In the present work, Bisphenol-A Glycidyl Methacrylate / Triethylene Glycol Dimethylacrylate based dental composites filled with 0-30 wt.% silane treated nano-ZnO were fabricated and tested for their dynamic mechanical properties. Samples were kept in each of three different mediums such as cold drink, distilled water and saliva for 7 days. The dynamic mechanical properties such as storage modulus, loss modulus and Tan delta were evaluated and compared for each composite under different conditions. The finding of results indicated that on adding 30 wt.% nano-ZnO, the storage modulus was increased by 109% in case of post cured, 120% in case of cold drink, 125% in case of artificial saliva but decreased by 70% in case of distilled water. The loss modulus was increased by 175% in case of post cured, 30% in case of cold drink, 50% in case of artificial saliva but decreased by 50% in case of distilled water. Further, minimum value of storage modulus was reported in case of distilled water medium followed by cold drink and then artificial saliva. Also, cold drink seems to be better medium than distilled water in terms of dynamic mechanical properties of dental composite. Graphical abstract Variation of storage modulus of sample kept in artificial saliva for 7 days Addition of 30 wt.% nano-ZnO increased the storage modulus by 109% in case of post cured, 120% in case of cold drink, 125% in case of artificial saliva but decreased by 70% in case of distilled water. Addition of 30 wt.% nano-ZnO increased the loss modulus by 175% in case of post cured, 30% in case of cold drink, 50% in case of artificial saliva but decreased by 50% in case of distilled water. Immersion of sample in each medium led to decrease in storage modulus but increase in Tan delta. Further, minimum value of storage modulus was reported in case of distilled water medium followed by cold drink and then artificial saliva. Cold drink seems to be better medium than distilled water in terms of dynamic mechanical properties of dental composite.

Skeletal class II malocclusion in adult patients with severe gummy smile is challenging for orthodontist and often requires surgical intervention. The difficulty increases when patients refuse orthognathic surgery, and orthodontists have limited treatment alternatives. This report describes the case of a patient with severe dento-skeletal class II malocclusion with excessive gingival display while smiling. The patient was treated with temporary anchorage devices, and an innovative method of lip repositioning was devised to correct the irregularity.

Objective: The objective of this study was to evaluate the effects of the four first premolars extraction compared with a non-extraction treated control group on the lower anterior facial height. Methods: Electronic search was conducted on PubMed, Cochrane, Scopus, Lilacs, Scielo, clinical trials, and opengrey.eu databases; only article published in English were included. The eligibility criteria were extraction of four first premolars compared with a non-extraction control group treated with fixed mechanotherapy. Anterior Nasal Spine to Menton (ANS-Me) (mm) was taken as the primary outcome; Frankfurt mandibular plane angle (FMA) and Nasion to Menton (N-Me) were selected as secondary outcomes. Non-randomized Studies-of Intervention (ROBINS-I) tool was used for the quality assessment and risk of bias. Heterogeneity was analyzed using statistical tests, including chi-squared-based Q-statistic, tau-square, and I-squared statistics. Review Manager was used for quantitative assessment and meta-analysis. Results: Five retrospective studies were included for quantitative assessment and three were included in the meta-analysis due to certain missing data. Extraction of four first premolars did not affect both primary and secondary outcomes with P = .65, P = .93, and P = .91, respectively, for ANS-Me, FMA, and N-Me. Conclusion: This review and meta-analysis concluded that there was no statistically significant effect of extraction of four first premolars on lower anterior facial height.

The Amazon EC2 offers spot-priced virtual machines (VMs) at a reduced price compared to on-demand and reserved VMs. However, Amazon EC2 can terminate these VMs anytime due to the spot price and demand fluctuation. Using spot VMs results in a longer execution time and disrupts service availability. Users can use fault-tolerant techniques such as checkpointing, migration, and job duplication to mitigate the unreliability of spot VMs. In this paper, a knowledge-based checkpointing strategy is proposed to minimize the overall checkpointing overhead during the execution of jobs. The proposed scheme uses real-time price history to decide when to take a checkpoint. Results show that the proposed approach can significantly reduce the turnaround time by 18% compared to Hourly Checkpointing Strategy and 9% compared to Rising-Edge Checkpointing Strategy. One can also achieve 54% to 78% reliability with a cost saving of 78% for the workload used with the described approach.

Introduction: The choice of orthodontic appliance depends upon the patients age, profession and availability of them. Lingual orthodontic appliances are preferred over labial by patients because of its invisibility. The aim of this research is to compare the Von Mises stress distribution and displacement of palatal implants in the lingual orthodontic system among four different combinations of palatal implant and lever arm. Materials and Method: Four Finite element models were constructed for the bilaterally extracted first premolar maxillary arch. In all these models 0.018” slot lingual brackets were placed at the center of the clinical crown. A similar retraction force (150gm) was applied with the help of NiTi closed coil spring for all the models but the length of the lever arm vary as well as the palatal implant position also varies in these models. Finite element analysis was then performed to compare the Von Mises stress distribution, and displacement of the palatal implant using ANSYS 12.1 software. Result: In this study, displacement was the same (0.0005 mm) for all four models. Highest amount von mises stress was observed in Model 3 (3.4798 MPa) as a comparison to Model 1 (2.5442 MPa), Model 2 (2.5018 MPa), and Model 4 (3.3854 MPa). The stress value for the palatal implant was within the acceptable fatigue limit of the titanium of 193 MPa therefore all four models combination was safe for the clinical application. Conclusion: Double palatal implant systems were more effective in comparison to the single palatal implant system in lingual orthodontics. In this study, we found that the displacement of the palatal implants was not affected by the length of the lever-arm and the amount of stress was decreased when we increase the length of the lever-arm.