Journal of Dental Medicine

Background and Aims: Various methods to induce anesthesia have been investigated in situations where the primary inferior alveolar nerve block (IANB) injections fail. The aim of this study was to compare the effect of synergic effects of anesthetic injection of prilocaine supplemental with that of lidocaine anesthesia in teeth with irreversible pulpitis.
Materials and Methods: This study was a parallel-controlled clinical trial on 58 patients with one mandibular molar tooth having irreversible pulpitis. The first anesthesia was injected with an inferior alveolar block with 2% lidocaine anesthesia. Patients who failed pulpal anesthesia were randomly divided into two groups; case and control groups. In the case group, IANB was injected with 3% prilocaine, and in the control group with 2% lidocaine anesthesia. Anesthesia after the second injection was evaluated by three methods of numerical evaluation of the patient's response to Electric Pulp Tester (EPT), the severity of the patient's response to the cold test, and the extent of pain during the onset of access cavity latency on the Visual Analog Scale (VAS). Statistical analysis was performed using T-test and Mann-Whitney tests.
Results: There was no significant difference between the two groups in terms of depth of anesthesia (P>0.05).
Conclusion: The results of this study showed that there was no difference between 2% lidocaine and 3% prilocaine in the depth of supplemental IANB anesthesia after failure of first IANB in mandibular molar teeth with irreversible pulpitis.
 

Background and Aims: Oral squamous cell carcinoma (OSCC) is one of the most prevalent oral cancers with increased risk in individuals younger than 40 years especially in developed countries. There are many evidences that people who have plenty of fruits and vegetables in their diets tend to have lower risk of cancer. In this study, we evaluated the anticancer effect of four medicinal plants of Otostegia Persica, Otostegia Michauxii, Otostegia Aucheri, and Hibiscus Sabdariffa on OSCC cell lines.
Materials and Methods: In this study, methanolic & dichloromethane extracts of the above medicinal plants were used in order to evaluate their effect on oral squamous cell carcinoma cell line in different concentrations and after 24 , 48 and 72 hrs by MTT assay test. Finally, the appropriate concentration for repeating the test were chosen.
Results: In this study, the mean amounts of IC50 for O. persica and O. Aucheri were less than the two other herbs and the least and most amount of IC50 were related to the dicloromethanolic extract of O. persica after 72 hrs and the water extract of H. sabdariffa after 24 hrs, respectively.
Conclusion: It was concluded that all of the plants evaluated especially O.Persica and O.Aucheri had anticancer properties and dichloromethalonic extracts of these plant were more effective than that of methanolic extract.

Background and Aims: One of the most important challenges for dentists is providing a crown with appropriate marginal fit and gap. The 135-degree tooth preparation found to have some advantages such as technical ease and appropriate finish line record. Despite the advantages of 135-degree tooth preparation, scant research has been done in this area. Therefore, the aim of this study was to compare 135-degree and deep chamfer tooth preparation on the marginal fit and marginal gap of posterior metal-ceramic crowns.
Materials and Methods: Deep chamfer and 135-degree tooth preparation were performed on the two first mandibular molars with healthy coronal tissue and similar size. Impression was taken from each tooth and 30 crowns were made on each die. The sample plastered with fit checkers were pressed under the force of 40 N for 3 min in a universal testing machine. They were measured and recorded under a loop with 40x power in three points on each aspect. Data were analyzed by Wilcoxon and Kolmogorov-Smirnov tests using SPSS version 24.
Results: The mean marginal fit values in deep chamfer and 135-degree were 48.5417µm and 55.3333 µm, respectively with no statistically significant difference (P>0.05). While the mean marginal gap in deep chamfer (2.4833 µm) was significantly higher (P<0.05) than 135-degree (1.0083).
Conclusion: It can be concluded that the marginal gap by 135-degree’s tooth preparation was lower than that of deep chamfer in metal-ceramic crowns. However, no significant difference in the marginal fit between the deep chamfer and 135-degree tooth preparation was found.

