Comparative assessment of the efficacy of low concentration bleaching agents using quantitative light induced fluorescence in removing stains An In vitro study

Background: Tooth discoloration has become a common esthetic problem in recent years. Removal of stains by bleaching is well-documented. Low concentration home bleaching products are available in market in different forms and concentrations. Aim: The aim of this study is to evaluate and compare the efficacy of low concentration commercially available home bleaching products (whitening strip, gel, and mouthwash) in removing stains and whitening the tooth using clinical and digital methods. Materials and Methods: Sixty permanent enamel samples mounted in an acrylic block were artificially stained and randomly divided into four groups. Negative control, 15 % Carbamide peroxide gel group, 2% Hydrogen 16 peroxide mouthwash group and 6% Hydrogen peroxide strip group respectively. The samples were bleached with respective agents according to the manufacturer's instructions. The efficacy on 7th and 14th day was evaluated clinically (SGU change), photographically (?E), and using quantitative light-induced fluorescence (?F). The data were analyzed using paired t-test and analysis of variance. Results: Postbleaching, 6% hydrogen peroxide strips and 15% carbamide peroxide gel showed maximum improvement (??F – 15.73 and 11.89, ?E – 19.8 and 18.9, respectively) when compared to 2% hydrogen peroxide mouthwash and negative control group (??F – 9.68 and 6.59, ?E – 15.04 and 9.44, respectively). The difference was statistically significant (P = 0.001). Conclusion: 6% hydrogen peroxide strips and 15% carbamide peroxide gel showed maximum improvement in stain removal and tooth whitening however, the strips showed better efficacy than the gel. Strips have the added advantage of lesser contact period, less salivary dilution, and no gingival contact. Therefore, strips can be a better alternative for gels and mouthwashes.

Comparison of Prevention Methods against Enamel Demineralization adjacent to Orthodontic Bracket Using Fluoride / 대한소아치과학회지

As a common side effect of fixed orthodontic treatment, demineralization of the enamel adjacent to the bracket and band occurs in patients with poor oral hygiene. The purpose of this study was to investigate what is the most effective method to prevent demineralization around the fixed orthodontic appliance among various methods using fluoride. 80 extracted bovine incisors with a healthy surface were classified into four groups as experimental materials: (Group I) Control group, (Group II) V varnish™, (Group III) Tooth Mousse Plus®, (Group IV) Vanish™ XT. After treatment for each group, mineral loss and Vickers surface microhardness were measured at 0, 30, 60 and 90 days after demineralization in artificial carious solution. Mineral loss was the lowest in group IV, followed by group II and group III, which showed a significant difference. The surface microhardness was the lowest in group IV, followed by group II and group III, which showed a significant difference. Through this study, group IV showed the best effect to prevent enamel demineralization around the bracket. Group III showed significant prevention of enamel demineralization compared with the control group, but the effect was less than that of the other groups.

Effectiveness of Oral Health Education Program using Home-using Portable Device for Children / 대한소아치과학회지

This study was performed to determine the effectiveness of oral health education program with a home-using portable device according to the individual oral health status in children.58 children who were 6 – 12 years old were included in this study. All subjects were affiliated to moderate or high caries risk group based on caries risk test. They were divided into 2 groups: (I) home-using portable device group (II) control group. Both groups were evaluated with simple plaque score (SPS) using camera type quantitative light-induced fluorescence device and educated with identical oral health education methods. Subjects in group I were demanded to use a home-using portable device. After 1 month, both groups were re-evaluated.Cariview score that can reflect the acidogenic potential of plaque bacteria was statistically reduced in both groups (p < 0.001). There was a statistically significant difference between two groups in the change of Cariview score (p = 0.022). In group I, the decrease was larger than that in group II. There was no statistically significant difference in the change of SPS (p = 0.937).Oral health education improved oral hygiene status in children. However, this study confirmed that it was much more effective to improve oral health status in children with a home-using portable device in their daily oral hygiene care.

