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1.
Environ Geochem Health ; 46(9): 322, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39012612

RESUMO

Efficient treatment of textile dyeing wastewater can be achieved through electrocoagulation (EC) with minimal sludge production; however, the selection of the appropriate electrode is essential in lowering overall costs. Also, the reuse of the treated aqueous azo dye solution from this process has not been explored in detail. With these objectives, this study aims to treat synthetic azo dye solutions and achieve high colour removal efficiency (CRE%) using similar (Ti-Ti) and dissimilar (Ti-Cu) metal electrodes through EC with an attempt to reduce the cost. The aqueous Coralene Rubine GFL azo dye was used to examine the efficiency and cost of the EC process. X-Ray Photoelectron Spectroscopy was used to study the EC mechanism, while High Performance Liquid Chromatography was used to analyse the degradation of the dye and the formation of intermediate compounds. The concentration of metal ions in the treated dye solution was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), with Ti-Ti treated solution having 14.20 mg/L concentration of Ti and Ti-Cu treated solution having 0.078 mg/L of Ti and 0.001 mg/L of Cu, respectively. Colour removal efficiency of 99.49% was obtained for both electrode sets, with a lower operating time and voltage for dissimilar metal combination. Ecotoxicity studies showed negligible toxicity of Ti-Cu treated dye samples compared to untreated solutions. Survival rate, protein estimation, and catalase activity was used to validate the treatment method's efficacy. The study found that the dissimilar electrode material exhibited reduced toxicity due to the presence of heavy metals below the permissible limit.


Assuntos
Eletrólise , Eletrodos , Corantes/química , Corantes/economia , Corantes/toxicidade , Eletrólise/métodos , Concentração de Íons de Hidrogênio , Espectrofotometria , Cromatografia Líquida de Alta Pressão , Animais , Peixe-Zebra , Titânio/química , Cobre/química
2.
Georgian Med News ; (349): 103-109, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38963212

RESUMO

Aims - to compare the color changes, the surface roughness and morphology of the enamel bleached with two different bleaching solutions (chemical and laser activated), preceded or not with acid etching. Thirty teeth of bovine prepared and haphazardly assigned to 2 groups (n=15) depending on bleaching technique. Each group subdivided to 3 subgroup (n=5) consistent with acid etching by 37% phosphoric acid. Atomic force microscopy and VITA easy shade spectrophotometer were performed twice for all the specimens before and after bleaching. ANOVA, the Paired sample t-test, and the independent sample t-test used for statistical analysis. As for the color changes, the groups that were bleached by the chemical method, the difference among the three subgroups was statistically significant. This also applies to the groups bleached with the laser method. When comparing the results of the chemical bleaching subgroups with the laser bleaching ones, the difference was not significant. Roughness results showed significant differences between certain subgroups and non-significant differences among others. However, the difference was statistically significant between the chemical and laser groups, laser technique resulted in less surface roughness than the chemical one. Acid etching before bleaching produced better colour change in both the chemical and laser assisted bleaching. In chemical bleaching, surface roughness was higher when acid etching was used. This was also true for laser bleaching technique. In general, laser assisted bleaching produced less surface roughness than chemical bleaching.


Assuntos
Condicionamento Ácido do Dente , Esmalte Dentário , Propriedades de Superfície , Clareamento Dental , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/química , Bovinos , Animais , Clareamento Dental/métodos , Propriedades de Superfície/efeitos dos fármacos , Cor , Ácidos Fosfóricos/química , Ácidos Fosfóricos/farmacologia , Microscopia de Força Atômica , Clareadores Dentários/química , Clareadores Dentários/farmacologia , Espectrofotometria , Lasers
3.
J Photochem Photobiol B ; 257: 112970, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38955079

RESUMO

The aim of this study was to evaluate the effectiveness of a laser-assisted in-office tooth bleaching treatment, employing a diode laser (445 nm) using different power and time settings. Two hundred human incisors were collected for evaluating tooth color change (ΔΕ00) and whiteness index in dentistry (ΔWID) following laser-assisted tooth bleaching treatment. The specimens were distributed into 25 groups (n = 8) according to laser output power (0.5-2 W) and duration of irradiation (10-60 s) that was applied. ΔΕ00 and ΔWID were evaluated using a spectrophotometer at three points of time (24 h, 1 week and 1 month after treatments). Three-way ANOVA revealed that power, duration of laser irradiation, and time of measurement after bleaching treatments significantly affected both ΔΕ00 and ΔWID(p < 0.05). Furthermore, laser irradiation increased ΔΕ00 and ΔWID at all applied powers compared to the control group (p < 0.05), but this increase was dependent on the duration of irradiation. Laser irradiation significantly increased ΔΕ00 when the duration of operation was 50-60 s at 0.5-1 W, while at 1.5-2 W was significantly increased when the duration was 30-60 s. ΔWID was significant higher in the laser groups compared to the control group at all powers, except for 0.5 W where it was significant higher when the duration was 50-60 s. The outcomes of the study can help in selecting the suitable power settings and duration of laser exposure to achieve the optimal whitening results while ensuring the safety of the tooth pulp.


