O desenvolvimento de cimentos endodônticos com maior capacidade antimicrobiana, leva a associação de cimentos endodônticos com agentes antimicrobianos. O vanadato de prata nanoestruturado decorado com nanopartículas de prata (AgVO3) é um nanomaterial com capacidade antimicrobiana com aplicação na odontologia. O objetivo desse trabalho foi avaliar quatro cimentos endodônticos (AH Plus, Sealapex, Sealer 26 e Endofill) incorporados com AgVO3, em diferentes concentrações (0%, 2,5%, 5% e 10%), através de testes in vitro de concentração inibitória mínima (CIM) e capacidade antimicrobiana (difusão em ágar) (n=6) frente aos micro-organismos: Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli. Testes das propriedades físicas de escoamento (n=6), radiopacidade (n=5), teste de alteração de cor da estrutura dental (n=3) e padrão de distribuição superficial do AgVO3 aos cimentos endodônticos (n=5) foram realizados. Para análise estatística da capacidade antimicrobiana e escoamento foram realizados teste paramétrico 2-way ANOVA e teste de Tukey honestly significant difference (HSD), os dados da radiopacidade foram analisados pelo teste Kruskal-Wallis e teste de permutação com nível de significância de 5%, e para a alteração de cor realizou-se análise estatística descritiva. A CIM do AgVO3 para E. faecalis foi de 500 &micro;g/mL e para P. aeruginosa e E. coli de 31,25 &micro;g/mL. A incorporação de 10% de AgVO3 promoveu maior atividade antimicrobiana a todos os cimentos frente a E. coli, ao Sealer 26 e Sealapex frente a E. faecalis e ao AH Plus e Endofill frente a P. aeruginosa (p<0,05). A incorporação de AgVO3 não influenciou na atividade antimicrobiana inerente do AH Plus frente a E. faecalis (p>0,05) e não promoveu tal propriedade ao Sealer 26 e Sealapex frente a P. aeruginosa (p>0,05). O escoamento do AH Plus e Endofill reduziu com o aumento da concentração de AgVO3 (p<0,05). Não houve influência no escoamento do Sealer 26 e Sealapex (p>0,05). Todos os grupos apresentaram valores de escoamento dentro do recomendado pela American National Standard/American Dental Association (ANSI/ADA), exceto o AH Plus 10%. O AgVO3 não influenciou na radiopacidade do Endofill (p=0,399) e Sealapex (p=0,316), e a concentração de 2,5% do Sealer 26 e AH Plus apresentou maior radiopacidade em relação ao controle (p=0,022 e p=0,006, respectivamente), que não diferiu dos demais grupos (p>0,05). Todos cimentos incorporados com AgVO3 apresentaram maiores alterações de cor após 180 dias, a menor alteração foi do Endofill 10% e a maior do Sealer 26 10%. O AgVO3 apresentou um padrão de distribuição superficial circular na composição dos cimentos endodônticos. Concluiu-se que a incorporação do AgVO3 tem potencial para aumentar a atividade antimicrobiana dos cimentos endodônticos avaliados, não influenciou no escoamento do Sealer 26 e Sealapex, e na radiopacidade dos cimentos avaliados. Os grupos incorporados com AgVO3 apresentaram maior alteração de cor com 180 dias, exceto o Endofill 10%. / The development of endodontic sealers with higher antimicrobial capacity, leads to the association of endodontic sealers with antimicrobial agents. The nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) is an antimicrobial nanomaterial with application in dentistry. The aim of this study was to evaluate four endodontic sealers (AH Plus, Sealapex, Sealer 26 and Endofill) incorporated with AgVO3, in different concentrations (0%, 2.5%, 5% and 10%), through in vitro tests of minimum inhibitory concentration (MIC) and antimicrobial capacity (agar diffusion method) (n=6) against microorganisms: Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli. Tests on physical properties of flow (n = 6), radiopacity (n = 5), tooth discoloration (n = 3) and superficial distribution pattern of the AgVO3 to endodontic sealers (n = 5) were performed. For statistical analysis of antimicrobial capacity and flow, were performed the 2-way ANOVA parametric test and the Tukey honestly significant difference (HSD) test, the radiopacity data were analyzed by the Kruskal-Wallis test and permutation test with significance level of 5%, and descriptive statistical analysis was performed for tooth discoloration. The MIC of AgVO3 for E. faecalis was 500 &micro;g/mL and for P. aeruginosa and E. coli 31,25 &micro;g/mL. The incorporation of 10% of AgVO3 