Optical coherence tomography (OCT) is one of the most important imaging modalities for biophotonics applications. In this work, an important step towards the clinical use of OCT in dental practice is ...reported, by following‐up patients treated from periodontal disease (PD). A total of 147 vestibular dental sites from 14 patients diagnosed with PD were evaluated prior and after treatment, using a swept‐source OCT and two periodontal probes (Florida probe and North Carolina) for comparison. The evaluation was performed at four stages: day 0, day 30, day 60 and day 90. Exceptionally one patient was evaluated 1‐year after treatment. It was possible to visualize in the two‐dimensional images the architectural components that compose the periodontal anatomy, and identify the improvements in biofilm and dental calculus upon treatment. In the follow‐up after the treatment, it was observed in some cases decrease of the gingival thickness associated with extinction of gingival calculus. In some cases, the improvement of both depth of probing with the traditional probes and the evidence in the images of the region was emphasized. The study evidenced the ability of OCT in the identification of periodontal structures and alterations, being an important noninvasive complement or even alternative for periodontal probes for treatment follow‐up.
OCT system being used in a clinical environment. Above OCT image (left) prior treatment and (right) 30 days after treatment.
Optical coherence tomography (OCT) was applied to following‐up patients treated from periodontal disease. The evaluation was performed monthly, from the beginning of the treatment until the day 90. It was possible to visualize the architectural components that compose the periodontal anatomy, and identify the improvements in biofilm and dental calculus upon treatment. OCT showed great performance as an important non‐invasive complement or alternative for periodontal probes for treatment follow‐up.
Background: Periodontitis is a multifactorial and infectious disease that may result in significant debilitation. The aim of this study is to exploit two optical coherence tomography (OCT) systems ...operating in the Fourier domain at different wavelengths, 930 and 1,325 nm, for structural analysis of periodontal tissue in porcine jaws.
Methods: Five fresh porcine jaws were sectioned and stored in formalin before OCT analysis. Two‐ and three‐dimensional OCT images of the tooth/gingiva interface were performed, and measurements of the gingival structures were obtained. The 930‐nm OCT system operates in the spectral domain, whereas the 1,325‐nm system is a swept‐source model. Stereomicroscope images, the gold standard, were used for direct comparison.
Results: Through image analysis, it is possible to identify the free gingiva and the attached gingiva, the calculus deposition over tooth surfaces, and the subgingival calculus that enables the enlargement of the gingival sulcus. In addition, the gingival thickness and the gingival sulcus depth can be non‐invasively measured, varying from 0.8 to 4 mm.
Conclusions: Regarding the ability of the two OCT systems to visualize periodontal structures, the system operating at 1,325 nm shows a better performance, owing to a longer central wavelength that allows deeper tissue penetration. The results with the system at 930 nm can also be used, but some features could not be observed due to its lower penetration depth in the tissue.
As changes in hard or soft oral tissues normally have a microbiological component, it is important to develop diagnostic techniques that support clinical evaluation, without destroying ...microbiological formation. The optical coherence tomography (OCT) represents an alternative to analyze tissues and microorganisms without the need for processing. This imaging technique could be defined as a fast, real-time, in situ, and non-destructive method. Thus, this study proposed the use of the OCT to visualize biofilm by Candida albicans in reline resins for removable prostheses. Three reline resins (Silagum-Comfort, Coe-Comfort, and Soft-Confort), with distinct characteristics related to water sorption and fungal inhibition were used. A total of 30 samples (10 for each resin group) were subjected to OCT scanning before and 96 h after inoculation with Candida albicans (URM 6547). The biofilm analysis was carried out through a 2D optical Callisto SD-OCT (930 nm) operated in the spectral domain. Then, the images were preprocessed using a Formula: see text Gaussian filter to remove the noise, and then Otsu binarization, allowing segmentation and pixel counting. The layer’s biofilm formed was clearly defined and, indeed, its visualization is modified by water sorption of each material. Silagum-Comfort and Soft-Confort showed some similarities in the scattering of light between the clean and inoculated samples, in which, the latter samples presented higher values of light signal intensity. Coe-Comfort samples were the only ones that showed no differences between the clean or inoculated images. Therefore, the results of this study suggest that OCT is a viable technique to visualize the biofilm in reline materials. Because findings in the literature are still scarcely using the OCT technique to visualize biofilm in reline resins, further studies are encouraged. It should not contain any references or displayed equations.
Abstract Objectives To analyze marginal integrity of resin composites dental restorations using optical coherence tomography (OCT). Methods Thirty extracted human premolars had occlusal cavities ...prepared and were randomly divided according to the restorative systems evaluated: Filtek P90™/P90 Adhesive System™, Filtek Z350™, and Filtek Z250™/Single Bond™ (3 M/ESPE). The teeth were then stored in the dark for 24 h in 0.9% saline solution. Restorations were finished and polished and stored again for 24 h before thermocycling (500 cycles, 5–55 °C). A commercially available OCT system was used (SR-OCT: OCP930SR/Thorlabs) with 930 nm central wavelength. Cross-sectional images were obtained every 250 μm and evaluated using Image J. A-scans were analyzed using the Origin 8.0 program, after a filter treatment using Matlab. Results The qualitative analysis of the internal margins did not observe gaps even after A-scan examination, although distinctive patterns were found for each restorative system. Penetration of Single Bond and Filtek P90 self-etch primer into dentin was also observed. A thick adhesive layer was found for Filtek P90 bonding agent. Significance Considering the characteristics of the OCT system, the setup used in this study was capable of evaluating the marginal integrity of resin composite restorations and detecting some interaction between dental bonding agents and dental substrates. OCT can be considered a promising method for the evaluation of the internal margins of restorations in vivo.
