Journal of Dental School

Bone regeneration is a complex process involving the orchestration of multiple cellular and molecular events. In recent years, significant interest has emerged in utilizing three-dimensional (3D) printed hydrogels for bone tissue engineering, owing to their potential in mimicking the natural extracellular matrix and providing a platform for cell growth and differentiation. The use of bioprinted hydrogels for bone regeneration has garnered attention due to its potential in addressing critical-sized bone defects.

Objectives Dental students experiencing stress and anxiety employ various coping strategies. Therefore, understanding these experiences is crucial for designing effective interventions. This qualitative study aimed to explore the coping strategies used by endodontic students at Shahid Beheshti University of Medical Sciences in Tehran, Iran.

Methods A qualitative content analysis was conducted on 10 purposively selected students from the Department of Endodontics at the Faculty of Dentistry in 2019. In-depth semi-structured interviews were conducted over three months. The interviews were recorded and transcribed verbatim. Data analysis was performed using the Dickelman’s method.

Results After coding the interview transcripts, four major themes related to student anxiety were identified: “endodontic department”, “education”, “clinical practice”, and “students”. According to the findings, the main sources of anxiety among students in dental education were professor-student interactions, challenging preclinical courses, the clinical learning environment, and a perceived lack of support.

Conclusion While some students demonstrated resilience, others struggled with ineffective coping strategies, potentially affecting their learning and wellbeing. The study identified various sources of anxiety among dental students, including curriculum factors, interactions with the faculty and staff, clinic facilities and equipment, radiography procedures, and preclinical training. Overall, the findings emphasize the need for a comprehensive approach to improve the educational environment.

Objectives Techniques used in root canal treatment (RCT) can cause postoperative pain. This clinical trial study aimed to compare the degree of postoperative pain following RCT using ProTaper Next rotary files and VDW reciprocating single-file systems.

Methods Initially, a pilot study involving 10 patients in each group was performed to determine the final sample size. Sixty molars with irreversible pulpitis were randomly prepared using the Reciproc or ProTaper system. Postoperative pain severity was assessed using the Visual Analog Scale (VAS), categorizing pain level as no pain, mild, moderate, or severe before and immediately after treatment, as well as at 2, 6, 12, 24, and 48 hours postoperatively. Pain scores were analyzed using the Mann-Whitney U test to compare the two groups, and the impact of various factors on predicting postoperative pain incidence was assessed using PLUM ordinal regression (P < 0.05). The non-parametric Friedman test was used to evaluate differences in means before and after treatment.

Results No significant differences were observed in pain score classifications between the Reciproc and ProTaper preparation systems before treatment, immediately after treatment, and at 2, 6, 12, 24, and 48 hours postoperatively. However, pain severity scores reported for the ProTaper system were slightly higher than those for Reciproc, with the difference becoming more noticeable 24 hours after treatment. None of the studied factors significantly predicted postoperative pain incidence.

Conclusion Within the study's limitations and despite the absence of significant differences, using the single-file Reciproc system for tooth preparation appeared to yield slightly more favorable outcomes in alleviating postoperative pain of RCTs.

Introduction: Herbal remedies can have a preventive role in malodor. This study aimed to investigate the clinical effect of green tea and peppermint on halitosis.

Materials and Methods: This study was a randomized clinical trial. Eighty-eight volunteers with an average organoleptic score of ≥2 were enrolled. The volunteers underwent two one-week phases of treatment with   green tea or peppermint mouthwashes separated by a washout period of one week. Main outcomes included the objective and subjective assessment of eventual changes in malodor. Organoleptic assessment was used as objective measure and self-perception of mouthwashes taste and smell as subjective one.

Results: The decrease in halitosis severity was significant in   green tea or peppermint mouthwashes (P<0.001). There was no significant difference between the decrease in organoleptic level (P=0.72). There was no significant difference between both mouthwashes regarding self-assessed satisfaction (P=0.78).

Conclusion: Both mouthwashes were useful in managing halitosis. Hence, considering the taste of individuals, each of them can be prescribed to halitosis treatment.

Objectives: The present study aimed at evaluating the onset and duration of the pubertal growth spurt in skeletal class I and II individuals, utilizing the cervical vertebral maturation (CVM) method.

Methods: A total of 132 Iranian individuals (class I=68, class II=64) were evaluated retrospectively in this cross-sectional study. Subjects were between 9 and 16 years old and had never undergone orthodontic treatment. Lateral cephalograms of the subjects were independently traced by two examiners to determine their skeletal class, employing Steiner and Wits analyses. Baccetti's CVM method was employed to assess skeletal maturation. The onset and duration of the pubertal growth spurt (CS3-CS4 interval) was analyzed among the two classes and genders using the Independent Samples t-Test.