increased antimicrobial activity to all sealers against E. coli, to Sealer 26 and Sealapex against E. faecalis and to AH Plus and Endofill against P. aeruginosa (p <0.05). The incorporation of AgVO3 did not influence on antimicrobial activity inherent of the AH Plus against E. faecalis (p> 0.05) and did not promote this property to Sealer 26 and Sealapex against P. aeruginosa (p> 0.05). The flow of AH Plus and Endofill decreased with increasing AgVO3 concentration (p <0.05). There was no influence on the flow of Sealer 26 and Sealapex (p> 0.05). The evaluated groups presented flow values within the recommended by the American National Standard/American Dental Association (ASNI/ADA), except the AH Plus 10%. The AgVO3 did not influence the radiopacity of Endofill (p = 0.399) and Sealapex (p = 0.316), the concentration of 2.5% of Sealer 26 and AH Plus presented higher radiopacity than the control (p = 0.022 and p = 0.006, respectively), which did not differ from the other groups (p> 0.05). All sealers incorporated with AgVO3 presented color alterations after 180 days, the lowest change was Endofill 10% and the highest was Sealer 26 10%. The AgVO3 presented a pattern of circular superficial distribution in the composition of the endodontic sealers. It is concluded that the incorporation of AgVO3 has the potential to increase the antimicrobial activity of the endodontic sealers evaluated, did not influence the flow of the Sealer 26 and Sealapex, and the radiopacity of sealers evaluated. The groups incorporated with AgVO3 presented color alterations with 180 days, except Endofill 10%.

Com o intuito de estudar in vivo a reprodutibilidade e a comparação de dois índices visuais (Ekstrand et al. (1998) ? E e Nyvad; Machiulskiene e Baelum (1999) ? N) e as medidas de fluorescência a laser AGNOdent®,KaVo - DD) na detecção de sulcos e fossetas descoloridos, um único examinador treinado, após a obtenção do consentimento livre e esclarecido de 28 pacientes, atribuiu os escores E, N e médias de fluorescência a laser de 190 molares decíduos com e sem descoloração em sulcos e fossetas oclusais. A reprodutibilidade dos índices visuais foi calculada a partir do teste kappa Cohen e kappa ponderado (kp), enquanto para as médias do DD foi calculado o índice de correlação de Pearson (rp). Para a comparação entre os índices visuais ainda se calculou a correlação de Spearman (rcs) e para a correlação entre os índices visuais e as médias do DD, foram aplicados o teste t de Student para as dicotomizações de presença de lesão, descoloração e atividade. Finalmente, foi calculada a análise de variância (ANOVA) para comparação entre as médias do DD e os graus de severidade das lesões. A reprodutibilidade dos índices visuais foi substancial (kpE = 0,645) e (kpN = 0,634) e as médias do DD apresentaram correlação de Pearson significativa e altamente positiva (rp = 0,930). A comparação entre os índices visuais também foi positiva e significativa principalmente quanto à severidade (rcs = 0,623) e nas dicotomizações para a presença de lesão (rcs = 0,765) e descoloração (rcs = 0,757). O teste t de Student para as comparações entre os índices e as médias do DD também se apresentaram significativos (p < 0,001) para presença de lesão e descoloração ao contrário dos resultados para atividade. A análise de variância entre os graus de severidade dos índices visuais e as médias do DD mostrou diferenças estaticamente significativas apenas entre os graus de severidade 0 e 1 (E - 2a) para o índice E e 0, 1 (N - 4) e 2 (N - 5) para o índice N. Conclui-se, para sulcos e fossetas descoloridos de molares decíduos, que (1) ambos os métodos (visuais e de fluorescência a laser) mostraram-se confiáveis (2) o DD foi capaz de diferenciar tecidos hígidos de lesões com descoloração e de (3) inativas intactas ou com microcavidades em esmalte. / Aiming at developing an in vivo study of the reproducibility and correlation of two visual indexes (Ekstrand et al. (1998) ? E and Nyvad; Machiulskiene and Baelum (1999) ? N) and the measures of laser fluorescence (DIAGNOdent®,KaVo - DD) for the detection of decolorised pits and fissures, a single trained examiner, after the free and aware consent of 28 patients, opened the scores E, N and laser fluorescence averages of 190 primary molars with and without occlusal discoloration in pits and