A irradiação com laser de CO2 e o emprego de compostos fluoretados podem contribuir para que o esmalte do dente decíduo se torne mais resistente a desafios ácidos. Assim, o presente estudo tem por objetivo avaliar in vitro o efeito do laser de CO2 e de compostos fluoretados no controle da progressão de lesões de cárie em esmalte de dentes decíduos por meio da análise de microdureza subsuperficial. Foram utilizados 40 caninos humanos decíduos, dos quais foram obtidos fragmentos de 3x3x2 mm. Estes foram submetidos a desafio cariogênico inicial que consistiu na imersão em solução desmineralizadora por 3 horas e remineralizadora por 21 horas, durante 5 dias. Os fragmentos foram distribuídos aleatoriamente em 4 grupos (n=10) de acordo com o tratamento superficial: CO2 - laser de CO2 (10,6 μm), VF - verniz fluoretado a 5%, FFA - flúor fosfato acidulado a 1,23% e ST - sem tratamento (controle). O laser de CO2 foi aplicado no modo ultra pulso, com potência de 0,5 W, densidade de energia de 0,04 J/cm2. Nos grupos que receberam tratamento com os fluoretos foi realizada uma aplicação de 0,1g durante um minuto. Após o tratamento superficial, foi realizado desafio cariogênico durante 5 dias, seguindo o protocolo anteriormente descrito. Foram realizadas 3 leituras de microdureza subsuperficial Knoop (KHN) a 30 μm da superfície. Os dados obtidos foram submetidos a análise de variância (ANOVA) e teste de Duncan com significância de 5%. Verificou-se que a microdureza subsuperficial do esmalte do dente decíduo obtida após irradiação com laser de CO2 foi semelhante à obtida após a aplicação do FFA, mas estatisticamente diferente dos grupos ST e VF (p≤0,05), que obtiveram as menores médias. Conclui-se que o laser de CO2 pode contribuir para o controle da progressão de lesões de cárie em esmalte de dentes decíduos. / The CO2 laser irradiation and the employment of fluoride compounds may contribute to the deciduous tooth enamel becoming more resistant to acid challenges. Thus, this study aims to evaluate in vitro the effect of CO2 laser irradiation and fluoride compounds in the control of the progression of carious lesions on enamel of deciduous teeth by subsurface microhardness analysis. A total of 40 deciduous canines were used, of which fragments were obtained 3x3x2 mm. These fragments were submitted to an initial cariogenic challenge that consisted of immersion on demineralizing solution for 3 hours and remineralizing solution for 21 hours, for 5 days. The fragments were randomly divided into 4 groups (n = 10) according to the superficial treatment: CO2 - CO2 laser (10.6 μm), VF - fluoride varnish 5%, FFA - acidulated phosphate fluoride 1.23% and ST - without treatment (control). The CO2 laser was applied in ultra pulse mode with power of 0.5 W and power density of 0.04 J/cm2. In the groups treated with fluoride application was performed from 0.1 g for one minute. After superficial treatment, cariogenic challenge was performed during 5 days, following the protocol described previously. Three Knoop subsurface microhardness (KHN) readings were performed at 30 μm from the surface. The data obtained were subjected to analysis of variance (ANOVA) and Duncan test with significance of 5%. It was found that the subsurface microhardness on the enamel of deciduos teeth obtained after irradiation with CO2 laser was similar to that obtained after the application of FFA but statistically different from the VF and ST groups (p≤0.05) that received the lowest average . It was concluded that the CO2 laser can contribute to the control of the progression of carious lesions on enamel of deciduous teeth.

