CLAUDIA BIANCHI ZAMATARO

CLAUDIA BIANCHI ZAMATARO

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SEM/EDS for determining the phosphorus and calcium content in human dentin submitted to radiotherapy for head and neck cancer
2020 - SCAPIN, MARCOS A.; MOREIRA JUNIOR, CLAUDIO; ZAMATARO, CLAUDIA B.; GONCALVES, SERGIO E. de P.; ZEZELL, DENISE M.
The research followed the CONSORT 2010 guidelines. Patients who underwent radiotherapy due to the head and neck cancer (n = 12) and healthy patients (n = 12) donated the teeth. Twenty-four urgently extracted teeth for periodontal reasons or in order to prevent infectious processes were used. All teeth obtained had the approval from the ICT - UNESP Human Experiments Ethics Committee. The teeth obtained were separated into two large groups: Control (n = 12 dentin teeth of healthy patients) and Irradiated (n = 12 dentin teeth of patients irradiated in vivo) and sectioned in their long axes, obtaining two halves (n = 24 per group). The samples were analyzed by Scanning Electron Microscopy with Energy Dispersive (SEM/EDS) and Surface Microhardness (SMH). The results obtained by SEM/EDS and X-Ray Fluorescence techniques were analyzed separately and then compared to each other. To validate the analytical method of the correlation between the two types of tests performed, the Horwitz equation was used, which would generate a Horwitz value and establishes for either method. Precision for repeatability was assessed using the relative percentage standard deviation (RDS%) and the acceptability criterion by the Horwitz test. Accuracy was assessed by relative percentage error (ER%) and acceptance criterion by z-score. The precision for repeatability was evaluated through the relative standard deviation (RSD%) and the acceptability was verified using the equation of Horwitz, in which the HORRAT’s (HOR) values fit more accordingly.
Comportamento da hidroxiapatita do esmalte e da dentina frente à radiação ionizante in vivo e in vitro
2019 - KUCHAR, NIELSEN G.; ZAMATARO, CLAUDIA B.; ZANINI, NATHALIA; RABELO, THAIS F.; JUVINO, AMANDA C.; SOGLIA, VICTOR; CASTRO, PEDRO A.A.; ZEZELL, DENISE
Heat-induced depth of Nd:YAG laser irradiation in biological hard tissues
2019 - PEREIRA, DAISA L.; CASTRO, PEDRO A.A.; GOMES, GABRIELA V.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.; RIBEIRO, HENRIQUE B.; MATOS, CHRISTIANO J.S.; ANA, PATRICIA A.
Confocal Raman spectroscopy is a non-destructive and non-invasive technique which provides surface Raman spectra and depth images of biological structures contactless with the sample, with no use of ionizing radiation to penetrate in the sample under analysis. These characteristics allow its experimental use without any side e®ects to the sample. The depth images are obtained by Raman microscopy and are related to the characteristics of the tissues. This study aims to characterize irradiated hard tissues and correlate the depth reached by the heat of the laser irradiation with the obtained images. For this, thirty 8 mm2 blocks of bovine enamel and bovine root dentin, were randomized into 6 groups: G1- enamel untreated; G2- enamel irradiated with Nd:YAG micropulsed laser (1064 nm, 10 Hz- Lares Research R°) using a coal paste as photoabsorber; G3- enamel irradiated with Nd:YAG nanopulsed laser (1064 nm, 20 Hz, Brilliant, Quantel Laser) using a coal paste as photoabsorber; G4-G6 (bovine root dentin in the same conditions of treatment of G1-G3). The measurements were performed in three di®erent depth regions of the cubic shaped samples: region A- left corner above of the sample, region B- middle of the sample and Region C- right corner below of the sample. The area under the phosphate, carbonate, amide I, II, and III bands were calculated. The Raman spectra of the Nd:YAG irradiated samples detected a reduction in all the organic components of the enamel after laser irradiation. Previous studies of our group demonstrated that di®erences in carbonate substitution in the apatite lattice are related to the apatite instability and demineralization susceptibility. Considering that carbonate free apatite is less susceptible to acid attack, the results of this study suggest that Nd:YAG lased enamel can be more resistant to caries, in a direct correlation to the thickness of the treated area. It was found that for micropulsed Nd:YAG laser, the heat induced depth was 10 § 2 ¹m and for nanopulsed laser the heat induced depth was 8 § 3 ¹m. So, it is possible to correlate the heat penetration depth of the laser irradiation with the images obtained by the confocal Raman.