Background and Aims: Nasal obstruction is a common condition among children, in which delaying treatment can stabilize its negative effects on dentoalveolar structures during adulthood. In this study we aimed to investigate the effect of total nasal obstruction on the craniofacial structures of rabbits.
Materials and Methods: In this animal study, total numbers of 44 rabbits with high genetic proximity were selected. Several metal implants were inserted in the anatomic landmarks of their skulls and then underwent three different types of x-ray exposure (lateral, posterior-anterior and occlusal views). Half of them underwent surgically assisted total nasal obstruction, and the other half were considered as control group. All rabbits were kept in the same environment up to maturation period. Then, they underwent the same x-ray exposures. The primary and final radiographs were traced and various linear and angular were compared between them.
Results: The anterior facial height (P=0.01), maxillary depth (P=0.005), articular angle (P=0.005), maxillary and mandibular plan angle were significantly more in the rabbits with total nasal obstruction. However, the interdental width (P=0.005), maxillary perimeter (P=0.005), nasopharyngeal width (P=0.01) and maxillary and mandibular width were significantly less in them. The skull base length (P=0.30), gonial angle (P=0.40), and maxillary length (P=0.10) were not significantly different between the two groups.
Conclusion: Total nasal obstruction had various impacts on the craniofacial structures.

Background and Aims: Dental caries is a multifactorial and common disease that leads to a decrease in the quality of life of individuals. The aim of this study was to determine the relationship between serum vitamin D and dental caries in the third year-to-last year students of dental school of Tehran University of Medical Sciences.
Materials and Methods: This descriptive cross-sectional study was conducted on 123 dental students. Demographic and health information were completed through a checklist. The level of vitamin D in individuals was measured by blood sampling. We recorded caries by ICDAS (international caries detection and assessment system) in two levels of D(1-6)MFT (total of decayed, filled and missing tooth) and D(3-6)MFT (total of progressive decayed, filled and missing tooth). Data analysis was done by the SPSS package version 25 using statistical tests of correlation and regression.
Results: The results showed that the correlation coefficient between vitamin D and caries index D(1-6)MFT was -0.89 with a P-value of 0.3328 which was not statistically significant. Based on the backward logistic regression, there was a positive significant statistical association between the D(3-6)MFT with vitamin D deficiency (P<0.001), weight (P=0.012), dental visit (P=0.023) and frequency of sweet snack consumption (P=0.03). In addition a significant and inverse statistical association was reported between the D(3-6)MFT and milk consumption (P=0.026).
Conclusion: Among dentistry students, no relation between vitamin D deficiency and early stages of decay was seen, however this relation was statistically significant in regard with progressive dental caries.

Background and Aims: Considering the role of primary teeth in children's dental health and the importance of parental role on children dental health the purpose of this study was to determine the knowledge and practice of parents of 3-9 year-old children regarding to maintaining primary teeth.
Materials and Methods: This cross-sectional descriptive-analytical study was conducted on the parents referring to Ahwaz dental school in 2017. Using a questionnaire, the participants' demographic characteristics, knowledge and performance regarding maintaining of the primary molars were collected. The percentage of correct responses was considered as the level of knowledge and performance. Analysis of K-square and Spearman and Pearson correlation coefficient and T-test were employed to determine the relationship between the participants' knowledge and performance and their demographic variables. The significance level was P<0.05.
Results: 176 parents completed the questionnaire. The mean parental knowledge score was 57.42±7.45
(range 15-75), and the mean practice score was, 9.42±1.86 (range 4-12). No relationship was found between the parents’ age, sex, knowledge, and performance. The knowledge of parents who had a history of referral to the dentist, fewer children (rs=0.428), higher education (rs=0.490) and higher income (r=0.226) was significantly better (P<0.001). Also practice increases with higher awareness of parents (r=0.549) (P<0.001). The parents’ practice was significantly related to the history of referral to the dentist, and having fewer children (rs=0.320), higher education (rs=0.369), and higher income (r=0.253) (P<0.01).
Conclusion: The findings of this study showed that the knowledge and practice of the parents about primary teeth were moderate. Regarding the important role of primary teeth in children's health, increasing the parents’ knowledge on the maintenance of primary teeth is essential.