Assuntos
Lasers Semicondutores , Clareamento Dental , Clareamento Dental/métodos , Humanos , Lasers Semicondutores/uso terapêutico , Incisivo/efeitos da radiação , Fatores de Tempo , Espectrofotometria , Cor
4.
Clin Lab ; 70(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38965940

RESUMO

BACKGROUND: Alcohol poisoning is a significant global problem that has become an epidemic. The determination of the alcohol type is hereby essential as it may affect the course of the treatment; however, there is no routine laboratory diagnostic method for alcohol types other than for ethanol. In this study, we aimed to define a simple method for alcohol type differentiation by utilizing a combination of breathalyzer and spectrophotometrically measured serum ethanol results. METHODS: A breathalyzer and spectrophotometry were used to measure four different types of alcohol: ethanol, isopropanol, methanol, and ethylene glycol. To conduct serum alcohol analysis, four serum pools were created, each containing a different type of alcohol. The pools were analyzed using the spectrophotometric method with an enzymatic ethanol test kit. An experiment was conducted to measure the different types of alcohol using impreg-nated cotton and a balloon, simulating a breathalyzer test. An algorithm was created based on the measurements. RESULTS: Based on the results, the substance consumed could be methanol or isopropanol if the breathalyzer test indicates a positive reading and if the blood ethanol measurement is negative. If both the breathalyzer and the blood measurements are negative, the substance in question may be ethylene glycol. CONCLUSIONS: This simple method may determine methanol or isopropanol intake. This straightforward and innovative approach could assist healthcare professionals in different fields with diagnosing alcohol intoxication and, more precisely, help reducing related morbidity and mortality.


Assuntos
2-Propanol , Testes Respiratórios , Etanol , Etilenoglicol , Metanol , Humanos , Etanol/sangue , Metanol/química , Testes Respiratórios/métodos , Etilenoglicol/sangue , Etilenoglicol/intoxicação , Espectrofotometria/métodos , Intoxicação Alcoólica/diagnóstico , Intoxicação Alcoólica/sangue , Concentração Alcoólica no Sangue , Algoritmos
5.
Clin Exp Dent Res ; 10(4): e918, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38970231

RESUMO

AIMS AND OBJECTIVES: To evaluate the effect of coffee thermocycling on color stability and translucency of CAD-CAM polychromatic high translucent zirconia compared with lithium disilicate glass ceramic. METHODS: Sixteen rectangular plates (14 × 16 × 1.0 mm) of two ceramic materials (IPS E.max CAD (IEC), IPS E.max ZirCAD Prime [IZP]) were prepared. Each specimen was measured for color coordinates using a spectrophotometer following 30,000 cycles of coffee thermocycling. CIELAB formula was used to determine color and translucency differences (ΔE and ΔTP). The means of ΔE and ΔTP were compared using independent samples t-test and were evaluated using their respective 50%:50% perceptibility and acceptability thresholds (PT and AT). One-way analysis of variance was performed to evaluate the translucency parameter (TP) and surface roughness (Ra) of each material. RESULTS: Mean ΔE values of IEC (4.69) and IZP (4.64) were higher than the AT (ΔE ≤ 2.7) with no significant difference found between the two groups (p = 0.202). Considering the TP, only IEC showed a statistically significant increase in TP value (p < 0.001). However, the mean ΔTP of IEC (3.25) remained within the range of acceptability (1.3 < ΔTP ≤ 4.4). CONCLUSIONS: Within the limitations of this current study, the color stability of all materials was clinically affected by coffee thermocycling. In terms of translucency, only lithium disilicate glass ceramic was influenced by coffee thermocycling. High translucent zirconia had superior translucency stability compared to lithium disilicate glass ceramic.