O objetivo do presente estudo foi avaliar in situ o efeito da associação do verniz fluoretado ao laser de Er:YAG e ao laser Nd:YAG na permeabilidade da dentina radicular erodida. Quarenta e oito fragmentos de dentina radicular bovina, com dimensões 2x2x2 mm, foram submetidos a um desafio erosivo inicial com ácido cítrico (0,3%, pH 3,2), por duas horas, sob agitação e armazenados em saliva artificial por vinte e quatro horas. Posteriormente, os espécimes foram divididos em relação aos tratamentos: verniz fluoretado e não fluoretado e subdivididos conforme a irradiação: laser de Er:YAG (100mJ, 3Hz), laser de Nd:YAG (70mJ, 15 Hz) e não irradiado. Após um período de lead in (2 dias), os voluntários (n=8) utilizaram dispositivos palatinos contendo três espécimes que foram submetidos a desafios erosivos ex vivo, quatro vezes ao dia, com ácido cítrico (0,3%, pH 3,2), durante 90s, por cinco dias. Na primeira fase do experimento, metade dos voluntários utilizou dispositivos contendo fragmentos tratados com verniz fluoretado, verniz fluoretado + laser de Er:YAG e verniz fluoretado + laser de Nd:YAG. A outra metade utilizou verniz não fluoretado, verniz não fluoretado + laser de Er:YAG e verniz não fluoretado + laser de Nd:YAG. Depois de um período de wash-out (15 dias), os voluntários foram cruzados quanto aos tratamentos, caracterizando um experimento cross-over 2x2. Ao final de cada fase experimental, a permeabilidade dentinária foi avaliada. A ANOVA dois critérios e o teste complementar de Duncan revelaram uma diferença significativa entre os espécimes tratados com o verniz fluoretado (p=0,005), verniz fluoretado + laser de Er:YAG (p=0,014) e verniz fluoretado + laser de Nd:YAG (p=0,025), em comparação aos tratados com verniz não fluoretado. Observou-se que, independentemente da associação aos lasers (Er:YAG ou Nd:YAG), o verniz fluoretado foi capaz de promover a redução da permeabilidade da dentina radicular erodida. Não se observou efeito adicional com a associação dos tratamentos. / The present study aimed to evaluate in situ the effect of associating the fluoride varnish to Er:YAG or Nd:YAG laser at permeability of eroded root dentin. Forty-eight specimens of bovine root dentin (2x2x2mm) were subjected to initial erosive challenge with citric acid (0.3%, pH 3.2), for 2 hours under agitation and stored at artificial saliva, at 37&deg C, for 24 hours, followed by a remineralization period in artificial saliva. After that, specimens were divided according to the treatment: fluoride varnish and non-flouride varnish, and subdivided according to the irradiation: Er:YAG laser (100mJ, 3Hz), Nd:YAG laser (70mJ, 15Hz) and non-irradiated. After a lead-in period (2 days), 8 volunteers (n=8) wore a palatal device containing 3 specimens that was subjected to erosive challenges ex vivo, four times a day with citric acid (0.3%, pH3.2), for 90s, during 5 days. At the first experimental phase, half of volunteers wore devices containing specimens treated with fluoride varnish, fluoride varnish + Er:YAG laser and fluoride varnish + Nd:YAG laser, and the other half wore the specimens treated with non-fluoride varnish, non-fluoride varnish + Er:YAG laser and non-flouride varnish + Nd:YAG laser. After a wash-out period (15 days), volunteers were crossed to different treatment, characterizing a 2x2 cross-over experiment. At the end of each experimental phase, the dentinal permeability was evaluated. Two-way ANOVA and Duncans test revealed a significant difference between specimens treated with fluoride varnish (p=0,005), fluoride varnish + Er:YAG laser (p=0,014) and fluoride varnish + Nd:YAG (p=0,025) compared to specimens treated with no-fluoride varnish. It was observed that regardless of association to laser (Er:YAG or Nd:YAG), fluoride varnish was able to promote, in situ, the reduction of permeability of eroded root dentin, but no additional effect was observed when the treatments were associated.