Calcium analysis from gamma sterilized human dentin and enamel
2019 - ZAMATARO, CLAUDIA B.; KUCHAR, NIELSEN G.; SCAPIN, MARCOS A.; ZANINI, NATHALIA; CASTRO, PEDRO; RABELO, THAIS F.; JUVINO, AMANDA C.; ZEZELL, DENISE
Gamma radiation changes the patients0 oral cavity undergoing radiotherapy. Alterations cause an unsaturated environment of calcium and phosphate into the oral cavity. After approval of the Ethics Committee, 20 hu- man teeth were sectioned to obtain 20 human enamel and 20 dentin samples, polished plane. Samples were randomized in the irradiated group and control group (untreated). Then, the treatment group was irradiated with 25:0 kGy at the 60Co multipurpose irradiator. After the gamma irradiation, Fourier Transformed Infrared Spectroscopy (FTIR), percentage of surface microhardness loss (%SMHL) and Scanning Electron Microscopy (SEM) were performed. At the end, acidic biopsies were performed to quantify the concentration of calcium present in the samples. FTIR showed that the molecular structure of HA of the enamel is similar to the non- irradiated, with no formation or loss of molecular compounds occurring. X-ray °uorescence at enamel samples was performed. Microscopic morphological analysis did not shown signi¯cant di®erences. Surface microhardness is an indirect indicator of the mineral content of the samples. The mean obtained was 258:2 (38:8) KHN within the hardness spectrum of the healthy natural enamel. The compounds present in the samples and the values of the ratios of Calcium and Phosphate oxides and relation between the elements Calcium and Phosphorus. The ratio of the most stable oxides shows a variation with linear correlation. In the enamel, the ratio (Ca/P) shows a change in the elemental content with linear correlation (R2 = 1). These ¯ndings lead us to a new hypothesis of behaviour of the HA crystal versus gamma irradiation. On the other hand for the irradiated dentin, the Knoop hardness number was within the range of the spectrum similar to that of natural dentin of human origin. X-ray °uorescence shows that irradiated dentin has great similarity with natural dentin from the point of view of chemical composition. SEM analyses showed that there was no thermal damage or interprismatic morpho- logical changes in the hydroxyapatite structure of human dental dentin outside the buccal environment when using doses of gamma irradiation up to 25 kGy.
Effects of gamma irradiation on bovine bone microhardness and molecular structure
2018 - DIAS, DERLY A.; PEREIRA, DAISA L.; GOMES, GABRIELA V.; SUGAHARA, VANESSA M.L.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.; MATHOR, MONICA B.
The skeletal systems is a complex mixed compounds, organic and inorganic, that should present a mechanical resistance to perform functions as protection of the vital organs and load distribution. Gamma radiation is an ionizing radiation that comes from radioative sources or X-ray generator and it is commonly used in health establishments such as radio diagnostic exams, radiotherapy and sterilization of allograft. The characterization of the irradiated bone tissue can be an important tool in the study of the components that are aÆected and how much each dose of ionizing radiation can alter its mechanical properties. This information will be very important in in vitro and ex vivo studies where sterilization of the bone material is necessary and may still be useful in understanding the eÆects on the bone tissue of patients undergoing short-term radiotherapy. For this, 110 samples of bovine femur diaphysis were randomized into 11 groups: G1- untreated (control); G2 to G11 were submitted to gamma irradiation (60Co Gammacel). Samples were polished before irradiation and submitted to a Knoop Microhardness Test to determine the hardness of bovine bone and Fourier transform Infrared spectroscopy (FTIR). Spectra were collected in the midinfrared range in Attenuated Total Reflectance (ATR) sampling mode associated whit PCA multivariate technique to evaluate the molecular changes in bone matrix. The microhardness analysis did not present a significant statistical diÆerence between the irradiated and control groups, showing that ionizing radiation did not aÆect the mechanical structure of the samples, on a micro scale. The results of FTIR with the PCA technique were eÆective in separating all groups, especially those irradiated with doses of 0.002 kGy, 10 kGy and 35 kGy. We conclude that ATR-FTIR spectroscopy associated with PCA is a good method to evaluate the biochemical changes promoted by ionizing radiation in bone matrix. It was observed that hardness was not altered by gamma irradiation and FTIR spectroscopy associated with PCA is a good method to analyze the changes in bone tissue submitted to ionizing radiation.
