CLAUDIA BIANCHI ZAMATARO

CLAUDIA BIANCHI ZAMATARO

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Gamma sterilized human dental enamel submitted to Er,Cr: YSGG laser irradiation associated to fluoride for in situ model
2018 - ZAMATARO, CLAUDIA B.; PEREIRA, DAISA de L.; LIMA, CASSIO A.; SCAPIN, MARCOS A.; ZEZELL, DENISE M.
Nd:YAG laser irradiation of darkened dental enamel by means of dentrifice use
2018 - PEREIRA, DAISA L.; GOMES, GABRIELA V.; SUGAHARA, VANESSA M.L.; SCAPIN, MARCOS A.; ANA, PATRICIA A.; ARANHA, ANA C.C.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.
As the world population is growing older, dental erosion became a real concern on dentistry. Optical Coherence Tomography and X-Ray fluorescence were used to analyze enamel samples covered by black dentifrice as photoabsorber irradiated with NdYAG laser, then submitted to an erosive cycling. Heat injury risk in deeper tissue decreases because of the dentifrice dark pigment, when the most of photons are absorbed in the surface. Sixty Bmm2 blocks of bovine enamel, were randomized into 4 groups: G1- untreated; G2- treated with acidulated phosphate fluoride (APF, [FJ::1.23%, pH::3.3 to 3.9); G3- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz- Lares Research®) using a coal paste as photoabsorber; G4- irradiated with Nd:YAG laser (1064nm, 0.6W, 10Hz), using a black dentifrice (Black is White, Curaprox®). All samples were submitted to a 3-day erosive demineralization (Citric acid 1%, pH::3.6, 5min, 2x/day) under agitation, and remineralization cycling (artificial saliva, pH::7, 120minJ. After treatments and pH cycling, the [Ca]/[P] ratio decreased in the laser irradiated groups. The samples were evaluated by OCT before and after treatment and after erosive cycling. OCT measurements found smaller lesion depths in laser irradiated groups than in the other groups and there were statistically significant differences between G3 and G4 groups (p<0.05). Heating promoted by Nd:YAG laser irradiation changed the morphological and crystallographic enamel surface properties and has shown to be a promissory alternative to prevent erosion.
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.
Avaliação in vitro do teor de cálcio e fósforo em dentina humana submetida a radiação ionizante in vivo
2020 - JUNIOR, CLAUDIO M.; ZAMATARO, CLAUDIA B.; CARVALHO, VICTORIA G.; SILVA, MATEUS R.; ZEZELL, DENISE M.; SCAPIN, MARCOS A.; GONÇALVES, SERGIO E.P.
INTRODUÇÃO: Câncer de cabeça e pescoço é um problema de saúde pública. A radioterapia é uma opção de tratamento, capaz de promover maior preservação de tecidos e estruturas adjacentes. Entretanto, comorbidades ocorrem, causando alterações em tecidos da cavidade oral. O entendimento da etiologia das cáries de radiação ainda é um tema complexo no atendimento destes pacientes. OBJETIVO: Realizar a validação de uma metodologia de análise quantitativa in vitro de Fósforo (P) e Cálcio (Ca) na dentina humana submetida a radioterapia. METODOLOGIA: Após aprovação do Comitê de Ética em Pesquisa (parecer 3.842.547) foram utilizados 12 dentes extraídos oriundos de pacientes submetidos a radioterapia (~0,07 kGy) por câncer de cabeça e pescoço. As amostras de dentina foram preparadas e analisadas por meio de Microscopia Eletrônica de Varredura com Energia Dispersiva de Raios X (MEV/EDS). RESULTADOS: A metodologia proposta teve seus resultados comparados aos resultados obtidos pela espectroscopia de Fluorescência de Raios X e validada em termos de precisão e exatidão por meio de testes estatísticos sugeridos pelo documento DOQ-CGCRE-008 do INMETRO e teste Z-score. A precisão, em termos do desvio padrão relativo (RSD%) acessado de P e Ca, foi de 2,6 e 3,2%, respectivamente. A aceitabilidade calculada pelo teste de HORRAT (𝐻𝑂𝑅) mostrou que ambos valores são ≤ 2 (1,3 e 1,6 para P e CA, respectivamente), indicando que a precisão é satisfatória. A exatidão acessada de P e Ca, em termos de erro relativo (ER%), foi de 2,6 e 1,8%, respectivamente. A aceitabilidade, calculada pelo teste Z-score (score-score), apresentou valores entre 1,0 e 0,5 para P e CA, respectivamente, com a exatidão também considerada satisfatória. CONCLUSÃO: Conclui-se ser possível quantificar in vitro o Fósforo e o Cálcio na dentina humana por MEV/EDS, com parâmetros de precisão e exatidão satisfatórias para a técnica.
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.
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.
Molecular analysis of human and bovine hydroxyapatite from dental enamel and dentin submitted to gamma radiation
2018 - ZAMATARO, CLAUDIA B.; SCAPIN, MARCOS; KUCHAR, NIELSEN G.; ZANINI, NATHALIA; ZEZELL, DENISE M.
The important alteration of gamma irradiated hydroxyapatite in the buccal cavity depends on the biochemical alteration of the environment. The hydroxyapatite analyzed isolated showed a minimal molecular change of the crystal.