Background and Aims: Advances of genetic science in genomic techniques have led introducing new diagnostic systems to study the diseases or treatment efficacies. In this science, which named “Personalized Medicine”, human genetic structure is used for evaluation of the diagnosis, treatment, and prevention of disease. Regarding the limited number of studies regarding this issue in Oral & Maxillofacial diseases, this study was aimed to evaluate the benefits and challenges of this new area (Personalized Medicine) in dental treatments.
Materials and Methods: In this study, complete evaluation of abilities and challenges in order to apply the “Personalized Dentistry” in Dental treatments, and also its effect on oral health indexes were done. All the existing related articles were searched with the relevant key words in the scientific data bases of PubMed, Google Scholar, Medline, Scopus, SID and Magiran. Based on the inclusion and exclusion criteria, 5 articles were selected, assessed and summarized.
Results: In the evaluated articles, the benefits of “Personalized Dentistry” in dental treatments as targeted and specialized treatment could result in lower time, energy and cost. In addition, its disadvantage as unknown biologic effective factors and also, the cross effects of some of the above items on each other and the treatment procedures were mentioned.
Conclusion: Regarding the specialized sciences and diagnostic tools for oral & maxillofacial disease, the benefits of “Personalized Dentistry” application can be increased for special treatments of patients. Also, it could reduce the side effects of conventional therapies and thus, could be introduced as an effective step for better dental treatments.

Background and Aims: All metal components of orthodontic appliances are somewhat corroded in the oral environment due to some changes in chemical, mechanical, thermal, microbiological and enzymatic factors which facilitates ion release. Ionic release can result in a discoloration of the surrounding soft tissue or allergic reactions in sensitive patients or even local pain in the area. In general, ions can cause toxic and biological side effects if their values reach the threshold, so the release of ions from the metal components of orthodontic appliances is important to us. The aim of this review article to determine the rate of orthodontic appliances ion release in different solutions.
Materials and Methods: A review of the literature was carried out in Pubmed, Google Scholare and Web of science database using selected key words (Saliva/ Titanium/Normal Saline/ Ion release Orthodontic appliance/Mouth wash/ Nickel/ Chromium). These searches were limited to the articles published from 2005 to 2018. According to the inclusion and exclusion criteria, 25 articles were obtained.
Results: Because of conflicts in the reported results, it was necessary to synchronize the measurement methods and also to use artificial saliva medium with normal pH as a control to achieve better systematic comparison.
Conclusion: There was significant differences in the ion release between mouthwashes. In all studies, the effect of pH and acidity has been shown to increase the release of these ions. In addition, stainless steel (SS) instruments had the least biocompatibility among all types of alloys evaluated.

Background and Aims: Human ergonomics or engineering with proper design and change of work and requirements creates the most productivity based on human physiology. The purpose of this study was to determine the level of awareness of dental students of Isfahan University of Medical Sciences about the basic principles of ergonomics in dentistry.
Materials and Methods: In this descriptive-analytical, sectional study, a questionnaire containing 10 questions was distributed and completed by easy sampling method among 74 final year students of the general doctorate of Isfahan school of dentistry. After collecting the questionnaires, the students were given an educational pamphlet. To evaluate the questionnaires, each correct answer was given a score of one and the wrong answers were given a score of zero. Data were analyzed by T-test, Kai Square, and Mann-Whitney statistical tests using SPSS23 software. P<0.05 was considered as a significant level. P<0.05 was considered as a significant level.
Results: The average score of the knowledge of principles of ergonomics was intermediate (6.23±1.25). Student knowledge was not significantly different based on the student gender (P=0.25) and academic semester (P=0.059). Also, 55% of students had a history of muscle pain that did not have a significant relationship with gender (P=0.258) and average score of the knowledge (P=0.288).
Conclusion: Unfortunately, ergonomics cannot be considered part of the principles of dental education and even later. Musculoskeletal pain is one of the most common complaints of dentists and is a factor in reducing their quality and function. Therefore, it seems that training and evaluation of ergonomic principles in dental education is necessary.