fissures. The reproducibility of the visual indexes was calculated with basis on the kappa Cohen and weighted kappa (wk) tests, while for the DD averages the Perason´s correlation (rp) was calculated. To provide a comparison among the visual indexes, the Sperman´s correlation (rcs) was calculated, and for the correlation among the visual indexes and the DD averages, the Student´s t test and the one-way analysis of variance (ANOVA) were applied to compare the DD averages and the degree of severity of the lesions. The reproducibility of the visual indexes was substantial (wkE= 0,645) and (wkN= 0,634); the DD averages presented a significant and highly positive Pearson´s correlation (rP= 0,930). The comparison among the visual indexes proved to be positive and significant, mainly in relation to the severity (rcs= 0,623) and the dichotomisations for the presence of lesion (rcs= 0,765) and discoloration (rcs= 0,757). The Student´s t test of for the comparisons among the indexes and the DD averages also proved to be significant (p < 0,001) for the presence of lesion and discoloration, contrary to the activity results. The one-way analysis of variance (ANOVA) among the degrees of severity and DD averages showed significant differences only at the degrees 0 and 1 (E ? 2a) of the E index and 0, 1 (N ? 4) and 2 (N ? 5) of the N index. The conclusions for pits and fissures with discoloration in primary molars are that (1) both methods (visual and laser fluorescence) were reliable (2) the DD was able to diferenciatte sound tissues from lesions with discoloration and (3) inactive intact or with microcavities lesions at the enamel level.

Com o intuito de estudar in vivo a reprodutibilidade e a comparação de dois índices visuais (Ekstrand et al. (1998) ? E e Nyvad; Machiulskiene e Baelum (1999) ? N) e as medidas de fluorescência a laser AGNOdent®,KaVo - DD) na detecção de sulcos e fossetas descoloridos, um único examinador treinado, após a obtenção do consentimento livre e esclarecido de 28 pacientes, atribuiu os escores E, N e médias de fluorescência a laser de 190 molares decíduos com e sem descoloração em sulcos e fossetas oclusais. A reprodutibilidade dos índices visuais foi calculada a partir do teste kappa Cohen e kappa ponderado (kp), enquanto para as médias do DD foi calculado o índice de correlação de Pearson (rp). Para a comparação entre os índices visuais ainda se calculou a correlação de Spearman (rcs) e para a correlação entre os índices visuais e as médias do DD, foram aplicados o teste t de Student para as dicotomizações de presença de lesão, descoloração e atividade. Finalmente, foi calculada a análise de variância (ANOVA) para comparação entre as médias do DD e os graus de severidade das lesões. A reprodutibilidade dos índices visuais foi substancial (kpE = 0,645) e (kpN = 0,634) e as médias do DD apresentaram correlação de Pearson significativa e altamente positiva (rp = 0,930). A comparação entre os índices visuais também foi positiva e significativa principalmente quanto à severidade (rcs = 0,623) e nas dicotomizações para a presença de lesão (rcs = 0,765) e descoloração (rcs = 0,757). O teste t de Student para as comparações entre os índices e as médias do DD também se apresentaram significativos (p < 0,001) para presença de lesão e descoloração ao contrário dos resultados para atividade. A análise de variância entre os graus de severidade dos índices visuais e as médias do DD mostrou diferenças estaticamente significativas apenas entre os graus de severidade 0 e 1 (E - 2a) para o índice E e 0, 1 (N - 4) e 2 (N - 5) para o índice N. Conclui-se, para sulcos e fossetas descoloridos de molares decíduos, que (1) ambos os métodos (visuais e de fluorescência a laser) mostraram-se confiáveis (2) o DD foi capaz de diferenciar tecidos hígidos de lesões com descoloração e de (3) inativas intactas ou com microcavidades em esmalte. / Aiming at developing an in vivo study of the reproducibility and correlation of two visual indexes (Ekstrand et al. (1998) ? E and Nyvad; Machiulskiene and Baelum (1999) ? N) and the measures of laser fluorescence (DIAGNOdent®,KaVo - DD) for the detection of decolorised pits and fissures, a single trained examiner, after the free and aware consent of 28 patients, opened the scores E, N and laser fluorescence averages of 190 primary molars with and without