Thesis (M.S.)--University of Michigan, 1992.

Thesis (Ph. D.)--Ohio State University, 1998. / Advisor: William M. Johnson, Oral Biology Program. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Southern California, 1998. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 2001. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 2001. / Includes bibliographical references.

Orientador: José Roberto Rodrigues / Banca: Marcelo Giannini / Banca: George Miguel Spyrides / Banca: Symone Cristina Teixeira / Banca: Silvio lssáo Myaki / Resumo: O objetivo deste estudo foi determinar o efeito de três agentes clareadores na resistência de união de um sistema restaurador ao esmalte, após armazenamento em saliva artificial durante vários intervalos de tempo (um dia, uma, duas e três semanas). Foram utilizados 78 pré-molares humanos, seccionados no sentido mésio-distal para a obtenção de duas metades. As superfícies vestibulares e linguais foram planificadas com lixa de granulação 600 e divididas em um grupo controle (n=12) e três grupos experimentais (n=48), de acordo com o agente clareador utilizado. O grupo 1 foi clareado com Crest Professional Whitestrips (peróxido de hidrogênio a 6,5%), usado durante 14 dias em duas aplicações de 30min cada. O grupo 2 recebeu o agente clareador Opalescence Quick (peróxido de carbamida a 35%) em três aplicações de 1 h cada, com intervalo de sete dias entre estas. O grupo 3 foi clareado com Opalescence Xtra (peróxido de hidrogênio a 35%), em três aplicações de 16min cada, com intervalo de sete dias entre estas. Os espécimes do grupo controle permaneceram armazenados em saliva artificial a 37°C por 14 dias. Após os tratamentos clareadores, os espécimes dos três grupos experimentais foram divididos em quatro subgrupos (n=12), de acordo com o tempo de armazenamento em saliva artificial a 37ºC (um dia, uma, duas e três semanas). Após os períodos de tempo descritos, procedeu-se o condicionamento ácido do esmalte, aplicação do agente adesivo Scotchbond Multi-Uso Plus (3M) e confecção de um cilindro de resina composta Z100 (3M), com 2mm de diâmetro. Os espécimes foram submetidos ao ensaio de cisalhamento em máquina lnstron Universal após 24h para obtenção dos valores de resistência adesiva. Os resultados foram analisados pelos testes estatísticos de ANOVA dois fatores, Tukey e Dunnett (5%). Observou-se que não houve diferença significante entre os valores.... / Abstract: The aim of this study was to determine the effect of three bleaching agents on the shear bond strength of a composite resin to enamel, after various artificial saliva storage time (1 day, 1, 2 and 3 weeks). 78 human premolars were mesiodistally sectioned to obtain two halves. The buccal and lingual surfaces were ground with 600-grit aluminum oxide abrasiva paper to obtain flat enamel surfaces and divided into a control group (n=12) and three experimental groups (n=48), according to the bleaching agents. The first group was bleached with Crest Professional Whitestrips (6,5% hydrogen peroxide), used 1 hour for 14 days. The second group was bleached with Opalescence Quick (35% carbamide peroxide), in three applications of 1h, with an interval of 7 days among them. The third group was bleached with Opalescence Xtra (35% hydrogen peroxide), in three applications of 16min, with an interval of 7 days among them. Specimens of control group were not bleached and were stored in artificial saliva at 37ºC for 14 days. After the bleaching treatments, the specimens of the experimental groups were divided into four groups (n=12), according to the storage time in artificial saliva (1 day, 1, 2 and 3 weeks). Bonds were formed with Scotchbond MP and Z-100 composite resin, and shear bond test was carried out in an lnstron Universal Testing Machine after 24 hours. The results were analyzed by two-way ANOVA, Tukey and Dunnett's tests (5%). There was no significant difference among the shear bond strength of the three bleaching agents. Regarding to the post-bleaching time, the bond strength values obtained after three weeks were significant higher than the values obtained after one day, one and two weeks and were similar to those obtained for the control group. Conclusion: external bleaching with the three agents tested significantly reduced the bond strength of composite resin to enamel and after a lapse of ... / Doutor