Molecular characterization of ex-vivo natural bovine dental enamel
2018 - ZAMATARO, CLAUDIA B.; PEREIRA, DAISA L.; GOMES, GABRIELA V.; ALVES, NATHALIA Z.; CASTRO, PEDRO A.A.; DIAS, DERLY A.; ZEZELL, DENISE M.; SCAPIN, MARCOS A.
Bovine teeth are widely used to infer results on a human population. Considering this, an analysis of the mineral content of bovine enamel, focusing the hidroxiapatite (HA), was carried out to evaluate the homogeneity of the sample universe for future experiments with laser irradiation as a substitute of human teeth enamel. Twelve samples of 5 x 5 mm bovine enamel were prepared and polished plane. The mineral content was calculated through surface microhardness (SMH) and morphology by scanning electron microscopy (SEM). Main molecular components of the enamel were analysed by Energy Dispersive X-ray Spectroscopy (EDS). Surface microhardness is an indirect indicator of the mineral content of the samples, which was 258.2 (38.8) KHN. The compounds present in the samples, the values of Calcium and Phosphate oxides and the ration Ca/P were analizes. As expected Phosphorus pentoxide and Calcium oxide were the main constituent of the samples (57.4 to 59.9%). The CaO/P2O5 ratio shows a variation with linear correlation (R2 = 1). The elemental ratio (Ca/P) shows a change in the elemental content with linear correlation (R2 = 1). 30% of the samples presented Strontium oxide, 30% had Zirconium dioxide, 10% had Magnesium oxide and 40% had Silicon dioxide. All samples showed Sulfur trioxide, Iron trioxide and Chlorine. 10% did not shown Zinc oxide. 5% had Potassium oxide and Nickel oxide in its composition. The surface microhardness results, although only for the initial homogenization of the sample universe, showed a Knoop hardness number within a spectrum similar to that of natural hydroxyapatite of human origin. The EDS results show that bovine enamel hydroxyapatite present great similarity with that from human enamel hydroxyapatite from the point of view of chemical composition. These results corroborate the use of bovine hydroxyapatite in substitution of hydroxyapatite of human origin. Despite the inter-species similarity, it is possible to note that in the same species the composition of hydroxyapatite varies. In the bovine species, the feeding, the period of formation of the dental germs and the origin are more standardized and controlled than in humans. Nevertheless, it is possible to notice a variation of the components elements of bovine dental enamel, and it is necessary to restrict an interval of hardness and Ca/P values to homogenise the samples properties for use in any experiment.
Analysis of temperature on microscope slide by a boron pulsed laser deposition process
2018 - SILVA, ANDRE F.; COSTA, PRISCILA; MACHADO, NOE G.P.; SAMAD, RICARDO E.; ZEZELL, DENISE M.; RAELE, MARCUS P.; ZAMATARO, CLAUDIA B.