occlusal discoloration in pits and fissures. The reproducibility of the visual indexes was calculated with basis on the kappa Cohen and weighted kappa (wk) tests, while for the DD averages the Perason´s correlation (rp) was calculated. To provide a comparison among the visual indexes, the Sperman´s correlation (rcs) was calculated, and for the correlation among the visual indexes and the DD averages, the Student´s t test and the one-way analysis of variance (ANOVA) were applied to compare the DD averages and the degree of severity of the lesions. The reproducibility of the visual indexes was substantial (wkE= 0,645) and (wkN= 0,634); the DD averages presented a significant and highly positive Pearson´s correlation (rP= 0,930). The comparison among the visual indexes proved to be positive and significant, mainly in relation to the severity (rcs= 0,623) and the dichotomisations for the presence of lesion (rcs= 0,765) and discoloration (rcs= 0,757). The Student´s t test of for the comparisons among the indexes and the DD averages also proved to be significant (p < 0,001) for the presence of lesion and discoloration, contrary to the activity results. The one-way analysis of variance (ANOVA) among the degrees of severity and DD averages showed significant differences only at the degrees 0 and 1 (E ? 2a) of the E index and 0, 1 (N ? 4) and 2 (N ? 5) of the N index. The conclusions for pits and fissures with discoloration in primary molars are that (1) both methods (visual and laser fluorescence) were reliable (2) the DD was able to diferenciatte sound tissues from lesions with discoloration and (3) inactive intact or with microcavities lesions at the enamel level.

<p>Eligibility for antiretroviral therapy (ART) in HIV-infected patients is defined either by a cluster of differentiation antigen 4 (CD4) count of less than 200cells/mm3 or clinical diagnosis of WHO stage III and IV. Therefore, the decision to start ART becomes difficult when CD4 cell count is not available. With limited laboratory infrastructure, the decision to start ART is usually made based on clinical symptoms leading to late commencement of ART. This calls for alternative criteria to see if nail discoloration (ND) correlates with low CD4 count among untreated HIV infected patients. This will serve as a complementary screening tool for identifying asymptomatic ARV naive HIV patients with a CD4 cell count of less than 200cells/mm3 which signifies&nbsp / severe immunosuppression. Study Design and Setting: This was a quantitative cross-sectional descriptive and analytical study involving adult ART na&iuml / ve HIV infected patients in WHO stage I and II. Systematic sampling was used to select the participants from all adult ART na&iuml / ve HIV infected patients attending APIN clinic, located at the Jos University Teaching Hospital (JUTH), Jos, Nigeria. Data Collection: Face-to-face interviews, physical examination and relevant laboratory investigations with selected participants were conducted using a questionnaire guide. Questions on socio-demographic characteristics, clinical data, general physical examinations including finger nail examination and photographing with subsequent laboratory investigations including CD4 count and western blot were employed. Data Analysis: Variables were categorized and data analyzed using descriptive statistics including the frequency, percentage frequency / mean and standard deviation of continuous variables. Association between CD4 count of &le / 200cells/mm3 and ND was tested using the chisquare test with an alpha level of 0.05. Prevalence of ND, sensitivity, specificity, positive predictive and negative predictive values and accuracy of the screening test of ND was calculated. Results: 394 patients had their fingernails photographed and assessed. It was shown that distal banded and grey nails were the common types of ND seen with a prevalence of 38%. There was an association between CD4 count &le / 200cells/mm3 and ND (p&lt / 0.0001). CD4 count &le / 200cells/mm3 was a risk factor for developing ND (RR=2.3[1.8-3.6]). The association has a sensitivity of 78%, specificity of 55%, positive predictive value of 50%, and negative predictive value of 80% and accuracy of test 63%. Conclusion: With a significant association (p&lt / 0.0001) and a sensitivity of 78%, ND can be a useful clinical