the students’ academic year.
Conclusion: The total score of dental students’ communication skills and all its dimensions was above average. However, students reported poorer performance in dimensions of introduction and closure than the other dimensions. Therefore, it is recommended to design and implement educational interventions specially to improve the dimensions of introduction and closure.

Background and Aims: By using the image processing capability in Cone-Beam Computed Tomography (CBCT), obtained information can be improved. The aim of the present study was to investigate the effect of sharpen image processing filter in determining the external resorption of the root apical region in single-rooted teeth due to the proximity of the impacted tooth using CBCT.
Materials and Methods: In this laboratory study, the lateral surfaces of the apical region of the root of 40 healthy extracted teeth were artificially cut by bur and the teeth were randomly divided into four groups: control, low, moderate, and high resorption. After preparing CBCT of the teeth, the samples were then processed with and without an image sharpening processing filter and examined by two observers. The results of this study were analyzed by SPSS22 and Medcalc Statistical Software version 14. The significance level was considered P≤0.05 for all the statistical tests.
Results: Specificity (100%) and sensitivity (66%>) were either complete or very high for both modes without and with the sharpen filter. The overall accuracy (0.83>) was high in both cases and no significant difference was observed between the two overall accuracies (P>0.05). Statistical analysis of both image observations by two observers showed that the overall sensitivity and accuracy in the medium and high resorption groups was much higher than the low resorption group, but the specificity in all groups was 100%.
Conclusion: The results showed that the images with a sharpening filter did not increase the detection power compared to the unfiltered images. However, as no loss of accuracy was observed with this filter, it could be used as a processing filter.

Background and Aims: Considering the preventive and therapeutic effects of resin infiltration (RI) and the unknown effect of bleaching on the enamel treated with this method, this in-vitro study aimed to assess the effect of bleaching on color stability of enamel lesions treated with RI.
Materials and Methods: In this in-vitro, experimental study, enamel-dentin samples measuring 5×5×3 mm were prepared on the buccal and lingual surfaces of 30 extracted humans third molars with no caries, cracks or enamel defects by a microtome. The specimens were divided into three groups of 10 specimens: 1) sound enamel (control), 2) demineralized enamel, 3) demineralized enamel plus RI. White spot lesions were artificially created by immersing the samples in hydroxyethyl cellulose demineralizing gel with a pH of 4.5 for 4 days. Next, Icon RI was applied on the samples in group 3. The baseline color of the specimens was measured using a spectrophotometer. Then, 35% hydrogen peroxide was applied on the specimens in three cycles and time interval of 10 min. After the end of the last cycle, the samples were completely washed for 1 min and then, underwent colorimetry again. Data were analyzed using one-way ANOVA.
Results: The results of this study showed that the highest level of color change (ΔE) in the demineralized group was 6.3±2.003, while the least amount of ΔE in the enamel lesion group treated with resin infiltration was 3.54±0.98 and in the control group ΔE was 4.13±1.14. Therefore, there was a significant difference between demineralized and treated by infiltratant groups (P=0.005). However, there was no significant difference between control group and treated with resin infiltration group (P=0.54).
Conclusion: Bleaching induced a less change in the color of the enamel lesions treated by resin infiltration compared with that of the demineralized teeth.
 
 

Background and Aims: The aim of this study was development and validation of a questionnaire measuring the pseudo-scientific unsupported of Iranians’ belief regarding oral health.
Materials and Methods: A list of 169 pseudo-scientific and invalid Iranian beliefs about oral health that was collected in the previous phase of the study were sent to a purposive sample of 13 professors at Mashhad dental school which resulted in extracting 34 beliefs being considered more common among Iranians. A list of 21 pseudo-scientific beliefs was obtained for preparing the questionnaire after receiving the sample opinions of 21 professors of Mashhad dental school about the invalidity and pseudoscientific propositions and their written revision. Finally, the questionnaire was completed by 44 participants to analyze the ease and clarity and to calculate Cronbach's alpha and Kuder Richardson measure as a homogeneity reliability index. It was completed in a group of 15 participants with a time interval of one month for test-retest analysis and consistency reliability evaluation.
Results: A questionnaire consisting of 21 beliefs was developed using four-point, three-point, or two-point Likert scales. The standardized Cronbach's alpha score and Kuder Richardson's measure score were 0.641 and 0.514, respectively, which indicated the moderate to good reliability of the homogeneity. The Interclass Correlation Coefficient (ICC) was calculated as 0.863, representing very good reliability of consistency of the questionnaire. Furthermore, the kappa coefficient of each of the 21 statements had a significant difference with zero (P<0.05) ranging between 0.605 and 1.
Conclusion: The result of the present study is a questionnaire measuring the level of Iranians’ belief in unsupported and invalid statements about oral health. Using this questionnaire would be helpful for dentists and oral health professionals to promote knowledge of Iranians about oral health.