A irradiação com laser de CO2 e o emprego de compostos fluoretados podem contribuir para que o esmalte do dente decíduo se torne mais resistente a desafios ácidos. Assim, o presente estudo tem por objetivo avaliar in vitro o efeito do laser de CO2 e de compostos fluoretados no controle da progressão de lesões de cárie em esmalte de dentes decíduos por meio da análise de microdureza subsuperficial. Foram utilizados 40 caninos humanos decíduos, dos quais foram obtidos fragmentos de 3x3x2 mm. Estes foram submetidos a desafio cariogênico inicial que consistiu na imersão em solução desmineralizadora por 3 horas e remineralizadora por 21 horas, durante 5 dias. Os fragmentos foram distribuídos aleatoriamente em 4 grupos (n=10) de acordo com o tratamento superficial: CO2 - laser de CO2 (10,6 μm), VF - verniz fluoretado a 5%, FFA - flúor fosfato acidulado a 1,23% e ST - sem tratamento (controle). O laser de CO2 foi aplicado no modo ultra pulso, com potência de 0,5 W, densidade de energia de 0,04 J/cm2. Nos grupos que receberam tratamento com os fluoretos foi realizada uma aplicação de 0,1g durante um minuto. Após o tratamento superficial, foi realizado desafio cariogênico durante 5 dias, seguindo o protocolo anteriormente descrito. Foram realizadas 3 leituras de microdureza subsuperficial Knoop (KHN) a 30 μm da superfície. Os dados obtidos foram submetidos a análise de variância (ANOVA) e teste de Duncan com significância de 5%. Verificou-se que a microdureza subsuperficial do esmalte do dente decíduo obtida após irradiação com laser de CO2 foi semelhante à obtida após a aplicação do FFA, mas estatisticamente diferente dos grupos ST e VF (p≤0,05), que obtiveram as menores médias. Conclui-se que o laser de CO2 pode contribuir para o controle da progressão de lesões de cárie em esmalte de dentes decíduos. / The CO2 laser irradiation and the employment of fluoride compounds may contribute to the deciduous tooth enamel becoming more resistant to acid challenges. Thus, this study aims to evaluate in vitro the effect of CO2 laser irradiation and fluoride compounds in the control of the progression of carious lesions on enamel of deciduous teeth by subsurface microhardness analysis. A total of 40 deciduous canines were used, of which fragments were obtained 3x3x2 mm. These fragments were submitted to an initial cariogenic challenge that consisted of immersion on demineralizing solution for 3 hours and remineralizing solution for 21 hours, for 5 days. The fragments were randomly divided into 4 groups (n = 10) according to the superficial treatment: CO2 - CO2 laser (10.6 μm), VF - fluoride varnish 5%, FFA - acidulated phosphate fluoride 1.23% and ST - without treatment (control). The CO2 laser was applied in ultra pulse mode with power of 0.5 W and power density of 0.04 J/cm2. In the groups treated with fluoride application was performed from 0.1 g for one minute. After superficial treatment, cariogenic challenge was performed during 5 days, following the protocol described previously. Three Knoop subsurface microhardness (KHN) readings were performed at 30 μm from the surface. The data obtained were subjected to analysis of variance (ANOVA) and Duncan test with significance of 5%. It was found that the subsurface microhardness on the enamel of deciduos teeth obtained after irradiation with CO2 laser was similar to that obtained after the application of FFA but statistically different from the VF and ST groups (p≤0.05) that received the lowest average . It was concluded that the CO2 laser can contribute to the control of the progression of carious lesions on enamel of deciduous teeth.

During this project it was investigated how the newly developed piezoelectric PVDF bicomponent fibre behaved when integrated in different weave constructions. The possibility to integrate conductive yarns as outer electrode was studied in order to see if it was possible to create a fully textile piezoelectric sensors. The piezoelectric properties of the bicomponent fibre is given by the sheath material, which is a polymeric material known as poly(vinylidene fluoride) (PVDF). Today only piezoelectric film made by PVDF is commercially available, but with a flexible PVDF bicomponent fibre it improves the possibility to integrate piezoelectric material into a textile construction. In this study the PVDF bicomponent fibre was integrated in the warp direction into weave constructions, such as plain weave, twill and weft rib. All the woven bands included 60 PVDF bicomponent yarns, with 24 filaments in each bundle and the average width of the bands produced was 30 mm. Different conductive materials and fibres, acting as outer electrode, were coated or integrated together with the PVDF fibre and the behaviour of the PVDF fibres was analysed. All the woven samples went through corona poling with a voltage of 7 kV in 70 ⁰C for 3 min. The weave construction that gave highest piezoelectric output signal was twill with weft that has low tex. The twill construction gave a range amplitude of 1.5- 3.3 V when subjected to a dynamic strain of about 0.25% at 4 Hz. It was shown that different conductive materials influenced the PVDF fibre in different ways, due to the resistance of the material. It was also shown that it was possible to integrate piezoelectric bicomponent fibre into a textile construction and that a fully textile piezoelectric sensor could be produced by using conductive yarns as outer electrode. / Program: Masterutbildning i textilteknik,