Abstract
Background
Nanosilver fluoride (NSF) was developed as an alternative in the prevention of dental caries.
Purpose
The aim of this study was to test the remineralizing action of NSF on ...incipient enamel caries and its antimicrobial action on the acid production and adhesion of
Streptococcus mutans.
Methods
Deciduous enamel fragments were treated with sodium fluoride (NaF), NSF and deionized water. Microhardness, fluorescence spectroscopy and optical coherence tomography imaging were performed on each specimen before chemical caries induction, after caries induction and after 14 days of pH cycling. The treated enamel fragments were also placed into test tubes containing bacterial suspension and saliva. The pH readings and quantification of the adhered microorganisms to the dental enamel were determined. Analysis of variance, Kruskal-Wallis, Mann-Whitney, Tukey and mixed linear regression model were applied.
Results
NSF and NaF were effective in enamel remineralization, with a statistically significant difference (p<0.001) to deionized water, and they had no statistically significant difference between themselves (p>0.005). NSF had greater effectiveness compared to NaF in preventing decreases of pH and adhesion of
S. mutans
to the enamel surface, with statistically significant (p<0.001) differences.
Conclusion
NSF may be more effective than conventional fluorides in treating incipient caries lesions due to its remineralization and antibacterial actions.
Since Hypersensitivity Pneumonitis (HP) categorization in fibrotic and nonfibrotic/inflammatory types seems to be more consistent with the distinctive clinical course and outcomes, recent ...international guidelines recommended the use of this classification. Moreover, fibrotic subtype may share immunogenetic and pathophysiological mechanisms with other fibrotic lung diseases.
To investigate HLA -A, -B, -DRB1 and TNF-α –308 gene polymorphisms among fibrotic and nonfibrotic HP patients due to avian exposure, also in comparison with asymptomatic exposed controls.
We prospectively enrolled 40 HP patients, classified as fibrotic or nonfibrotic/inflammatory, and 70 exposed controls. HLA and TNF-α polymorphisms were determined by polymerase chain reaction–sequence specific primer amplification.
While HLA alleles were not associated to HP susceptibility, fibrotic HP patients showed increased frequencies of HLA A*02 (46.7% vs 25.7%; OR=2.53, p = 0.02) and HLA DRB1*14 (10.0% vs 0.7%; OR=15.44, p=0.02) alleles when compared with exposed controls, although not statistically significant after correction for multiple comparisons. TNF-α G/G genotype (associated with low TNF-α production) frequencies were significantly increased among the non-fibrotic/inflammatory HP patients comparatively to fibrotic presentations (88% vs 60%; RR=0.44; p=0.04) and controls (88% vs 63%, OR 4.33, p=0.037). Also, these patients had a significantly increased frequency of the G allele (94.0% vs 73.3%, RR=0.44, p=0.01), while fibrotic HP patients predominantly presented the A allele (26.7% vs 6.0%, RR=2.28, p=0.01).
Our results support the hypothesis that fibrotic and non-fibrotic HP subtypes exhibit a distinct profile of TNF-α and HLA polymorphisms, which may be relevant to predict disease course and better define treatment strategies.
Summary
Approximately 3500 children with sickle cell disease (SCD) are born in Brazil each year, but the burden of SCD morbidity is not fully characterised. A large, multi‐centre cohort was ...established to characterise clinical outcomes in the Brazilian SCD population and create the infrastructure to perform genotype‐phenotype association studies. Eligible patients were randomly selected from participating sites and recruited at routine visits. A biorepository of blood samples was created and comprehensive demographic and clinical outcome data were entered in a centralized electronic database. Peripheral blood genome‐wide single nucleotide polymorphism (SNP) genotyping was performed using a customized Transfusion Medicine (TM) Array. A total of 2795 participants at six Brazilian sites were enrolled between 2013 and 2015. The cohort included slight predominance of children <18 years (55·9%) and females (53·0%). Haemoglobin (Hb) SS was the most common SCD genotype (70·7%), followed by HbSC (23%), Sβ0 (3·0%) and Sβ+ (2·9%). SNP data from the TM Array were analysed to evaluate the genetic ancestry of the cohort and revealed significant admixture among the population. Demographics and clinical complications, stratified by age and SCD genotype, are summarized and future studies in this cohort are discussed.
In the search for new metal complexes with antitumor potential, two dithiocarbazate ligands derived from 1,1,1-trifluoro-2,4-pentanedione (H
L
) and (H
L
) and four Ni(II) complexes, Ni(L
)PPh
(1), ...Ni(L
)Py (2), Ni(L
)PPh
(3), and Ni(L
)Py (4), were successfully synthesized and investigated by physical-chemistry and spectroscopic methods. The crystal structure of the H
L
and the Ni(II) complexes has been elucidated by single-crystal X-ray diffraction. The obtained structure from H
L
confirms the cyclization reaction and formation of the pyrazoline derivative. The results showed square planar geometry to the metal centers, in which dithiocarbazates coordinated by the
donor system and a triphenylphosphine or pyridine molecule complete the coordination sphere. Hirshfeld surface analysis by
function was investigated and showed π-π stacking interactions upon the molecular packing of H
L
and non-classical hydrogen bonds for all compounds. Fingerprint plots showed the main interactions attributed to H⋅H C⋅H, O⋅H, Br⋅H, and F⋅H, with contacts contributing between 1.9% and 38.2%. The mass spectrometry data indicated the presence of molecular ions M + H
and characteristic fragmentations of the compounds, which indicated the same behavior of the compounds in solution and solid state. Molecular docking simulations were studied to evaluate the properties and interactions of the free dithiocarbazates and their Ni(II) complexes with selected proteins and DNA. These results were supported by
cytotoxicity assays against four cancer cell lines, showing that the synthesized metal complexes display promising biological activity.
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