Assuntos
Cerâmica , Café , Cor , Desenho Assistido por Computador , Porcelana Dentária , Teste de Materiais , Propriedades de Superfície , Zircônio , Cerâmica/química , Porcelana Dentária/química , Zircônio/química , Café/química , Humanos , Espectrofotometria , Materiais Dentários/química
6.
Clin Exp Dent Res ; 10(4): e916, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38970227

RESUMO

OBJECTIVES: This study assessed the effects of 15% and 20% carbamide peroxide (CP) on color, surface roughness, and hardness of computer-aided design/computer-aided manufacturing (CAD/CAM) dental ceramics. MATERIALS AND METHODS: This in vitro study was conducted on 120 Vita Mark II, Celtra Duo, and Suprinity CAD/CAM ceramic specimens. The ceramic specimens in each group (n = 40) were randomly assigned to two subgroups (n = 20) for polishing and glazing, and their baseline color, surface roughness (Ra), and hardness were assessed. In each subgroup, half of the specimens were exposed to 15% CP, while the other half were exposed to 20% CP. Their color change (ΔE), surface roughness, and hardness were then measured again. Surface roughness, hardness, and color were analyzed sequentially by profilometer, Vickers hardness tester, and spectrophotometer, respectively. Data were analyzed by repeated measures ANOVA, one-way ANOVA, and post hoc Bonferroni test (α = 0.05). RESULTS: The surface roughness of all groups significantly increased after bleaching treatment (p < 0.05). Surface hardness of all groups decreased after bleaching treatment, but this reduction was only significant in Vita Mark II subgroups (glazed, polished, 15%, and 20% CP). The ΔE was not clinically and visually perceivable in any group. CONCLUSION: The present results revealed that concentration of CP and type of surface treatment affected the surface properties of CAD/CAM ceramics. Type of surface treatment only affected the surface hardness of Vita Mark II ceramics (p < 0.05). Concentration of CP had a significant effect only on polished Vita Mark II.


Assuntos
Peróxido de Carbamida , Cerâmica , Cor , Desenho Assistido por Computador , Dureza , Teste de Materiais , Peróxidos , Propriedades de Superfície , Peróxido de Carbamida/química , Propriedades de Superfície/efeitos dos fármacos , Dureza/efeitos dos fármacos , Cerâmica/química , Peróxidos/química , Porcelana Dentária/química , Ureia/química , Ureia/análogos & derivados , Ureia/farmacologia , Clareadores Dentários/química , Humanos , Técnicas In Vitro , Materiais Dentários/química , Espectrofotometria
7.
Clin Oral Investig ; 28(8): 436, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030259

RESUMO

OBJECTIVES: To evaluate the effect of whitening toothpastes with different hydrogen peroxide (HP) concentrations on HP permeability, color change, and physicochemical properties, compared to at-home bleaching treatment. MATERIALS AND METHODS: Forty-nine premolars were randomized into seven groups (n = 7): untreated (control); at-home bleaching with 10% carbamide peroxide gel (AH; 10% CP) with 14 and 28 applications of 180 min each (AH [14 × 180 min] and AH [28 × 180 min]); three whitening toothpastes (3% HP; 4% HP and 5% HP) and 10% CP brushed 28 times for 90 s each (TB [28 × 90 s]). HP permeability was measured using a UV-VIS spectrophotometer and color change by a digital spectrophotometer (ΔEab, ΔE00, and ΔWID). Initial concentration, pH, and viscosity were measured through titration, digital pH meter, and rheometer, respectively. Statistical analysis included one-way ANOVA, Tukey's test, and Dunnett's test (α = 0.05). RESULTS: 4% HP group showed acidic pH, the lowest viscosity and the highest HP concentration into the pulp chamber (p < 0.05). The 10% CP groups had lower HP in the pulp chamber and greater color change than other groups (p < 0.05), except the 5% HP group in ΔEab and ΔE00. For ΔWID, the 10% CP AH groups showed greater whitening than other groups (p < 0.05). CONCLUSIONS: Whitening toothpaste with up to 5% HP resulted in higher HP permeability and less color change compared to 10% CP. Higher HP commercial concentrations in toothpaste increased whitening effect; however, acidic pH toothpastes exhibited greater HP permeability. CLINICAL RELEVANCE: Whitening toothpastes with high hydrogen peroxide concentrations were less effective than at-home bleaching, resulting in less color change and greater permeability of hydrogen peroxide, potentially increasing the risk of tooth sensitivity.


