Orientador: Marinês Nobre dos Santos Uchôa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T09:08:01Z (GMT). No. of bitstreams: 1 Rodrigues_LiviaPagotto_M.pdf: 2190671 bytes, checksum: 59ef6221009e42c7c0c783952e447920 (MD5) Previous issue date: 2013 / Resumo: Este estudo teve como objetivo verificar in situ se a irradiação do esmalte com laser de dióxido de carbono (CO2) com comprimento de onda 10,6 ?m e densidade de energia de 20,0 J/cm2 associada ao emprego de um adesivo ortodôntico seria capaz de reduzir a perda mineral do esmalte ao redor de bráquetes ortodônticos, submetidos à situação de alto desafio cariogênico. Para isto, 80 dentes terceiros molares humanos retidos, foram cortados, obtendo-se ao final 160 espécimes de 5 x 5 x 2 mm, os quais foram divididos entre os grupos. Durante duas fases de 14 dias cada, 20 voluntários (idade média de 24 anos) utilizaram um dispositivo intraoral palatino contendo quatro espécimes de esmalte dentário humano, que foram aleatoriamente divididos em quatro grupos: (1) Adesivo + Dentifrício não fluoretado (DNF) (Controle), (2) Laser de CO2 + Adesivo + Dentifrício não fluoretado (DNF), (3) Adesivo + Dentifrício fluoretado (DF) e (4) Laser de CO2 + Adesivo + Dentifrício fluoretado. Para simular o alto desafio cariogênico os voluntários gotejaram sobre os espécimes dentais, solução de sacarose a 20%, oito vezes ao dia, em horários pré-determinados. Após cada fase, foi coletado o biofilme ao redor dos bráquetes e analisada a concentração de flúor no biofilme seco empregando-se eletrodo específico para íon flúor. A perda mineral do esmalte ao redor dos bráquetes ortodônticos foi avaliada indiretamente pela análise de microdureza. Os resultados da concentração de flúor no biofilme seco foram analisados pelo teste de Lilliefors e teste de Kruskal-Wallis, seguidos do teste de Student Newman-Keuls (? = 0,05); e os resultados da perda mineral foram analisados pelo teste de Lilliefors para verificação da normalidade dos dados seguidos do teste ANOVA. A análise da concentração de flúor no biofilme seco mostrou que os grupos 1 e 2 diferiram dos grupos 3 e 4, sendo que nos grupos 3 e 4 a concentração de flúor foi significativamente maior que aquelas observadas nos grupos 1 e 2. Nas condições experimentais empregadas nesta pesquisa, o sistema adesivo mostrou-se efetivo em inibir a desmineralização, in situ, ao redor de bráquetes ortodônticos, mediante alto desafio cariogênico. Assim, a presença ou não do laser de CO2 e do dentifrício fluoretado não teve influência quanto à perda mineral do esmalte ao redor de bráquetes ortodônticos / Abstract: The aim of this study was to verify whether the irradiation of carbon dioxide (CO2) laser with a wavelength of 10.6 ?m and density of 20.0 J/cm2 combined with the use of an orthodontic adhesive could reduce enamel demineralization around orthodontic brackets, subjected to a situation of high cariogenic challenge in the oral environment. For this, 80 human third molars retained were cut into 160 specimens of 5 x 5 x 2 mm, which were divided into the groups. During two phases of 14 days each, 20 volunteers (mean age 24 years) used a device intraoral palatal containing four specimens of human enamel, which were randomly divided into 4 groups: 1- Adhesive + Non Fluoride Toothpaste (NFT) (control), 2- CO2 Laser + Adhesive + Non Fluoride Toothpaste (NFT), 3- Adhesive + Fluoride Toothpaste (FT) and 4- CO2 Laser + Adhesive + Fluoride toothpaste. To simulate a high cariogenic challenge, volunteers dripped on the slabs a 20% sucrose solution eight times a day at predetermined times. After each phase, the biofilm around the brackets was collected and the fluoride concentration in the dry biofilm was analyzed, using an ion specific electrode. The mineral loss around orthodontic brackets was determined by cross-sectional microhardness measurement. The results of the fluoride concentration in dried biofilm were analyzed by Lilliefors and Kruskal-Wallis test followed by the Student Newman-Keuls test (? = 0.05) and the results of the mineral loss were analyzed by Lilliefors test followed by ANOVA. Regarding the fluoride concentration in the dry biofilm, the data showed a significant difference between groups 1 and 2 when compared to groups 3 and 4, and the groups 3 and 4 showed fluoride concentrations in the biofilm higher than those observed for groups 1 and 2. Under the experimental conditions employed in this study, the adhesive system was showed to be effective in reducing demineralization in situ around orthodontic brackets in a high cariogenic challenge situation. Thus, the presence or absence of CO2 laser and fluoride toothpaste showed to have no influence on the enamel mineral loss around orthodontic brackets / Mestrado / Odontopediatria / Mestra em Odontologia

Indiana University-Purdue University Indianapolis (IUPUI) / While advances in lasers for soft tissue applications have drastically increased its usage in dentistry, laser use for hard tissue still needs development. This study was conducted to determine the difference between permanent and primary enamel after their exposure to the Nd:YAG laser. Four parameters were studied: Surface topography, acid resistance, surface hardness and caries-like lesion depth creation. Differences between lased primary and permanent teeth were seen in two parameters. Calcium disassociation during acid attack was significantly higher for lased primary enamel (p=0.0126), and lased primary enamel became softer while permanent enamel became harder (p=0.0001). While this study adds to the body of knowledge related to hard tissue laser use, further evaluation and research is needed prior to the routine use of the laser on primary enamel.

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Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 118 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 65-73).

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1984.

Thesis (M.S.)--University of Michigan, 1986.

Thesis (M.S.)--University of Michigan, 1977.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains ix, 123 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 71-82).