Background:Although studies focused mainly on the identification of periopathogenic bacteria, recent reports have suggested that various herpes viruses may also be involved in the occurrence and progression of different forms of periodontal diseases.Objectives:This study aimed to compare the prevalence and load of Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV) in subgingival tissue specimens between chronic periodontitis and healthy sites.Patients and Methods:A total of 60 samples from the systematically healthy patients with chronic periodontitis participated in this study (mean age, 35 ± 7). Clinical periodontal evaluation included the plaque index (PI) (Loe and Silness), bleeding on probing (BOP) (O’Leary), bleeding index, periodontal pocket depth (PPD) and clinical attachment level measurement. Tissue specimens harvested from > 6 mm periodontal pockets and from ≤ 3 mm sulcus depth in a quadrant of the same patient using periodontal curettes. Moreover, the unstimulated whole saliva was gathered as a shedding medium. A Taq-man Real-Time Polymerase Chain Reaction assay was used to identify genomic copies of periodontal HCMV and EBV. Data were analyzed by the Wilcoxon-signed ranks and Friedman tests using the SPSS 16 software.Results:Out of 60 samples of subgingival tissues taken from the patients with chronic periodontitis, EBV count was the highest in saliva and the least in the tissue sample with PD < 3 mm (P < 0.05). The highest HCMV count was in saliva and tissue samples with PD > 6 mm (P < 0.05).Conclusions:According to the results of this study, quantification of HCMV and EBV observed in this study is high in periodontal tissue samples of severe chronic periodontitis.

Aim:The aim of the present study was to evaluate these two high intensity light curing units regarding microleakage beneath metal and ceramic brackets. Materials and methods:A total of 60 freshly extracted human premolar teeth were randomly divided into four groups of 15 samples; group I: Metal bracket + LED cured, group II: Ceramic bracket + LED cured, group III: Metal bracket + plasma arc cured, group IV: Ceramic bracket + plasma arc cured.After photopolymerization, the teeth were immersed in water and thermocycled (500 cycles between 5 and 55). Specimens were further sealed with nail varnish and stained with 5% basic fuchsin for 24 hours. All of the teeth were sectioned with two parallel longitudinal occlusogingival cuts and examined under a stereomicroscope. The microleakage was measured with a digital caliper and scored from 0 to 3 for marginal microleakage at the bracket-adhesive and adhesive-enamel interfaces from both the occlusal and gingival margins. Results:Microleakage was detected in all groups. The plasma arc cured group showed less microleakage than light emitting diode (LED) cured in all samples at the enamel-adhesive interface at the gingival margin (ceramic brackets, p = 0.009 and metal brackets, p = 0.005). The plasma arc cured samples showed less microleakage than LED cured in metal brackets at the adhesive-brackets interface at the occlusal margin (p = 0.033). While curing with an LED unit, ceramic brackets displayed significantly less microleakage than metal ones at the gingival margin of adhesive-enamel interface (p = 0.013).The gingival margin in all groups exhibited higher microleakage compared with those observed in occlusal sides in all sample groups (p < 0.001). Conclusion1. LED units cause more microleakage than plasma arc units. 2. In all groups the microleakage at the gingival margin is greater than the occlusal margin.Clinical significance: The microleakage formation permits the passage of bacteria and oral fluids initiating white spot lesions beneath the bracket base.

Morphology of glenoid fossa might help the clinician in the diagnosis, establishing more biological treatment modalities and treatment response between patients with different skeletal malocclusions. This study aimed to assess the glenoid fossa morphology in different sagittal facial types using CBCT. The CBCT images of 64 patients with normal vertical growth patterns were classified into class I, class II, and class III based on the skeletal sagittal analysis. Depth, width, and angle of glenoid fossa were measured and assessed on CBCT images. One-way analysis of variance (ANOVA) and Tukey post-hoc test were used to compare mean values among the groups. There was a significant statistical difference in means of glenoid fossa’ width between groups with skeletal class III and skeletal class I (P value: 0.038). However, no significant statistical differences were found in angle(P value = 0.18) and depth (P value = 0.40) of glenoid fossa among 3 groups. This study showed the glenoid fossa in class I patients was wider than class III patients. There were no statistically significant differences in the angle and depth of glenoid fossa in patients with a different sagittal skeletal pattern.

The aim of this study was to evaluate the mechanical properties of stainless steel (SS) orthodontic wires coated with zinc (Zn), using a Physical Vapored Deposition (PVD) machine. A total of 100 straight SS orthodontic wires were cut into pieces of 5 centimeters in length and were divided into two groups. Half of the wires were coated with Zn using a PVD machine, and the others remained uncoated. Tensile strength (n = 15), three-point bending (n = 15), and frictional resistance at 0° (n = 10) and 10° (n = 10) were measured to compare the mechanical properties of the Zn-coated and uncoated orthodontic wires using the universal testing machine. The surface of the coated wires was observed by SEM and AFM. An independent t-test, multivariate ANOVA, and measurement ANOVA were used for data analysis. SEM and AFM showed a homogenous Zn layer of 0.28 ± 0.006 µm on the SS wires. The tensile strength and three-point bending strength significantly increased after Zn coating of wires with the PVD method ( P < 0.05 ). The friction resistance significantly reduced at both angulations following the coating procedure. The angle between the wire and bracket had no significant effect on the frictional resistance ( P > 0.05 ). Coating with Zn improved the tensile and load-bending strength of SS orthodontic wires and reduced their frictional resistance which might be advantageous in terms of reducing the risk of root resorption during the orthodontic treatment.

Objective Team based learning (TBL) is shown to have a positive impact on learning abilities. In this study, we compared the individual and group readiness assurance grades of dental students toward a modified TBL protocol for an orthodontic topic. Methods All of the dentistry students in 2 different annual intakes from Shiraz University of Medical Sciences took part in the study. The references and methods for holding the class was presented to the vice dean of educational affairs and to the students. At the beginning of the session, individual readiness assurance test (iRAT) was held. Then, the students were asked to arrange in 15‐member groups for a modified TBL exercise. Each group took part in the team readiness assessment test (tRAT) and draw concept maps of 5 major topics. Then, they presented their team work, discussed them, and concluded. At the end of the session, the students reported their attitude on the pre‐constructed assay form. The data were analyzed with SPSS software 17, using paired T test and Wilcoxon signed rank test. Results We observed statistically significant improvement in the tRAT score compared with iRAT in the male and female participants (P‐value <0.001). More than 60% of the participants felt that TBL enhanced the overall satisfaction and pleasure from participation in class. Conclusions Based on our study, team work depicted significant improvement in the students' scores of an orthodontic topic. According to students, satisfaction with TBL was favorable and improved with additional experience.