Assuntos
Peróxido de Carbamida , Peróxido de Hidrogênio , Espectrofotometria , Clareadores Dentários , Clareamento Dental , Cremes Dentais , Clareamento Dental/métodos , Cremes Dentais/química , Humanos , Clareadores Dentários/química , Técnicas In Vitro , Dente Pré-Molar , Viscosidade , Concentração de Íons de Hidrogênio , Espectrofotometria Ultravioleta , Ureia/análogos & derivados , Ureia/farmacologia
8.
Planta ; 260(2): 40, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954049

RESUMO

MAIN CONCLUSION: Rainwater most probably constitutes a relatively effective solvent for lichen substances in nature which have the potential to provide for human and environmental needs in the future. The aims were (i) to test the hypothesis on the potential solubility of lichen phenolic compounds using rainwater under conditions that partly reflect the natural environment and (ii) to propose new and effective methods for the water extraction of lichen substances. The results of spectrophotometric analyses of total phenolic metabolites in rainwater-based extracts from epigeic and epiphytic lichens, employing the Folin-Ciocalteu (F.-C.) method, are presented. The water solvent was tested at three pH levels: natural, 3, and 9. Extraction methods were undertaken from two perspectives: the partial imitation of natural environmental conditions and the potential use of extraction for economic purposes. From an ecological perspective, room-temperature water extraction ('cold' method) was used for 10-, 60-, and 120-min extraction periods. A variant of water extraction at analogous time intervals was an 'insolation' with a 100W light bulb to simulate the heat energy of the sun. For economic purposes, the water extraction method used the Soxhlet apparatus and its modified version, the 'tea-extraction' method ('hot' ones). The results showed that those extractions without an external heat source were almost ineffective, but insolation over 60- and 120-min periods proved to be more effective. Both tested 'hot' methods also proved to be effective, especially the 'tea-extraction' one. Generally, an increase in the concentration of phenolic compounds in water extracts resulted from an increasing solvent pH. The results show the probable involvement of lichen substances in biogeochemical processes in nature and their promising use for a variety of human necessities.


Assuntos
Líquens , Fenóis , Solubilidade , Espectrofotometria , Água , Líquens/química , Líquens/metabolismo , Fenóis/metabolismo , Fenóis/análise , Água/química , Solventes/química , Concentração de Íons de Hidrogênio , Chuva/química
9.
Clin Oral Investig ; 28(8): 431, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39017918

RESUMO

OBJECTIVES: The aim of this study was to evaluate the peri-implant perfusion, such as oxygen saturation, the relative amount of hemoglobin, and blood flow, in implants placed in pristine bone and avascular and microvascular grafts using a non-invasive measurement method. MATERIALS AND METHODS: A total of 58 patients with 241 implants were included. Among them, 106 implants were based in native bone (group I), 75 implants were inserted into avascular bone grafts (group II), and 60 implants were placed in microvascular bone grafts (group III). Gingival perfusion was measured using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS). Implants with signs of gingival inflammation were excluded to analyze healthy implant perfusion in different bony envelopes. RESULTS: The mean values for oxygen saturation, relative hemoglobin levels, and blood flow did not differ significantly between the groups (p = 0.404, p = 0.081, and p = 0.291, respectively). There was no significant difference in perfusion between implants that were surrounded by mucosa and implants based within cutaneous transplants (p = 0.456; p = 0.628, and p = 0.091, respectively). CONCLUSION: No differences in perfusion were found between implants inserted into native bone and implants involving bone or soft tissue augmentation. However, implants based in avascular and microvascular transplants showed higher rates of peri-implant inflammation. CLINICAL RELEVANCE: Peri-implant perfusion seems to be comparable for all implants after they heal, irrespective of their bony surroundings. Although perfusion does not differ significantly, other factors may make implants in avascular and microvascular transplants vulnerable to peri-implant inflammation.


Assuntos
Implantes Dentários , Fluxometria por Laser-Doppler , Espectrofotometria , Humanos , Fluxometria por Laser-Doppler/métodos , Masculino , Estudos Prospectivos , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Implantação Dentária Endóssea/métodos , Gengiva/irrigação sanguínea , Transplante Ósseo/métodos
10.
Methods Mol Biol ; 2792: 41-49, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38861077

RESUMO

Glutamate:glyoxylate aminotransferase (GGAT; EC 2.6.1.4) and serine:glyoxylate aminotransferase activities (SGAT; EC 2.6.1.45) are central photorespiratory reactions within plant peroxisomes. Both enzymatic reactions convert glyoxylate, a product of glycolate oxidase, to glycine, a substrate of the mitochondrial glycine decarboxylase complex. The GGAT reaction uses glutamate as an amino group donor and also produces α-ketoglutarate, which is recycled to glutamate in plastids by ferredoxin-dependent glutamate synthase. Using serine, a product of mitochondrial serine hydroxymethyltransferase, as an amino group donor, the SGAT reaction also produces hydroxypyruvate, a substrate of hydroxypyruvate reductase. The activities of these photorespiratory aminotransferases can be measured using indirect, coupled, spectrophotometric assays, detailed herein.