Background and Aims: Atypical facial pain (AFP) is a chronic disease associated with local pain in the craniofacial area. A wide range of treatments including drug therapy, psychiatric methods and open surgery are used for its treatment. Opiorphin is a pentapeptide that can block pain and also has proven antidepressant effects. The aim of this study was conducted to investigate the opiorphin concentration in AFP patients and to compare it with healthy people.
Materials and Methods: This study was performed on 30 AFP patients and 40 healthy individuals. Unstimulated saliva was collected from both groups by spitting method. HAD-A (Hamilton Anxiety Test) and HAD-D (Hamilton Depression Test) questionnaires were completed for all patients and controls. Psychological interview with the patients and psychological analysis were performed to determine anxiety and depression scores. Data analysis was done using SPSS (ver.24) statistical software
Results: The subjects of two groups were homogeneous in terms of age and sex. The mean salivary opiorphin concentrations in the case and control groups were 1.8050±0.2923 and 1.8032±0.3682 ng/ml, respectively. According to the results of t-Test, no significant difference was observed in the mean opiorphin concentration between the AFP group and control group (P=1.000). According to the Pearson's test, no significant relationship was found between the opiorphin levels and the age, sex, and anxiety or depression score in the patient and control groups (P>0.05). Also, there was no remarkable correlation between initial VAS, duration of pain and previous treatments with opiorphin levels in the AFP patients (P>0.05). No significant correlation was found between the opiorphin concentration and menopausal period in the case and control women (P>0.05).
Conclusion: The results showed that most AFP patients had some degree of anxiety and depression. However, salivary opiorphin concentration did not significantly increase in the AFP patients.

Background and Aims: The aim of this study was to investigate the tooth discoloration caused by cold ceramic compared to MTA Angelus in contact with the washing solutions such as sodium hypochlorite (NaOCl) and normal saline.
Materials and Methods: 50 samples of extracted human maxillary anterior teeth were selected. After preparing the access cavity, they were divided into 4 experimental groups and 1 control group (10 in each group). The access cavities of teeth in groups 2 and 4 were rinsed with 5.25% sodium hypochlorite and those in groups 1 and 3 were rinsed with normal saline. Then, after drying, 3 mm thickness of cold ceramic (groups 1 and 2) and MTA Angelus (groups 3 and 4) were placed in the access cavities of the teeth. After setting of the materials, all specimens were restored with a resin modified glass ionomer. Based on the CIE Lab system, each sample’s total color change (∆E) was obtained before, one, and 90 days after application. Data were statistically analyzed using the Wilcoxon test.
Results: According to the results, there was no statistically significant difference in the average tooth discoloration between the groups filled with cold ceramic and in different time periods (P>0.05). While, in the groups filled with MTA Angelus, the difference in the average tooth discoloration in 90 days after application was significantly higher than one day (P<0.05).
Conclusion: The results of this study showed that compared to MTA Angelus, cold ceramic causes less tooth discoloration over time and therefore, it can be suggested as a more suitable alternative endodontic cement than MTA Angelus.

Background and Aims: The surgical removal of mandibular third molar is frequently accompanied by significant postsurgical complications, and different protocols have been described to decrease such complications. The aim of this study was to compare the postoperative complications of mandibular impacted third molar removal with two conventional rotary and piezoelectric methods.
Materials and Methods: In this study 27 patients with bilateral mandibular impacted third molars were selected. The patients’ teeth were extracted by the piezoelectric method on a random side and the opposite tooth was extracted by conventional rotary technique. On operation and post operation days, edema, pain, and mouth opening were assessed. The duration of each operation was also measured. Data were analyzed by Mann-Whitney test and independent t-test.
Results: The mean duration of operation in the rotary group was less than that of the piezoelectric group, which was statistically significant (P=0.001). Pain was significantly higher in the rotary group on days 0 to 5 (P<0.05). Whereas, difference in pain on day 6 was not statistically significant (P=0.067). There was no significant difference between the two groups in each day after surgery regarding mouth opening (P>0.05). Edema was significantly higher in the rotary group on the first, third, and fifth days after surgery (P<0.05). Also, edema was higher in the rotary group on the seventh day after surgery, but not statistically significant (P=0.076).
Conclusion: According to the results of the present study, it can be concluded that pain and swelling in patients after impacted tooth surgery using time consuming piezoelectric technique can be reduced.

