Cláudio Maniglia Ferreira

Activity of endodontic antibacterial agents against selected anaerobic bacteria

The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol - PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent) on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroidesfragilis ATCC 25285), using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC), two culture broths, Reinforced Clostridial Medium (RCM) and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.

Penetração intratubular de cimentos endodônticos

The purpose of this study was to evaluate the capacity of penetration of four endodontic sealers (Endo Fill, Sealapex, AH Plus and Pulp Canal Sealer) into dentinal tubules. Seventy-two extracted human maxillary anterior teeth were utilized in this study. The teeth were cleaned and shaped by means of the balanced-forces technique. The work length was established at 1 mm beyond the apex. Copious irrigation with 10 ml of 5.25% sodium hypochlorite was carried out. The teeth were divided in 8 groups - 4 had the smear layer maintained, and 4 had it removed. The smear layer was removed with a commercial solution of 17% EDTA, and the root canal system was flushed for 3 min. Finally, the roots were irrigated with 3 ml of 5.25% sodium hypochlorite. All teeth were sealed by means of the technique of the condensation wave with a medium nonstandardized cone. After filling, the roots were grooved, longitudinally split and examined under a scanning electron microscope (SEM). The focus of observation was the interface between the dentin and the sealing material. The Rickert sealer (Pulp Canal) presented the maximum penetration depths into the dentinal tubules, and Sealapex, the minimum. The Spearman test was used to determine whether there were significant differences between the groups. The removal of smear layer allowed significant penetration of the sealers (p £ 0.01).

Production, maintenance and plant regeneration from cell suspension cultures of Stevia rebaudiana (Bert.) Bertoni.

A method is described for producing and maintaining Stevia rebaudiana suspensions and regeneration of plants from calli derived from cell suspensions. Suspension cultures composed of isolated cells (ca. 10%) and cellular aggregates (5–100 cells) were obtained in 20–30 days by using friable callus as the initial inoculum in liquid mediā with BA (0.5 mg/l)+2,4-D (1.0 mg/l), and periodic filtering (100–500 μm sieves) with 6–7 days interval between subcultures. Cultures derived from actively growing calli are mainly diploid (2n=22) whereas those derived from senescent calli showed a wide variation in chromosome number (55–200). Stock cell suspensions which had been maintained for 3 years were plated on basal LS agar medium with BA (0.5 mg/l)+2,4D (0.5 mg/l) to form callus. Calli originating from predominantly 2n cell suspensions when transferred to medium with K (2.0 mg/l)+NAA (0.02 mg/l) were able to form buds. Shoot elongation and further rooting of isolated shoots was better on LS medium devoid of growth regulators. Variation in rooting capacity, plant vigour, morphological characters and chromosome number was found amongst regenerated plants.

Three-Rooted Maxillary Second Premolar

The possibility of three canals in maxillary second premolars is quite small; however, it must be taken into account in clinical and radiographic evaluations during endodontic treatment. Many times their presence is noticed only after canal treatment, due to continuing postoperative discomfort. This article describes a clinical case of three-canal maxillary second premolars that are endodontically treated.

In vitro effect of intracanal medicaments on strict anaerobes by means of the broth dilution method

The determination of bacterial susceptibility to intracanal medicaments is a necessity. Nevertheless, few studies utilize the proper methodology to carry out that evaluation with anaerobes. In this study, the steps of a broth dilution method, carried out in microplates (microdilution) and tubes (macrodilution), to test the effect of traditional intracanal medicaments on anaerobic bacteria are described. The results are presented as values of minimal inhibitory and bactericidal concentrations (MIC and MBC). Standardized inocula of the anaerobic bacteria Prevotella nigrescens (ATCC 33563), Fusobacterium nucleatum (ATCC 25586) and Clostridium perfringens (ATCC 13124), in reinforced Clostridium medium (RCM) and supplemented Brucella broth, were submitted to different concentrations of calcium hydroxide, chlorhexidine digluconate, camphorated paramonochlorophenol and formocresol solutions. The drugs were diluted in the same culture broths, in microplates and tubes, and were then incubated in anaerobiosis jars at 37 degrees C for 48 or 96 hours. The determination of MICs was carried out through visual and spectrophotometric readings, and the determination of MBCs, through the plating of aliquots on RCM-blood agar. For that kind of study, the macromethod with spectrophotometric reading should be the natural choice. MICs and MBCs obtained with the macromethod were compatible with the known clinical performance of the studied medications, and the values varied according to the bacteria and culture media employed. RCM was the most effective medium and C. perfringens, the most resistant microorganism.

