Journal of Dental Medicine

Background and Aims: Dentists faced the highest risk of infection during the COVID-19 pandemic. Educating competent students is the first task of the dental school to overcome the created problems and thus, it is necessary to recognize the created educational deficiencies. This study aimed to assess the students' perspectives from the Dental School at Tehran University of Medical Sciences during the academic year 2019-2020, concerning the competencies expected to be developed during the clinical phase of the general dentistry curriculum during the COVID-19 pandemic. The findings are intended to inform the formulation of educational strategies in the post-pandemic period to address identified gaps in training.
Materials and Methods: During the academic year 2019-2020, a cross-sectional descriptive study was conducted at the School of Dentistry, Tehran University of Medical Sciences, Iran. The study consisted of three phases: checklist design, psychometrics, and a survey of general dentistry students in their third to sixth year. The checklist design phase involved a team of four individuals, including educational officials from the faculty, academic staff members, and medical education experts. Experts confirmed the content validity of the checklist, while reliability was assessed using the Intraclass Correlation Coefficient (ICC), which indicated favorable validity and reliability. Subsequently, questionnaires formatted as Google Forms and a census approach were distributed to all students enrolled in the general dental course within the clinical section of the School of Dentistry at Tehran University of Medical Sciences. Ultimately, following the data collection process, statistical analysis was conducted utilizing descriptive statistics, including the mean and standard deviation, and the findings were communicated to the group managers.
Results: The assessment of content validity was established at a minimum of 71%, based on the evaluations provided by five experts. Additionally, reliability was measured using an intra-cluster correlation coefficient (ICC) exceeding 0.79, signifying a strong level of both validity and reliability. 122 students (53%) in the clinical stage completed the forms related to the pre-clinical/clinical units passed during the Covid era. Despite having enough training, basics Removable Partial Prosthodontics, Surgery 1, and Restorative 3 courses needed more training. In addition, Basics Removable Partial Prosthodontics, Surgery 1, and Surgery 4 needed the most practical training to acquire the necessary competencies.
Conclusion: The findings of this research indicated that the dental students expressed a desire for increased practice across various levels of pre-clinical and clinical courses. This would suggest that the challenges associated with patient interactions during the COVID-19 pandemic may not be the sole contributing factor. Consequently, alongside the need for educational planning to address the requirements of enrolled students, it appears essential to conduct similar studies in the post-pandemic context. Furthermore, this approach may also prove beneficial in evaluating educational needs for ongoing professional development courses.

Background and Aims: Emotional intelligence helps dental students better manage stress and establish effective communication with patients, while self-efficacy strengthens their confidence in performing clinical tasks and acquiring professional skills. The connection between these two factors leads to improved academic and professional performance. The aim of this study was to examine the relationship between the emotional intelligence, self-efficacy, and academic success among dental students.
Materials and Methods: This cross-sectional study included 55 dental students from Shahid Beheshti University of Medical Sciences - Iran, selected by convenient sampling. To measure academic self-efficacy beliefs, the Sherer questionnaire was used, which consisted of 17 questions with a theoretical score range of 17-85. To measure emotional intelligence, the Bar-On questionnaire was used, consisting of 90 questions with a theoretical score range of 90-450. Academic achievement was assessed using the students' grade point average (GPA). Additionally, gender, living at home or in a dormitory, and parental education levels were considered as background variables. The data were analyzed using descriptive statistics, t-tests, and Pearson correlation coefficient.
Results: Among the 55 students who participated in this study, including 30 women and 25 men, the average emotional intelligence score was 84.85, the average self-efficacy score was 62.02, and the average GPA was 16.42. There was a significant difference in the emotional intelligence scores based on gender and living situation, with male students scoring higher than female students and dormitory residents scoring higher than those living at home (P=0.02). There was no significant difference in the self-efficacy scores and GPA between males and females. Students whose mothers had higher levels of education and those living at home had higher GPAs (P<0.03). No statistically significant relationship was found between the academic success and emotional intelligence or self-efficacy (P>0.05).
Conclusion: The findings suggest that while emotional intelligence and self-efficacy may not directly influence academic success, other factors like living environment and parental education can play a role. Understanding these dynamics can help educators focus on holistic student development, addressing not just academic skills but also personal and social factors that contribute to student performance and well-being.