Background and Aims: One of the concerns of dentists is selecting a suitable brand of stainless steel crowns with maximum dimensional adaptation with primary teeth. The aim of this study was to compare the primary molar crown dimensions with that of two brands of stainless steel crowns (SSCs) in a sample of Iranian children.
Materials and Methods:  In this study, 130 eligible children between 3 and 12 years (66 boys, 64 girls) were selected. After recording the demographic information, the mesiodistal, buccolingual and occluso-gingival dimensions of first (D) and second (E) primary molars were measured on dental casts and compared with the dimensions of KTR (MeiMeiMinBenjing, Benjing, China) and Shinghung (Shinhungcompany, Seoul, South Korea) SSCs. Data were assessed using chi-square test and Pearson correlation coefficient. P<0.05 was considered statistically significant.
Results: In this study, the most dimension matching of the teeth with that of SSCs were observed mesiodistally in upper D and lower D, buccolingualy in the upper D and lower D, and occluso-gingivaly in upper D and lower E. The most cases of mismatch in the mesiodistal dimensions of the teeth with that of SSCs were observed in the lower E and upper D. Also, the most cases of mismatch in the buccolingual dimension were found for upper E and lower E.
Conclusion: Both SSCs brands in this study showed significant dimensional adaptation with the primary teeth in Iranian children. The most dimensional adaptation was between KTR SSCs and maxillary primary molars, and between Shinhung SSCs and mandibular primary molars.

Background and Aims: Journal of Dental Research is among the dentistry journal with the highest impact factor. This study aimed to map the most important topics for journal editors and readers.
Materials and Methods: The world's active research topics in the field of dentistry related to the Journal of Dental Research in the last 5 years were extracted from SciMapper's SciTrends. Also, we clustered the most cited papers in that journal to show the most important research topics for the journal editors and readers.
Results: We identified and mapped 11 active international research areas in the field of dentistry and related to this journal. Among 146 faculty members of the school of dentistry, 12 had at least one article related to the most active research areas in the journal. In this regard, they had similar articles elated to the 7 clusters out of 13, but their articles are mainly related to the clusters 7 and 19. Among the investigated faculty members, nine had directly collaborated with 21 authors of the mapped clusters. Moreover, 12 faculty members could also connect to the 126 authors with articles in that journal through their scientific collaborators.
Conclusion: One way to publish in a top international journal is to know the most active and interesting research areas for the journal editors and readers. About 8% of the school of dentistry faculty members at Tehran University of Medical Sciences had some research related to the Journal of Dental Research.

Background and Aims: Temporomandibular disorders refer to a set of musculoskeletal problems that affect the temporomandibular joint, masticatory muscles, and surrounding anatomical structures. These disorders are associated with symptoms such as pain, click, asymmetry, or reduced maximum opening. The etiology of many temporomandibular disorders is complex, for this reason the initial treatments must be reversible and non-invasive. The use of occlusal splints is effective in reducing symptoms, and therefore, it is recommended in early and even long-term treatment of these disorders. These appliances play major role in developing conditions such as stabilizing joint position, creating favorable occlusal conditions that lead to normal muscle function, and protecting teeth and supporting structures against dental wear. The purpose of this article was to present a comprehensive review of occlusal splints in Persian language. Materials and Methods: A search on Pubmed and Google scholar databases was done and the keywords "occlusal splints" and "temporomandibular disorders" were used. The inclusion criterion was articles published in English in the field of the types of occlusal splint between 1980 and 2020. Conclusion:  In this review, the occlusal splints and their applications have been introduced.The success or failure of treatment with occlusal splints depends on various factors such as the correct selection of patients, the process of manufacturing, occlusal adjustment of splints, and the patients’ cooperation.

Background and Aims: Idiopathic osteosclerosis is an asymptomatic local growth of cortical bone and is discovered incidentally on panoramic radiographs. The purpose of this study is to evaluate the frequency of idiopathic osteosclerosis and its radiographic features in panoramic images of patients referred to the Department of Maxillofacial Radiology, Faculty of Dentistry, Arak University of Medical Sciences (Iran) in 2022-2023.
Materials and Methods: In this cross-sectional study, 460 panoramic images from the radiology department of Arak Faculty of Dentistry were randomly selected and analyzed. The demographic information of patients, frequency of idiopathic osteosclerosis, location, and also its relationship with adjacent teeth in terms of proximity to lamina dura and periodontal ligament and radiographic features in terms of size and morphology were evaluated. The data were analyzed using the SPSS24 software.
Results: Panoramic images of 460 patients (266 men and 194 women) with an average age of 38.12 (11.75) years were evaluated. The frequency of idiopathic osteosclerosis was 6.1% (28 images). 92.9% of the lesions were in the lower jaw and 46.4% of them were near the premolar teeth. In 39.3% of the cases, the lesion was adjacent to the periodontal ligament and laminadora of the tooth. In 3.6% of the cases, it was associated with a small displacement of the adjacent tooth, and 17.9% was associated with tooth root resorption. According to the results, there was no correlation between the incidence of this lesion with age and gender (P>0.05).
Conclusion: According to the findings of this study, the frequency of idiopathic osteosclerosis in the patients referred to Arak dental school was reported as 6.1%. Most of these lesions were observed in the back of the lower jaw and thus, it is important to be able to distinguish this lesion from the radiopaque lesions of the jaw which need treatment.