Assuntos
Espectrofotometria , Transaminases , Transaminases/metabolismo , Espectrofotometria/métodos , Glioxilatos/metabolismo , Ácido Glutâmico/metabolismo , Ensaios Enzimáticos/métodos , Respiração Celular
11.
Methods Mol Biol ; 2792: 29-39, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38861076

RESUMO

Phosphoglycolate phosphatase (PGLP) dephosphorylates 2-phosphoglycolate to glycolate that can be further metabolized to glyoxylate by glycolate oxidase (GOX) via an oxidative reaction that uses O2 and releases H2O2. The oxidation of o-dianisidine by H2O2 catalyzed by a peroxidase can be followed in real time by an absorbance change at 440 nm. Based on these reactions, a spectrophotometric method for measuring PGLP activity using a coupled reaction with recombinant Arabidopsis thaliana GOX is described. This protocol has been used successfully with either purified PGLP or total soluble proteins extracted from Arabidopsis rosette leaves.


Assuntos
Oxirredutases do Álcool , Arabidopsis , Monoéster Fosfórico Hidrolases , Proteínas Recombinantes , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Arabidopsis/metabolismo , Oxirredutases do Álcool/metabolismo , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/química , Monoéster Fosfórico Hidrolases/metabolismo , Monoéster Fosfórico Hidrolases/genética , Glicolatos/metabolismo , Ensaios Enzimáticos/métodos , Peróxido de Hidrogênio/metabolismo , Oxirredução , Folhas de Planta/metabolismo , Folhas de Planta/enzimologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Espectrofotometria/métodos
12.
Methods Mol Biol ; 2792: 77-81, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38861079

RESUMO

Hydroxypyruvate reductase (HPR; EC 1.1.1.81) activity is integral to the photorespiratory pathway. Within photorespiration, HPR catalyzes the reduction of hydroxypyruvate, a product of the serine:glyoxylate aminotransferase reaction to glycerate, a substrate for glycerate kinase, using NADH as cofactor. Here we detail a spectrophotometric assay for measuring HPR activity in vitro by following the consumption of NADH at 340 nm.


Assuntos
Ensaios Enzimáticos , Hidroxipiruvato Redutase , Espectrofotometria , Espectrofotometria/métodos , Hidroxipiruvato Redutase/metabolismo , Ensaios Enzimáticos/métodos , NAD/metabolismo
13.
BMC Oral Health ; 24(1): 712, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902697

RESUMO

OBJECTIVE: To evaluate the effects of different polishing techniques and coffee staining on the color stability of four commercially available bleach-shade composite resins, namely microhybrid, nanohybrid, nanofilled, and injectable nanohybrids. MATERIAL AND METHODS: A total of 224 discs (8 mm diameter and 2 mm thickness) were fabricated from four different bleach-shade composite resins, namely microhybrid (Gradia Direct Anterior), nanohybrid (Palfique LX5), nanofilled (Filtek Universal), and injectable nanohybrid (flowable G-aenial universal injectable). The composite resin groups were polished via four techniques: no polishing, 4-step polishing using aluminum oxide discs, 3-step polishing using silicon rubber diamond discs, and one-step polishing. Half of each group was immersed in water, while the other half was immersed in coffee for 12 days (n = 7). Colors were measured using a clinical spectrophotometer, and color differences were calculated (ΔE). The results were analyzed statistically. RESULTS: The alterations in color were significantly influenced by the techniques employed for finishing and polishing techniques, composite resin type, and degree of coffee staining. Regardless of the polishing technique and storage medium, different material types showed a significant color change (ΔE) at P < 0.001. Filtek exhibited the most significant color change, followed by Gradia and Palfique, with no significant differences between them. In addition, Different polishing techniques resulted in significant color changes (P < 0.001). The highest degree of color change was seen in the no-polishing group, followed by the 4-step and 1-step polishing groups, with negligible differences between each other. Also, Storage media had a significant effect on ΔE values. CONCLUSION: Appropriate finishing and polishing procedures can improve the color stability of bleach-shaded composite resins. Coffee has a deleterious effect on color; however, injectable flowable nanohybrid composites are more resistant to staining.