Results: The duration of the pubertal growth spurt equaled 1.62 (±1.33) years in skeletal class I subjects and 1.34 (±1.21) years in skeletal class II subjects. The difference in duration between the two classes, with an average of 0.28 years (3.36 months), was statistically significant (p<0.001). The average onset age of growth spurt was estimated to be 11.91 (±1.32) years in class I subjects and 11.41 (±1.19) years in class II subjects, but this difference was insignificant (p=0.110). The onset and termination of the pubertal growth spurt occurred later by 1.49 years (p<0.001) and 1.27 years (p<0.001), respectively, in male subjects.

Conclusion: Class I and II subjects had similar growth spurt onset ages, but class II spurt duration was shorter by 3.36 months. Females experienced longer and earlier growth spurts compared to males.

Objectives This study aimed to assess the correlation between the second cervical vertebra (C2) density and the mandibular inferior cortical bone thickness at the mental foramen in women before and after menopause on cone-beam computed tomography (CBCT) scan as a predictor of the risk of osteoporosis.

Methods This retrospective cross-sectional study analyzed 176 CBCT scans from a sample of 88 post-menopausal women and 88 non-menopausal women. The thickness of the mandibular inferior cortical bone was assessed using cross-sectional CBCT images at the mental foramen, a measurement referred to as the mental index (MI), using the NNT viewer software. Additionally, the density of the C2 vertebra was measured on both coronal and axial CBCT sections. The collected data were then analyzed using various statistical tests, including the independent t-test, ANOVA, Tukey’s test, and Pearson’s correlation test, with a significance level set at α=0.05.

Results No significant difference was found in the mean density of the C2 vertebra or the mean MI between menopausal and non-menopausal women. However, a significant correlation was found between the C2 density and MI in all women (r=0.445, P<0.001) and also in non-menopausal women (r=0.704, P<0.001); this correlation was more pronounced in younger age groups.

Conclusion The present results showed that the C2 density and the mandibular inferior cortical bone thickness were not significantly different between menopausal and non-menopausal women. The C2 density had a significant correlation with the mandibular inferior cortical bone thickness in all women and also in non-menopausal women on CBCT images.

Objectives In endodontics, mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM cement) are commonly used bioceramic materials. Regenerative endodontics often involves the use of double or triple antibiotic pastes (DAP or TAP), which are effective but may cause discoloration. This study aims to examine the effectiveness of internal bleaching in addressing discoloration caused by 4 different materials.

Methods This in vitro study was conducted on 40 single-rooted anterior and premolar human teeth that did not have caries, restorations, obvious discoloration, or fractures and were extracted due to periodontal disease or orthodontic treatment. The teeth were randomly assigned to 4 groups (n=10). After root canal instrumentation, the baseline color of the specimens was measured using a spectrophotometer. After applying the aforementioned materials in the canals, access cavities were sealed with glass ionomer (GI), and the color of the specimens was measured again after 1 month to calculate color change (∆E). Internal bleaching was performed with 35% hydrogen peroxide 3 times within 3 weeks, and values were calculated at each time point. Data were analyzed using paired t-tests and 1-way analysis of variance (ANOVA).

Results Clinically noticeable discoloration (∆E>3.7) occurred in the MTA Angelus (∆E=4.88) and TAP (∆E=17.3) groups. The ∆E of the TAP group was significantly higher than that of all other groups (P<0.05). The discoloration was borderline detectable in the CEM group (∆E=3.89) and clinically undetectable in the DAP group (∆E=2.02). Discoloration significantly improved after 3 rounds of bleaching in the TAP group (P<0.05), as well as after 2 rounds of bleaching in the MTA (P<0.05) and CEM (P<0.05) groups. In all groups, ∆E increased after each round of bleaching.

Conclusion The CEM cement may yield better results with lower discoloration compared to MTA and exhibit a more favorable response to internal bleaching. For canal disinfection using antibiotic paste, DAP is a good alternative to TAP.

Objectives On December 11, 2019, the World Health Organization declared the outbreak of the new coronavirus (COVID-19). The rapid transmission of the COVID-19 virus through aerosols in the air and on contaminated surfaces highlights the increased importance of personal hygiene. By April 7, 2023, approximately 684 million people worldwide had contracted the virus, with over 6 million lives lost. This survey summarizes dentists' knowledge, attitude, and performance during the COVID-19 pandemic.

Methods A keyword search was conducted in April 2023 on Google Scholar and PubMed databases. The search results for MeSH words such as awareness, attitude, performance, dentist, COVID-19, and self-care yielded 24 articles published from 2019 to 2023. Nine articles were excluded from the study for not addressing one of the 3 knowledge, attitude, and performance (KAP) factors.

Results This study analyzed a total of 15 articles. The results were organized in three categories: knowledge, attitude and performance. Generally, dentists in these studies had a good knowledge about COVID-19 but based on most studies continuous education in this field is necessary. Regarding attitude and performance, studies showed that most of dentists prefer to perform only emergency procedures using personal protective equipment.

Conclusion Dentists included in these studies generally demonstrated an acceptable level of knowledge, attitude and performance about COVID-19.