Background and Aims: The display of an individual's teeth varies in different facial expressions, which significantly affects the beauty of the lower face and overall appearance. The ideal display of incisors is influenced by lip morphology and is an essential aspect of treatment planning. This study aimed to evaluate the ideal display of incisors at rest in women with different lip forms, as assessed by dentists and laypeople.
Materials and Methods: This was a cross-sectional study that was conducted in 2024 at Babol University of Medical Sciences. 46 dentists and 92 laypeople were selected and included in the study in an easy and accessible way. The distance between the uppermost area from the lower edge of the vermilion of the upper lip to the imaginary line between the two commissures was used to classify the lip shape, which was divided into three categories: straight (0-3 mm), medium (3-6 mm) and long (more than 6 mm). Smile images of three women in the age range of 15-30 years were collected and manipulated, resulting in six new images from each original image with varying degrees of incisor display using Photoshop (a total of 18 images). The designed images were randomly placed in a booklet and given to participants, who scored each image on a scale of zero to 100. The data were analyzed by SPSS software version 22 and using the Mann-Whitney test at a significance level of 0.05.
Results: A total of 138 participants took part in the study, including 46 dentists (33.3%), comprising 17 males (37%) and 29 females (63%), and 92 laypeople (66.7%), including 46 males (50.0%) and 46 females (50.0%). Laypeople gave higher scores to images of straight and moderate lip forms than dentists. However, this difference was not statistically significant (P>0.05). In addition, dentists gave significantly higher scores to all images related to the  long lip form than laypeople (P<0/05). In addition, among laypeople, men gave a higher score than women to images related to straight and moderate lip form, which was statistically significant (P<0.05).
Conclusion: The findings of this study indicated that a 2.5 mm incisal display at rest was suitable for patients with a straight lip form. In general, it can be concluded that by changing the shape of the lip from straight to long, there is a preference for increasing the amount of incisal display in the resting state.

Background and Aims: The present investigation was conducted on the evaluation of the microstructure, phase transformation behavior, mechanical properties, and fatigue resistance of nickel-titanium rotary endodontic files. The main purpose of this investigation was to find the effect of microstructural parameters on the performance of these files.
Materials and Methods: Three rotary tools with brand names Denco, Edgeendo, and Eighteeth were studied. To evaluate the microstructure and transformation behavior of tools, metallography, X-ray diffraction, and differential scanning calorimetry methods were used. The bending test was used to check the behavior of superelasticity and memory and the microhardness test was used to evaluate the hardness of the samples. Also, cyclic fatigue behavior in a mold containing a simulated tooth canal was investigated and calculated by parametric statistical analysis. The fracture surface of the samples was also studied by scanning electron microscope.
Results: Analyses revealed the existence of a high volume fraction of R phase in the microstructure of the Edgeendo file. Rotary files with higher volume fraction of martensitic phase showed higher shape memory effect and fatigue resistance. Denco and Edgeendo rotary files with better surface quality and high volume fraction of martensitic phases in the microstructure showed better fatigue resistance compared with the Eighteeth file. In all the results, the P-value was less than 0.05.
Conclusion: Multiphase microstructure containing austenite and martensite together with appropriate phase transformation and hardness of the alloy have key roles on functional properties of rotary files. This study provides dentists with a deeper understanding of the fatigue behavior and mechanical properties of these files, enabling them to make more informed decisions in choosing the appropriate instruments for endodontic treatment.