Study of Interaction of Nanoparticles and Proteins in Taylor Dispersion Analysis / 分析化学

The diffusion coefficient ((4. 11±0. 78)×10-11 m2/s) and hydrated radius ((6. 12±1. 21) nm) of FITC-DSA ( fluorescein isothiocyanate conjugate dog albumin ) were investigated and measured by combining Taylor dispersion analysis with laser induced fluorescence in microchip. The influence of size of gold nanoparticles (15, 30 and 50 nm) on the interactions between FITC-DSA and gold nanoparticles was studied. The preliminary result demonstrated that the binding of protein and gold nanoparticle displayed a size-dependent relationship. It was interesting that the 50-nm gold nanoparticles could enhance the FITC-DSA fluorescence in microchannel driven with pressure. This method was simple, fast, low sample consumption and high throughput and could be used to study the interaction of nanoparticles and proteins. Systematical study using this method would enable us to have a deep understanding of the toxicity of nanomaterials, and promote the development of safe nanomedicine.

Evaluation of Detection Ability of a Quantitative Light-Induced Fluorescence Digital Device for Initial Secondary Caries Lesion / 치위생과학회지

The purpose of this study was to evaluate the detection ability of secondary caries using qunatitative light-induce fluorescence-digital (QLF-D) device. Twenty bovine teeth with cavity on surface were demineralized during 21 days for secondary caries lesion of cavity wall. After 21 days, cavity was filled using composite resin and cut the specimen in half with disc. Fluorescence loss of lesion on surface by time flow, cross sectional lesion, and lesion of filled or unfilled surface were analyzed using analysis software. ΔF (value of fluorescence loss) of the lesion on surface assessed by the QLF-D increased significantly over time up to 21 days. And ΔF value of lesion of filled surface is significantly lower than that of unfilled surface (p<0.001). ΔF of filled surface is 1.31 times of cross section lesion. The correlation of between ΔF of filled surface lesion and ΔF of cross section lesion was showed low agreement (0.026) and correlation of between ΔF of unfilled surface lesion and ΔF of cross section lesion was showed high agreement (0.613). In conclusion, secondary caries can be detected on surface using QLF-D. However, interference of fluorescence of filling material is the points to be especially considered for exact analysis of secondary caries lesion.

Detection of proximal caries using quantitative light-induced fluorescence-digital and laser fluorescence: a comparative study

PURPOSE: The purpose of this study was to evaluate the in vitro validity of quantitative light-induced fluorescence-digital (QLF-D) and laser fluorescence (DIAGNOdent) for assessing proximal caries in extracted premolars, using digital radiography as reference method. MATERIALS AND METHODS: A total of 102 extracted premolars with similar lengths and shapes were used. A single operator conducted all the examinations using three different detection methods (bitewing radiography, QLF-D, and DIAGNOdent). The bitewing x-ray scale, QLF-D fluorescence loss (ΔF), and DIAGNOdent peak readings were compared and statistically analyzed. RESULTS: Each method showed an excellent reliability. The correlation coefficient between bitewing radiography and QLF-D, DIAGNOdent were −0.644 and 0.448, respectively, while the value between QLF-D and DIAGNOdent was −0.382. The kappa statistics for bitewing radiography and QLF-D had a higher diagnosis consensus than those for bitewing radiography and DIAGNOdent. The QLF-D was moderately to highly accurate (AUC = 0.753 – 0.908), while DIAGNOdent was moderately to less accurate (AUC = 0.622 – 0.784). All detection methods showed statistically significant correlation and high correlation between the bitewing radiography and QLF-D. CONCLUSION: QLF-D was found to be a valid and reliable alternative diagnostic method to digital bitewing radiography for in vitro detection of proximal caries.

Application of quantitative light-induced fluorescence to determine the depth of demineralization of dental fluorosis in enamel microabrasion: a case report

Enamel microabrasion has become accepted as a conservative, nonrestorative method of removing intrinsic and superficial dysmineralization defects from dental fluorosis, restoring esthetics with minimal loss of enamel. However, it can be difficult to determine if restoration is necessary in dental fluorosis, because the lesion depth is often not easily recognized. This case report presents a method for analysis of enamel hypoplasia that uses quantitative light-induced fluorescence (QLF) followed by a combination of enamel microabrasion with carbamide peroxide home bleaching. We describe the utility of QLF when selecting a conservative treatment plan and confirming treatment efficacy. In this case, the treatment plan was based on QLF analysis, and the selected combination treatment of microabrasion and bleaching had good results.

