Objectives. This study aimed to compare the fracture resistance (FR) of severely damaged primary anterior teeth restored with five different post and core systems. Materials and Methods. This in vitro, experimental study evaluated 60 extracted primary maxillary central incisors. The teeth were horizontally sectioned at 1 mm above their cementoenamel junction (CEJ), underwent pulpectomy, and their root canals were filled with Metapex paste. After post space preparation and sealing of root fillings with light-cure glass ionomer (1 mm thickness), the teeth were randomly assigned to five groups (n = 12) of (1) glass fiber post and everX composite (reinforced with short fibers), (2) glass fiber post and bulk-fill composite, (3) everX composite post and core, (4) bulk-fill composite post and core, and (5) Filtek conventional composite post and core. The teeth underwent 5,000 thermal cycles between 5°C and 55°C, and their FR was measured in a universal testing machine (0.5 mm/min, 148°). The mode of failure was also determined. Data were analyzed by ANOVA and Tukey’s test at 0.05 level of significance. Results. The FR was the highest in fiber post and everX composite, and the lowest in Z250 conventional composite post and core group ( P < 0.001 ). The FR of fiber post and everX composite group was significantly higher than that of everX composite post and core ( P = 0.04 ), bulk-fill composite post and core ( P = 0.001 ), and Z250 composite post and core ( P < 0.001 ) groups. The frequency of repairable fractures was the highest in glass fiber post plus everX composite (91.66%) and the lowest in Filtek conventional post and core group (66.66%) ( P > 0.05 ). Conclusion. Within the limitations of this in vitro study, the results showed that restoration of severely damaged primary maxillary central incisors with glass fiber post and everX composite reinforced with short fibers enhanced their FR, and increased the chance of reparability in case of restoration fracture. This technique may be recommended for the restoration of primary anterior teeth since it is simple and saves time.

Background: Conventional oral health education is not suitable for visually impaired children. Objectives: Considering the importance of oral health, this study aimed to investigate the effectiveness of different educational methods on oral hygiene status. Methods: Following a clinical trial design, 88 visually impaired children, aged 7 to 13 years, living in Tehran were recruited and randomly allocated to four groups of verbal-tactile, verbal-braille, multisensory, and control. Initially, all children were well informed about the importance of oral hygiene; then, the baseline levels of plaque score and gingivitis were recorded by Silness & Loe plaque index and Loe & Silness gingival index, respectively. Experimental groups received oral health education through different methods. The instructions were repeated after one month, and plaque and gingival indices were reevaluated after two months. Data analysis was administered by analysis of variance (ANOVA) and posthoc tests using SPSS 20.0. Results: After receiving the intervention, all groups showed a decrease in plaque and gingival indices, with the most reduction in the multisensory group (with a statistically significant difference (P = 0.0001) between multisensory & control for both plaque & gingival indices). The least change was observed in the verbal-braille group compared to the control (for plaque index and gingival index after two months (P = 0.04) and (P = 0.17), respectively). Conclusions: This study demonstrated that the multisensory method (verbal-tactile-braille) is the best option to educate visually impaired children, with significantly more acceptable results.

Comparison of the antibacterial effect of nanosilver and chlorhexidine mouthwash on Streptococcus mutans (invitro)

In the presence of contamination with saliva, use of bonding under the fissure sealant can reduce microleakage.

Background:Prevention from caries is a principle in dentistry and fissure sealant therapy is being used as a preventive method success of sealants is directly depending on their retention.Aim:The Aim of the present study is to evaluate effects of enamel preparation on sealant retention.Settings and Design:Clinical trial.Materials and Methods:About 57 children aged 6-8 year old took part in this study. 200 first molar teeth of these children has been randomly separated into two groups: A case group (Mechanically preparation of enamel) and a control group (conventional method, without preparation). After applying fissure sealants children were followed up 6 months later.Statistical Analysis Used:Mann- U- Whitney Test was used.Results:Complete retention after 6 month follow up was 86.7% in case group and 82.8% in control group. No significant difference was seen between the groups after 6 month follow up. (P = 0.508).Conclusion:Although statistical evaluation didn't show significant difference, but sealant retention was more after preparation technique.

Reinforced concrete shear walls are the main elements of resistance against lateral loads in reinforced concrete structures. These walls should not only provide sufficient resistance but also provide sufficient ductility in order to avoid brittle fracture, particularly under strong seismic loads. However, many reinforced concrete shear walls need to be stabilized and reinforced due to various reasons such as changes in requirements of seismic regulations, weaknesses in design and execution, passage of time, damaging environmental factors, patch of rebar in plastic hinges and in some cases failures and weaknesses caused by previous earthquakes or explosion loads. Recently, Fiber Reinforced Polymer (FRP) components have been extensively and successfully used in seismic improvement. This study reinforces FRP reinforced concrete shear walls and steel strips. CFRP and steel strips are evaluated by different yield and ultimate strength. Numerical and experimental studies are done on walls with scale 1/2. These walls are exposed to cyclic loading. Hysteresis curves of force, drift and strain of FRP strips are reviewed in order to compare results of numerical work and laboratory results. Both numerical and laboratory results show that CFRP and steel strips increase resistance, capacity and ductility of the structure.

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Our findings suggest that the Callander blade decreases the risk for dental injury and provides tracheal intubating conditions in children with normal airways similar to those obtained with a traditional Macintosh blade.