Violet LED-Based Tooth Whitening and Resin Composite Restorations to Reestablish Smile Aesthetics Case Report

ABSTRACT: This clinical case described the aesthetic treatment of a patient complaining about the aspect of their upper teeth. After anamnesis and clinical examination, the association of tooth whitening photoactivated by violet LED and resin composite restorations was indicated. Prior to restorative treatment, three bleaching sessions were performed with low concentration hydrogen peroxide (6 %; Nano white flex) for 30 minutes. During this period, violet LED irradiation was intercalating performed every 1 minute, totalizing 15 minutes. Ten days after the final bleaching session, old restorations in the upper lateral incisors were removed for better color selection of resin composites. Then, all upper anterior teeth were directly restored with nanofilled resin composite (Filtek Z350XT), reestablishing anatomy, form, and function. At the end of the treatment, the association of techniques proved to be cost-effective, restoring the esthetics satisfactorily and promoting the patient's well-being by a minimally invasive approach.

RESUMEN: En este reporte de caso se describió el tratamiento para una paciente que se quejaba del aspecto de sus dientes superiores. Tras anamnesis y exploración clínica, se indicó la asociación de blanqueamiento dental fotoactivado por LED violeta y restauraciones de resina compuesta. Antes del tratamiento restaurador, se realizaron tres sesiones de blanqueamiento con peróxido de hidrógeno de baja concentración (6 %; Nano white flex) durante 30 minutos. Durante este período, la irradiación con LED violeta se intercalaba cada 1 minuto, totalizando 15 minutos. Diez días después de la última sesión de blanqueamiento, se retiraron las restauraciones antiguas de los incisivos laterales superiores para una mejor selección del color de la resina compuesta. Luego, todos los dientes anteriores superiores fueron restaurados de manera directa con resina de nanorrelleno (Filtek Z350XT), restableciendo la anatomía, forma y función. Al final del tratamiento, la asociación de las técnicas resultó beneficioso, restaurando la estética de forma satisfactoria y promoviendo el bienestar de la paciente mediante un abordaje mínimamente invasivo.

The effects of repetitive firing processes on the optical, thermal, and phase formation changes of zirconia

PURPOSE: The aim of this study was to investigate the effect of different numbers of heat treatments applied to superstructure porcelain on optical, thermal, and phase formation properties of zirconia.MATERIALS AND METHODS: Forty zirconia specimens were prepared in the form of rectangular prism. Specimens were divided into four groups (n = 10) according to the number of firing at heating values of porcelain. Color differences and translucency parameter were measured, and X-ray diffraction (XRD) analysis and differential scanning calorimetry (DSC) were performed. Data were analyzed with analysis of variance (ANOVA).RESULTS: There were no statistically significant differences in ΔE, TP, L, a, and b value changes of the zirconia specimens as a result of repetitive firing processes (P>.05).CONCLUSION: Although additional firing processes up to 4 increase peak density in thermal analysis, additional firing processes up to 4 times can be applied safely as they do not result in a change in color and phase character of zircon frameworks.

Optical properties of polyvinyl alcohol membrane with n-HAp for bio-medical applications

Composite membrane as a flexible materials have found diverse applications in industrial and biomedical simultaneously, the recent studies have shown intrinsic improvement for membrane properties by inclusion of nanoparticles as a fillers with high portion ratio in inorganic polymers, the combination between two parts polymer and filler is as a result of collection the advantage of two component systems parts together. In this work, samples of polyvinyl alcohol (PVA)-nanoHaydroxyapatite (nHAp) composites were prepared by using casting method. The effects of addition of (nHAp) with different concentration on the optical properties of (PVA- nHAp) composite membrane have been studied by using wavelength range (220-820) nm. The absorption spectra, transmittance spectra, absorption coefficient, energy gap, refractive index, optical conductivity and extinction coefficient have been determined. The results show that the optical constants change with the increase of nHPA concentrations.

