Caspian Journal of Dental Research

8-19

Authors: Mahsa Malekmohammadi , Azita Tehranchi , Maryam Sadeghipour , Nona Attaran , Mohsen Dalband , Mahshid Namdari , Zohre Ahangari , Mehdi Ekhlasmand Kermani *

Introduction: Mental health is an inseparable part of overall health and healthcare workers have experienced mental issues during the COVID-19 pandemic. This study aimed to investigate the amount of stress undergone by dental students and its affecting factors. Materials & Methods: This cross-sectional study included all students of Shahid Beheshti Dental School, Tehran. The data on demographic and individual-social characteristics of the participants and questions related to the perceived stress level (PSS-10 questionnaire) were collected using an online questionnaire. The results were analyzed using a T-test and the correlations in SPSS-26 (P<0.05). Results: A total of 511 students participated in the study. The mean score of the perceived stress level was 15.9 out of 40, indicating a moderate level of perceived stress. Eleven students had suffered from COVID-19 and 13% were in close contact with those infected. Most of the students (72%) used public transportation. About 60% regularly did exercise, and the majority had enough hours of sleep. After examining the relationship between the individual factors and perceived stress level, it was revealed that the PSS was significantly lower in people who had adequate and a regular sleeping timetable (p<0.05). Furthermore, people who had contracted the COVID-19 virus (p=0.019) or had relatives who were infected (p =0.007) experienced higher levels of stress. Suffering from preexisting medical conditions was another significant factor in higher perceived stress levels (p=0.027). Conclusion: This study indicated that students had gone through a moderate level of stress during the COVID-19 pandemic. People with systemic conditions, sleep disorders, and those who had contracted the COVID-19 virus themselves or their reletives, experienced higher levels of stress. The requirement to provide courses on stress management skills, family awareness, and use of mental health services to reduce the negative effects of this psychological burden is highly recommended.

30-37

Authors: Zahra Tafakhori * , Mehrad Rafiei

Introduction: Considering the effect of ethnicity and race on the root canal morphology of different teeth, this study was conducted to determine the root canal anatomy of permanent maxillary first premolars using cone-beam computed tomography (CBCT) in an Iranian population. Materials & Methods: This descriptive cross-sectional study was performed on 150 CBCT radiographs of an Iranian population, referred to a Radiology Clinic in Rafsanjan, Iran. The CBCT images were evaluated in terms of the number of roots and canals of maxillary first premolar and also canal types in axial and sagittal images. The Vertucci classification was used for assessing the root morphology. Data were collected using a checklist. The independent t-test and Chi-square test were used and analyzed at a significance level of 0.05. Results: A study of 150 radiographs showed that 81 and 69 ones had one root and two roots, respectively. In terms of canal type in the single-root teeth, 13 radiographs (16%) were type I, 36 (44.4%) were type II, 6 (7.4%) were type III, 17 (21%) were type IV, two (2.5%) were type V, four (4.9%) were type VI, and three (16%) were type VII. It should be noted that none of the radiographs had a type-VIII canal. Conclusion: This study has indicated that the Iranian population has a complex maxillary first premolars root canal morphology, and according to Vertucci classification, types II and IV are more common; hence, the Clinician must be very careful before treating the root canal of the first maxillary premolars.

45-51

Authors: Faezeh Heydari , Hemmat Gholinia , Reza Ghorbanipour *

Introduction: Palatal rugae is a collection of mucosal folds in front of the palatal and is unique to each individual. Rugae have been studied for various purposes. This research investigates the pattern of palatal rugae with different skeletal relationships in the sagittal dimension in a group of the Iranian population. Materials & Methods: A cross-sectional study was examined on 135 pre-orthodontic dental casts. The patients were grouped as Class I, Class II, and Class III according to the Nasion -A to Nasion -B angle (ANB) 45 patients in each group. Palatal rugae were recorded based on length, orientation, and pattern in each group, then compared. Data were analyzed by Chi-square, ANOVA, and Tukey post hoc test. In this study p<0.05 was considered significant. Results: The mean number of total rugae was significantly different among groups (p value=0.02). Cl III malocclusion had less number of rugae in comparison to other groups (p value=0.03). The number of straight pattern was significantly different between groups, (p value=0.04) and Cl I malocclusion had more straight pattern than other groups . Conclusion:This study showed some differences in the palatal rugae pattern between different classes of malocclusion according to Angle’s classificatin. In addition, orientation of some rugae were also found to be significantly different between malocclusiongroups.

60-64

Authors: Ehsan Rouhollahpour , Maryam Rezaei Dastjerdi , Mohammad Ebrahim Ahmadnezhad , Kamran Amirian Chaijan *

Introduction: Today, the use of all-ceramic restorations has increased due to their physical properties as well as translucency and esthetic appearance.The aim of this study was to compare the shear bond strength (SBS) between two methods of e-max ceramic cementing. Materials & Methods: The study groups were 1 flowable composite as cement (FC group) and 2) choice2 cement (C2 group). The samples were fixed to a KOOPA universal testing machine for SBS testing. Tthe data were analyzed using SPSS 20 through T-test at significant level of P˂0.05. Results: The average SBS in the FC group was 10.41±2.17 and The average SBS in the C2 group was 13.28 ±1.52. There was a statistically significant difference between the SBS of both groups (p<0.001). Conclusion: This study demonstrated that ,the use of flowable composite instead of C2 cement is not recommended for cementing e-max ceramics.