Background and Aims: The quality of sleep plays a significant role in the academic performance of dental students, especially in the clinical years. Identifying and treating students at risk of sleep disorders can reduce or limit the drop in academic performance. The purpose of this study was to determine the relationship between the sleep quality and educational performance of Rafsanjan dental Student-Iran.
Materials and Methods: The present study was a descriptive-analytical cross-sectional study that was conducted among all dental students in Rafsanjan University of Medical Sciences - Iran. This study was presented to all dental students in Rafsanjan by online questionnaire method on Pressline website. The questionnaire included demographic information and student number along with the Pittsburgh Sleep Quality Standard Questionnaire. The Pittsburgh Questionnaire examines the quality of sleep in the range of 0 to 21. The link of the questionnaire was made available to the students through Telegram, and the GPA of the total students was obtained by using the student number from the Vice-Chancellor of University Education. The data were analyzed with SPSS26 software. First, the data were analyzed with Smironov's kermograph test. The results of this test showed that the data distribution is not normal (P<0.05). Due to the non-normality of the data distribution, non-parametric tests such as K-score, Mann-Whitney, Kruskal-Wallis and Spearman were used.
Results: 151 students participated in the questionnaire of which, 73 were men (48.3%) and 78 were women (51.7%). The mean and standard deviation of the age of the subjects studied was 22.11±2.3 years. The overall average sleep quality score of dental students was equal to 8.13, which according to the questionnaire, students experience poor sleep quality. 86.1% of students had poor sleep quality. Examining the correlation between the sleep quality and academic performance showed that there was no significant relationship between them. Sleep quality had no significant relationship with gender, marital status, place of residence, and entry year (P<0.05).
Conclusion: The results of the present study showed that majority of dental students in Rafsanjan had low sleep quality. Although, there was no relationship between the quality of sleep and academic performance, it seems necessary to pay attention to the sleep status of these students in order to improve their sleep quality, which is an important factor in improving their health by administrators and Rizan health program.

Background and Aims: The development and regular use of adhesive systems has started to revolutionize many aspects of restorative and preventive dentistry. The success of adhesive restorations highly depends on correct application of them. Therefore, the present study was conducted with the aim of determining the knowledge of dentists in Rafsanjan city (Iran) in choosing correct dental adhesive systems in 2023.
Materials and Methods: In this cross-sectional descriptive study, all dentists working in Rafsanjan city were included. The data was collected by a valid and reliable electronic questionnaire, which included two parts of demographic information (gender, age, place of work and year of graduation) and the 12 multiple-choice questions aimed to assess respondents' knowledge regarding the selection of dental adhesive materials in combination with self-cure or dual-cure composites, anterior and posterior composite restorations, fiber posts, fissure sealants, primary teeth, anterior composite veneers, ceramic laminates, and non-carious cervical lesions. The scoring of this questionnaire was as follows: 0 to 3 correct answers = Low level of knowledge; 4 to 6 correct answers = Moderate level of knowledge; 7 to 9 correct answers = Good level of knowledge; 10 to 12 correct answers = Very good level of knowledge.  The four answer choices included "etch-and-rinse (three-step)", "etch-and-rinse (two-step)", "self-etch (two-step)", and "self-etch (all-in-one bottle)". Then data were analyzed by parametric tests (ANOVA, t-test, and Pearson). The significant level was considered as P<0.05.
Results: Out of 91 dentists in Rafsanjan, 79 (86.8%) participated in the study, of which 35 (46.3%) were men. The average work experience was 3.49±3.96 years for men and 2.98±3.73 years for women. The average knowledge score was 4.38±2.16 out of 12 (4.29±2.23 in men and 4.45±2.12 in women). The results showed that there was no significant relationship between the knowledge score and the gender, age, work experience, and workplace (P>0.05).
Conclusion: According to the results which indicated the insufficient knowledge of dentists in  choosing correct dental adhesive systems, it is suggested to pay more attention on teaching in this field at the dental schools. For graduate dentists, new and practical information about the choice of adhesive systems should be provided by continuous education programs.