UV-induced red fluorescence on facial part of patients with acne vulgaris and seborrheic dermatitis: a fluorescence spectrum study / 中华医学美学美容杂志

Objective To measure the fluorescence spectral information of UVRF in the facial skin of patients with acne vulgaris and seborrheic dermatitis and to comprehend the optical properties of UVRF.Methods The lesions were squeezed to extract the sebaceous secretions containing UVRF in the facial skin.Ocean Optics USB2000 +F02243 Spectrometer and the 308nm excimer laser were used as an excitation light source to measure the signal of the LIF spectrum of UVRF in 6 acne vulgaris and 4 seborrheic dermatitis patients' facial part,compared with protoporphyrin Ⅸ.Results 1-4 peaks were detected in 10 patients' UVRF specimen respectively.The fluorescence spectra's characteristic peak of UVRF in 10 patients was at 680 nm.Protoporphyrin Ⅸ was at 688 nm and more gentle and generous than UVRF's characteristic peak.Conclusions LIF system can be used to detect the fluorescence spectroscopy of UVRF.UVRF has similar spectral characteristics to protoporphyrin Ⅸ,but it is not the same species.

Determination of Four Aflatoxins by Pressurized Capillary Electrochromatography-Laser Induced Fluorescence Detection / 分析化学

A rapid, reliable and sensitive pressurized capillary electrochromatography-Laser induced fluorescence ( pCEC/LIF ) method with trifluoroacetic acid ( TFA ) pre-column derivation for simultaneous determination of four aflatoxin ( AFB1 , AFB2 , AFG1 , AFG2 ) was developed. This method included separation on a capillary column packed with 1. 8μm C18 particles using 0. 05% FA aqueous solution/methanol (55:45, V/V) as mobile phase at a pump flow rate of 0. 05 mL/min when the split ratio was 1:300. Under the optimum conditions including running voltage of 15 kV, excitation wavelength of 375 nm and emission wavelength of 450 nm, the baseline separation of four aflatoxins was achieved within 10 minutes. The limits of detection (LODs) were 0. 02, 0. 016, 0. 008 and 0. 01 μg/L for AFG1, AFB1, AFG2, AFB2(S/N=3), respectively. The linear detection ranges of AFG1 , AFB1 , AFG2 , AFB2 were 0. 1-10, 0. 1-10, 0. 1-3 and 0. 1-3 μg/L with correlation coefficients (R2) of 0. 9999, 1. 0000, 0. 9995 and 0. 9997, respectively. The established method was applied to analyze the peanut butter, and the recoveries of standard addition experiment were between 90 . 0% and 112 . 0% for all analytes ( RSDs=0 . 5%-1 . 9%) .

Evaluation of the validity of Qraycam for tooth examination during epidemiological surveys / 대한구강보건학회지

OBJECTIVES: The aim of this study was to evaluate applicability of the Qraycam device for detecting caries and filling body during tooth examinations. METHODS: Fifty-two subjects aged 25 to 34 years were recruited for tooth examination. Two examiners (an epidemiologic expert and a non-expert) performed visual tooth examination using only dental operating light, dental mirror, and air-drying without a dental explorer. Pictures or videos of every tooth surface were obtained under visual ray and 405 nm blue ray, respectively, by using Qraycam. The two examiners then evaluated these videos or images more than 7 days after visual examination. RESULTS: The results of the visual, visible ray image, and 405 nm blue ray image examinations showed very good kappa agreement with the gold standard for both examiners. The 405 nm blue ray image examination showed higher kappa agreement than visible ray image examination, and was similar to visual examination. Accuracy of detecting caries was enhanced by using 405 nm blue ray images from Qraycam. Accuracy of detecting filling body on 405 nm blue ray image examination was almost same as that by visual examination. CONCLUSIONS: Tooth examination with Qraycam images revealed high agreement with the gold standard and showed accuracy for detecting caries and filling body. Therefore, Qraycam would enhance the quality of oral epidemiologic survey including tooth examination and save cost and time of survey.