indicator of immune dysfunction mediated by HIV among patients in WHO stage I or II. ND can either be a clinical sign or a symptom in HIV patients with a CD4 of &le / 200cells/mm3 as seen in the study as the specificity and sensitivity of ND compared favourably with other WHO stage III diagnosis. Recommendations: Nail discoloration should complement CD4 count as an additional staging sign to help identify patients likely to benefit from ART especially in resource-limited settings. Finally, all patients with grey or distal banded should be on co-trimoxaxole prophylaxis in line with WHO /national guideline on the use of co-trimoxaxole for all HIV positive patients with a CD4 cell count of &le / 350cells/mm3.</p>

<p>Eligibility for antiretroviral therapy (ART) in HIV-infected patients is defined either by a cluster of differentiation antigen 4 (CD4) count of less than 200cells/mm3 or clinical diagnosis of WHO stage III and IV. Therefore, the decision to start ART becomes difficult when CD4 cell count is not available. With limited laboratory infrastructure, the decision to start ART is usually made based on clinical symptoms leading to late commencement of ART. This calls for alternative criteria to see if nail discoloration (ND) correlates with low CD4 count among untreated HIV infected patients. This will serve as a complementary screening tool for identifying asymptomatic ARV naive HIV patients with a CD4 cell count of less than 200cells/mm3 which signifies&nbsp / severe immunosuppression. Study Design and Setting: This was a quantitative cross-sectional descriptive and analytical study involving adult ART na&iuml / ve HIV infected patients in WHO stage I and II. Systematic sampling was used to select the participants from all adult ART na&iuml / ve HIV infected patients attending APIN clinic, located at the Jos University Teaching Hospital (JUTH), Jos, Nigeria. Data Collection: Face-to-face interviews, physical examination and relevant laboratory investigations with selected participants were conducted using a questionnaire guide. Questions on socio-demographic characteristics, clinical data, general physical examinations including finger nail examination and photographing with subsequent laboratory investigations including CD4 count and western blot were employed. Data Analysis: Variables were categorized and data analyzed using descriptive statistics including the frequency, percentage frequency / mean and standard deviation of continuous variables. Association between CD4 count of &le / 200cells/mm3 and ND was tested using the chisquare test with an alpha level of 0.05. Prevalence of ND, sensitivity, specificity, positive predictive and negative predictive values and accuracy of the screening test of ND was calculated. Results: 394 patients had their fingernails photographed and assessed. It was shown that distal banded and grey nails were the common types of ND seen with a prevalence of 38%. There was an association between CD4 count &le / 200cells/mm3 and ND (p&lt / 0.0001). CD4 count &le / 200cells/mm3 was a risk factor for developing ND (RR=2.3[1.8-3.6]). The association has a sensitivity of 78%, specificity of 55%, positive predictive value of 50%, and negative predictive value of 80% and accuracy of test 63%. Conclusion: With a significant association (p&lt / 0.0001) and a sensitivity of 78%, ND can be a useful clinical indicator of immune dysfunction mediated by HIV among patients in WHO stage I or II. ND can either be a clinical sign or a symptom in HIV patients with a CD4 of &le / 200cells/mm3 as seen in the study as the specificity and sensitivity of ND compared favourably with other WHO stage III diagnosis. Recommendations: Nail discoloration should complement CD4 count as an additional staging sign to help identify patients likely to benefit from ART especially in resource-limited settings. Finally, all patients with grey or distal banded should be on co-trimoxaxole prophylaxis in line with WHO /national guideline on the use of co-trimoxaxole for all HIV positive patients with a CD4 cell count of &le / 350cells/mm3.</p>

