This study was conducted to evaluate the effect of three nanoparticle solutions used as final root canal irrigants on the fracture resistance of endodontically treated roots. Materials and Methods: Sixty intact single-rooted premolar teeth were used after removing the crowns below the cementum-enamel junction to standardize the length of the remaining roots to 13 mm. After instrumenting the roots using ProTaper Universal rotary instruments up to size F4, the roots were randomly divided into six groups (n=10) according to the final irrigating solutions: Group 1: normal saline; Group 2: 2% chlorhexidine (CHX); Group 3: 17% EDTA+2.5% NaOCl; Group 4: 17% EDTA+0.1% silver nanoparticle (SNP) solution; Group 5: 17% EDTA+0.1% titanium dioxide nanoparticle (TNP) solution; Group 6: 17% EDTA+0.1% zinc oxide nanoparticle (ZNP) solution. After filling the root canals with gutta-percha and AH Plus sealer, the fracture resistance (FR) values were measured. The data were subjected to the one-way analysis of variance and the Tamhane post hoc test (p=0.05). Results: EDTA + NaOCl had the lowest FR value, followed by normal saline and CHX (p values < 0.05). No significant difference was found between the FR of roots irrigated with CHX and normal saline (p > 0.05). The application of nanoparticles (SNP, TNP, and ZNP) was associated with a significantly greater FR than that of other irrigation solutions (p values < 0.05). Conclusion: The final irrigation of root canals with nanoparticles enhanced the fracture resistance of the endodontically treated roots. The lowest FR value was observed for NaOCl.

Background. Quality of sleep and stress level can affect the health, capacity of learning, and academic performance of the students. This study aimed to investigate the association between stress and sleep quality with academic performance among undergraduate clinical dental students in Shiraz, Iran. Methods. This cross-sectional study was conducted during the second semester of the academic year 2020–2021 among clinical dental students at Shiraz Dental School, Iran. A total of 138 students completed Pittsburgh Sleep Quality Index (PSQI) and dental environment stress (DES) questionnaire. The grade point averages (GPAs) of the previous terms of the participants were also collected. Data analysis was performed using Kolmogorov–Smirnov test, the one-way ANOVA, post hoc Duncan’s test, nonparametric Kruskal–Wallis H test, Wilcoxon–Mann–Whitney test, and the chi-squared test. The p values of less than 0.05 were considered statistically significant. Results. Clinical dental students participated in this study experienced moderate levels of stress and poor sleep quality. Mean total DES and PSGI scores did not differ by sex, year of study, marital status, and place of residence ( p values >0.05). Most of the students (52.9%) had moderate GPAs. A significant relationship was observed between sex and GPA as well as between place of residence and GPA ( p values <0.05). No significant differences were found between DES total score or PSQI score and GPA categories ( p values >0.05). A significant direct relationship between DES total score and PSQI score was observed ( p < 0.05 ). Conclusion. Dental undergraduates in Shiraz, Iran, experienced moderate levels of stress and poor sleep quality. The results showed no significant difference between sleep quality or DES and academic achievement. However, a significant direct correlation was observed between sleep quality and dental environment stress.

