DAISA DE LIMA PEREIRA
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Artigo IPEN-doc 26767 Effect of Nd:YAG laser and aluminum oxide sandblasting preconditioning on lingual enamel2019 - LOPES, MONICA S.; MOTA, CLAUDIA C.B.O.; PEREIRA, DAISA L.; AMARAL, MARCELLO M.; ZEZELL, DENISE M.; GOMES, ANDERSON S.L.It is known that Nd:YAG laser radiation on dental structure can increase enamel resistance to demineralization; however, few studies report its impact in orthodontics. This study aimed to verify the interaction of Nd:YAG laser and aluminum oxide sandblasting (Al2O3) as preconditioning treatment of lingual brackets bonding to quantify the shear bond strength (SBS) and to characterize the enamel after different surface preconditioning techniques. Thirty-five bovines’ incisors were divided in 5 groups (n=7), according to the preconditioning. All groups had the lingual brackets bonded with Transbond XT adhesive according to manufacturer’ protocol, and shear bonded after 72h. Samples were analyzed by Optical Coherence Tomography (OCT) and Scanning Eletronic Microscope (SEM) to verify enamel alterations. Optical attenuation coefficient (α) was measured before any preconditioning (T0) and after preconditioning surface (T1) for each group. Statistics analysis ANOVA-test was used, followed by Post Hoc Tukey for shear bond strength data, and Kruskal Wallis and post hoc Dunn test for α data. SEM and OCT qualitative analysis showed the melting effect with laser irradiation and enamel crystal surface disorganization with sandblasting in T1 and after shear bond. All groups were adequate for SBS and the statistical differences (p=0.0034) among groups showed better results for groups with techniques association (laser and Al2O3 used in this or in reverse order) and the highest SBS when laser was used after. The Al2O3 removes part of melting effect. The α had statistical difference (p= 0.0124) among groups, increasing with laser and Al2O3 isolated and decrease with techniques association.Artigo IPEN-doc 26755 Optical properties of bovine dentin when irradiated by Nd:YAG and a black dentifrice aimed at treating dentin erosion2019 - PEREIRA, DAISA L.; DEL VALLE, MATHEUS; GOMES, GABRIELA V.; ZEZELL, DENISE M.; ANA, PATRICIA A.Dental erosion has been extensively studied as a risk factor for tooth loss or injure, and the early diagnosis of lesions is essential for avoiding greater damages. Optical Coherence Tomography (OCT) is a potential tool for early diagnosis of demineralization. In this study, this technique was used to analyze the optical changes of dentin samples irradiated with Nd:YAG laser using a black dentifrice as photoabsorber, then submitted to an erosive cycling. 75 slabs of bovine root dentin were randomized into 5 groups: G1—untreated; G2—treated with acidulated phosphate fluoride gel (APF-gel, [F-] = 1.23%, pH = 3.3–3.9); G3—irradiated with Nd: YAG laser (100 μs, 1064 nm, 0.6 W, 10 Hz) without photoabsorber; G4—irradiated with Nd:YAG laser using a coal paste as photoabsorber; G5—irradiated with Nd: YAG laser using a black dentifrice as photoabsorber. All samples were submitted to a 3-day erosive demineralization (Citric acid 1%, pH = 3.6, 5 min, 2 /day) under agitation, and remineralization (artificial saliva, pH = 7, 120 min) cycling. The samples were evaluated by OCT before treatments (baseline), after treatments and after erosive cycling. Optical attenuation coefficient (μ) was calculated using a Matlab routine, and the statistical analysis was performed (a = 0.05). It was observed a significant decrease on μ values after all treatments. Also, the μ values decreased after erosive cycling, except for the groups G3 and G5. It was concluded that OCT technique is capable to distinguish among sound, treated and demineralized dentin. As well, the black paste was efficient to act as a photoabsorber, helping the Nd:YAG laser to decrease dentin erosion.Artigo IPEN-doc 26077 Advances in the prevention and monitoring of root dentin demineralization using lasers2019 - ANA, PATRICIA A.; PEREIRA, DAISA de L.; FERREIRA, ELIZABETE dos S.; FIGUEREDO, DANIELA C.; DAGUANO, JULIANA K.F.B.; ZEZELL, DENISE M.The increase in the life expectancy and the longer permanence of the teeth in the oral cavity also led to an augment in the prevalence of root caries lesions. These lesions require more attention because of their rapid progression and difficulty in early diagnosis and monitoring. In this context, the irradiation of the tissues with high intensity lasers has been shown as an important way for preventing lesion formation because lasers chemically modify the irradiated dental hard tissues and make them more resistant to acid challenge. In addition, the association with ceramic biomaterials may allow additional remineralizing results. Together with therapeutics, the effective early diagnosis of incipient lesions is indispensable. Techniques that use lasers, such as optical coherence tomography, have also been promising in this aspect because they allow the early diagnosis and monitoring of demineralizations with high resolution and in a non-detrimental way. This article aims to show the actions of high intensity laser therapies when associated or not with biomaterials, on the prevention and remineralization of root caries lesions, as well as the effectiveness of optical coherence tomography in the diagnosis and monitoring the effects of the treatments in these lesions.