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No. of bitstreams: 1 crastechini_e_dr_sjc.pdf: 1828754 bytes, checksum: fd9d04fce38028ef480de9b998017af4 (MD5) Previous issue date: 2017-02-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi avaliar o efeito da aplicação de agentes remineralizantes contendo silicato de cálcio / fosfato e flúor ou fluoreto de sódio somente, sobre a redução da microdureza do esmalte causada pelo clareamento dental, cor dos dentes e perda de estrutura resultante da abrasão. Duzentos e quarenta amostras circulares de esmalte bovino foram preparadas, embutidas e polidas. Em seguida foram realizados testes iniciais de cor, microdureza e perfilometria. As amostras foram distribuídas aleatoriamente em 6 grupos (n=40): Grupo C –(controle negativo) – nenhum tratamento; Grupo CL (controle positivo)- Aplicação do agente clareador a base de peróxido de hidrogênio a 40% (Opalescence boost, Ultradent); Grupo CL/Rs – Aplicação do agente clareador seguido da aplicação do gel remineralizante a base de silicato de cálcio/fosfato (Regenerate Boosting serum- Unilever); Grupo Rs/CL - Aplicação do gel de silicato de cálcio/fosfato seguido da aplicação do agente clareador; Grupo Rs/CL/Rs - Aplicação do gel de silicato de cálcio/fosfato seguida da aplicação do agente clareador e aplicação novamente do gel de silicato de cálcio/fosfato; Grupo CL/F – Aplicação do agente clareador seguida da aplicação do gel de fluoreto de sódio a 2%. Após a etapa de clareamento (3 aplicações de 20 min) foram novamente realizadas as leituras de cor e microdureza. Em seguida os espécimes foram submetidos a 100.000 ciclos abrasivos em máquina de escovação. Cada grupo foi dividido em dois subgrupos de acordo com o dentifrício utilizado (n=20): Subgrupo Cp –creme dental Close Up proteção bioativa (Unilever); Subgrupo Rp- creme dental Regenerate (Unilever). Os perfis finais das superfícies do esmalte foram avaliados e o desgaste calculado. Os dados foram analisados utilizando o teste de análise de variância ANOVA e Tukey. Diferenças significativas foram observadas para a variação de cor (∆E) (p = 0,000). Os resultados do teste Tukey foram: C (1,31±0,58)a , Rs/CL/Rs (3,72±1,28)b, CL (3,75±1,04)b , CL/Rs (3,87±0,91)b, Rs/CL (3,88±0,94)b, CL/F (4,03±1,22)b. Diferenças estatisticamente significantes foram observadas para a microdureza (Knoop) após os tratamentos (p= 0,00001). Os resultados do teste Tukey foram: CL (246,28±30.46)a, Rs/CL/Rs (263,55±18,66)b, CL/Rs (264,06±28,54)b, Rs/CL (265,22±23,58)b, CL/F (269,10±25,66)b C (323,28±10,96)c. Para o desgaste dental (µm) o teste ANOVA a dois fatores mostrou diferenças significativas entre os grupos e os dentifrícios. Os resultados do teste de Tukey para os grupos foram: CL/F (2,12±0,70)a, Rs/CL (2,13±0,85)a, Rs/CL/Rs (2,19±0,70)a, CL/Rs (2,23±0,91)a, C (2,85±0,98)b , CL (3,36±0,84)c. Os resultados do teste de Tukey para os dentifrícios foram: Rp (2,04±0,80)a, Cp (2,92±0.88)b. Concluiu-se que todos os tratamentos com géis remineralizantes testados minimizaram a redução da microdureza promovida pelo clareamento, embora não evitaram que ela acontecesse. Além disso, a aplicação desses não interferiu na mudança da cor promovida pelo clareamento dental. O clareamento sozinho aumentou o desgaste abrasivo dos dentes, porém todos os tratamentos da superfície com géis remineralizantes testados reduziram a perda de estrutura por abrasão. O dentifrício Regenerate resultou em menor desgaste abrasivo do esmalte em relação ao Close UP. Não existiram diferenças significativas entre os diferentes tratamentos remineralizantes com relação aos efeitos sobre a microdureza, cor e desgaste. / This study aimed to evaluate the effect of the application of remineralizing agents containing calcium/phosphate silicate and fluoride or only sodium fluoride on the reduction of enamel microhardness caused by tooth bleaching, tooth color and loss of structure resulting from abrasion. Two hundred and forty circular bovine enamel samples were prepared, embedded and polished. After that, initial tests of color, microhardness and profile were performed. Samples were randomized into six groups (n=40): Group C - (negative control) - no treatment; Group CL (positive control) – application of 40% hydrogen peroxide bleaching agent (Opalescence boost, Ultradent); Group CL/Rs - Application of bleaching