Molecular Microbiological Evaluation of Passive Ultrasonic Activation as a Supplementary Disinfecting Step: A Clinical Study

IntroductionThis in vivo study used molecular microbiology methods to evaluate the effects of passive ultrasonic irrigation (PUI) as a supplementary disinfecting step after root canal preparation.MethodsSamples were taken from 10 necrotic root canals of teeth with apical periodontitis before (S1) and after rotary nickel-titanium instrumentation using 2.5% NaOCl as the irrigant (S2) and then after PUI for NaOCl activation (S3). The parameters examined included the incidence of positive broad-range polymerase chain reaction (PCR) results for bacterial presence, the impact on bacterial diversity evaluated by PCR-denaturing gradient gel electrophoresis (DGGE), the quantitative bacterial reduction determined by real-time PCR, and the identification of persistent species by clone library analysis.ResultsAll S1 samples were positive for bacteria in all tests. Treatment procedures were significantly effective in reducing the incidence of positive results for bacteria, the number of bacterial cells (infectious bioburden), and the bacterial diversity (number of species and abundance). However, the supplementary PUI approach did not succeed in significantly enhancing disinfection beyond that achieved by chemomechanical preparation. Several bacterial species/phylotypes were identified in post-treatment samples that were positive for bacteria.ConclusionsFindings from this clinical study including a small sample size suggest that PUI can be ineffective in significantly improving disinfection of the main root canal after chemomechanical procedures.     

Inhibition of mineral loss at the enamel/sealant interface of fissures sealed with fluoride- and non-fluoride containing dental materials in vitro

Objective. In this in vitro study we evaluated the enamel mineral loss effect of fluoride-containing and non-fluoride-containing materials at different distances from the sealant margin, and verified the fluoride-releasing capability of these materials. Material and methods. Extracted molars were randomly assigned into nine groups (n=12): Concise (C), FluroShield (F), Helioseal Clear Chroma (H), Vitremer (V), Fuji II-LC (FII), Ketac Molar (KM), Fuji IX (FIX), Single Bond (SB), and Clearfil Protect Bond (CF). All groups were subjected to thermo and pH cycling. Enamel mineral loss was evaluated by cross-section micro-hardness analysis at distances: ?100?µm, 0?µm, 100?µm, 200?µm. The mineral loss data were analyzed using a multi-factor ANOVA with split-plot design, and fluoride-released data were submitted to ANOVA and Tukey tests. Results. FIX demonstrated a lower mineral loss than C, F, and H, but did not differ from the SB, CF, V, FII, and KM groups, which also demonstrated no difference among them. C, F, H, and V presented the highest mineral loss, with no difference among them. V did not differ from the other groups (p>0.05). Regarding the different distances from the sealant margin, ?100?µm presented the lowest mineral loss. FIX showed the highest fluoride release on the 7th and 14th days of evaluation, while CF showed high fluoride release only on the 7th day. Conclusion. Resin sealant did not prevent enamel mineral loss, contrary to glass-ionomer cement, which showed the highest capacity for fluoride release. It is not exclusively the presence of fluoride in a material's composition that indicates its capability to interfere with the development of enamel caries-like lesions.     

The role of pro/anti-inflammatory adipokines on bone metabolism in NAFLD obese adolescents: effects of long-term interdisciplinary therapy

To investigate the role of pro- and anti-inflammatory adipokines in the bone metabolism of non-alcoholic fatty liver disease (NAFLD) obese adolescents as well as the effects of long-term interdisciplinary therapy on metabolic-related risk factors. Forty post-puberty obese adolescents were randomly assigned into two groups: (1) NAFLD group and (2) non-NAFLD group (diagnosis by ultrasonography) and submitted to a weight loss therapy. Body composition was analyzed by air displacement plethysmography, bone mineral density (BMD) and content by dual-energy X-ray absorptiometry, blood samples were collected to measure lipid profile, hepatic enzymes, and adipokines. Leptin and adiponectin concentrations were measured by ELISA. A decrease in total body mass, BMI, body fat, visceral and subcutaneous fat, insulin concentration, HOMA-IR, total cholesterol and an increase in lean body mass were observed in both groups after therapy. It was found positive correlation between the Δ BMD and the Δ fat mass (%) (r = 0.31, P = 0.01) and negative correlations between Δ BMC with Δ HOMA-IR (r = -0.34, P = 0.02) and Δ HOMA-IR with Δ leptin (r = -0.34, P = 0.02). In addition, increased levels of adiponectin and reduction in leptin concentrations were observed in NAFLD group. In the simple regression analysis, the HOMA-IR was an independent predictor changes in BMC in total obese adolescents and in the non-NAFLD group. One year of interdisciplinary weight loss therapy for obese adolescents with or without NAFLD, could regulate bone mineral metabolism as result of an increased BMC and improved inflammatory state.     

