The effect of periodontal therapy on IL-17 and IL-23 in Gingival Crevicular Fluid (GCF) of patients with severe periodontitis

Introduction: Cytokines are the important factors in the progression of periodontal diseases. The aim of this study was to find out the effect of the first phase of the periodontal therapy on the amount of existing IL-17 and IL-23 in gingival crevicular fluid in patients with severe periodontitis and in the control group. Methods: In this clinical trial intervention study,after purifying the parts which were under consideration in 22 patients with severe periodontitis, gingival crevicular fluid was gathered using periopaper located within the gingival sulcus, Then, the first phase of periodontal therapy was carried out and sample taking from the same parts was conducted after 4 weeks. The same phase was carried out on 24 healthy patients (control group). All patients were selected from the Department of Periodontology, Tehran Islamic Azad University Dental Branch. Since the data did not have a normal distribution, therefore, nonparametric tests were used for comparing the groups (Mann-Whitney U Test). A p≤0.05 is considered as significant. Results: The results showed that there was a meaningful and significant difference between the IL-17 viscosity before (p<0005) and after (p<005) the therapy and IL-23 viscosity before (p<0001) and after (p<001) the therapy between the two groups. Conclusions: According to the results of the present study, we can conclude that IL-17 and IL-23 have a significant role in the pathogeneses of periodontal disease

The effect of office bleaching on the color and bond strength of resin restorations

Background: Bleaching may affect the bond strength of existing composite fillings and may weaken it. Hence, the aim of this study was to find the best method of in-office bleaching with the least effect on microshear bond strength (MSBS) of existing composite resin fillings to tooth structure. Materials and Methods: In this in vitro study, Class V cavities were prepared on buccal surface of 50 extracted third human sound molars. The cavities in 25 teeth had enamel axial walls, Group E, which were divided into five subgroups of E1 through E5 and in 25 teeth had dentin axial walls, Group D, which were divided into five subgroups of D1 through D5. Cavities were treated with Single Bond 2 adhesive system and restored with composite resin (Z250). The corresponding subgroups received similar bleaching methods and materials; 1 – not bleached, 2 – hydrogen peroxide (HP) 25%, 3 – HP + ultraviolet light, 4 – HP + light-emitting diode-curing device, and 5 – HP + diode laser. Teeth colors were monitored before and after bleaching, and MSBS test and failure modes were examined. Results were analyzed with one-way ANOVA and Kruskal–Wallis tests. P < 0.05 was considered significant. Results: One-way ANOVA did not show differences in MSBS of enamel subgroups but showed significant differences in dentin subgroups (P < 0.00). Adhesive fracture in all of the subgroups was the most frequent mode of failure. Kruskal–Wallis test showed that laser was the most effective instrument to change ΔE. Conclusion: Diode laser was the best method for tooth bleaching because lowering the shear bond strength between composite resin and enamel was minimum and also had the most ΔE in tooth bleaching

Evaluate different nanoparticles into dental restorative materials: A systematic review and meta-analysis

Background and aim: The purpose of this study was to evaluate different nanoparticles in dental restorative materials. Method: Databases of PubMed, Scopus, Web of Science, EBSCO, ISI Web of Knowledge, and Embase were searched for systematic literature between 2012 to July 2022.&nbsp; Data analysis was performed using STATA/MP V17 software. 95% confidence interval for mean differences or Hedges' g (a measure of effect size) with fixed effect model and Inverse-variance method were calculated. Result: In the initial review, duplicate studies were eliminated and abstracts of 151 studies were reviewed, the full text of 42 studies was reviewed by two authors, and finally, 11 studies were selected. Hedges' g of changes to the bacterial activity of dental restorative materials for silver nanoparticles was –1.90 (Hedges' g -1.90 95% CI -2.52, -1.28), for calcium phosphate nanoparticles, was –0.64 (Hedges' g -0.64 95% CI -2.03, 0.94), for CaP/Ag nanoparticles was –0.44 (Hedges' g -0.44 95% CI –1.83, 0.94) and Hedges' g of changes to the bacterial activity of dental restorative materials for Titanium dioxide nanoparticles was –2.41 (Hedges' g -2.41 95% CI –3.11, -1.72).&nbsp

The Incidence of Lung Cancer and Smoking in Iran, Turkey, England, and the USA: A Comparative Study

Objectives: Lung cancer is the deadliest and the costliest cancer in the world. In this study, we compared the situation of this disease in several countries by considering the most important risk factor of lung cancer (smoking). Methods: This is a comparative study, a comprehensive one which was done on lung cancer rates in four countries: Iran, Turkey, England, and the USA, during the past twenty years (2002-2021). Age-standardized rate (ASR) index and the percentage of smokers were extracted from available information in the World Health Organization (WHO) databases, The Organization for Economic Co-operation and Development (OECD) Health Statistics 2021, and other valid related articles. After comparison, control procedures were examined. Results: England, with an ASR of 46, has the highest rate of lung cancer, and Iran, with an ASR of 21, has the lowest rate. Turkey has the highest percentage of smokers (29.3%), and the lowest percentage belongs to Iran (20%). Regarding the increasing trend of the ASR index, lung cancer in Iran and Turkey has had an upward trend, and England and the United States have a downward trend. Taxes on cigarettes are a significant factor in smoking reduction. Among these 4 countries, the lowest cigarette tax belongs to Iran (4.83%). Discussion: The result of this study shows that the incidence of lung cancer in Iran is rising, so following successful countries in imposing cigarette taxes can be an effective step to reduce smoking. Training programs, cultural improvement, and new diagnostic methods can also be useful in reducing lung cancer ASR