Diagnosis and Effective Management of Preterm Labor.

Despite extensive research, we are still unable to diagnose, prevent and treat preterm labor. Monitoring efficacy of interventions that would allow this is largely biased by the inability to accurately identify true labor with the currently used crude technology. Progestin supplementation appears to be a promising approach to both preventing initiation of preterm labor and treating it once it is already established, given progesterone’s role in maintaining pregnancy as well as support from basic and clinical research. However, the questions on mechanisms of action, optimal progestin formulation, dose, route and timing of administration remain unanswered. We have established and reported noninvasive means to accurately monitor cervical ripening, by measuring collagen light-induced fluorescence (LIF) and myometrial contractility, by measuring uterine electromyography (EMG). By accurately assessing the two components of parturition, cervical LIF and uterine EMG can help to identify effective prevention strategies and treatment of preterm labor.

Detection of early changes in caries lesion using QLF-D and OCT / 대한구강보건학회지

OBJECTIVES: We aimed to compare the differences in caries lesion changes when measured by QLF-D as fluorescence loss and by SS-OCT as lesion depth with respect to demineralized time, during formation of artificial early caries lesion. We also demonstrated that QLF-D and SS-OCT can be used effectively in monitoring the longitudinal progression of simulated caries lesions. METHODS: Ten bovine incisors were sectioned (5x4 mm) and embedded in epoxy resin. An acid-resistant nail varnish was applied to a part of the tooth surfaces to protect sound enamel (2x4 mm). To generate lesions, each specimen was immersed in 40 ml of a demineralizing gel for 20 days at 37degrees C. To measure mineral loss of the demineralized specimens, fluorescence loss (DeltaF, %) was measured by QLF-D and lesion depth (microm) was determined by SS-OCT from the captured cross-sectional image. All the specimens were analyzed daily by QLF-D image analysis software and SS-OCT image analysis program for 20 days. The repeated measures analysis of DeltaF and lesion depth was used. The paired t-test was used to assess differences between each day. The correlation between DeltaF and lesion depth was determined using the Pearson's correlation coefficient. RESULTS: On the 5th, 10th, and 15th day, compared to baseline values, DeltaF decreased in 12.7%, 25.0%, and 33.6% of the specimens, respectively, and the lesion depth increased in 9.9%, 16.0%, and 22.6% of the specimens, respectively. However, after 15 days, there was no change in the DeltaF and lesion depth. High significant correlation was identified between the resultant values of DeltaF obtained by QLF-D and those of lesion depth obtained by SS-OCT (r = -0.811, P<0.0001). CONCLUSIONS: The QLF-D and SS-OCT could detect subtle changes in mineral loss and lesion depth with respect to demineralized time. Furthermore, these devices were useful for monitoring changes in mineral amount and lesion depth.

Ontogenia de los estróbilos, desarrollo de los esporangios y esporogénesis de Equisetum giganteum (Equisetaceae) en los Andes de Colombia