Assuntos
Óxido de Alumínio , Café , Cor , Resinas Compostas , Polimento Dentário , Propriedades de Superfície , Resinas Compostas/química , Polimento Dentário/métodos , Óxido de Alumínio/química , Teste de Materiais , Espectrofotometria , Técnicas In Vitro , Humanos , Diamante/química , Nanocompostos/química , Clareadores Dentários/química , Água/química , Materiais Dentários/química , Fatores de Tempo
14.
BMC Oral Health ; 24(1): 744, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937719

RESUMO

BACKGROUND: The translucency of different zirconia generations at each time point after thermocycling aging is still lacking. METHODS: Four zirconia materials were used with a total of 60 samples produced from monolithic third generation (5Y) 5 mol% yttria-stabilized zirconia polycrystalline ceramic and fourth generation zirconia (4Y) 4 mol% yttria-stabilized zirconia polycrystalline ceramic, represented by [group1:[CM-5Y] Ceramill Zolid fx (3rd generation zirconia) (Amann Girrbach, Koblach, Austria), group 2:[CM-4Y] Ceramill Zolid HT + (4th generation zirconia) (Amann Girrbach, Koblach, Austria), group 3:[CC-5Y] Cercon XT/ML (Dentsply Sirona, Germany) (3rd generation), and group 4:[CC-4Y] Cercon HT/ML (Dentsply Sirona, Germany) (4th generation)]. The L*a*b* figures were measured by using a spectrophotometer at baseline and after 10,000, 30,000, and 50,000 cycles of thermocycling. At each interval, the translucency of the samples was estimated by using the translucency formula CIEDE2000. The Scheffe post-hoc compared differences among each of the four materials. The Repeated measures ANOVA tested the differences between the materials at each of the different thermocycling intervals (p < .001). Data analyses were evaluated at a significance level of p < .05 (CI 95%). RESULTS: Two-way ANOVA revealed that at baseline the third and fourth generation's zirconia showed statistically significant differences in translucency (P < .001). Translucency values at baseline and after thermocycling exhibited statistically significant changes (p = .003). At each of the time interval; CM-4Y had the highest translucency values followed by CM-5Y, CC-4Y and CC-5Y had the least translucency values. CONCLUSIONS: The third and fourth generations of zirconia displayed different translucencies. Thermocycling affected the translucency of both third and fourth generations of zirconia. At each of the time intervals group 2:[CM-4Y] had the highest TP followed by group1:[CM-5Y], while, group 3:[CC-5Y] and group 4:[CC-4Y] had the least TP.


Assuntos
Teste de Materiais , Zircônio , Zircônio/química , Fatores de Tempo , Ítrio/química , Espectrofotometria , Materiais Dentários/química , Luz , Propriedades de Superfície , Cor , Temperatura , Humanos , Porcelana Dentária/química
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 320: 124614, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-38865892

RESUMO

Celecoxib and tramadol have been combined in a novel FDA-approved medication to address acute pain disorders requiring opioid treatment when other analgesics proved either intolerable or ineffective. The absorbance spectra of celecoxib and tramadol exhibit significant overlap, posing challenges for their individual quantification. This study introduces a spectrophotometric quantification approach for celecoxib and tramadol using a principle component regression assistive model to assist resolving the overlapped spectra and quantifying both drugs in their binary mixture. The model was constructed by establishing calibration and validation sets for the celecoxib and tramadol mixture, employing a five-level, two-factor experimental design, resulting in 25 samples. Spectral data from these mixtures were measured and preprocessed to eliminate noise in the 200-210 nm range and zero absorbance values in the 290-400 nm range. Consequently, the dataset was streamlined to 81 variables. The predicted concentrations were compared with the known concentrations of celecoxib and tramadol, and the errors in the predictions were evidenced calculating root mean square error of cross-validation and root mean square error of prediction. Validation results demonstrate the efficacy of the models in predicting outcomes; recovery rates approaching 100 % are demonstrated with relative root mean square error of prediction (RRMSEP) values of 0.052 and 0.164 for tramadol and celecoxib, respectively. The selectivity was further evaluated by quantifying celecoxib and tramadol in the presence of potentially interfering drugs. The model demonstrated success in quantifying celecoxib and tramadol in laboratory-prepared tablets, producing metrics consistent with those reported in previously established spectrophotometric methods.


Assuntos
Celecoxib , Análise de Componente Principal , Espectrofotometria , Tramadol , Celecoxib/análise , Celecoxib/química , Tramadol/análise , Espectrofotometria/métodos , Calibragem , Reprodutibilidade dos Testes , Formas de Dosagem , Analgésicos Opioides/análise
16.
BMC Oral Health ; 24(1): 660, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38840111