Made available in DSpace on 2015-05-14T12:56:03Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2131747 bytes, checksum: 29f26f35febbc01863dacd7a6d17e909 (MD5) Previous issue date: 2013-10-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this clinical trial was to evaluate the efficacy, safety and acceptability of whitening toothpaste containing blue covarine in the treatment of tooth discoloration. It is a parallel controlled double-blind randomized clinical trial which followed the guidelines published by CONSORT. Seventy-five subjects with shade mean C1 or darker for the six maxillary anterior teeth were randomized in three treatment groups (n= 25): G1- conventional fluoridated toothpaste, G2- whitening toothpaste containing a silica system and blue covarine, and G3- bleaching with 10% carbamide peroxide. Subjects from G1 and G2 were instructed to brush their teeth for 90 seconds, twice per day during 2 weeks. Subjects from G3 used 10% carbamide peroxide gel in a tray for 4h/night also for two weeks. Shade evaluations were done with a spectrophotometer (Vita Easyshade® Advance) at baseline, after first application and at 2 and 4 weeks. Subjects perception about tooth color appearance was assessed by a visual analog scale (VAS). Tooth sensitivity (TS) and gingival irritation (GI) were measured daily using a scale ranging from 1 (no sensitivity) to 5 (severe sensitivity) during three weeks, and the acceptability of products was measured with a questionnaire that included questions about subjects opinion regarding the treatment regimen. At all evaluations periods, there was not statistical difference between G1 and G2 groups considering the CIEL*a*b* color parameters (p> 0.3) or the tooth shade means (p> 0.7). At 2-week evaluation, &#916;E* value for G3 was statistically higher (9.2) than for G1 (2.3) and G2 (2.1) (p= 0.0001). G1 and G2 reported a major dissatisfaction with tooth color appearance than G3 (p= 0.0001).Tooth sensitivity and gingival irritation were reported by 12% of subjects from G2, while the same symptoms were perceived by 84% and 80% of G3. At first and second weeks of treatment, G2 experienced tooth sensitivity and gingival irritation similarly to G1 group and statistically lower than G3 (p< 0.01). It was observed a negative correlation between TS/GI and day of evaluation (r= -0.08 and r= -0.91) in G3. Within the limitations of this study, it could be concluded that the whitening toothpaste containing a silica system and blue covarine resulted in no significant changes on tooth color, as the conventional toothpaste. These groups did not show whitening effect as the group treated with 10% carbamide peroxide. However, all could be considered safe and acceptable to be used daily for a short term. / O objetivo do presente estudo foi avaliar a eficácia, segurança e aceitabilidade de um dentifrício branqueador contendo partículas azuis no tratamento da descoloração dentária. Trata-se de um ensaio clínico randomizado duplo-cego controlado e paralelo, cujo delineamento seguiu o guia publicado pelo CONSORT. Setenta e cinco participantes com média de cor C1 ou mais escura para os seis dentes ântero-superiores foram randomizados em três grupos de tratamento (n=25): G1- dentifrício fluoretado convencional, G2- dentifrício branqueador contendo um sistema de sílica e partículas azuis, e G3- clareamento dentário com peróxido de carbamida a 10%. Os participantes dos grupos G1 e G2 foram instruídos a escovarem seus dentes por 90 segundos, duas vezes ao dia durante duas semanas. Os participantes do grupo G3 usaram o gel clareador peróxido de carbamida a 10% em moldeira personalizada 4h/noite também por duas semanas. Avaliações de cor dentária foram realizadas por meio de espectrofotômetro digital (Vita Easyshade® Advance) nos tempos baseline, após primeira aplicação e com duas e quatro semanas. A percepção estética dos participantes quanto à aparência da cor dentária foi avaliada por meio de escala analógica visual (EAV). Sensibilidade dentinária (SD) e Irritação Gengival (IG) foram mensuradas usando uma escala que variou de 1 (nenhuma sensibilidade) a 5 (severa sensibilidade) durante três semanas, e a aceitabilidade dos produtos foi avaliada com um questionário o qual incluiu questões sobre a opinião dos participantes quanto aos regimes de tratamento propostos. Em todos os períodos de avaliação não houve diferença estatisticamente significante entre os grupos G1 e G2, considerando os parâmetros de cor do CIEL*a*B* (p> 0,3) e as medidas de cor da escala Vita (p>0,7). Na segunda semana de avaliação, o