Conclusion: According to the results of this study and the application of anaerobic conditions, forced anaerobic bacteria can be isolated from clinical specimens of oral infections and by Tetra Arms-PCR no significant relationship between TGF-1β genomic polymorphism and periodontitis was observed. In addition, therer was no significant difference in the frequency of alleles and genotypes between the control and patient groups.

Conclusion: Many elderly people avoid the treatment of oral diseases during coronavirus pandemic due to fear of coronavirus, high dental costs, lack of access to appropriate services, and this causes irreparable problems in their health. Therefore, it is recommended to provide practical solutions to facilitate the dental treatment of elderly patients.

Background and Aims: The objective of this study was to evaluate the knowledge, attitude, and practice of ergonomics during dental treatment among students of Urmia university of medical sciences in 2020.
Materials and Methods: In this descriptive-analytical study, self-administered questionnaires were given to 78 dental students of Urmia University in 2020 and the knowledge, attitude, and practice of every participant were evaluated. Demographic data including sex, age, and University grade were recorded as well. Data were analyzed by SPSS software24 with One Way ANOVA and t-test and the significance level of P<0.05.
Results: 78 students (44 males and 34 female) by Mean Age 23.9±2.12 were included in the study. The difference between the attitudes of different age groups was significant (P=0.006). The age group of 20 to 24 years had a more positive attitude than other age groups. However, the results of this study did not show a significant r elationship between the participants' knowledge and practice with their age (P>0.05).
Conclusion: According to this study, the knowledge, attitude and practice of Urmia dental students were in the desired range. 20-24 year students had significantly higher attitude in comparison to others. Therefore, more endeavors should be taken to improve these parameters in ergonomics.

Background and Aims: The 2019 coronavirus pandemic has resulted in a lot of pressure on health systems around the world. The risk of transmission of infection in dentistry is significantly high. The aim of this study was to evaluate Covid-19 protection knowledge and practice of dentists in Isfahan in clinical environment.
Materials and Methods: In this study which was performed in April 2021 by available sampling method, an online questionnaire was used as a data collection tool. Questions included demographic characteristics, knowledge of proper protective protocols, protection protocols taken against Covid-19, and the prevalence of Covid-19 infection. Descriptive and analytical analyzes were performed using SPSS26 software including frequency distribution tables, graphs, independent t-test, and Pearson and Spearman correlation coefficients.
Results: 310 questionnaires were collected with complete answers. 87.4% of dentists had moderate and high knowledge of proper protective protocols against Covid-19. The mean knowledge score had no significant relationship with the demographic characteristics of age (P=0.59), gender (P=0.31 and r=0.05), work experience (P=0.16 and r=0.07) and degree (0.33=P). In the pandemic period, 87% of dentists treated dental emergencies and 40% delayed the dental treatment for patients with high risk of Covid-19. Dentists used personal protective equipment correctly. Among all the included dentists, 75% used high protection masks, 75% used face shields, 67% used hats, and 60% used sterile gowns in all of their treatment activities. The clinical environment was equipped well to prevent spreading of Covid-19. The results showed that 55.8% of the participants had one or more similar signs/symptoms of Covid-19 and 9% had a positive SARS-CoV-2 test during the last months.
Conclusion: The majorities of dentists had enough knowledge of proper protective protocols against Covid-19 and efficiently used all protections while performing dental procedures.
 

