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Aim: To quantitatively and qualitatively compare the host proteomic profile in samples of symptomatic and asymptomatic apical periodontitis (AP) using nano‐liquid chromatography–electron spray tandem mass spectrometry. Methodology: Samples were obtained from 18 patients with radiographically evident AP, divided into symptomatic and asymptomatic groups (nine per group) according to clinical characteristics. After sample collection, protein extraction, purification and quantification of the samples were performed, which were analysed by reverse‐phase liquid chromatography coupled to mass spectrometry. Label‐free quantitative proteomic analysis was performed by Protein Lynx Global Service software. Differences in expression of proteins between the groups were calculated using the Monte Carlo algorithm, considering P < 0.05 for down‐regulated proteins and 1 − P > 0.95 for up‐regulated proteins. Proteins were identified with the embedded ion accounting algorithm in the software and a search of the Homo sapiens UniProt database. Results: A total of 853 individual human proteins were identified. In the quantitative analysis, common proteins to both groups accounted for 143 proteins. Differences in expression between groups resulted in 51 up‐regulated proteins (1 − P > 0.95) in the symptomatic group, including alpha‐1‐antitrypsin, protein S100‐A8, myeloperoxidase, peroxiredoxin and lactotransferrin. This group also had 43 down‐regulated proteins (P < 0.05), comprising immunoglobulin, neutrophil defensin, pyruvate kinase and alpha‐enolase. The qualitative analysis considered only the exclusive proteins of each group. For the symptomatic group, 318 complete proteins and 29 fragments were identified, such as dedicator of cytokinesis protein, intersectin, prostaglandin, phospholipase DDHD2 and superoxide dismutase. For the asymptomatic group, 326 complete proteins and 37 fragments were identified, including azurocidin, C‐reactive protein, collagen alpha, cathepsin, heat shock and laminin. Conclusions: Quantitative differences in the expression of common proteins in cases of symptomatic and asymptomatic AP were found, which were mostly related to host immune response in both groups. Exclusive proteins in the symptomatic group were mainly related to the host response to the presence of viruses in endodontic infections, oxidative stress and proteolytic enzymes. The results provide a basis for a better understanding of cellular and molecular pathways involved in AP, establishing specific proteomic profiles for symptomatic and asymptomatic conditions. [ABSTRACT FROM AUTHOR]

In the development of new metallic biomaterials, the Ti-15Mo alloy has great prominence because of its excellent corrosion resistance and good combination of mechanical properties. In this study, the element niobium was added to the Ti-15Mo alloy, forming the Ti-15Mo-Nb system for the purpose of improving their properties and promoting its application as a biomaterial. These alloys are very promising to use as biomedical implants, because they integrate a new class of titanium alloys without the presence of aluminum and vanadium, which may cause cytotoxic effects. The alloys were produced by arc-melting and characterized by density, X-ray diffraction, scanning electron microscopy, microhardness, elastic modulus, corrosion, and cytotoxicity assays. The developed alloys have β phase predominance (with bcc crystalline structure). The addition of niobium decreases the microhardness and elastic modulus, with values around 80 GPa, which is well below that of the metallic alloys used commercially for this type of application. Very low passive current densities were found for all alloys studied showing that the passive film on these alloys is highly protective. In vitro cytotoxicity tests revealed that the introduction of niobium did not cause cytotoxic effects in the studied alloys. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 639-648, 2018. [ABSTRACT FROM AUTHOR]

Fractional fluoride retention is important during the early years of life when considering the risk of development of dental fluorosis. This study aimed to measure fractional fluoride retention in young children. The objectives were to investigate the relationships between fractional fluoride retention and total daily fluoride intake, age, and body mass index ( BMI). Twenty-nine healthy children, up to 4 yr of age, participated; 14 lived in a fluoridated area (0.64 μg ml−1 of fluoride in drinking water) and 15 lived in a non-fluoridated area (0.04 μg ml−1 of fluoride in drinking water). The total daily fluoride intake of each child was calculated from the daily dietary fluoride intake and toothpaste ingestion (if fluoride toothpaste was used). Total daily fluoride excretion was measured by collecting voided urine and faeces over a 24-h period, and fractional fluoride retention was calculated by dividing the amount of fluoride retained in the body (total daily fluoride intake minus total daily fluoride excretion) by the total daily fluoride intake. Nine children were excluded from data analysis because of suspected invalid samples. Mean (range) fractional fluoride retention for the remaining 20 children was 0.61 (0.06-0.98). There were no statistically significant correlations between fractional fluoride retention and either age or BMI. However, fractional fluoride retention was correlated with total daily fluoride intake: fractional fluoride retention = 1 − exp (−C × total daily fluoride intake), where C = 28.75 (95% CI = 19.75-37.75). The wide variation in fluoride retention in young children could have important implications when recommendations for fluoride use are being considered. [ABSTRACT FROM AUTHOR]