agent followed by remineralizing gel based on calcium/phosphate silicate (Regenerate Boosting serum- Unilever); Group Rs/CL – Application of calcium/phosphate silicate gel followed by bleaching agent; Group Rs/CL/Rs – Application of calcium/phosphate silicate gel followed by bleaching agent and new application of calcium/phosphate silicate gel; Group CL/F – Application of bleaching agent followed by 2% sodium fluoride gel. After bleaching stage (3 applications/20 min), color and microhardness readings were performed. Then, the specimens were subjected to 100.000 abrasive cycles in a brushing machine. Each group was divided into two subgroups according to the dentifrice used (n=20): Subgroup Cp –Close Up bioactive protection toothpaste (Unilever); Subgroup Rp- Regenerate toothpaste (Unilever). Final profiles of enamel surface were evaluated and the wear was calculated. Data were analyzed using ANOVA and Tukey variance analysis. Significant differences were observed for color variation (∆E) (p=0.000). Tukey test results were: C (1.31±0.58)a, Rs/CL/Rs (3.72±1.28)b, CL (3.75±1.04)b, CL/Rs (3.87±0.91)b, Rs/CL (3.88±0.94)b, CL/F (4.03±1.22)b. Statistically significant differences were observed for microhardness (Knoop) after treatments (p=0.00001). Tukey test results were: CL (246.28±30.46)a, Rs/CL/Rs (263.55±18.66)b, CL/Rs (264.06±28.54)b, Rs/CL (265.22±23.58)b, CL/F (269.10±25.66)b, C (323.28±10.96)c. For dental wear (µm), two-factor ANOVA test showed significant differences among groups and dentifrices. Tukey test results were were: CL/F (2.12±0.70)a, Rs/CL (2.13±0.85)a, Rs/CL/Rs (2.19±0.70)a, CL/Rs (2.23±0.91)a, C (2.85±0.98)b, CL (3.36±0.84)c. Tukey test results for the dentifrices were: Rp (2.04±0.80)a, Cp (2.92±0.88)b. It was concluded that all treatments with the remineralizing gels minimized the reduction of microhardness promoted by bleaching, although they did not prevent it from happening; In addiction, their application did not interfere in the color change promoted by dental bleaching. Bleaching alone increased the abrasive wear of the teeth. However, all surface treatments, with the remineralizing gels, reduced abrasion structure. Regenerate toothpaste resulted in less abrasive enamel wear regarding Close up toothpaste. There were no significant differences among the different remineralizing treatments with regarding their effects on microhardness, color and wear.

O presente estudo foi conduzido durante vinte meses, sob supervisão, em região não fluoretada, para avaliar e comparar o efeito anticariogênico de um bochecho semanal, durante um minuto, com lO ml de solução aquosa de fluoreto de sódio a 0,2 por cento (grupo A) ou solução aquosa de monofluorfosfato de sódio a O,7 por cento (grupo B), ou solução aquosa de monofluorfosfato de sódio a 0,7 por cento contendo 4 por cento de álcool etílico (grupo C) sendo utilizada como controle solução aquosa de cloreto de sódio a 0,1 por cento (grupo D). A amostra inicial era constituída de 1.023 crianças, de 9 a 12 anos de idade, de seis escolas públicas estaduais, da região de Bauru, no Estado de São Paulo, balanceadas pelo número de dentes permanentes e pelo CPOS. Após doze meses restavam 220 crianças em cada grupo de estudo. As crianças dos grupos A e B apresentaram reduções de 16,00 por cento no CPOD e as do grupo C de 22,40 por cento , não significantes estatisticamente, em relação ao grupo controle. As reduções no CPOS foram de 26,06 por cento para crianças do grupo A, 26,63 por cento para as do grupo B e 30,88 por cento para as do grupo C, todas significantes ao nível de 5 por cento em relação ao grupo controle ,não significantes entre si. Após vinte meses, havia 206 crianças remanescentes em cada grupo de estudo. As reduções no CPOD foram de 36,76 por cento para as crianças do grupo A, 33,96 por cento para as do grupo B e 31,15 por cento para as do grupo C. As reduções no CPOS foram de 34,63 por cento para as crianças do grupo A, 27,54 por cento para as do grupo B e 32, 22 por cento para as do grupo C, todas estatisticamente significantes ao nível de 5 por cento , em relação ao grupo controle, mas não significantes entre si. / Children 9 to 12 years of age rinsed their teeth once a week during the school year for one minute with 10 ml of one of the following: A- 0,2 per cent sodium fluoride solution, B - 0,7 per cent sodium monofluorophosphate solution, C - 0,7 per cent sodium monofluorophosphate solution containing 4 per cent of ethanol, D- 0,1 per cent sodium chloride solution. The sample was constituted of school children from six public schools in the Bauru area, State of São Paulo. The children were evenly divided in four groups and care was taken to ensure that the groups had similar initial dental caries experience. The twelve months evaluation, based on 220 children in each group showed that children in groups A and B had 16,00 per cent less decayed teeth than the controls, the