Made available in DSpace on 2015-12-10T14:24:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-03-20. Added 1 bitstream(s) on 2015-12-10T14:30:47Z : No. of bitstreams: 1 000192316.pdf: 4096622 bytes, checksum: ea918f86359340d85e76362a26921e35 (MD5) / O objetivo deste estudo foi determinar o efeito de três agentes clareadores na resistência de união de um sistema restaurador ao esmalte, após armazenamento em saliva artificial durante vários intervalos de tempo (um dia, uma, duas e três semanas). Foram utilizados 78 pré-molares humanos, seccionados no sentido mésio-distal para a obtenção de duas metades. As superfícies vestibulares e linguais foram planificadas com lixa de granulação 600 e divididas em um grupo controle (n=12) e três grupos experimentais (n=48), de acordo com o agente clareador utilizado. O grupo 1 foi clareado com Crest Professional Whitestrips (peróxido de hidrogênio a 6,5%), usado durante 14 dias em duas aplicações de 30min cada. O grupo 2 recebeu o agente clareador Opalescence Quick (peróxido de carbamida a 35%) em três aplicações de 1 h cada, com intervalo de sete dias entre estas. O grupo 3 foi clareado com Opalescence Xtra (peróxido de hidrogênio a 35%), em três aplicações de 16min cada, com intervalo de sete dias entre estas. Os espécimes do grupo controle permaneceram armazenados em saliva artificial a 37°C por 14 dias. Após os tratamentos clareadores, os espécimes dos três grupos experimentais foram divididos em quatro subgrupos (n=12), de acordo com o tempo de armazenamento em saliva artificial a 37ºC (um dia, uma, duas e três semanas). Após os períodos de tempo descritos, procedeu-se o condicionamento ácido do esmalte, aplicação do agente adesivo Scotchbond Multi-Uso Plus (3M) e confecção de um cilindro de resina composta Z100 (3M), com 2mm de diâmetro. Os espécimes foram submetidos ao ensaio de cisalhamento em máquina lnstron Universal após 24h para obtenção dos valores de resistência adesiva. Os resultados foram analisados pelos testes estatísticos de ANOVA dois fatores, Tukey e Dunnett (5%). Observou-se que não houve diferença significante entre os valores.... / The aim of this study was to determine the effect of three bleaching agents on the shear bond strength of a composite resin to enamel, after various artificial saliva storage time (1 day, 1, 2 and 3 weeks). 78 human premolars were mesiodistally sectioned to obtain two halves. The buccal and lingual surfaces were ground with 600-grit aluminum oxide abrasiva paper to obtain flat enamel surfaces and divided into a control group (n=12) and three experimental groups (n=48), according to the bleaching agents. The first group was bleached with Crest Professional Whitestrips (6,5% hydrogen peroxide), used 1 hour for 14 days. The second group was bleached with Opalescence Quick (35% carbamide peroxide), in three applications of 1h, with an interval of 7 days among them. The third group was bleached with Opalescence Xtra (35% hydrogen peroxide), in three applications of 16min, with an interval of 7 days among them. Specimens of control group were not bleached and were stored in artificial saliva at 37ºC for 14 days. After the bleaching treatments, the specimens of the experimental groups were divided into four groups (n=12), according to the storage time in artificial saliva (1 day, 1, 2 and 3 weeks). Bonds were formed with Scotchbond MP and Z-100 composite resin, and shear bond test was carried out in an lnstron Universal Testing Machine after 24 hours. The results were analyzed by two-way ANOVA, Tukey and Dunnett's tests (5%). There was no significant difference among the shear bond strength of the three bleaching agents. Regarding to the post-bleaching time, the bond strength values obtained after three weeks were significant higher than the values obtained after one day, one and two weeks and were similar to those obtained for the control group. Conclusion: external bleaching with the three agents tested significantly reduced the bond strength of composite resin to enamel and after a lapse of ...

Made available in DSpace on 2018-07-27T18:25:55Z (GMT). No. of bitstreams: 0 Previous issue date: 1996-06-19. Added 1 bitstream(s) on 2018-07-27T18:29:54Z : No. of bitstreams: 1 000139324.pdf: 2030369 bytes, checksum: f21a2a5a9f9c699a700fd5835486e8b1 (MD5) / O objetivo deste estudo foi desenvolver em silicona, uma escala de tonalidades de pele humana. Foram confeccionados vinte e sete corpos de prova em silicona acética (Silastic 732 RTV), pigmentados com óxidos de ferro e dióxido de titânio. A quantidade da silicona acética manteve-se constante (duas gramas) em todos os corpos de prova, e os pigmentos foram misturados a ela, em várias proporções, até a obtenção das vinte e sete diferentes tonalidades. A partir da comparação dos corpos de prova, com a cor da pele de quarenta e um indivíduos, foram selecionados os cinco corpos de prova com as tonalidades que mais se igualavam à cor da pele dos mesmos, compondo assim, um guia de tonalidades. Variações nas quantidades dos pigmentos utilizados permitiram a obtenção de novas tonalidades. Com a metodologia empregada, foi possível desenvolver uma escala de tonalidades de pele que poderá facilitar a definição do tom da pele do paciente, quando da confecção de próteses faciais em silicona, permitindo economia de tempo e de material no momento da seleção da cor / The objective of this paper was to develop one silicone guide for human skin shades. Twenty-seven samples were manufactured in acetic silicone rubber (Silastic 732 RTV) pigmented with iron oxides and titanium dioxide. The qua ntity of acetic silicone rubber used in each specimen was kept constant (two grams) and the pigments were mixed to it in several proportions until the obtention of twenty-seven different shades. Through the comparison of the color of each sample with the skin color of forty-one individuals were selected the five samples which shades best matched the individuals' skin colar, determining in this way, a shade guide. Variations in the quantity of pigments used permited the obtention of new shades. With the employed methodology it was possible to develop a shade guide that can facilitate the definition of the patient's skin color when making facial prostheses in silicone allowing economy of time and material at the moment of color selection

