Influence of preventive remineralizing techniques on surface roughness and volume loss of dentin submitted to erosive and/or abrasive challenges.

Background: The objective this study was to evaluate the influence of preventive remineralizing techniques on surface roughness and volume loss of dentin submitted to erosive and/or abrasive challenges. Material and Methods: One hundred and eighty specimens of bovine root dentin were made; half of each was isolated (without treatment - WT) and half was subjected to the following remineralizing techniques: fluoride varnish (FV); Regenerate Boosting Serum® (RBS); Er,Cr:YSGG laser (L); fluoride varnish+laser (FV+L); Regenerate Boosting Serum®+laser (RBS+L). The specimens were submitted to erosive, abrasive and erosive followed by abrasive challenge. Erosion was carried out for 5 minutes, twice a day for 10 days. Abrasion was performed with an electric toothbrush and slurry solution for 60 seconds. The evaluation was performed by confocal laser scanning microscopy. Analysis of variance and Tukey tests were used for surface roughness; volume loss comparison was performed using the Kruskal-Wallis test and Dunn's post-hoc (p<0.05). Results: There was no statistically significant difference in the surface roughness of the reference area in relation to the areas submitted to different types of treatment and challenges (p>0.05). Regarding volume loss, the untreated group submitted to erosive/abrasive challenges showed greater percentage of volume loss compared to the other groups (p<0.05). Conclusions: It is concluded that preventive remineralizing techniques are effective in maintaining dentin volume after erosive/abrasive challenges. Key words:YSGG lasers, Dentin, Erosion, Tooth Abrasion.

Alteração de Cor de Resinas Compostas Imersas em Diferentes Bebidas / Colors Change of Composite Resins Immersed in Different Beverages

O presente estudo analisou resinas compostas imersas em diferentes bebidas (café, vinho tinto, refrigerante a base de cola e água destilada) nos diferentes tempos de polimento. Avaliou-se também a estabilidade de cor após o repolimento. As resinas compostas utilizadas foram: Resina Filtek Z350 XT e Resina Brilliant NG; as bebidas para o experimento foram: café, refrigerante à base de cola, vinho tinto e água destilada, que corresponde ao grupo controle. Foram confeccionados 160 corpos de prova: 80 de cada resina composta. Vinte corpos de prova receberam polimento imediato, vinte receberam polimento após 24 horas, vinte o polimento após 7 dias e os outros vinte não receberam polimento. As análises de cor foram feitas utilizando o aparelho espectrocolorímetro, que utiliza o sistema CIELab. Foi avaliado o ΔE dos grupos após 30 dias (ΔE= 30d ­ baseline). Os dados foram submetidos à ANOVA e teste de Tukey (α=5%). Os corpos-de-prova passaram por processo de repolimento com discos de Sof-Lex Pop On e, posteriormente, foram analisados em busca de identificar se houve aproximação equivalente à cor inicial. As bebidas testadas possuem capacidade de manchamento, sendo o café e o vinho tinto os grupos com maiores valores de alteração de cor, seguido do refrigerante à base de cola. As resinas compostas polidas apresentaram valores menores de alteração de cor, independentemente, do tempo de polimento. Com o repolimento, a água destilada e o refrigerante à base de cola tiveram seus valores considerados clinicamente aceitáveis ΔE<3,3. Já o café e o vinho tinto tiveram seus valores de manchamento reduzidos, porém perceptíveis ao olho humano. (AU)

The present study examined composite resins in different beverages (coffee, red wine, cola-based soda and distilled water) in the different times of polishing and after the re-polishing. The composite resins used were: resin Filtek Z350 XT and resin Brilliant NG; the tested beverages were: coffee, red wine, soft-drink and distilled water corresponding to the control group. 160 specimens were made, 80 of each composite. Twenty specimens were given immediate polishing, twenty were polished after 24 hours, twenty were polished after 7 days and the other twenty had no polishing. Color analysis was made using the spectrophotometer device that uses CIELab system. ΔE was evaluated after 30 days immersion period (ΔE = 30-days - baseline). The data were submitted to ANOVA and Tukey tests (α=5%). Then, specimens were re-polished with Sof- Lex Pop On and subsequently analyzed if there was approach equivalent to the initial color. All the tested beverages had ability to staining, and coffee and red wine groups showed higher values of color change, followed by soft-drink. The composite resins polished showed lower values of color change, regardless of the polishing time. After re-polishing, distilled water and soft-drink had their values considered clinically acceptable ΔE<3.3; coffee and red wine had their staining values reduced, but perceptible to the human eye. (AU)