Mechanical and optical properties of conventional restorative glass-ionomer cements - a systematic review

Abstract Objectives To perform a systematic review of test methodologies on conventional restorative glass-ionomer cement (GIC) materials for mechanical and optical properties to compare the results between different GICs. Material and Methods Screening of titles and abstracts, data extraction, and quality assessments of full-texts were conducted in search for in vitro studies on conventional GICs that follow the relevant specifications of ISO standards regarding the following mechanical and optical properties: compressive strength, flexural strength, color, opacity and radiopacity. Sources The Latin American and Caribbean Health Sciences (LILACS), Brazilian Bibliography of Dentistry (BBO) databases from Latin-American and Caribbean System on Health Sciences Information (BIREME) and PubMed/Medline (US National Library of Medicine - National Institutes of Health) databases were searched regardless of language. Altogether, 1146 in vitro studies were selected. Two reviewers independently selected and assessed the articles according to pre-established inclusion/exclusion criteria. Among all the properties investigated, only one study was classified as being of fair quality that tested compressive strength and was included. It was observed that many authors had not strictly followed ISO recommendations and that, for some properties (diametral tensile strength and microhardness), there are no guidelines provided. Conclusions It was not possible to compare the results for the mechanical and optical properties of conventional restorative GICs due to the lack of standardization of studies.

Synthesis of Bifunctional Graphene Quantum Dots and Its Application in Fluorescence Detection of pH and Cell Imaging / 分析化学

Functional groups may change the electrical characteristics of graphene quantum dots,thus leading to the improvement of their properties and related applications. To improve the optical properties,we designed and synthesized pentaethylene hexamine and dodecylamine functionalized graphene quantum dots (PEHA-GQD-DA). Citric acid was mixed with pentaethylene hexamine and heated at 170℃ for 0.5 h. Then dodecylamine was added and the reaction was continued at 160℃ for 1.5 h to obtain PEHA-GQD-DA. The Yesults revealed that the PEHA-GQD-DA was composed of the graphene sheets from 1 nm to 3 nm,and their edges contained abundant functional groups. The introduction of pentaethylene hexamine greatly improved the fluorescence emission. The fluorescence quantum yield reached 72.7%,which was much higher than that of the GQD prepared by the thermal hydrolysis of single citric acid. The introduction of dodecylamine created a special amphiphilic structure that allows the quantum dots more likely to enter cell through the phospholipid bilayer of cell membrane. The PEHA-GQD-DA exhibited an excellent optical behavior for pH value of the medium. Within pH range of 1.0-6.5, the fluorescence intensity increased with the increase of pH value. The fluorescence spectrum sensitively changed with the change of pH value. There was a good linear relationship between the maximum emission wavelength and the pH value. When the pH was in the range of 6.5-12.0,the fluorescence spectrum didn't change with the change of pH value. However, its fluorescence intensity linearly decreased with the increase of pH value. The existence of common inorganic ions and organic small molecules does not interfere with pH response of the quantum dots. The PEHA-GQD-DA has been successfully applied to fluorescent detection of pH value in water samples and Hela cell imaging.

Change of optical properties and microstructure of an Ag-Pd-In alloy according to Ag content / 대한치과재료학회지

In this study, change of optical properties and microstructure of an Ag-Pd-In alloy according to Ag content was investigated. For this purpose, specimen alloys were prepared by adding 0–100 wt.% of Ag to the 50Pd-50In (wt.%) alloy. When the content of Ag was more than 40 wt.%, the color difference with pure gold specimen was increased(p < 0.001). L* value increased as the Ag content of the specimen increased, but a* and b* value increased until the addition of 20 wt.% Ag, and then decreased with increasing Ag content(p < 0.001). Ag-free specimen was single phase in the as-cast state, but when the content of Ag was more than 20 wt.%, the phase separation occurred and two phases of matrix and dendrite or granular structure were confirmed. The dendrite or granular structure was composed of the InPd phase, and the matrix was composed of the Ag-rich phase. From these results, it can be concluded that the specimens with Ag content of 20–70 wt.% have the Ag-rich matrix which has a high L* value and low a* and b* value, and have the dendrite structure which has a low L* value and high a* and b* value. As the content of Ag increased, the color changed from light yellow to silver white due to the increase in the ratio of the matrix to the dendrite or granular structure.