Stability of di-butyl-dichalcogenide-capped gold nanoparticles: experimental data and theoretical insights

Metals capped with organochalcogenides have attracted considerable interest due to their practical applications, which include catalysis, sensing, and biosensing, due to their optical, magnetic, electrochemical, adhesive, lubrication, and antibacterial properties. There are numerous reports of metals capped with organothiol molecules; however, there are few studies on metals capped with organoselenium or organotellurium. Thus, there is a gap to be filled regarding the properties of organochalcogenide systems which can be improved by replacing sulfur with selenium or tellurium. In the last decade, there has been significant development in the synthesis of selenium and tellurium compounds; however, it is difficult to find commercial applications of these compounds because there are few studies showing the feasibility of their synthesis and their advantages compared to organothiol compounds. Stability against oxidation by molecular oxygen under ambient conditions is one of the properties which can be improved by choosing the correct organochalcogenide; this can confer important advantages for many more suitable applications. This paper reports the successful synthesis and characterization of gold nanoparticles functionalized with organochalcogenide molecules (dibutyl-disulfide, dibutyl-diselenide and dibutyl-ditelluride) and evaluates the oxidation stability of the organochalcogenides. Spherical gold nanoparticles with diameters of 24 nm were capped with organochalcogenides and were investigated using X-ray photoelectron spectroscopy (XPS) to show the improved stability of organoselenium compared with organothiol and organotellurium. The results suggest that the organoselenium is a promising candidate to replace organothiol because of its enhanced stability towards oxidation by molecular oxygen under ambient conditions and its slow oxidation rate. The observed difference in the oxidation processes, as discussed, is also in agreement with theoretical calculations.

This study presents the improved stability against oxidation by molecular oxygen under ambient conditions of organoselenium compared with organothiol, and organotellurium.     

Reactive Oxygen Species Independent Cytotoxicity Induced by Radiocontrast Agents in Tubular Cells (LLC-PK1 and MDCK)

Purpose. Radiocontrast agents (RAs) cause renal tubular damage by hemodynamic imbalance, which could cause hypoxic stimulus and direct cytotoxicity. However, reactive oxygen species (ROS) could be an important factor in RAs' direct cytotoxicity. This study investigated the involvement of ROS in deleterious effects produced by RAs on normoxic and hypoxic renal tubular cells. Materials and Methods. LLC-PK1 and MDCK were exposed to diatrizoate and ioxaglate in normoxic and hypoxic conditions. Apoptotic and necrotic cell death were assessed by acridine orange/ethidium bromide and annexin V methods. Hydrogen peroxide, superoxide anion, and malondialdehyde levels were analyzed by, respectively, 2′,7′-dichlorofluorescein, luminal, and thiobarbituric acid. Antioxidant agents were used to prevent cellular RAs damage. Results. Diatrizoate and ioxaglate decreased cellular viability in both cells, and this effect was enhanced by hypoxic conditions. Diatrizoate induced more injury than ioxaglate to both cell lines. LLC-PK1 underwent necrosis, while MDCK cells underwent apoptosis when exposed to diatrizoate. These results could not be attributed to an increase in osmolality. RAs did not increase hydrogen peroxide, superoxide anion or malondialdehyde levels in both cells. Additionally, N-acetyl-L-cysteine (NAC), ascorbic acid, α-tocopherol, glutathione, β-carotene, allopurinol, cimetidine, and citric acid did not protect cells against RAs damage. Surprising, NAC increased the cellular damage induced by ioxaglate in the both cell lines. Conclusion. The present study shows that RAs induce damage in cultured tubular cells, especially in hypoxic conditions. ROS were not involved in the observed RAs' cytotoxicity, and NAC increased ioxaglate-induced tubular damage.     

Pentraxin-3 levels in gingival crevicular fluid during orthodontic tooth movement in young and adult patients

Abstract Objectives: To measure the levels of pentraxin-3 (PTX-3) in gingival crevicular fluid (GCF) in orthodontic young and adult patients in the first 2?weeks after the orthodontic appliance to determine whether those changes occur during orthodontic treatment and if those values could be the expression of an inflammatory state. Materials and Methods: GCF samples were collected with paper strips from 16 orthodontic young patients and 13 orthodontic adult patients from an upper canine requiring distalization as a test tooth. A contralateral canine was used as a control tooth. The absorbed volume was eluted in 100?μL phosphate-buffered saline (pH = 7.2). PTX-3 levels in GCF were determined using a commercial enzyme-linked immunosorbent assay kit, and the results were expressed in ng/mL. Results: The results showed an increase of GCF levels of PTX-3 from 1?hour before the orthodontic appliance to a maximum at 24?hours, followed by a decrease in both groups of adult and young patients. Conclusions: The results suggest PTX-3 involvement in periodontal orthodontic remodeling and the aseptic inflammation induced by the orthodontic forces.     

Sickle cell disease does not predispose to caries or periodontal disease

This study investigated the prevalence of dental caries and periodontal condition in a population with sickle cell disease (SCD), analyzing some associations with disease severity. The Decayed, Missing and Filled Teeth index (DMFT) and Community Periodontal Index (CPI) were recorded for 99 individuals with SCD and 91 matched controls. Socio-demographic status, oral health behaviors, and history of clinical severity of SCD were assessed. Statistical comparisons were performed between the group with SCD and the control group, as well as multivariate logistic regression analyses with DMFT index and CPI as the dependent variables. The mean number of decayed teeth was significantly higher in individuals with HbSS. Older age, female gender, and daily smoking were identified as risk factors for higher DMFT, while older age and absence of daily use of dental floss were risk factors for the development of periodontal disease. In conclusion, risk factors known to cause caries and periodontal disease had more influence on oral health than the direct impact of SCD.