Background and Aims: Dentists’(specialists and general practitioners) perceptions of smile esthetics, which are often shaped academically based on standard criteria and hard and soft tissue relationships, may differ from those of the general public and patients, potentially failing to meet patients’ expectations of treatment. This study aimed to assess and compare the views of dental specialists, general dentists, and members of the general public regarding the influence of different labio-palatal inclinations of maxillary incisors on smile esthetics.
Materials and Methods: This descriptive cross-sectional study was conducted in 2024 on general dentists, dental specialists, and laypersons. General dentists and specialists practicing in Mazandaran Province were recruited, while laypersons were selected through convenience sampling from patients attending the Faculty of Dentistry in Babol-Iran. One male and one female subject were chosen based on the clinical and lateral cephalometric criteria, and two photographs (neutral facial expression and smiling) were taken of each. After image editing, five final photographs of each subject were prepared and presented in a questionnaire to evaluate participants’ perceptions of smile esthetics according to different labio-palatal inclinations of maxillary incisors, rated on a five-point Likert scale. Data were analyzed using SPSS software with independent t-tests and ANOVA.
Results: A total of 92 laypersons, 47 general dentists, and 141 specialists (47 orthodontists, 47 restorative dentists, and 47 oral and maxillofacial surgeons) participated in this study. Across all three groups, the most attractive male smile was associated with the -5° inclination (medium negative), whereas, the most attractive female smile was rated at 0°. Conversely, the least attractive smile in all groups was the −10° inclination (severe negative) in female images. Photographs with −10° inclination received the lowest scores for both male and female subjects. Specialists assigned lower mean scores to the 0° inclination images compared to general dentists and laypersons.
Conclusion: The divergence between dentists’ and laypersons’ perceptions of the impact of different labio-palatal inclinations of maxillary incisors on smile esthetics highlights the need for greater attention to patients’ expectations and treatment goals.

Background and Aims: Sleep quality may be a predictive factor for temporomandibular disorders (TMD) compared to other risk factors. Patients with TMD may experience quality-of-life problems such as sleep disorders and orofacial pain. Timely diagnosis of TMD can halt its progression in the initial stages and reduce its severity. This study aimed to investigate the frequency and severity of temporomandibular joint disorders and their co-occurrence with sleep quality among dental students in Yazd in 2023.
Materials and Methods: This descriptive study was conducted among 211 students at the Yazd Dental School. The Fonseca and PSQI questionnaires were used to determine the severity of TMD and sleep quality, respectively. Clinical examination was conducted to assess the symptoms of TMD. Additionally, demographic information such as gender, marital status, and place of residence was recorded. The data were analyzed using chi-square and t-tests.
Results: The final analysis was performed on 211 individuals, comprising 118 males (56%) and 93 females (44%). Among all the participants, 204 individuals (83.88%) had at least one symptom of TMD.  The participants' most prevalent symptoms were jaw sounds, midline deviation, pain, and mouth opening limitation. There was no significant difference in the frequency of TMD symptoms, jaw sounds, jaw deviation, and limitation in opening, based on gender. Similarly, the prevalence and severity of TMD and their symptoms showed no significant association with residence or marital status (P>0.05). Although, a correlation was observed between the poor sleep quality and the severity of TMD, no association was found between the presence of TMD symptoms and poor sleep quality (P>0.05).
Conclusion: While, the frequency of TMD symptoms did not differ significantly between genders, the severity of TMD and jaw pain was significantly higher among female students. Individuals with poor sleep quality exhibited significantly higher severe degree of TMD.

Background and Aims: Oral health affects the quality of life and plays the main role in achieving optimal conditions of health and general well-being. Therefore, this study was conducted with the aim of investigating the psychosocial effects and quality of life related to oral health in patients treated with composite veneers.
Materials and Methods: In this cross-sectional study, 48 patients who referred to the restorative department of Jundishapur University of Ahvaz for composite veneer treatment were participated. The PIDAQ questionnaire was used to investigate the aesthetic effects of composite veneer treatment on the psychosocial conditions of the patients, and the OHIP-14 questionnaire was used to investigate the quality of life related to oral health. Patients were asked to complete both questionnaires before treatment and one month after composite veneer treatment. Also, demographic information including age, sex, education and marital status of the patients were recorded. The purpose and benefits of participating in this study were fully explained to the patients and the patients voluntarily participated in this study. Then, an informed consent form was given to the patients. In order to compare the scores before and after the treatment, the paired T-test and its non-parametric equation expression (Will-Coxon) were used, and P<0.05 was considered.
Results: According to the results, the average age of the respondents was 28 years. In terms of gender, 54.2% of the patients were male, and in terms of education, most of the participants in the study had a bachelor's degree (35.4%). The total score of OHIP-14 before treatment was 26 and after treatment 22. Also, the total score of PIDAQ before treatment was 49 and after treatment 28. Comparing the scores of psychosocial effects and quality of life related to the oral health before and after composite veneer treatment showed that there was a difference between the average score of psychosocial effects and quality of life. There was a significant difference related to the oral health before and after composite veneer treatment, which significantly decreased after treatment (P<0.05).
Conclusion: The present study showed that suitable veneer composite treatments could improve the oral health related to the quality of life of people. Also, treatment with composite veneers could have a significant effect on patients' self-confidence. Composite veneers could reduce social effects, psychological effects, and cosmetic concerns related to patients’ teeth.