A boron thin ¯lm can be used for neutrons conversion and in electrically charged particles and further detection. Since boron has a high evaporation temperature and the thickness of the boron layer needs to have few microns, pulsed laser deposition also known as PLD can be used. When producing thin ¯lms with the PLD technique, the target absorbs energy promoting the material ablation creating a plasma plume that deposits material on a substrate, thus creating a thin ¯lm. Since all the deposition occurs in a vacuum chamber, the residual heat of the plasma that condensate at the substrate can build up, thus potentially source of concern if the substrate sensitive to temperature somehow. This work reports the analysis of the variation of temperature in a microscope slide (substrate) as a function of the energy of femtosecond laser pulses. For measuring the substrate temperature a type-K thermocouple was used together with associated electronics. The thermocouple was ¯xed to the back of substrate with thermal grease for vacuum and connected to the microchip using a feed through in the vacuum chamber. Was detected the increase of the substrate+¯lm starting at 6oC from initial temperature (room) for the minimal laser energy 100 microjoules (25 femtoseconds).
In vivo study of holmium laser irradiation on dental structure
2011 - ZEZELL, DENISE M.; EDUARDO, PATRICIA L. de P.; STREFEZZA, CLAUDIA; ZAMATARO, CLAUDIA B.; CORREA, PAULO; SALVADOR, VERA L.R.; ROSSI, WAGNER de; BACHMANN, LUCIANO
Thermal diffusivity measurement of enamel and dentin as function of temperature obtained by infrared thermography
2010 - PEREIRA, T.M.; ZAMATARO, C.B.; ZEZELL, D.M.
Estudo in situ da resistência à desmineralização do esmalte dental submetido à irradiação com laser Er, Cr:YSGG associada ao uso de produtos fluoretados
2012 - ZAMATARO, CLAUDIA B.
A irradiação com o laser de Er,Cr:YSGG promove aumento da área de superfície do esmalte dental irradiado, o que pode resultar em uma maior retenção e um efeito prolongado do fluoreto (F-) presente em produtos fluoretados de diferentes concentrações. O produto formado na superfície de esmalte originado de uma única aplicação de flúor fosfato acidulado (FFA 12.300 μg F-/g) ou da frequente aplicação tópica de dentifrício contendo 1.100 μg F-/g poderia ter seu efeito cariostático prolongado, pelo aumento de sua retenção na superfície do esmalte dental irradiado. Uma vez que o esmalte dentário livre de biofilme não sofre desmineralização na cavidade bucal, sugerimos um estudo in situ onde se possa avaliar o prolongamento do efeito do destas associações, também na presença de placa. As condições de irradiação do estudo in situ, foram determinadas, in vitro, com laser Er,Cr:YSGG no esmalte de maneira isolada ou combinada com as aplicações tópicas de: 1- dentifrício de concentração 1.100 μg F-/g ou 2- FFA, para posteriores análises da formação e retenção de CaF2. Foram realizadas análises morfológicas por microscopia eletrônica de varredura, determinação da concentração do flúor solúvel em álcali por meio do eletrodo íon específico e análise da microdureza em corte longitudinal. Os resultados por microscopia eletrônica de varredura verificaram qualitativamente a formação de produtos na superfície de esmalte na forma de CaF2. A análise bioquímica para determinação quantitativa do F- solúvel em álcali determinou como sendo estatisticamente diferentes (p≤0,05) os Grupos nos quais o laser foi utilizado previamente à aplicação tópica dos dois tipos de produtos fluoretados de diferentes concentrações (dentifrício e FFA), in vitro. Em seguida, foi realizado o estudo in situ quando voluntários utilizaram dispositivos palatinos, contendo blocos de esmalte humano, previamente tratados, com o objetivo de acúmulo da placa nativa sobre os mesmos. Durante a fase in situ, os voluntários permaneceram utilizando dentifrício F- para verificação da ação do mesmo na presença de biofilme sobre os blocos irradiados. Foram correlacionados os efeitos da formação de F-, decorrentes dos tratamentos propostos, na redução da desmineralização. A análise bioquímica para quantificação do F- solúvel em álcali determinou como sendo estatisticamente diferentes (p0,05) os Grupos nos quais o laser foi utilizado após a aplicação tópica dos dois tipos de produtos fluoretados de diferentes concentrações (dentifrício e FFA), in situ, sugerindo um efeito prolongado da sinergia dos tratamentos na diminuição da desmineralização.