percentage of reduction being 22,40 per cent for group C. For dental surfaces the reduction were 26,06 per cent for group A, 26,63 per cent for group B and 30,88 per cent for group C, all statistically significant at 5 per cent level. However the groups did not differ statistically among themselves. A second evaluation, which was based on 206 children in each group, was made twenty months after the base line survey. The caries reductions on teeth were 36,76 per cent , 33,9.6 per cent and 31,15 per cent for groups A, B and C respectively. For dental faces the reductions on caries incidence were 34,63 per cent for children in group A, 27,54 per cent for those in group B and 32,22 per cent for group C. All these reductions were statistically significant against the control group, but again there were not significance when the fluoride groups were compared one with the other.

O presente trabalho tem por objetivo avaliar &ldquo;in vitro&rdquo; diferentes tratamentos na remineralização do esmalte desmineralizado em situação de alto desafio cariogênico. Foram obtidos 55 blocos de esmalte de dentes bovinos com dimensões de 4x4x2mm, que tiveram sua superfície planificada e polida. Metade da superfície foi protegida com resina, antes da formação de lesão de mancha branca, mantendo-a íntegra. Para a formação da lesão de desmineralização os blocos foram imersos em solução tampão de acetato por 43h. Os espécimes foram divididos aleatoriamente em 5 grupos: controle (sem tratamento), Verniz Duraphat; Flúor gel; Mi Paste e Mi Paste Plus. Todas as superfícies desmineralizadas receberam tratamento, com os seus respectivos produtos, 1x/semana durante 3 semanas. Nos intervalos das aplicações os espécimes foram submetidos a ciclos de pH num total de 21 dias. Antes da desmineralização, após, em seguida à 1a aplicação e ao final dos 21 dias de ciclagem foram obtidas imagens da superfície e análise da rugosidade superficial, e morfologia por meio de Microscopia Confocal a Laser, ao final a resina que protegia a área controle foi removida e capturada uma nova imagem para análise do perfil de desgaste. Os dados foram analisados quanto a sua distribuição e verificada a normalidade e a homogeneidade da distribuição amostral, foi realizada Análise de Variância e teste de tukey (p<0,05). Pode-se observar que tanto para a rugosidade superficial como para o perfil de desgaste os grupos estudados apresentaram resultados similares entre si (p>0,05). Na rugosidade superficial observou-se que apenas no verniz ocorreu um aumento significante de rugosidade com o tempo (p<0,05). Na morfologia pode-se observar uma topografia irregular que foi mais evidenciada ao término da ciclagem, tendo o controle e os Mi Paste (convencional e plus) apresentado perda de estrutura mais evidente. Baseado nos resultados obtidos pode-se concluir que nenhum tratamento preventivo isolado foi efetivo para paralisação do desenvolvimento da lesão de cárie que foi agravado com o tempo de exposição ao processo DES-RE. / The aim of this study was to evaluate, in vitro, different treatments in previously demineralized enamel in a high cariogenic challenge. 55 enamel slabs of bovine teeth with dimensions of 4x4x2mm were planned and polished surface. Half the surface was protected with resin before the formation of white spot lesions, and half stay sound. For the formation of the demineralization challenge the blocks were immersed in acetate buffer solution for 43h. The specimens were randomly divided into 5 groups: control (no treatment), Duraphat; Fluoride gel; Mi Paste and Mi Paste Plus. All demineralized surfaces were treated with their respective products, 1x/week for 3 weeks. During intervals among applications specimens were subjected to pH cycles in a total of 21 days. Before demineralization, after the first application and after 21 days of cycling were obtained images of surface and it was analyzed for surface roughness and morphology by 3D Confocal Laser microscope, the end the resin protecting the control area was removed and a new image captured for analysis of the wear profile. Data were analyzed for distribution and checked for normality and homogeneity of the sampling distribution, it was performed analysis of variance and Tukey test (p <0.05). It can be seen that both the surface roughness and profile for the wear groups had similar results (p> 0.05). Surface roughness was observed only in the duraphat showed a significant increase in roughness with time (p <0.05) occurred. Morphology can be observed an irregular topography that was more evident at the end of cycling, it had been control and Mi Paste (conventional and plus) presented more evident loss of structure. Based on the results obtained in vitro can be concluded that no preventive treatment alone was effective in paralyzed the development of caries lesion. The integrity of enamel surface was deteriorated with time of exposure in DES-RE process.

