CLAUDIA BIANCHI ZAMATARO

CLAUDIA BIANCHI ZAMATARO

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Evaluation of the anti-caries effect beyond the critical enamel pH of preventive treatment of fluoride associated with Nd:YAG laser irradiation
2021 - JUVINO, AMANDA C.; ROMANO, MARIANA; ALVES, NATHALIA Z.; FREITAS, THAIS R.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.
This study aimed to evaluate the anti-caries effect of fluoride associated with Nd:YAG laser irradiation in the h-eatment of enamel Eight groups (n = S) were analyzed: Negative Control pH 4.5; Negative control pH 4; Fluoride pH 4.5; Fluoride pH 4; Nd-YAG pH 4.5; Nd-YAG pH 4; (Fluoride + Nd-YAG) pH 4.5 and (Fluoride + Nd-YAG) pH 4. All samples were analyzed by Scanning Electron Microscopy (SEM) before and after the cycle. Quantification of phosphorus in the cycling solutions was carried out using the colorimetric method, as an indication of enamel demineralization. The anti-caries effect of the Fluoride + Nd: YAG treatment in addition to the critical pH of the enamel can be observed in the morphological analysis, however in the analysis of the demineralization solutions, the amount of phosphorus showed a difference only in the Fluoiide group compared to the others in the investigative pH.
Removal of laminates with Er,Cr:YSGG laser from dental enamel submitted to gamma radiation
2019 - RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; ZANINI, NATHALIA; JUVINO, AMANDA C.; KUCHAR, NIELSEN G.; CASTRO, PEDRO A.A.; ZEZELL, DENISE M.
Background: Modern Dentistry is characterized by the search for aesthetic perfection in the smile. Many efforts are made regarding procedures related to manufacturing, cementing, maintenance and removal of ceramic laminates. The laser removal of laminates has become more frequent when the aesthetical procedures needs to be replaced. On the other hand, the head and neck cancer treatment causes comorbidities in the buccal environment when laminates are in place. Objective: To evaluate in vitro the removal of ceramic fragments by means of Er,Cr:YSGG laser irradiation, after gamma radiation. Methods: 20 Lithium disilicate veneers were cemented with Variolink to human dental enamel and then samples were irradiated with 0.07 kGy. After gamma irradiation, the laminates removal with Er,Cr:YSGG laser was performed. The control group was not subjected to gamma radiation. Dental enamel samples were analyzed by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared Spectroscopy (FTIR) and Surface Microhardness Loss (SMH). Results: SEM has shown that less cement was found after removal of the facets in gamma irradiated group when compared to the control. For both groups there was alteration of the SMH possibly due to the use of the adhesive system. When performed intra group analysis, the sample being its own control of baseline in the FTIR analysis, there were no band shifts or formation of new compounds on the surface of human dental enamel. Conclusions: The Er,Cr:YSGG laser is an effective alternative for laminates removal in human dental enamel even when it is subjected to gamma radiation.
Morphological, optical, and elemental analysis of dental enamel after debonding laminate veneer with Er,Cr:YSGG laser
2021 - ZANINI, NATHALIA A.; RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; CARAMEL-JUVINO, AMANDA; ANA, PATRICIA A.; ZEZELL, DENISE M.
Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty‐four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 μm) using two different protocols:3.5 W, 48.14 J/cm2, 20 Hz non‐contact and 3.0 W, 48.14 J/cm2, 20 Hz non‐contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy‐dispersive X‐ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.
Human dental enamel evaluation after radiotherapy simulation and laminates debonding with Er,Cr:YSGG using SEM and EDS
2019 - RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; KUCHAR, NIELSEN G.; ZANINI, NATHALIA; JUVINO, AMANDA C.; DEL-VALLE, MATHEUS; CASTRO, PEDRO A.A.; SANTOS, MOISES O.; ZEZELL, DENISE M.
The pursuit of perfection makes younger people undergo aesthetic procedures without formal indication. However, young patients may be susceptible to a disease such as head and neck cancer which treatment can compromise the adhesion of these indirect mate-rials. Here, we present an analyze, of the gamma radiation effects on crystallographic morphology of human dental enamel after laminate veneer debonding with Er,Cr:YSGG laser. Thus, human dental enamel samples were prepared and randomized into 2 groups (n=10): Laser Irradiation (L) and Gamma + Laser Irradiation (GL) group. Scanning elec-tron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were performed before bonding and after debonding using Er,Cr:YSGG. Only Gamma + Laser Irradia-tion group received a cumulative dose of 70 Gy gamma radiation used in head and neck cancer radiotherapy. SEM images showed that both GL and L groups presented altered morphology. EDS showed an decrease in Ca and P intensities after laser debonding of laminates veneers in both group. Therefore, a proper laser facet removal protocol should be established for healthy patients and patients who have been exposed to radiotherapy for head and neck cancer.
Dental enamel submmitted to gamma radiation and ER,CR: YSGG laser associated to fluoride
2019 - ZAMATARO, CLAUDIA B.; CARAMEL, AMANDA; RABELO, THAIS F.; KUCHAR, NIELSEN G.; SOGLIA, VICTOR M.L.; ZEZELL, DENISE M.