RESUMO

BACKGROUND: Effects of ceramic translucency, layer thickness, and substrate colour on the shade of lithium disilicate glass-ceramic restorations proved to be significant in several studies, however, quantitative, numerical results on the relationship between the colour difference and these parameters are still lacking. The purpose of this in vitro study was to quantitatively determine how the colour reproduction ability of a lithium disilicate glass-ceramic is affected by its translucency, layer thickness, and substrate colour. METHODS: Ceramic samples were prepared from A2 shade IPS e.max CAD blocks with high and low translucencies (HT and LT) in a thickness range of 0.5-2.5 mm (+/- 0.05 mm). Layered samples were acquired utilizing composite substrates in 9 shades; transparent try-in paste was used. The spectral reflectance of the specimens was assessed under D65 standard illumination with a Konica Minolta CM-3720d spectrophotometer. The CIEDE2000 colour difference (ΔE00) between two samples was analysed using perceptibility and acceptability thresholds set at 50:50%. Statistical analysis involved linear regression analysis and the Kruskal-Wallis test. RESULTS: An increase in the thickness of 0.5 mm reduced the ΔE00 of the HT samples to 72.8%, and that of the T samples to 71.1% (p < 0.0001). 7 substrates with HT and LT specimens had significantly different results from the mean (p < 0.05). A thickness of 0.5 mm is not sufficient to achieve an acceptable result at any level of translucency, while the low translucency ceramic at a thickness of 1.5 mm gave acceptable results, except for severely discoloured substrates (ND8 and ND9). CONCLUSIONS: The colour reproduction ability of lithium disilicate glass-ceramics is significantly affected by their translucency, layer thickness, and 7 substrates out of 9 substrates examined.


Assuntos
Cerâmica , Cor , Porcelana Dentária , Porcelana Dentária/química , Cerâmica/química , Pigmentação em Prótese , Espectrofotometria , Teste de Materiais , Humanos , Propriedades de Superfície
17.
Clin Oral Investig ; 28(7): 370, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869624

RESUMO

OBJECTIVES: To investigate the effect of multiple firings on color, translucency, and biaxial flexure strength of Virgilite-containing (Li0.5Al0.5Si2.5O6) lithium disilicate glass ceramics of varying thickness. MATERIALS AND METHODS: Sixty discs were prepared from Virgilite-containing lithium disilicate blocks. Discs were divided according to thickness (n = 30) into T0.5 (0.5 mm) and T1.0 (1.0 mm). Each thickness was divided according to the number of firing cycles (n = 10); F1 (Control group): 1 firing cycle; F3: 3 firing cycles, and F5: 5 firing cycles. The discs were tested for color change (ΔE00) and translucency (TP00) using a spectrophotometer. Then, all samples were subjected to biaxial flexure strength testing using a universal testing machine. Data were collected and statistically analyzed (α = 0.5). For chemical analysis, six additional T0.5 discs (2 for each firing cycle) were prepared; for each firing cycle one disc was subjected to X-ray diffraction analysis (XRD) and another disc was subjected to Energy dispersive X-ray spectroscopy (EDX) and Scanning electron microscope (SEM). RESULTS: Repeated firing significantly reduced the translucency of F3 and F5 compared to F1 in T0.5 (p < 0.001), while for T1.0 only F5 showed a significant decrease in TP00 (p < 0.001). For ΔE00, a significant increase was recorded with repeated firings (p < 0.05) while a significant decrease resulted in the biaxial flexure strength regardless of thickness. CONCLUSIONS: Repeated firings had a negative effect on both the optical and mechanical properties of the Virgilite-containing lithium disilicate glass ceramics. CLINICAL RELEVANCE: Repeated firings should be avoided with Virgilite-containing lithium disilicate ceramics to decrease fracture liability and preserve restoration esthetics.


Assuntos
Cerâmica , Porcelana Dentária , Resistência à Flexão , Teste de Materiais , Propriedades de Superfície , Difração de Raios X , Cerâmica/química , Porcelana Dentária/química , Cor , Análise do Estresse Dentário , Espectrofotometria , Microscopia Eletrônica de Varredura , Temperatura Alta
18.
BMC Oral Health ; 24(1): 699, 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38880907

RESUMO

BACKGROUND: The black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF). MATERIALS AND METHODS: Forty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made. RESULTS: The SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time. CONCLUSIONS: It was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.