Influence of Resin Cements on Color Stability of Different Ceramic Systems

Abstract The purpose of this study was to evaluate color stability of two dental ceramics cemented with two resin cements, assessing the color difference (ΔE00) by the measurement of L*, a*, b*, c* and h* of transmittance. The combination of two ceramic system (feldspathic and lithium disilicate) and two resin cements - color A3 (RelyX ARC and Variolink II) resulted in 4 groups (n=5). Ten disks-shaped specimens were fabricated for each ceramic system (10x1.5 mm), etched with hydrofluoric acid (10%) and silanized prior to cementation. The color analysis was performed 24 h after cementation of the samples and after 6 months of storage in relative humidity by means of spectrophotometry. The ΔE00 values were analyzed statistically by two-way ANOVA followed by the Tukey test (p<0.05). One-way ANOVA were calculated for the means of individual color coordinates (L*, a*, b*, c* and h*). Two-way ANOVA showed that only the ceramic factor was significant (p=0.003), but there was no difference for the cement factor (p=0.275) nor for the ceramic/cement interaction (p=0.161). The feldspathic ceramic showed the highest values of ΔE00. Variations in L*, a*, b*, c* and h* were more significant for feldspathic ceramic. In conclusion, storage alters similarly the optical properties of the resin cements and feldspathic porcelain was more susceptible to cement color change after aging.

Resumo O objetivo deste estudo foi avaliar a estabilidade da cor de dois sistemas cerâmicos em função de dois cimentos resinosos, avaliando a diferença de cor (ΔE00) pela mensuração de L*, a*, b*, c* e h* de transmitância. Formou-se 4 grupos (n=5) de acordo com as duas cerâmicas (reforçada com dissilicato de lítio e feldspática) e dois cimentos resinosos - cor A3 (RelyX ARC e Variolink II). Dez discos foram confeccionados para cada sistema cerâmico (10 x 1,5 mm), tratados com ácido fluorídrico (10%) e silanizados antes da cimentação. A análise de cor foi feita 24 h após a cimentação das amostras e após 6 meses de armazenamento em umidade relativa por meio de espectrofotometria. ANOVA a dois fatores foi utilizada para análise dos dados de ΔE00 seguido pelo teste de Tukey (p<0,05). ANOVA a um fator foi realizada para avaliação das coordenadas individuais de cor (L*, a*, b*, c* e h*). Apenas o fator cerâmica foi significativo (p=0,003),mas não houve diferença para o fator imento (p=0,275) nem para a interação entre cerâmica e cimento (p=0,161). A cerâmica feldspática apresentou os maiores valores de ΔE00. Variações de L*, a*, b*, c* e h* foram mais significativas para cerâmica feldspática. Concluiu-se que o armazenamento alterou as propriedades ópticas dos cimentos resinosos de forma semelhante e a porcelana feldspática foi mais susceptível à mudança de cor do cimento após o envelhecimento.

Contrast observation of the effect of frame mirror and corneal contact lens correction on the optical properties of the human eye / 中国生化药物杂志

Objective To explore the effect of the contrast frame mirror and the corneal contact lens correction on the optical properties of the human eye.Methods120 cases of myopia patients from 2014 September to September 2015 in our hospital for vision correction were randomly divided into two groups: control group, observation group wearing frame mirror, wearing contact lens, the optical properties of the eye were compared between the two groups.ResultsThe corrected visual acuity of observation group hadno significant difference compared with the control group;no significant difference in the values of refractive foveal contrast;foveal refractive value contrast in the two groups had no statistical difference;the observation group T30 degrees for peripheral refraction was (1.00±0.21) D, N30°peripheralrefraction was (0.34±0.08) D,were significantly lower than the control group (P<0.05).The good rate of observation group was significantly higher than the control group, the incidence of corneal complications was significantly lower than that of the control group (P<0.05).ConclusionThe frame and the corneal contact lens can be well corrected visual acuity, the corneal contact lens for the correction of certain peripheral hyperopic defocus has advantages, can effectively reduce the peripheral hyperopic defocus, delaying myopia, and improve the comfort and safety.