The in situ caries model can use bovine dental samples in human volunteers. Gamma radiation is a very efficient sterilization method that is not expected to alter the mineral content of the hard tissues, avoiding biases in the results. Samples (n=40) were irradiated through a source of 60Co multipurpose irradiator aiming complete sterilization (25 kGy/h) with the purpose of accumulating the native plaque on them at an in situ study. An Er,Cr:YSGG laser was used alone and in combination with the topical applications of: 1 dentifrice (1,100 μg F /g) or 2 APF (12,300 μg F--/g). Morphological and chemical analyses were performed by scanning electron microscopy (SEM), determination of alkali soluble fluoride concentration by specific ion electrode and surface microhardness determination. Then, the 15 volunteers used palatal devices containing previously treated samples and remained using F dentifrice. The effects of Fformation, on the reduction of demineralization were correlated. The biochemical analysis for quantification of alkaline soluble F determined the groups in which the laser was used after the topical application of the two types of fluoride products of different concentrations (dentifrice and APF) to be statistically different (p≤0.05), suggesting a prolonged effect of the synergy of the treatments in the reduction of the demineralization. Electronic Microscopy Scanning analysis has not shown thermal damage neither interprismatics changes from hydroxyapatite crystals, at dental enamel outside the buccal environment, after 25 kGy gamma irradiation, established that gamma radiation could be used aiming dental enamel sterilization.
Effect of Er,Cr:YSSG laser on dental Veneers removal submitted to gamma radiation
2019 - ZANINI, NATHALIA; RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; JUVINO, AMANDA C.; KUCHAR, NIELSEN G.; CASTRO, PEDRO A.A. de; ANA, PATRICIA A. da; ZEZELL, DENISE M.
The search for aesthetical rehabilitive treatment such as porcelain veneers is increasing over the past years. After CEP-FOUSP approval, the present study investigated the debonding of 20 ceramic fragments of lithium disilicate(5x5x1 mm) from human dental enamel bond with Variolink ® N. The samples were splitted in two groups: control (without gamma irradiation) and treatment (gamma irradiation: GL). EDS and FTIR was performed on enamel in both groups, before and after treatment. After cementation of the ceramic fragments the control group was only irradiated with Er, Cr: YSGG laser (λ = 2.78 nm) to remove the fragments, whereas the GL was gamma irradiated with 0.07 kGy followed by laser irradiation Er, Cr: YSGG for removal of laminates.The laser parameters were previously determined as follows: 3.5 W. The gamma and laser (GL) group was exposed to gamma radiation and the erbium laser was applied in both groups to remove lithium disilicate laminates from human dental enamel. Thus, the load required to remove the laminates after simulation of the radiotherapy treatment in the human dental enamel was analyzed by mechanical assay. In this assay, the GL group presented higher loads for the removal of the laminates compared to the control group. This indicates that the gamma radiation induces a water radiolysis by modifying the hybrid layer of the adhesive cement and increases the bond between the enamel and the resin cement, which hinders the laser debonding of the laminates.
FTIR analysis of human dentin submitted to gamma radiation
2019 - KUCHAR, NIELSEN G.; ZAMATARO, CLAUDIA B.; CASTRO, PEDRO A.A. de; RABELO, THAIS F.; JUVINO, AMANDA C.; ZANINI, NATHALIA; ZEZELL, DENISE M.
Global data indicate that head and neck cancer express one of the sixth most common types of malignant cancers. In 2030, head and neck cancer predict 1,031,439 new cases per year around the world. Radiation therapy is used as a major therapy step in the treatment protocol for head and neck malignancies. Radiation caries consists in a side effect of xerostomia, ie a considerable reduction in the quantity and quality of saliva in the oral cavity, being defined as a type of cavity that advance severely with fast progression being able to injure the dental pulp. Gamma radiation effects can promote changes associated to modification in the enamel prismatic structure, the reduction in surface microhardness and biochemically alterations in the tooth composition. However, other studies where the human dental enamel using ionizing radiation present no differences found in the integrity of the dental enamel and there was no interference in the surface microhardness. In this study, 20 human dentin samples were evaluated, split randomly into the control group and irradiated group at 25 kGy, in the Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The FTIR shows that no significant changes were found in the Phosphate band representing the inorganic material. On the other hand, the Amide I band -chosen as the representative of the organic matrix composed mainly of collagen- showed a significant difference, suggesting a degradation of the organic content. These findings corroborate with SEM analysis after the gamma irradiation dose at 25 kGy.
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.
Wavelength comparison for laser induced breakdown spectroscopy caries detection
2018 - AMARAL, MARCELLO M.; RAELE, MARCUS P.; ANA, PATRICIA A.; NUNEZ, SILVIA C.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.
Laser Induced Breakdown Spectroscopy (LIBS) is a technique capable to perform elemental analyses of a variety of samples, independent of matter state. Other spectroscopy techniques may require a destructive and time-consuming sample preparation. On the other hand, LIBS is a less destructive technique with no (or considerably less) sample preparation, using a relatively simple experimental setup. LIBS also provides a multielement analysis into one single spectrum acquisition, applying a Nd:YAG short-pulsed laser to ensure the stoichiometry between the sample and the generated plasma. LIBS have been applied on the study of carious lesions using a Nd:YAG into its fundamental emission at 1064 nm. It was shown that ratio of P/Ca and Zn/Ca can be used to monitor the cariogenic process. Another minor elements, e.g. C and Cu, associated with bacteria biofilm were also measured with the Nd:YAG laser. The fundamental wavelength emission (1064 nm) of Nd:YAG is coincident with a hydroxyapatite transmission window and it may affect the result. In order to address this issue a study used the second harmonic of the Nd:YAG laser at 532 nm. It was show that it is also possible perform LIBS on carious lesion using the Nd:YAG at 532 nm. However, there is not a work direct comparing the LIBS at 532 nm and 1064 nm for carious lesion detection. So, the aim of this work was to investigate the influence of laser wavelength on the LIBS performance for carious lesion detection. In both cases the carious lesion was detected with the advantage of no interference with hydroxyapatite at 532 nm.