Assuntos
Fluoretos Tópicos , Iodeto de Potássio , Compostos de Amônio Quaternário , Compostos de Prata , Compostos de Amônio Quaternário/farmacologia , Compostos de Amônio Quaternário/uso terapêutico , Iodeto de Potássio/uso terapêutico , Humanos , Fluoretos Tópicos/uso terapêutico , Técnicas In Vitro , Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Descoloração de Dente/induzido quimicamente , Dente Decíduo , Espectrofotometria , Dente Molar
19.
PLoS One ; 19(6): e0305650, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38885212

RESUMO

Accurate DNA quantification is key for downstream application including library preparations for whole genome sequencing (WGS) and the quantification of standards for quantitative PCR. Two commonly used technologies for nucleic acid quantification are based on spectrometry, such as NanoDrop, and fluorometry, such as Qubit. The DS-11+ Series spectrophotometer/fluorometer (DeNovix) is a UV spectrophotometry-based instrument and is a relatively new spectrophotometric method but has not yet been compared to established platforms. Here, we compared three DNA quantification platforms, including two UV spectrophotometry-based techniques (DeNovix and NanoDrop) and one fluorometry-based approach (Qubit). We used genomic prokaryotic DNA extracted from Streptococcus pneumoniae using a Roche DNA extraction kit. We also evaluated purity assessment and effect of a single freeze-thaw cycle. Spectrophotometry-based methods reported 3 to 4-fold higher mean DNA concentrations compared to Qubit, both before and after freezing. The ratio of DNA concentrations assessed by spectrophotometry on the one hand, and Qubit on the other hand, was function of the A260/280. In case DNA was pure (A260/280 between 1.7 and 2.0), the ratio DeNovix or Nanodrop vs. Qubit was close or equal to 2, while this ratio showed an incline for DNA with increasing A260/280 values > 2.0. The A260/280 and A260/230 purity ratios exhibited negligible variation across spectrophotometric methods and freezing conditions. The comparison of DNA concentrations from before and after freezing revealed no statistically significant disparities for each technique. DeNovix exhibited the highest Spearman correlation coefficient (0.999), followed by NanoDrop (0.81), and Qubit (0.77). In summary, there is no difference between DeNovix and NanoDrop in estimated gDNA concentrations of S. pneumoniae, and the spectrophotometry methods estimated close or equal to 2 times higher concentrations compared to Qubit for pure DNA.


Assuntos
DNA Bacteriano , Streptococcus pneumoniae , DNA Bacteriano/análise , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Fluorometria/métodos , Espectrofotometria Ultravioleta/métodos , Espectrofotometria/métodos , Lisados Bacterianos
20.
Am J Dent ; 37(3): 141-146, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38899994

RESUMO

PURPOSE: To evaluate the effect of air abrasion and polishing procedures on roughness and color stability of ceramic and composite materials after artificial accelerated aging. METHODS: In this study, six restorative materials were tested: feldspathic ceramic (CEREC Blocks), glass ceramic (IPS e.max CAD), resin-based hybrid ceramic (Cerasmart), microhybrid composite (Charisma Classic), nanohybrid composite (Charisma Diamond) and nanoceramic composite (CeramXOne). Forty square-shaped composite specimens were fabricated from each composite and CAD-CAM ceramic material. Initial surface roughness measurements were performed using a profilometer and color measurements of each specimen with a spectrophotometer. Ten control specimens for each group did not receive air abrasion. The other specimens were treated by an air abrasion device and then were randomly divided into three subgroups of 10 specimens (n= 10). After air abrasion, 10 specimens of each group did not receive polishing (Air abrasion group) and others were repolished with Sof-Lex kit (Sof-Lex group) or a rubber kit (Rubber group). Surface roughness and color measurements were repeated before and after 300 hours of artificial accelerated aging (AAA). The univariate test and then three-way ANOVA and two-way ANOVA were performed for comparison of groups (α= 0.05). RESULTS: The univariate statistical analysis revealed that the restorative materials were differently affected after air abrasion, polishing methods and AAA (P< 0.001). Three-way ANOVA showed that the surface roughness of the restorative materials increased after air abrasion and AAA (P< 0.001). Two-way ANOVA showed statistically significant differences between color changes of ceramic (CEREC and IPS e.max CAD) and composite based restorative materials (P< 0.001). CLINICAL SIGNIFICANCE: Clinicians should be aware that air abrasion at a specified power and time significantly changes the surface roughness of the materials except for CEREC. Additionally, polishing procedures (Sof-Lex, Rubber) did not significantly reduce the surface roughness of the ceramic groups. After air abrasion, depending on the material type used clinically, restorations should be repolished to reduce roughness and ensure color stability.


Assuntos
Cerâmica , Cor , Resinas Compostas , Polimento Dentário , Porcelana Dentária , Teste de Materiais , Propriedades de Superfície , Polimento Dentário/métodos , Resinas Compostas/química , Cerâmica/química , Porcelana Dentária/química , Materiais Dentários/química , Abrasão Dental por Ar , Fatores de Tempo , Desenho Assistido por Computador , Silicatos de Alumínio/química , Espectrofotometria , Humanos , Compostos de Potássio/química
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