Background: Matrix metalloproteinase (MMP) inhibitors reduce dentine erosion. This in vitro study evaluated the effect of the supplementation of soft drinks with green tea extract, a natural inhibitor of MMPs, on their erosive potential against dentine. Methods: For each drink tested (Coca-Cola™, Kuat™ guarana, Sprite™ and light Coca-Cola™), 40 dentine specimens were divided into two subgroups differing with respect to supplementation with green tea extract at 1.2% (OM24®, 100% Camellia sinensis leaf extract, containing 30 ± 3% of catechin; Omnimedica, Switzerland) or not (control). Specimens were subjected to four pH cycles, alternating de- and remineralization in one day. For each cycle, samples were immersed in pure or supplemented drink (10 minutes, 30 mL per block) and in artificial saliva (60 minutes, 30 mL per block) at 37 °C, under agitation. Dentine alterations were determined by profilometry (μm). Data were analysed by two-way ANOVA and Bonferroni's test (p < 0.05). Results: A significant difference was observed among the drinks tested with Sprite™ leading to the highest surface loss and light Coca-Cola™ to the lowest. Supplementation with green tea extract reduced the surface loss by 15% to 40% but the difference was significant for Coca-Cola™ only. Conclusions: Supplementation of soft drinks with green tea extract might be a viable alternative to reduce their erosive potential against dentine. [ABSTRACT FROM AUTHOR]

This in vitro study evaluated the effect of a prolonged erosive pH cycling on the superficial microhardness change (SMHC) and the erosive wear of different restorative materials. Eighty enamel specimens with prepared cavities of 1·5 × 1·5 mm were randomly divided into eight groups according to the restorative materials used for the fillings (RMGI – resin-modified glass–ionomer, CGI – conventional glass–ionomer, CR– composite resin, A – amalgam) and immersion media used (ERO – erosive medium or SAL – artificial saliva). During 35 days, half of the specimens were immersed in a cola drink (ERO), for 5 min, three times a day, and they remained in SAL between the erosive cycles. The other half of the specimens was immersed in SAL only, for the entire experimental period (control). Data were tested for significant differences byanova and Tukey’s tests ( P < 0·05). Scanning electron microscopy images were made to illustrate the enamel erosive wear and restorative materials alterations. The mean SMHC (%) and mean erosive wear (μm) of the materials were: RMGI-ERO (30/0·5); CGI-ERO (37/0·5); CR-ERO (−0·3/0·3); A-ERO (−4/0·3); RMGI-SAL (4/0·4); CGI-SAL (−6/0·4); CR-SAL (−3/0·2) and A-SAL (2/0·4). Scanning electron microscopy images showed pronounced enamel erosive wear on groups submitted to erosive pH cycling when compared with groups maintained in saliva. In conclusion, the prolonged pH cycling promoted significantly higher alterations (SMHC and erosive wear) on the glass–ionomer cements than the CR and amalgam. [ABSTRACT FROM AUTHOR]

This blind and randomized-controlled trial analysed chlorhexidine dentifrices in relation to dental plaque, gingivitis, bleeding, calculus and enamel extrinsic staining development. Volunteers in fixed orthodontic therapy used the following dentifrices: 1100 ppmF, NaF (group A, n=27); experimental, 1100 ppmF, NaF and chlorhexidine 0.95% (group B, n=28); and experimental, chlorhexidine 0.95% (group C, n=28). At baseline, after 6, 12 and 24 weeks, clinical examinations were carried out. The gingivitis, bleeding and plaque data were tested byanova and Tukey's post hoc tests. Stain and calculus data were analysed by Kruskal–Wallis and Dunn's post hoc tests ( p<0.05). Plaque, gingivitis and bleeding scores improved in all three groups, but up to the 6 and 12 weeks examination the products containing chlorhexidine were statistically better. The chlorhexidine dentifrices significantly increased the mean of the stain index, although most of the patients did not notice the stains. The calculus index was not significantly modified. In summary, this study suggests that the use of dentifrices containing chlorhexidine seems to be effective for the treatment of gingivitis in orthodontic patients, although the intense motivating contact that the volunteers had with the researchers may have also played a role. [ABSTRACT FROM AUTHOR]

The bonding of resin-modified glass ionomer cements to dentin remains a challenge in clinical routine. In an attempt to improve this property, different materials and techniques have been proposed. This study investigated the shear bond strength of resin-modified glass ionomer cements (Vitremer, 3M/ESPE and Fuji II LC Improved, GC) to human dentin using two one-bottle adhesive systems (Prime & Bond 2·1, Dentsply and Single Bond, 3M/ESPE). The restored specimens were stored in deionized water for 24 h at 37 ± 1 °C, and then the bonded surfaces were tested in shear strength using a Universal testing machine at a crosshead speed of 0·5 mm min−1. Bond strength means were recorded and failure modes were assessed with a stereomicroscope at 40× magnification. Data were submitted to two-wayanova and multiple comparisons were performed using a Tukey statistical test ( P < 0·05). Fuji II LC Improved yielded higher bond strength ( P < 0·05) than Vitremer in all experimental conditions. No statistically significant differences ( P > 0·05) were observed among the proposed dentin surface treatments, although a slight decrease in bond strength was observed when phosphoric acid was used alone. Bond strengths of the resin-modified glass ionomer cements to dentin seemed to be more material-dependent than surface treatment-dependent. It may be concluded that the one-bottle adhesive systems tested in this study did not improve the bond strength of the resin-modified glass ionomer cements to dentin. [ABSTRACT FROM AUTHOR]