Color stability of ceramic brackets immersed in potentially staining solutions

OBJECTIVE: To assess the color stability of five types of ceramic brackets after immersion in potentially staining solutions.METHODS: Ninety brackets were divided into 5 groups (n = 18) according to brackets commercial brands and the solutions in which they were immersed (coffee, red wine, coke and artificial saliva). The brackets assessed were Transcend (3M/Unitek, Monrovia, CA, USA), Radiance (American Orthodontics, Sheboygan, WI, USA), Mystique (GAC International Inc., Bohemia, NY, USA) and Luxi II (Rocky Mountain Orthodontics, Denver, CO, USA). Chromatic changes were analyzed with the aid of a reflectance spectrophotometer and by visual inspection at five specific time intervals. Assessment periods were as received from the manufacturer (T0), 24 hours (T1), 72 hours (T2), as well as 7 days (T3) and 14 days (T4) of immersion in the aforementioned solutions. Results were submitted to statistical analysis with ANOVA and Bonferroni correction, as well as to a multivariate profile analysis for independent and paired samples with significance level set at 5%.RESULTS: The duration of the immersion period influenced color alteration of all tested brackets, even though these changes could not always be visually observed. Different behaviors were observed for each immersion solution; however, brackets immersed in one solution progressed similarly despite minor variations.CONCLUSIONS: Staining became more intense over time and all brackets underwent color alterations when immersed in the aforementioned solutions.

OBJETIVO: avaliar a estabilidade da cor de cinco tipos de braquetes cerâmicos após imersão em soluções potencialmente corantes.MÉTODOS: noventa braquetes foram divididos em 5 grupos (n = 18) de acordo com a marca comercial dos braquetes e as soluções em que foram imersos (café, vinho tinto, Coca-Cola e saliva artificial). Os baquetes avaliados foram Transcend (3M / Unitek, Monrovia, CA, EUA), Radiance (American Ortodontia, Sheboygan, WI, EUA), Mystique (GAC International Inc., Bohemia, NY, EUA) e Luxi II (Rocky Mountain Orthodontics, Denver, CO, EUA). Alterações cromáticas foram analisadas com o uso de um espectrofotômetro de reflectância e por inspecção visual, em cinco intervalos de tempo específicos. Os momentos de avaliação foram: 24 horas (T1), 72 horas (T2), 7 dias (T3) e 14 dias (T4) de imersão nas soluções. Os resultados foram submetidos à avaliação estatística com análise de variância e correção de Bonferroni, bem como a uma análise do perfil multivariada para amostras independentes e pareadas, com nível de significância de 5%.RESULTADOS: a duração do período de imersão influenciou na alteração de cor de todos os braquetes testados, mesmo admitindo-se que essas alterações nem sempre puderam ser observadas visualmente. Diferentes comportamentos foram observados em cada solução de imersão; no entanto, braquetes imersos em um mesmo tipo de solução progrediram de forma semelhante, apesar das pequenas variações.CONCLUSÕES: a coloração se tornou mais intensa com o tempo, e todos os braquetes sofreram alteração de cor nas soluções imersas.

Gold Nanoparticles synthesis, properties, and forthcoming applications – A review .

Gold nanoparticles (AuNPs) have several biomedical applications in diagnosis and treating of disease such as targeted chemotherapy and in pharmaceutical drug delivery due to their multifunctionality and unique characteristics. AuNPs can be conjugated with ligands, imaging labels, therapeutic drugs and other functional moieties for site specific drug delivery application. In this present review we are discussing the synthesis, properties, and forthcoming applications of gold nanoparticle (AuNPs) which is the most studied among all other metallic-nanoparticles. Here our main focus is to explain the AuNPs application in cancer treatment. AuNPs provides non-toxic carrier system for pharmaceutical drug and gene delivery applications. Currently various anticancer drugs are available but these are cause the necrosis of cancerous cell as well as normal cells. AuNPs cause the necrosis of only cancer cells therefore we can utilize it as a delivery vehicle as well as anticancer agent.

A comparison of tensile weld strength and microstructural changes in four arch wires, before and after immersion in 1.23% acidulated phosphate fluoride solution: An in-vitro study.