A comparison of the antimicrobial efficacy of silver diamine fluoride and silver nitrate on various cariogenic bacteria: an ex vivo study By: Reham AlNajjar, D.D.S. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2019 Thesis Advisor: William Dahlke, D.M.D., Associate Professor and Chair of Pediatric Dentistry, School of Dentistry Purpose: The use of silver-based antimicrobials is an emerging method for the treatment of dental caries. In this study, the authors compare the efficacy of the two most prominent silver- based therapeutics, silver diamine fluoride (SDF) and silver nitrate (AgNO3), on cariogenic and non-cariogenic multispecies biofilms. Currently there is a lack of studies comparing the efficacy of SDF to AgNO3. Methods: Plaque samples from anterior and posterior tooth sites from children presenting both with early childhood caries and caries-free children were collected, pooled, and utilized to create four ex vivo biofilm systems in artificial saliva. SDF and AgNO3 were administered to these biofilms and bacterial survival was quantified and compared to untreated controls. Results: Each of the four pooled sample types was applied to plates coated in artificial saliva + 1% sucrose. Both SDF and AgNO3 were very effective against plaque derived biofilms when compared to untreated biofilms (P0.05) in the potency of each compound. Conclusions: SDF and AgNO3 significantly inhibit ex vivo cariogenic and non-cariogenic biofilms at similar levels.

京都大学 / 新制・課程博士 / 博士(人間・環境学) / 甲第23995号 / 人博第1047号 / 新制||人||245(附属図書館) / 2022||人博||1047(吉田南総合図書館) / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 内本 喜晴, 教授 中村 敏浩, 教授 陰山 洋, 教授 雨澤 浩史 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

Apatites are a diverse class of phosphate minerals that are important in a great variety of natural and industrial processes. They are, for example, used as raw material in fertiliser production and in the remediation of metal-contaminated soils. Hydroxyapatite Ca5(PO4)3OH, (HAP) and fluorapatite Ca5(PO4)3F, (FAP) are similar to the biological apatite that is the main constituent of mammalian bone and teeth, and they are therefore promising materials for artificial bone and tooth implants. This thesis is a summary of four papers with focus on dissolution and surface complexation reactions of HAP and FAP in the absence and presence of both organic ligands and the natural and commonly occurring iron oxide goethite (α-FeOOH). The dissolution and surface complexation of HAP and FAP was investigated with a combination of different techniques. Potentiometric acid/base titrations and batch experiments were combined with X-ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectroscopy to generate dissolution and surface complexation models for both apatites. The results from these studies showed that both apatites form surface layers that are different from their bulk compositions when equilibrated in aqueous solutions. The modeling efforts predicted speciation of these surfaces as well as the concentration of the dissolution products in the solution. The interaction between organic ligands and the apatite surfaces was also investigated and the results from this study show that the organic ligands form outer-sphere complexes on the apatite surfaces over a large pH interval, and that this adsorption enhances the dissolution of apatites. The presence of goethite also enhances the dissolution of FAP as it acts as a sink for the phosphate released from FAP. Phase transformation in this system was detected using ATR-FTIR as the phosphate adsorbed to the goethite surface precipitates as FePO4 (s) after approximately 15 days of reaction time. This changes the speciation, and possibly also the bioavailability of phosphate in this two-mineral system.