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.

8-18

Authors: Lily A. Hartsock, Alexandre R. Vieira*

Introduction: The goal of this study was to test the impact of both diabetes type and control via the hemoglobin A1C biomarker on oral health outcomes. Materials & Methods: In this observational study, data were extracted from the University of Pittsburgh Dental Registry and DNA Repository and analyzed. From 6,026 subjects, 414 ones with a diagnosis of diabetes were matched by sex, age and ethnicity with 414 individuals without diabetes. A number of statistical approaches (chi-square, Fisher’s exact, Student’s t, Wilcox, and Mann Whitney tests) were used and all comparisons were set with an alpha of 0.05. Results: Patients with type 1 diabetes experienced xerostomia more often compared to non-diabetic matched pairs (p=0.02). Patients with diabetes (n=414) experienced temporomandibular joint (TMJ) discomfort more often than their non-diabetic matched pairs, as did type 1 diabetic patients alone, in comparison to both their matched pairs and type 2 diabetic patients (p=0.01, p=0.004, and p=0.02, respectively). Among patients grouped by diabetic control, all patients reporting control (n=39) experienced xerostomia more often than their non-diabetic matched pairs (p=0.05). Patients in poor diabetic control experienced restoration failure more often than patients in good control (p=0.04). The experience of restoration failure was no different between patients in good diabetic control and their matched controls (p=0.26). The number of restoration failures was higher in patients in poor control, as compared to their matched non-diabetic controls (p=0.03). Conclusion: Patients with diabetes experienced xerostomia but not necessarily more severe caries experience, and may be protected from TMJ discomfort. Patients in good control of their diabetes were at no greater risk for restoration failure as compared to non-diabetic patients; however, the patients in poor control were at higher risk for failed restorations.

27-34

Authors: Zahra Lari, Fariba Ezoji, Hemmat Gholinia, Effat Khodadadi*

Introduction: The resin-modified glass ionomer (RMGI) materials are hybrid materials including conventional glass ionomer and small addition resin. They have the advantages of both, such as adhesion to tooth structure, esthetics and fluoride release. The purpose of this study was to compare the fluoride release and wear resistance of two types of RMGI. Materials & Methods: In this in vitro study, specimens for measuring the fluoride release were made with brass mold from two types of RMGI EQUIA Forte glass ionomer and Fuji II conventional glass ionomer. After incubating the specimens in a plastic vial containing 7 ml of distilled water, the release of fluoride for each specimen was measured on days 1, 7 and 15 using a PH/Ion meter device. For evaluating the wear resistance, 8 specimens were prepared using a brass mold in each group. Then, each specimen was exposed to 5000, 10000, 20000, 40000, 80000 and 120000 cycles in wear simulator. The specimens’ weight was measured by an electronic weight balance before and after each wear cycle. The data were analyzed by SPSS-17 through repeated-measurement ANOVA and independent T-test. Results: Fluoride released from Fuji II glass ionomer was significantly higher in the first 24 hours and on day 7. During the day 15, the differences in fluoride release between the two glass ionomer groups were not statistically significant. (p<0.001). The EQUIA Forte glass ionomer exhibited significantly greater wear resistance in different wear cycles. (p<0.001) Conclusion: Due to its good wear resistance, acceptable fluoride release, ease of clinical use and infection control, the capsular glass ionomer can be a useful material in people at high risk of caries, temporary restoration techniques, pediatric dentistry and root caries.

42-47

Authors: Motahareh Zarei, Mehdi Rajabnia, Ali Akbar Moghadamnia, Soraya Khafri, Effat Khodadadi*

Introduction: Due to the limitations of chemical antimicrobial methods in the treatment of dental caries, the recent studies have focused on the use of plant-derived antibacterial agents to inhibit tooth decay bacteria. Therefore, the aim of this study was to investigate the effect of Vitis vinifera seed extract (VVSE) on Lactobacillus acidophilus and casei bacteria. Material & Methods: In this cross-sectional study, the VVSs were dried, the obtained powder was poured into separate containers to prepare aqueous, alcoholic and acetone extracts, and the desired solvents were added. After being placed in the shaker incubator and passing through the filter paper, the solvents were transferred to the plates. After cultivation of Lactobacillus acidophilus and casei bacteria in tubes containing Mueller Hinton Broth, the aqueous, alcoholic and acetone extracts were added to them. A tube with no extract was considered as control. The resulting samples were cultured on chocolate agar medium. The initial concentrations (2, 4 and 8 μg/ml) were not able to inhibit bacterial growth; thus, the higher concentrations were assessed to determine minimum inhibitory concentration (MIC). The data were analyzed using SPSS-17 via Chi-square, Mann-Witney and Kruskal-Wallis. Moreover, α=0.05 was considered significant. Results: The MIC of aqueous extract was 32 and 64 μg/ml for Lactobacillus acidophilus and casei, respectively. The alcoholic extract stopped the growth of both bacteria at concentration of 128 μg/ml. The MIC of acetone extract was 64 and 128 μg/ml for Lactobacillus acidophilus and casei, respectively. So, aqueous extract was more effective than alcoholic one (p=0.016). However, there was no significant difference between alcoholic and acetone (p=0.1267) as well as aqueous and acetone (p=0.061) extracts. Conclusion: Antibacterial activity of aqueous extract was more than that of alcoholic and acetone extracts. Alcoholic and acetone extracts had no significant difference in inhibition of bacterial growth. Therefore, it is possible to use aqueous extract of VVSs to control caries.

57-63

Authors: Masoumeh Mohsen pourian, Azin Alasvand Javadi, Mohammad Yazdizadeh*

Introduction: Effective endodontic treatment requires identification of all root canals. The inability of dentists to locate all root canals can lead to failure in endodontic treatment. Consequently, an accurate diagnostic device is essential to detect all root canals. The aim of this study was to examine the accuracy of cone-beam computed tomography (CBCT) as a diagnostic tool to detect the root canals of maxillary first premolars in a selected Iranian population. Material & Methods: In this in vitro study, 48 human extracted maxillary first premolar teeth were scanned by CBCT, and then all teeth were sectioned. In the current study, sectional method was chosen as the gold standard. The CBCT scans were observed by an oral and maxillofacial radiologist, and the sections were evaluated by an endodontist using stereomicroscope. Finally, the collected data were entered into SPSS- 22 and analyzed by Kappa coefficient and Chi-square test. Significance level was set at 0.05. Results: The agreement between CBCT and sectional methods for root canal detection was 97.2% which was significant (95.8% in the first section, 97.9% in the second and third sections), (p <0.001). Conclusion: It seems that CBCT is a safe and non-invasive tool that can be used to detect root canals if other low-dose radiation imaging techniques do not provide acceptable results.