Background and Aims: The status of oral diseases in children with visual impairments is a topic of concern for dental researchers. The aim of this study was to evaluate the rate of dental caries in these children according to the PUFA index.
Materials and Methods: To evaluate the rate of tooth decay, sixty 6-12 year old children with visual impairments were selected by convenience sampling in 2022 in Isfahan-Iran. The examination and pufa/PUFA index (exposed pulp, residual root mucosal ulcers, fistulas, and abscesses) were recorded.  Data were analyzed with Mann-Whitney tests (comparison of pufa/PUFA index according to gender, type of disorder and severity of disorder) and Spear-Man (examining the relationship between pufa/PUFA index and child age).

Results: The means of pufa/PUFA index in primary and permanent dental systشems were 0.89±0.68 and 0.44±0.2, respectively, of which the highest portion was related to the caries with pulp involvement. There was no significant relationship between the pufa and PUFA index according to gender, type of disorder, and severity of visual impairment (P<0.05). Also, only a significant and direct relationship was observed in pufa between the primary tooth system and age (P=0.042).

Conclusion: Untreated caries in children with visual impairment based on the PUFA index in primary and permanent dental systems had a relatively low prevalence. The highest  PUFA index portion was related to the tooth decay with pulpal involvement. Furthermore, untreated caries in primary teeth were increased by increasing the children’s age.

Background and Aims: Despite significant advancements in rehabilitation of edentulism with implants, complications such as implant failure before and after prosthetic loading remain concerns. This study aimed to evaluate the frequency of dental implant failure before and after prosthetic loading in some of Yazd dental clinics between 2018 and 2023.
Materials and Methods: In this descriptive cross-sectional study, 1060 patients’ files from three public dental clinics were reviewed. These patients were treated by dental implants between April 2018 and June 2023. The collected data included patients’ age and gender, implant diameter, brand, and placement site, type of prosthesis, and fixture failure after surgical and prosthetic phases. Data were statistically analyzed by independent t-tests and chi-square tests.
Results: The mean age of patients was 55.25 ± 12.37 years and 56.3% were female. The frequency of overall implant failure was 3.4%. The implant failure rate after prosthetic loading was 2.8% in females and 2.3% in males (P=0.47). This rate was 2% and 1.9% for maxillary and mandibular implants, respectively (P=0.5). This amount was 2.4% in molar areas,1.7% and 1.8% in premolar and anterior regions, respectively  (P=0.8). Implant failure rate was 1.3% in overdentures, 5.9% in cement-retained, and 3.2% in screw-retained prosthesis (P<0.001). This amount for implants with a diameter less than 3.75 mm was 2.6% and for those with a diameter more than 4.5 mm was 3.7% (P<0.001). Implants with a diameter less than 3.75 mm had a 2.6% failure rate, whereas those with a diameter greater than 4.5 mm had a 3.7% failure rate (P<0.001). The implants failure rate was 1.6% for Dio brand and 2.5% for Dentis (P=0.5).
Conclusion: The overall implant failure rate in this study was 3.4%, of which 1.5% occurred before and 1.9% occurred after prosthetic loading. The frequency of implant failure after loading was significantly associated with the implant diameter and prosthesis type. This was not related to the patient's gender, implant site, or the implant brand.