Utilização de duas técnicas alternativas para localização do forame apical em endodontia: avaliação clínica e radiográfica

Uma das dificuldades durante o tratamento endodontico e a determinacao do comprimento de trabalho, devido as limitacoes impostas pela imagem radiografica. Muitas tecnicas tem sido desenvolvidas com o intuito de facilitar a execucao da odontometria durante o tratamento endodontico. Nosso objetivo foi comparar clinicamente a eficacia de dois metodos auxiliares na odontometria: a tela milimetrada e o localizador apical eletronico (APIT, Osada, Japao). Os resultados foram concordantes em 76,47% dos casos quando se tratava de dentes com polpa vital, e em dentes com polpa em estado necrotico os resultados foram concordantes em 83,64% dos casos. O APIT nao foi eficiente na determinacao do comprimento radicular somente nos canais obliterados ou com apices que apresentavam grandes reabsorcoes. A tela milimetrada apresentou menor eficacia na determinacao do comprimento de trabalho devido a propria limitacao radiografica. O localizador eletronico mostrou-se mais eficiente que a tela milimetrada, porem apresenta um custo elevado.

Tissue, cell culture and micropropagation of Mandevilla velutina, a natural source of a bradykinin antagonist.

Leaf, stem and root explants of Mandevilla velutina were cultured in vitro and produced vigorous callus in LS basal medium containing one auxin (2,4-D or NAA) plus BAP. Calli can be subcultured indefinitely with vigorous growth. Subculture of calli to NAA (1.0 mg/l) plus BAP (5.0 mg/l) caused profuse regeneration of shoots. Isolated shoots were rooted in basal medium plus NAA (5.0 mg/l) or IBA (8.0 mg/l). Rapidly growing cell suspensions can be easily obtained from friable callus cultured in liquid medium.

Chromosomal variability and growth rate in cell suspension cultures of Stevia rebaudiana (Bert.) Bertoni

Abstract Several cell lines were obtained from a predominantly diploid ( 2n = 22 ) cell suspension culture of Stevia rebaudiana by colchicine treatment (10−3M/72 h), filtration in 100–500μm sieves and plating followed by visual selection. Colchicine treatment resulted in a highly polyploid line, but with a tendency for reversion to a chromosome distribution profile (CDP) similar to the initial culture, but with a higher growth rate. Selection by filtration showed a relationship between cell aggregate size and the CDP, cells of higher ploidy having a tendency to form smaller aggregates. After plating, calli with several characteristics (shape, colour, degree of friability) were selected, and gave rise to cell lines with different CDPs; these cell lines were used to initiate predominantly diploid, tetraploid or aneuploid cell suspensions that showed characteristics growth rates and aggregate sizes.

Alteração da temperatura radicular externa durante o preparo para contenção intra-radicular

The objective of the present study was to compare the change in temperature on the external surface of the root in vitro during post and core preparation using 4 different techniques. Forty lower single-root premolars instrumented and filled with gutta-percha and stored in 10% formalin were divided into 4 groups according to the technique of gutta-percha removal employed, using heated endodontic pluggers and Peeso, Largo and Gates-Glidden burs. The experiment was performed in a chamber with controlled temperature maintained at about 26°C. For gutta-percha removal from the canals, 2/3 of the root length was calculated and approximately 4 mm of apical filling was left. The temperature of the external surface of the root was measured with a thermo-couple connected to a multimeter and measurements were made in 3 regions: cervical (about 3 mm below the cementum-enamel junction), middle and apical regions of a predetermined measurent. Analysis of variance indicated significant differences (p < 0.01) between regions and techniques. The complementary Tukey test indicated that the heated endodontic pluggers produced the greatest increased in temperature among the three techniques, and the Peeso bur produced the greatest increase in temperature among the burs used. Among regions, the apical one presented the greatest change in temperature for all the techniques evaluated.

Ansiedade odontológica: nível, prevalência e comportamento - doi:10.5020/18061230.2004.p51

Literature reveals very devoid regarding dental anxiety in the brazilian population. The purposal of this study was to evaluate the dental anxiety expressed among pacients undergoing dental treatment at the University of Fortaleza, Ceara, Brazil, considering social parameter, past dental experience, time of last visit to dentist, and tooth related simptoms. A total of 300 individuals (150 male and 150 female) selected at random responded to a questionary containing the dental anxiety scale (DAS) and to questions about their socio-economic level and their behavior with respect to dental treatment. The mean DAS score for the sample was 11,65±0,15 (11,8±0,21 for women and 11,5±0,21 for men). Individuals with scores of 15 or more were considered anxious, and their prevalence in the sample was 18%. Comparision of normal and anxious individuals showed that there was no difference in their distribution in relation to educational level or monthly family income, but that anxious individuals avoid dental treatment more frequently either by failing to appear for their visits or looking for a dentist after longer periods of time.