Orientador: Lauro Cardoso Villela / Banca: Maria Auxiliadora Junho de Araújo / Banca: Rolf Rode / Resumo: O objetivo deste estudo foi desenvolver em silicona, uma escala de tonalidades de pele humana. Foram confeccionados vinte e sete corpos de prova em silicona acética (Silastic 732 RTV), pigmentados com óxidos de ferro e dióxido de titânio. A quantidade da silicona acética manteve-se constante (duas gramas) em todos os corpos de prova, e os pigmentos foram misturados a ela, em várias proporções, até a obtenção das vinte e sete diferentes tonalidades. A partir da comparação dos corpos de prova, com a cor da pele de quarenta e um indivíduos, foram selecionados os cinco corpos de prova com as tonalidades que mais se igualavam à cor da pele dos mesmos, compondo assim, um guia de tonalidades. Variações nas quantidades dos pigmentos utilizados permitiram a obtenção de novas tonalidades. Com a metodologia empregada, foi possível desenvolver uma escala de tonalidades de pele que poderá facilitar a definição do tom da pele do paciente, quando da confecção de próteses faciais em silicona, permitindo economia de tempo e de material no momento da seleção da cor / Abstract: The objective of this paper was to develop one silicone guide for human skin shades. Twenty-seven samples were manufactured in acetic silicone rubber (Silastic 732 RTV) pigmented with iron oxides and titanium dioxide. The qua ntity of acetic silicone rubber used in each specimen was kept constant (two grams) and the pigments were mixed to it in several proportions until the obtention of twenty-seven different shades. Through the comparison of the color of each sample with the skin color of forty-one individuals were selected the five samples which shades best matched the individuals' skin colar, determining in this way, a shade guide. Variations in the quantity of pigments used permited the obtention of new shades. With the employed methodology it was possible to develop a shade guide that can facilitate the definition of the patient's skin color when making facial prostheses in silicone allowing economy of time and material at the moment of color selection / Mestre

Indiana University-Purdue University Indianapolis (IUPUI), Indiana University School of Dentistry / Background: With the emerging of digital dentistry, IPS e.max® CAD lithium disilicate (LD) glass-ceramic material has become one of the most popular esthetic restorative materials in digital assisted dental esthetic restoration. The mechanical and optical properties of this material have been investigated in several studies. However, there is a lack of information and consensus regarding the optical properties of IPS e.max® LD glass-ceramic materials. Objectives: 1) To investigate the optical properties as translucency parameters (TP), Contrast ratio (CR), light transmissions (Lt) and color changes (CC) between high-translucent (HT) and low-translucent (LT) IPS e.max® CAD LD glass-ceramic materials with different crystalline phases and thickness in different firing stages. 2) To investigate the optical properties as TP, CR, Lt and CC of each translucent (HT and LT) IPS e.max® CAD LD glass-ceramic materials with different crystalline phases and thickness in different firing stages. 3) To determine the mathematical relationships of thicknesses of IPS e.max® CAD LD glass-ceramics materials with TP and Lt. Materials and methods: The total of 120 of shade A2 IPS max CAD samples (HT and LT) were prepared into square shape (15.25 mm X 15.25 mm) and were divided into two main groups according to the material translucency (HT and LT) (n=60). Each main group was further divided into 5 sub-groups according to the thickness (1.00, 1.25, 1.5, 1.75, and 2.00 mm) (n=12). Each thickness group was assigned into three groups based on different crystallization (firing) temperatures (750, 820 °C in single stage heating schedule with 1 second and 10 second holding times, respectively, and 840 °C with two-stage heating schedule (RECOM) (820°C, 840 °C with 10 second and 7 min holding time, respectively) as recommended by manufacturer (n=4). CIEL*a*b*, TP, CR, and Lt were measured and calculated for all samples. Statistical analysis: The effects of the test results were evaluated using 3-way ANOVA with factors for Translucency (HT and LT), Firing Temperature (750, 850, and RECOM) and Thickness (1, 1.25, 1.5, 1.75, and 2), as well as all two-way and three-way interactions among the factors. Pair-wise comparisons were made using Least Significant Differences to control the overall significance level at 5%. Results: The mean irradiance and TP for both HT and LT decrease as the thickness of the samples increases from 1 to 2mm with significant difference between the thickness groups within each material translucency groups (HT and LT) and between both HT and LT. The coefficients of absorption (c) of the two materials were calculated. The effective incidence irradiance when material thickness approaches zero (Ie) was also calculated. There is an unexpected spectral peak shift as the thickness of the samples increases. There is no statistically significant difference in Ie at 750˚C and 820 ˚C between the HT and LT. However, there is a statistically significant higher Ie in HT at the recommended firing temperature as expected. Coefficients of translucency parameter (p) of the materials in various firing temperature were defined and the TP of the material as the thickness approaches zero were calculated (TP0). The TP of the materials is directly correlated to the mean irradiance passing through the samples. There is no statistically significant difference in the TP0 and Ie of the HT and LT groups at the recommended firing temperature. Conclusion: In this project we developed modified Beer-Lambert law to describe the parameters governing the effect of thickness on light transmission in dental ceramic material. We also applied the same equation to describe the translucency parameter. The parameters defined in these equations allow us to compare the optical property of dental ceramic material independent of the thickness of the samples.