Antimicrobial analysis of chlorhexidine gel and intracanal medicaments against microorganisms inoculated in root canals.

AIM: The aim of this paper was to evaluate the antimicrobial activity of 2% chlorhexidine gel (CLX) associated with various intracanal medicaments against Candida albicans and Enterococcus faecalis inoculated in root canals. METHODS: Thirty six human single-rooted teeth were contaminated with C.albicans and E.faecalis. The canals were instrumented using 2% CLX gel and were divided into three groups according to the intracanal medicaments (ICM) used. Group 1: calcium hydroxide paste [Ca(OH)2], Group 2: 2% chlorhexidine gel (CLX) and Group 3: 2% CLX gel + Ca(OH)2. The root canal collections were performed after 21 days of contamination (control collection), after instrumentation (1st collection), after 14 days of intracanal medicament (2nd collection) and 7 days after medicament removal (3rd collection). The microbiological samples were plated in culture media and incubated for 48 hours. The results were submitted to Kruskal-Wallis test (P ≤ 0.05). RESULTS: It was verified that the instrumentation with CLX reduced the number of CFU/ml significantly when compared with the confirmation collection (control). However, the use of the ICM was only capable to eliminate completely the microorganisms in the root canals without difference statistics between them. CONCLUSION: Although the use of 2% chlorherixidine gel reduces the number of microorganisms significantly, only the ICM calcium hydroxide and calcium hydroxide associated with chlorhexidine are able to eliminate these microorganisms completely.

Germinação de sementes de Aristolochia esperanzae O. Kuntze em diferentes temperaturas e condições de luminosidade / Germination of Aristolochia esperanzae O. Kuntze seeds under different temperatures and light conditions

O objetivo deste estudo foi verificar a influência da temperatura e da luz, em interação com a temperatura e de forma isolada, bem como, determinar a temperatura mais adequada para a condução do teste de germinação de sementes de Aristolochia esperanzae O. Kuntze (cipó mil-homens). Foram realizados três ensaios. No primeiro, as temperaturas utilizadas foram 15, 20, 25, 30, 35 e 40ºC. No segundo, foi avaliada a germinação das sementes nas temperaturas de 25, 30 e 35ºC, na presença e ausência de luz e no terceiro ensaio, foram testadas quatro condições de luminosidade, de forma isolada: (a) luz branca; (b) luz vermelha; (c) vermelho-distante e (d) ausência de luz, na temperatura de 25ºC. Em ambos os ensaios, foram avaliados, durante 30 dias, as porcentagens de sementes germinadas, de plântulas normais e de sementes não germinadas, e os tempos médios de sementes germinadas e de plântulas normais. Nas temperaturas de 15ºC e de 40ºC, não ocorreram germinação de sementes de A. esperanzae. O melhor resultado para sementes germinadas e para formação de plântulas normais (96 por cento) foi obtido na temperatura de 30ºC. A presença de luz e as temperaturas de 25ºC e 30ºC favoreceram a germinação de sementes e a formação de plântulas normais. As sementes de Aristolochia esperanzae tiveram sua germinação inibida na ausência de luz, caracterizando-as como fotoblásticas positivas.

The aim of this study was to verify the influence of temperature and light, interacting or separately, as well as to establish the most suitable temperature to conduct the germination test of Aristolochia esperanzae O. Kuntze ("cipó mil-homens") seeds. Three assays were performed. In the first one, temperatures were 15, 20, 25, 30, 35 and 40ºC. In the second assay, seed germination was evaluated at 25, 30 and 35ºC, in the presence and absence of light. In the third assay, four light conditions were tested separately: (a) white light; (b) red light; (c) far-red light; and (d) no light, at 25ºC. In all assays, the percentages of germinated seeds, normal seedlings and non-germinated seeds, besides the mean times of germinated seeds and normal seedlings, were evaluated during 30 days. At 15ºC and 40ºC, there was no A. esperanzae seed germination. The best result for germinated seeds and normal seedlings (96 percent) was obtained at 30ºC. The presence of light and the temperatures 25ºC and 30ºC favored seed germination and normal seedling formation. Aristolochia esperanzae seeds had their germination inhibited in the absence of light, which characterizes them as positive photoblastic.