Ontogeny of strobili, sporangia development and sporogenesis in Equisetum giganteum (Equisetaceae) from the Colombian Andes. Studies on the ontogeny of the strobilus, sporangium and reproductive biology of this group of ferns are scarce. Here we describe the ontogeny of the strobilus and sporangia, and the process of sporogenesis using specimens of E. giganteum from Colombia collected along the Rio Frio, Distrito de Sevilla, Piedecuesta, Santander, at 2 200m altitude. The strobili in different stages of development were fixed, dehydrated, embedded in paraffin, sectioned using a rotatory microtome and stained with the safranin O and fast green technique. Observations were made using differential interference contrast microscopy (DIC) or Nomarski microscopy, an optical microscopy illumination technique that enhances the contrast in unstained, transparent. Strobili arise and begin to develop in the apical meristems of the main axis and lateral branches, with no significant differences in the ontogeny of strobili of one or other axis. Successive processes of cell division and differentiation lead to the growth of the strobilus and the formation of sporangiophores. These are formed by the scutellum, the manubrium or pedicel-like, basal part of the sporangiophore, and initial cells of sporangium, which differentiate to form the sporangium wall, the sporocytes and the tapetum. There is not formation of a characteristic arquesporium, as sporocytes quickly undergo meiosis originating tetrads of spores. The tapetum retains its histological integrity, but subsequently the cell walls break down and form a plasmodium that invades the sporangial cavity, partially surrounding the tetrads, and then the spores. Towards the end of the sporogenesis the tapetum disintegrates leaving spores with elaters free within the sporangial cavity. Two layers finally form the sporangium wall: the sporangium wall itself, with thickened, lignified cell walls and an underlying pyknotic layer. The mature spores are chlorofilous, morphologically similar and have exospore, a thin perispore and two elaters. This study of the ontogeny of the spore-producing structures and spores is the first contribution of this type for a tropical species of the genus. Fluorescence microscopy indicates that elaters and the wall of the sporangium are autofluorescent, while other structures induced fluorescence emitted by the fluorescent dye safranin O. The results were also discussed in relation to what is known so far for other species of Equisetum, suggesting that ontogenetic processes and structure of characters sporoderm are relatively constant in Equisetum, which implies important diagnostic value in the taxonomy of the group. Rev. Biol. Trop. 59 (4): 1845-1858. Epub 2011 December 01.

Estudios sobre la ontogenia del estróbilo, los esporangios y la biología reproductiva de Equisetum son escasos, por lo tanto, para la especie E. giganteum, se estudiaron estos aspectos en especímenes recolectados a orillas del Río Frío, Santander, Colombia (2 200m). Los estróbilos en diferentes etapas de maduración fueron fijados, deshidratados, embebidos en parafina, seccionados en micrótomo rotatorio y teñidos con safranina O-fast green. Las observaciones se efectuaron mediante un microscopio óptico de alta resolución con contraste diferencial de interferencia (DIC) y microscopio de fluorescencia. Los estróbilos se inician a partir del meristemo apical, tanto en el eje principal como en los laterales, sin diferencias en el proceso de ontogenia y esporogénesis entre estróbilos de diferentes ejes. Sucesivas mitosis y diferenciación celular conducen al crecimiento del estróbilo, y a la formación de los esporangióforos peltados, formados por el manubrio, o porción basal con aspecto de pedicelo, el escutelo, o porción apical aplanada y las iniciales del esporangio, los cuales se diferenciarán para formar la pared del esporangio, los esporocitos y el tapete. No se forma arquesporio y los esporocitos experimentan meiosis para formar tétradas de esporas. El tapete mantiene la integridad histológica hasta la formación de las tétradas y en esa etapa forma un plasmodio que invade la cavidad esporangial la cual rodea parcialmente las tétradas y luego las esporas, y aparecen las cámaras plasmodiales, un término propuesto aquí para las formaciones designadas en inglés "tapetal gaps". La pared del esporangio queda reducida a dos capas celulares: una externa con engrosamientos lignificados en todas las paredes celulares y una interna picnótica. Al finalizar la esporogénesis, el tapete degenera, y las esporas, con exosporio, perisporio delgado, casi membranáceo y eláteres quedan libres en la cavidad esporangial. El esporodermo, los núcleos y nucléolos presentan fluorescencia roja, inducida por coloración con safranina O, mientras que los eláteres y las células de la pared del esporangio presentan autofluorescencia amarillo-naranja.

ENDOCRINE-PARACRINE CELLS IN THE SEMINAL VESICLES OF THE GUINEA PIG / 解剖学报

Endocrine-paracrine (EP) cells, also known as APUD or neuroendocrine cells, have been known to exist in the mammalian genito-urinary system. A fairly common localization is in the prostate and urethra. In this study we demonstrated for the first time the presence of small number of EP cells in the dissociated epithelial cells of the seminal vesicles of the guinea pig. The EP cells exhibited yellow FIF, while a few green or yellow-green FIF cells can be observed after L-dopa treatment. They were stained positive by the Masson-Fontana's method but consistently negative with the Grimelius silver methods indicating that they were of argentaffin nature or other paracrine cells.