Objectives: The objective of this study is to evaluate and to compare the tensile weld strengths and microstructural changes in four archwires namely beta titanium, stainless steel (SS), blue elgiloy and timolium before and after immersion in 1.23% acidulated phosphate fluoride (APF) solution. Materials and Methods: The mean tensile weld strength of a weld joint of four arch wires were compared pre‑fluoride (Group 1) with post fluoride (Group 2) and the microstructural characteristics of weld joints were evaluated under an optical microscope. Results: The mean tensile weld strength for beta titanium was 445.64 N/mm2, blue elgiloy was 363.26 N/mm2, SS was 358.30 N/mm2 and timolium was 308.62 N/mm2. After immersion in fluoride the mean tensile strength for beta titanium was 427.16 N/mm2, blue elgiloy was 359.86 N/mm2, SS is 349.44 N/mm2 and timolium is 294.86 N/mm2. After immersion in fluoride, the beta titanium and SS had a smooth fusion at the center of weld assembly with characteristic nugget formation. The beta titanium weld assembly had greater tensile weld strength than other welded assemblies. Blue elgiloy ranked second, whereas SS and timolium were third and fourth respectively. Conclusion: The wires in descending order of their mean tensile weld strength, on evaluation of their weld joints were found to be: Beta titanium > blue elgiloy > SS > timolium. The reduction in tensile weld strength was statistically insignificant for all the archwires after exposure to 1.23% APF at 37°C for 90 min.

Influence of exogenous pigmentation on the optical properties of orthodontic elastic ligatures

OBJECTIVES: The aim of this study was to assess the optical properties of orthodontic elastic ligatures under the influence of exogenous pigments contained in the daily diet. MATERIAL AND METHODS: For the analysis, colorless (clear) elastic segments (ORTHO Organizers, lot 660625A10) were used as received from the manufacturer, and were divided into 8 groups of 3 segments each. Each group was immersed in 200 mL of a solution containing a determined substance, as follows: distilled water (control group), Coca-Cola®, Pomarola brand tomato sauce (Cica®), açai, Jasmine® brand green tea, Royal Blend® black tea brand, Pilão® brand coffee and Palmares® wine brand. All test specimens were immersed in the solutions and kept in an appropriate receptacle for 7 days at 37°C14. After the staining session, the test specimens were washed with distilled water in an ultrasonic vat for 5 min and dried with paper tissues6. The portable digital spectrophotometer Vita Easyshade Compact was used to assess if there was color variation of the test specimens. This variation was quantified and qualified at the initial time (T0) and after staining (T1). RESULTS: These results were analyzed statistically using the software SPSS version 18.0. The Shapiro-Wilk test of normality was applied followed by the one-way analysis of variance and the Tukey's post hoc test. The level of significance adopted was 5%. CONCLUSIONS: From the substances evaluated in this study, those with higher staining potential on esthetic elastic ligatures were black tea, coffee and wine, respectively. Knowing this information, the dentist may advise their patients to avoid certain foods because of elastic staining may occur thus decreasing the aesthetics of the material.

Different Optical Properties between Human Hepatocellular Carcinoma Tissues and Non-tumorous Hepatic Tissues In Vitro / 华中科技大学学报（医学）（英德文版）

There has been an ongoing search for clinically acceptable methods for the accurate,efficient and simple diagnosis and prognosis of hepatocellular carcinoma (HCC).Optical spectroscopy is a technique with potential clinical applications to diagnose cancer diseases.The purpose of this study was to obtain the optical properties of HCC tissues and non-tumorous hepatic tissues and identify the difference between them.A total of 55 tissue samples (HCC tissue,n=38; non-tumorous hepatic tissue,n=17)were surgically resected from patients with HCC.The optical parameters were measured in 10-nm steps using single-integrating-sphere system in the wavelength range of 400 to 1800 nm.It was found that the optical properties and their differences varied with the wavelength for the HCC tissue and the non-tumorous hepatic tissue in the entire wavelength range of research.The absorption coefficient of the HCC tissue (1.48±0.99,1.46±0.88,0.86±0.61,2.15±0.53,0.54±0.10,0.79±0.15 mm-1) was significantly lower than that of the non-tumorous hepatic tissue (2.79±1.73,3.13±1.47,3.06±2.79,2.57±0.55,0.62±0.10,0.93±0.16 mm-1) at wavelengths of 400,410,450,1450,1660 and 1800 nm,respectively (P＜0.05).The reduced scattering coefficient of HCC tissue (5.28±1.70,4.91±1.54,1.26±0.35 mm-1) and non-tumorous hepatic tissue (8.14±3.70,9.27±3.08,2.55±0.57 mm-1) was significantly different at 460,500 and 1800 nm respectively (P＜0.05).These results show different pathologic liver tissues have different optical properties.It provides a better understanding of the relationship between optical parameters and physiological characteristics in human liver tissues.And it would be very useful for developing a non-invasive,real-time,simple and efficient way for medical management of HCC in the future.