Made available in DSpace on 2014-08-20T14:30:07Z (GMT). No. of bitstreams: 1 dissertacao_rafael_guerra_lund.pdf: 2856587 bytes, checksum: 01149241eaab789cb42b16915e1cbebd (MD5) Previous issue date: 2007-02-05 / A great variety of diseases can affect the oral cavity, such as dental caries, that is considered the most prevalent oral disease worldwide. The multifactorial and infectcontagious characteristics of dental caries have been established, associated with resident bacterial pathogens of dental biofilm. These microorganisms are responsible by the production of acids and citotoxic products, which could respectively promote the demineralization of dental structure and gingival inflammation, with posterior destruction of supporting tissues. Therefore, the use of efficient antimicrobial agents against pathogenic bacteria is an important tool in the control of oral diseases. Several natural antimicrobial agents are been investigated because of their possible pharmacological properties. The mushroom Agaricus brasiliensis S. Wasser et al. ( Royal-Sun-Agaricus ) is pointed out as a natural product with noticeable antibacterial, antifungicidal, anti-inflammatory and antineoplasic properties. In this study the potential effect of this natural product was evaluated using three ethanolic crude extracts (100%, 75% and 50% EtOH) on growth and adherence of mutans streptococci. The ethanolic extracts were obtained by maceration process. Negative controls were 100%, 75% and 50% ethanol. The antimicrobial tests used against Streptococcus mutans UA 159 and Streptococcus sobrinus 6715 were agar diffusion method, Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and bacterial cell adherence to a glass surface. In agar diffusion method, only the 100% etanol extract revealed a slight inhibiton of bacterial growth. Yet, in MIC and MBC tests, the three extracts presented antimicrobial properties and MIC and MBC values ranged between 87.4 and 444.5 μg/mL. The MBC for the three ethanolic extracts was similar to MIC against S. mutans, but only 75% ethanol extract was bactericidal against S. sobrinus. Among the ethanolic extracts tested, 100% ethanol extract was the most active (MIC 87.4μg/mL). The celular adherence also was inhibited at concentrations from 100 to 400 μg/mL of 50% and 75% ethanol extracts. In conclusion, the ethanolic extracts from A. brasiliensis showed remarkable inhibitory effects on bacterial growth and the 100% ethanol extract was the most active / Uma variedade de doenças envolve a cavidade oral, como a cárie dental, considerada a patologia oral mais prevalente em todo o mundo. Atualmente, a cárie dental é uma doença multifatorial infecto-contagiosa, associada a bactérias patogênicas residentes do biofilme dental. Estes microrganismos são os responsáveis pela produção de ácidos e produtos citotóxicos que, respectivamente, levam à desmineralização de esmalte dental e inflamação gengival com posterior destruição dos tecidos de suporte dos dentes. Assim, o uso de agentes antimicrobianos eficientes contra essas bactérias é um importante meio de controle dessa doença bucal. Vários agentes antimicrobianos de origem natural estão sendo investigados devido as suas possíveis propriedades farmacológicas. O cogumelo Agaricus brasiliensis S. Wasser et al. ( cogumelo-do-sol) destaca-se entre os produtos naturais com notáveis propriedades antibacterianas, antifúngicas, antiinflamatórias e antitumorais. Neste estudo foi avaliado o efeito de três extratos etanólicos brutos (EtOH 100%, 75% e 50%) deste cogumelo sobre o crescimento e a aderência de estreptococos do grupo mutans. Os extratos etanólicos foram obtidos através do método de extração por maceração. Os controles negativos foram etanol 100%, 75% e 50%. Os testes antimicrobianos utilizados contra Streptococcus mutans UA 159 e Streptococcus sobrinus 6715 foram o método de difusão em ágar, Concentração Inibitória Mínima (CIM), Concentração Bactericida Mínima (CBM) e aderência dos microrganismos à superfície de vidro (Adh). No método de difusão em agar, apenas o extrato 100% etanólico apresentou sinal de inibição do crescimento microbiano. Já nos testes de determinação da CIM e CBM, os três extratos apresentaram propriedades antimicrobianas e os valores de CIM e CBM variaram entre 87,4 e 444,5 μg/mL. A CBM para os três extratos etanólicos foi igual a CIM para S.sobrinus, mas apenas o extrato etanólico 75% foi bactericida para S. mutans. Entre os extratos etanólicos testados, o extrato 100% etanólico foi o mais ativo (CIM 87.4μg/mL). A aderência celular também foi inibida em concentrações de 100 a 400μg/mL dos extratos obtidos com etanol 50% e 75%. Concluindo, os extratos etanólicos de A. brasiliensis mostraram notáveis efeitos inibitórios no crescimento bacteriano e o extrato 100% etanólico foi o mais ativo

Indiana University-Purdue University Indianapolis (IUPUI)School of dentistry / BACKGROUND: Fluoride and stannous ions have been reported to be relevant for dental erosion prevention. However, their interaction with the acquired dental pellicle (ADP), a clinically relevant erosion protective factor, is not well known and needs to be investigated. OBJECTIVES: To investigate the anti-erosive properties of fluoride-containing solutions and stannous solutions on enamel and dentin surfaces with a previously formed ADP. To characterize the protein profile of the ADP treated with the test solutions. METHODS: Phase I tested four solutions: SnCl2/NaF, NaF, SnCl2 and deionized water (DIW) (as negative control). Forty bovine enamel and dentin specimens 104 (4x4x2 mm3) were prepared and randomly distributed into 4 groups (n = 10). The specimens were incubated in clarified human saliva (CHS) for 24 h for pellicle formation and then they were subjected to a cycling procedure that included a 5-min erosive challenge (0.3-percent citric acid, pH 2.6); a 2-min treatment with the solution (between 1st, 3rd and 6th cycles); a 2-h immersion in CHS, and overnight immersion in CHS. Cycles were repeated 6x/day for 5 days. The outcome measure was surface loss (SL) using profilometry. Phase II: Thirty-two (32) bovine enamel specimens (882 mm3) (n = 8) were similarly prepared and incubated in saliva for 24 h and then treated with the solutions for 2 min followed by CHS immersion for 2 h. This cycle was repeated 3x for one day. The pellicles formed and treated with the test rinse solutions were collected, digested, and analyzed for specific protein content using liquid chromatography electrospray ionization tandem mass spectrometry (LCESI-MS/MS). RESULTS: Phase I: for enamel, SnCl2/NaF, SnCl2, NaF solutions provided 89 percent, 67 percent, and 42 percent SL reduction respectively compared with the control, while in dentin they provided 60 percent, 23 percent, and 36 percent, respectively, all significant at p < 0.05. Phase II: Seventy-two (72) common proteins were identified in all groups, 30 exclusive to DIW, 20 to SnCl2/NaF, 19 to NaF, and 13 to SnCl2. SnCl2/NaF increased the abundance of pellicle proteins than each one alone. CONCLUSION: SnCl2/NaF showed the best anti-erosive effect on both enamel and dentin. The findings suggest that the composition of acquired pellicle changes with different solutions, which may be related to their anti-erosive effect.