Efeito do licor de absinto e do seu princípio ativo (thujone) proveniente da losna (arthemisia absinthium) nas glândulas salivares de ratos / Effect of the absinthe and its active component (thujone) of the Arthemisia absinthium on the salivary glands of the rats

Introdução - O objetivo do presente estudo foi avaliar , através do microscópio de luz , as glândulas salivares de ratos tratados com álcool, absinto ou seu princípio ativo, thujone (extraído da Arthemisia absinthium ). Material e Métodos - Vinte ratos machos (Wistar) foram divididos em quatro grupos: controle, tratados com álcool, absinto, e thujone. A administração das drogas foi feita por via oral, controlada diariamente através do volume ingerido. Os animais do grupo controle sofreram os mesmos procedimentos com água comum. Após 13 dias do início do experimento, os ratos foram sacrificados, sendo suas glândulas salivares removidas e submetidas às técnicas laboratoriais e de coloração, para a análise em microscópio comum. Resultados - Foram observadas alterações morfológicas nos ratos que receberam álcool, thujone e absinto. As glândulas salivares dos ratos tratados com absinto apresentaram alterações mais acentuadas, ilustradas pela presença de células dismórficas, atrofia e fibrose. Conclusão - Pelos resultados encontrados, o absinto exacerba as lesões celulares induzidas pelo álcool nas glândulas salivares de ratos.

Introduction - The aim of this study was to evaluate on light microscopy the glands salivary of rats treated with ethanol, absinthe and its active principle, thujone (removed from Arthemisia absinthium). Material and Methods - Twenty male rats (Wistar) were used that were equally divided in 4 groups: control, treated with absinthe, treated with ethanol and, the last, treated with thujone. The drugs administration was done in oral way, daily checked trough the control of ingested volume. The animals of the control group had the same procedure, with common water. After 13 days of the start of the experiment, the rats were killed with anesthetic overdose and their glands salivary were removed a submitted to the laboratorial routine process to the embedding on paraffin. The cuts were stained using H&E and analysed on light microscopy. Results - Morphological changes were observed on the glands salivary of the rats treated with absinthe, thujone and ethanol. The glands salivary of the rats treated with absinthe showed more accentuated alterations, comparing with the animals treated with ethanol or thujone, showed by dimorphism cell, atrophy and fibrosis. Conclusion - The results indicated that absinthe exacerbate the cellular lesions induced by ethanol that occur on the salivary glands in rats.

Frequência de candida sp em biópsias de lesöes da mucosa bucal / The frequency of candida sp in biopsies of oral mucosal lesions

O objetivo desse trabalho foi determinar a freqüência da infecçäo por Candida sp em biópsias de lesöes da mucosa bucal coradas pelo PAS, assim como associar a presença de Candida sp com lesöes malignas e lesöes com vários graus de displasia. Foram utilizadas 832 biópsias da mucosa bucal, previamente incluidas em parafinas, cujos blocos foram obtidos de arquivo, no período entre 1990-2001. Três cortes sequenciais foram corados com PAS. Do total de biópsias 27,2 por cento foram PAS positivas, dessas 83,25 por cento eram provenientes de pacientes do sexo masculino. Houve associaçäo positiva entre infecçäo com displasia epitelial leve, moderada, severa, carcinoma espino celular e hiperqueratose (P<0,05). Näo houve associaçäo entre hiperplasia fibrosa inflamatória, liquen plano, granuloma piogênico (P<0,05) com infecções fúngicas. A língua foi o sítio mais acometido por infecções em relaçäo a outros sítios (P<0,05). A partir dos dados quantitativos, concluiu-se que houve correlaçäo positiva entre infecçäo por fungos lesöes displásicas e carcinoma, sendo mais frequente no sexo masculino. Estes dados näo permitem inferir se o fungo causa displasia epitelial e carcinoma, mas confirmam a maior presença de Candida nessas lesöes