ÖZAmaç: Bu çalışma, sıçanlarda oluşturulan deneysel yara modelinde Pistacia atlantica yağı ile hazırlanmış jel formülasyonunun, enzimatik antioksidanlar üzerindeki etkisini araştırmak amacıyla yapılmıştır. Gereç ve Yöntemler: Genel anestezi altına alınan hayvanlarda, aseptik koşullarda, insizyon yapmak suretiyle kare şeklinde yaralar (2x2 cm) oluşturulmuştur. Daha sonra, hayvanlar rasgele dört gruba ayrılmıştır (I-tedavi edilmemiş kontrol grubu, II-haricen uygulanan baz jel grubu, IIIharicen %5 jel uygulanan grup, IV-haricen %10 jel uygulanan grup). Bulgular: Sonuçlar, Pistacia atlantica yağı ile hazırlanmış jel formülasyonunun haricen uygulanmasının, kontrol ve baz jel gruplarına kıyasla, bütünlüğü bozulmamış stratum bazalisi, olgun granülasyon dokusunu, kıl folikülleri ve ter bezleri ile reepitelizasyonu arttırdığını göstermektedir. Yara oluşumundan 21 gün sonra, %10 yağlı jel ile tedavi edilen hayvanların dokularındaki gerilme kuvveti, kopma gerilimi ve bükülme direnci, kontrol ve baz jel grubu ile karşılaştırıldığında önemli ölçüde artmıştır. Aynı evredeki kontrol ve baz jel ile muamele edilen gruplara kıyasla, kollajen liflerin daha organize bir düzenlenme ve dokunun daha düzgün bir iyileşme gösterdiği belirlenmiştir. Sonuç: Pistacia atlantica yağ jelinin haricen uygulanmasının, sıçanlarda oluşturulan deneysel yaralar üzerinde morfolojik, biyokimyasal ve biyomekanik yönden düzeltici rol oynadığı ortaya koyulmuştur. Anahtar kelimeler: Pistacia atlantica, yara iyileşmesi, histopatoloji, biomekanik, deri Objectives: This study has been undertaken to investigate the antioxidant activity of the gel formulation from Pistacia atlantica oil extraction on enzymatic antioxidants in experimental wound created in rats. Materials and Methods: Under anesthesia, a square-shaped skin defect (2x2 cm) was created aseptically by surgical incision. Then, animals were randomly allocated to four groups (I-untreated controls, II-topically treated with base gel, III-topically treated with 5% gel, IV-topically treated with 10% gel). Results:The results suggest that topical application of Pistacia atlantica oil gels improved reepithelialization with continuous stratum basalis and a mature granulation tissue and adnexa (hair follicles and sweat gland) compared with control and base gel groups. Treatment with 10% oil gel significantly enhanced the tensile strength, ultimate stress, yield strength and stiffness in this group compared with the control and base gel groups at 21 days post injury. The collagen fibers showed a more organized pattern and the tissue alignment was greater as compared to the control and base gel-treated groups at the same stage. Conclusion:The results suggest that topical application of Pistacia atlantica oil gel improved the morphological, biochemical and biomechanical properties of experimentally-induced wound defects in rats.

Background: Pediatricians have an important role to play in motivating and instructing parents on oral health in children. The aim of this study was to assess knowledge of, attitude to, and behavior regarding oral health care in children among pediatricians and students in the pediatric field in Iran. Methods: This cross-sectional study included all students in the pediatric field (those who had started a residency or fellowship) and practicing pediatricians in provincial centers and universities (61 setting centers), throughout Iran in the course of 2021. Participants completed an online questionnaire assessing details of the parameters of attitude to, knowledge of, and behavior toward oral health for each individual. Convenience sampling technique was used to gather the study sample. All data were coded for each of the parameters. The data were analyzed by one-way ANOVA/Tukey and Pearson’s correlation tests and path analysis. Results: Out of 582 participants visited the website, a total of 217 completed the entire questionnaire (participation rate of 37.2%). On the attitude parameter, 84.8% of participants scored above 75% of the possible attainable score, while only 37.9% and 48.1% of them had adequate knowledge and behavior for the possible score, respectively. Specialists had a higher mean score on behavior and knowledge than residents (P=0.001). There was a significant correlation between the scores on attitude and behavior (r=0.42, P˂0.001), attitude and knowledge (r=0.19, P=0.005), and behavior and knowledge (r=0.25, P˂0.001). Nearly all of the participants, 216 (99.5%), felt the need for the principles of dentistry to be included in curriculum. Conclusions: Pediatricians showed a favorable attitude to oral health, but their knowledge of and behavior in the field was inadequate. Improvement of pediatricians’ interest and performance in oral health in children should be encouraged through the inclusion of these parameters in the curriculum for student of the pediatric field. Implementing training programs for practical pediatricians or incorporating independent theoretical and clinical courses offered by pediatric dentists in dental school departments into the field curriculum of the students in the pediatric field is recommended.