Background and Aims: Dental caries is one of the most prevalent chronic oral diseases worldwide. Timely and accurate diagnosis of dental caries plays a crucial role in preventing lesion progression and reducing complications. This study aimed to systematically review the studies on dental caries detection using machine learning algorithms applied to periapical radiographs.
Materials and Methods: A comprehensive search was conducted in PubMed, Scopus, Web of Science, IEEE Xplore, and Google Scholar databases up to the end of 2024. Inclusion criteria comprised studies using machine learning algorithms for detecting dental caries in periapical or intraoral radiographs. The quality of studies was assessed using the QUADAS-2 tool.
Results: From 825 initial articles, 13 studies met the inclusion criteria. All studies used Convolutional Neural Networks (CNNs) with various architectures including ResNet, VGG, Inception, DenseNet, and YOLO. ResNet-based models and their hybrid variants showed the best performance with diagnostic accuracy ranging from 82% to 98%. Comparison with human experts in 6 studies revealed that deep learning algorithms demonstrated similar or superior performance.
Conclusion: From the results, deep learning especially convolutional neural networks, had significant potential for improving dental caries detection in periapical radiographs. However, challenges such as limited high-quality training data and generalizability issues need further investigation.

Background and Aims: Student perspectives play a crucial role in evaluating educational systems. This study assessed the self-efficacy of dental students at Yazd Dental School in diagnosing and managing oral and maxillofacial pathological lesions.
Materials and Methods: This cross-sectional study was conducted among dental students from semesters 6 to 12. A total of 250 self-efficacy questionnaires, designed to evaluate students' abilities in lesion management, were distributed. The questionnaire covered biopsy procedures, differential diagnosis, and treatment planning. Data were collected using structured self-reporting methods and analyzed through SPSS version 16, employing descriptive and inferential statistics, including chi-square tests. The semester progression, gender, age, academic performance, and marital status were examined for their impact on self-efficacy. According to the mean and standard deviation obtained in this study, the scores were divided qualitatively.
Results: The response rate of the questionnaire was 91.6%. The average self-efficacy score was 80.30±14.72 (out of 150), indicating a moderate level of confidence. Performing biopsies had the lowest self-efficacy, while diagnosing and managing oral ulcers had the highest. Higher-semester students showed significantly greater self-efficacy (P=0.018), whereas variations based on gender, age, academic performance, and marital status were not statistically significant (P>0.05). Increased exposure to the clinical cases and theoretical knowledge contributed to a growth in self-efficacy over time.
Conclusion: Overall, the students demonstrated moderate self-efficacy in lesion management. Higher-semester students benefited from accumulated experience, though specific areas, such as biopsy procedures and lesion diagnosis, which require further emphasis. Future strategies should enhance teaching methods, clinical practice opportunities, and assessment approaches to prepare students for the practical challenges they will face.

Background and Aims: In recent years, the use of artificial intelligence (AI) has become increasingly common in dentistry because it facilitates the process of diagnosis and clinical decision-making. It is necessary for dentists to be aware of the advantages and disadvantages of artificial intelligence before implementing it. The present study aimed to comprehensively review the various applications of artificial intelligence in the diagnosis of dental diseases along with its challenges and disadvantages.
Materials and Methods: For this review article, a complete search was conducted on the PubMed and Google Scholar databases and studies published in recent years as well as studies published in 2024 were collected using the keywords "artificial intelligence," "dentistry," "diagnosis." Finally, the relevant articles were selected and evaluated, focusing on artificial intelligence in dentistry and the diagnosis of dental diseases.
Results: Advances in artificial intelligence in dental imaging, particularly through machine learning (ML) and artificial neural networks (ANN), have dramatically transformed the way dental disease is diagnosed. These technologies help dentists to analyze complex information and produce more accurate results by using algorithms that allow systems to learn and respond to data. The most recent development in this area is deep learning (DL), which uses multiple layers of neural networks to process unlabeled data and predict outcomes. These techniques are used in various fields such as diagnostic imaging, periodontology, dental caries detection, and osteoporosis screening, which help to improve the quality of dental services. Despite the benefits of AI in clinical dentistry, three controversial challenges remain and need to be addressed: ease of use, return on investment, and evidence of performance, or reliability.
Conclusion: Based on the results, the most important advantage of AI is the diagnosis of dental diseases. AI has great potential to reduce the pressure on health systems by automating routine tasks and improving patient care. However, this technology can never replace human expertise and must be guided by ethical principles. Ultimately, AI is recognized as a valuable tool in dentistry and the final decision-making always remains with the dentist.