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: Dentists are at risk of musculoskeletal disorders due to their job characteristics. The purpose of this study was to compare the posture and musculoskeletal disorders of dentists with high and low work experience.
Materials and Methods: This analytical cross-sectional study research was conducted on 76 dentists in Urmia city. Based on work experience, the samples were divided into two groups: less experienced (less than 15 years) and experienced (15 years and more). The variables of forward head, kyphosis, round shoulder, and musculoskeletal disorders were compared in two groups. Forward head and round shoulder variables were evaluated by photography, kyphosis variable by flexible ruler, and musculoskeletal disorders were evaluated by Nordic questionnaire. Data analysis was done using descriptive statistics and analytical statistics (Kolmogorov-Smirnov test, Leven test, independent t-test and Yeoman-Whitney test).
Results: The independent t-test results showed that the angle of forward head, round shoulder, and kyphosis was higher in the high work-experience group than that of the low work-experience group (P=0.001). In comparing the prevalence of neck disorders, the results were significant such that the experienced group had more neck disorders (P=0.002). However, in examining the difference in the amount of disorders in other parts of the body, the difference between the two groups was not statistically significant (P>0.05).
Conclusion: Experienced dentists had a higher degree of forward head, round shoulder and kyphosis positions. Although, there are musculoskeletal disorders in both groups of dentists with low and high level of experience, neck disorders were more common in high-experienced dentists than that of low-experienced ones.

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: Today's working conditions in medical sciences, including dentistry, are changing rapidly. The explosion of scientific information on the one hand and the increase in consumer awareness on the other hand, along with the ever-increasing advances in artificial intelligence and access to the internet and the wide information network, has made health service providers face complex and different conditions. One of the ways to properly respond to the treatment needs of patients is to benefit from the best available evidence and clinical experience and to pay attention to the values and preferences of patients, which is manifested in the form of evidence-based practice. Dentists as members of the group of health service providers, must be familiar with evidence-based dental concepts and procedures and use them in their professional performance. This article discusses the steps of evidence-based dentistry to help empower dentists in the field of clinical decision-making based on the latest research benefiting from the best evidence and improving their clinical practice.
Materials and Methods: To find relevant articles in the field of evidence-based dentistry, PubMed scientific database and Google Scholar search engine were searched from 2000 to 2023 with keywords of Evidence-based dentistry, clinical practice, and decision making. Among the articles searched based on the inclusion and exclusion criteria, 15 articles in English whose main topic was evidence-based dentistry with an educational approach were selected and used to describe evidence-based dentistry and its components.
Conclusion: Due to the complexity of patients' issues and their increasing awareness, it is essential for dentists to possess specialized skills to meet patients' needs in accordance with their expectations and values, while also utilizing research findings.

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: Educational planning is one of the main areas of education and training, which plays an essential role in the optimal training of human resources. The aim of this study was to compare the educational program (curriculum) of general dentistry in Iran with that of several prestigious dental schools in the Middle East countries.
Materials and Methods: This is a descriptive comparative study using the dental education curricula of six prominent countries in the Middle East in the field of dental sciences. Their selection was based on similarities and common cultural, economic and social characteristics. After collecting the selected curriculums, four steps including description, interpretation, juxtaposition and comparison were done. Tables were drawn based on goals such as the number of years of education, mission, general goals, and the role of graduates in the medical system of that country.
Results: The educational curriculum of the countries reviewed in the Middle East have many similarities in terms of the number of years of study in the field of dentistry, the general mission and goals, and the role of students in the medical system of that country. The main differences were in the number and type of teaching units in the curriculum of this countries. The method of teaching and the distribution of topics in the curricula of the countries differentiated them from each other. According to the results of this study, the curriculum of the countries of Iran, Saudi Arabia and the UAE were the most similar among the countries of the Middle East. The teaching method and distribution of topics in the curricula of countries distinguished them from each other.
Conclusion: Countries that are based on Russian language education have a shorter number of years of education and are similar to Russia. However, countries with an American educational base such as Saudi Arabia, the United Arab Emirates, and even Iran have a longer academic years and more general similarities in educational content.