CLAUDIA BIANCHI ZAMATARO

CLAUDIA BIANCHI ZAMATARO

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Effect of Nd:YAG laser on caries prevention of dental enamel by optical attenuation coefficient with optical coherence tomography (OCT)
2018 - MORAES, MARCIA C.D.; PEREIRA, DAISA L.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.; FREITAS, ANDERSON Z.
Caries is a multifactorial disease, caused by the continuing loss of hydroxyapatite crystals. The association of topical acidulated phosphate fluoride application (APF) and high intensity lasers has the potencial to increase the resistance to demineralization of dental tissues. The Nd:YAG laser, specially associated to a photoabsorber over the dental surface, may induce thermal changes in order to increase the resistance to demineralization. Optical Coherence Tomography (OCT) is a non-ionizing radiation imaging technique that can be performed in real time in vivo and can detect early changes in the optical properties of t issues. This study aimed to characterize the effectiveness of the association of Nd:YAG la ser and APF gel in the prevention of caries lesions in human dental enamel in vitro, due to structural changes in function of the pH cycling, the treatments performed as well as to evaluate the potential of OCT to diagnose early demineralization. 160 human enamel samples were divided in four groups and submitted to pH cycling during 20 days, after the following treatments: G1- untreated; G2- treated with APF gel (1.23% F-, 4min); G3- irradiated with Nd:YAG (1064nm, 84.9J/ cm2, 10Hz) followed by APF application and G4- APF application before Nd:YAG laser irradiation (same conditions of G3). OCT (930 nm) analysis were performed before and after the treatments, 5th, 10th, 15th and 20th day of pH cycling. The optical attenuation coefficient decreased significantly (p<0.05) as demineralization increased over time and better results were achieved in group G4. OCT technique can diagnose early demineralization in enamel.
Longevity of diode laser irradiation in dentine
2018 - PEREIRA, DAISA L.; MORAES, MARCIA C.D.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.
The efficacy of pulsed infrared lasers on clinical dentin wear sensitivity is well stablished in the Literature. This work aims to evaluate the effect of diode laser combined with fluoride products regarding the longevity of the sensibility treatment under the effect of the domestic use products. After Ethics Committee approval, 75 slabs of bovine root dentin measuring 8 mm2, were randomized into 5 groups (n=1 5): G1- untreated; G2- treated with acidulated phosphate fluoride (APF-gel, [F-J=1.23 %, pH=3.3 to 3.9); G3- irradiated with diode laser (980 nm, 2.5W, 5ms, 25Hz) using a cool paste as photoabsorber; G4- irradiated with diode laser (same conditions of G3) using a coal paste as photoabsorber + application of APF-gel and G5- application of APF-gel+ diode laser irradiation (same conditions of G3). All samples were submitted to an erosive and abrasive demineralization (Sprite Zero, pH=2.8, 90s, 4x/day), and remineralization (artificial saliva, pH=7.4) cycling for 10 days. Twice a day, slabs were brushed for 15s using a whitening dentifrice (Sensodyne True White, GSK, EUA). Slabs were evaluated by Optical Coherence Tomography (OCT) at the initial and 7th day of cycling. OCT measurements found a significant increase on dentin wear depth and area of lesions with the increase of cycling days. G1 and G2 hod significant higher mineral loss compared to the other groups. G3, G4 and GS showed no significant differences between them. Results suggested that the sensibility of the treatment with the diode laser has longevity despite the high abrasivity of dentifrice used in maintenance.
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.
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.
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.
The use of Nd:YAG laser as an alternative to prevent dentin wear
2016 - PEREIRA, D.L.; ZAMATARO, C.B.; ZEZELL, D.M.; FREITAS, A.Z.; ANA, P.A.
The aim of this study is to verify the potential of Nd:YAG laser and topical acidulated phosphate fluoride application (APF) on preventing dentin wear using the optical coherence tomography (OCT) on monitoring this process.