valor de &#916;E* para o G3 foi estatisticamente maior (9,2) do que para o G1 (2,3) ou para G2 (2.1) (p=0,0001). Sensibilidade dentinária e irritação foram reportadas por 12% dos participantes do G2, enquanto os mesmos sintomas foram percebidos por 84% e 80% do G3. Na primeira e segunda semana de tratamento, G2 apresentou sensibilidade gengival e irritação gengival similares ao grupo G1 e estatisticamente menores que o G3 (p< 0,01). Observou-se uma correlação negativa entre SD/IG e dia de avaliação (r= -0,08 e r= -0,91) no grupo G3. Dentro das limitações desse estudo, pôde-se concluir que o dentifrício branqueador contendo um sistema de sílica e partículas azuis resultou em nenhuma mudança significante na cor dentária, assim como o dentifrício convencional. Tais grupos não mostraram efeito clareador como o grupo tratado com peróxido de carbamida a 10%. Entretanto, todos foram considerados seguros e aceitáveis para serem utilizados diariamente em um curto período de tempo.

Magister Public Health - MPH / Eligibility for antiretroviral therapy (ART) in HIV-infected patients is defined either by a cluster of differentiation antigen 4 (CD4) count of less than 200cells/mm3 or clinical diagnosis of WHO stage III and IV. Therefore, the decision to start ART becomes difficult when CD4 cell count is not available. With limited laboratory infrastructure, the decision to start ART is usually made based on clinical symptoms leading to late commencement of ART. This calls for alternative criteria to see if nail discoloration (ND) correlates with low CD4 count among untreated HIV infected patients. This will serve as a complementary screening tool for identifying asymptomatic ARV naive HIV patients with a CD4 cell count of less than 200cells/mm3 which signifies severe immunosuppression. Study Design and Setting: This was a quantitative cross-sectional descriptive and analytical study involving adult ART naïve HIV infected patients in WHO stage I and II. Systematic sampling was used to select the participants from all adult ART naïve HIV infected patients attending APIN clinic, located at the Jos University Teaching Hospital (JUTH), Jos, Nigeria. Data Collection: Face-to-face interviews, physical examination and relevant laboratory investigations with selected participants were conducted using a questionnaire guide. Questions on socio-demographic characteristics, clinical data, general physical examinations including finger nail examination and photographing with subsequent laboratory investigations including CD4 count and western blot were employed. Data Analysis: Variables were categorized and data analyzed using descriptive statistics including the frequency, percentage frequency; mean and standard deviation of continuous variables. Association between CD4 count of ≤200cells/mm3 and ND was tested using the chisquare test with an alpha level of 0.05. Prevalence of ND, sensitivity, specificity, positive predictive and negative predictive values and accuracy of the screening test of ND was calculated. Results: 394 patients had their fingernails photographed and assessed. It was shown that distal banded and grey nails were the common types of ND seen with a prevalence of 38%. There was an association between CD4 count ≤200cells/mm3 and ND (p<0.0001). CD4 count ≤200cells/mm3 was a risk factor for developing ND (RR=2.3[1.8-3.6]). The association has a sensitivity of 78%, specificity of 55%, positive predictive value of 50%, and negative predictive value of 80% and accuracy of test 63%. Conclusion: With a significant association (p<0.0001) and a sensitivity of 78%, ND can be a useful clinical indicator of immune dysfunction mediated by HIV among patients in WHO stage I or II. ND can either be a clinical sign or a symptom in HIV patients with a CD4 of ≤200cells/mm3 as seen in the study as the specificity and sensitivity of ND compared favourably with other WHO stage III diagnosis. Recommendations: Nail discoloration should complement CD4 count as an additional staging sign to help identify patients likely to benefit from ART especially in resource-limited settings. Finally, all patients with grey or distal banded should be on co-trimoxaxole prophylaxis in line with WHO /national guideline on the use of co-trimoxaxole for all HIV positive patients with a CD4 cell count of ≤350cells/mm3. / South Africa

<p>Duplex stainless steels are a very attractive alternative to austenitic grades due to their higher strength and good corrosion performance. The austenitic grades can often be welded autogenously, while the duplex grades normally require addition of filler metal. This is to counteract segregation of important alloying elements and to give sufficient austenite formation to prevent precipitation of chromium nitrides that could have a negative effect on impact toughness and pitting resistance. The corrosion performance of the recently-developed lean duplex stainless steel LDX 2101 is higher than that of 304 and can reach the level of 316. This thesis summarises pitting resistance tests performed on laser and gas tungsten arc (GTA) welded LDX 2101. It is shown here that this material can be autogenously welded, but additions of filler metal, nitrogen in the shielding gas and use of hybrid methods increases the austenite formation and the pitting resistance by further suppressing formation of chromium nitride precipitates in the weld metal. If the weld metal austenite formation is sufficient, the chromium nitride precipitates in the heat-affected zone (HAZ) could cause local pitting, however, this was not seen in this work. Instead, pitting occurred 1–3 mm from the fusion line, in the parent metal rather than in the high temperature HAZ (HTHAZ). This is suggested here to be controlled by the heat tint, and the effect of residual weld oxides on the pitting resistance is studied. The composition and the thickness of weld oxide formed on LDX 2101 and 2304 were determined using X-ray photoelectron spectroscopy (XPS). The heat tint on these lean duplex grades proved to contain significantly more manganese than what has been reported for standard austenitic stainless steels in the 300 series. A new approach on heat tint formation is consequently presented. Evaporation of material from the weld metal and subsequent deposition on the weld oxide are suggested to contribute to weld oxide formation. This is supported by element loss in LDX 2101 weld metal, and nitrogen additions to the GTA shielding gas further increase the evaporation.</p><p> </p>

Duplex stainless steels are a very attractive alternative to austenitic grades due to their higher strength and good corrosion performance. The austenitic grades can often be welded autogenously, while the duplex grades normally require addition of filler metal. This is to counteract segregation of important alloying elements and to give sufficient austenite formation to prevent precipitation of chromium nitrides that could have a negative effect on impact toughness and pitting resistance. The corrosion performance of the recently-developed lean duplex stainless steel LDX 2101 is higher than that of 304 and can reach the level of 316. This thesis summarises pitting resistance tests performed on laser and gas tungsten arc (GTA) welded LDX 2101. It is shown here that this material can be autogenously welded, but additions of filler metal, nitrogen in the shielding gas and use of hybrid methods increases the austenite formation and the pitting resistance by further suppressing formation of chromium nitride precipitates in the weld metal. If the weld metal austenite formation is sufficient, the chromium nitride precipitates in the heat-affected zone (HAZ) could cause local pitting, however, this was not seen in this work. Instead, pitting occurred 1–3 mm from the fusion line, in the parent metal rather than in the high temperature HAZ (HTHAZ). This is suggested here to be controlled by the heat tint, and the effect of residual weld oxides on the pitting resistance is studied. The composition and the thickness of weld oxide formed on LDX 2101 and 2304 were determined using X-ray photoelectron spectroscopy (XPS). The heat tint on these lean duplex grades proved to contain significantly more manganese than what has been reported for standard austenitic stainless steels in the 300 series. A new approach on heat tint formation is consequently presented. Evaporation of material from the weld metal and subsequent deposition on the weld oxide are suggested to contribute to weld oxide formation. This is supported by element loss in LDX 2101 weld metal, and nitrogen additions to the GTA shielding gas further increase the evaporation. / QC 20101126