Effect of different exposure times on microwave irradiation on the disinfection of a hard chairside reline resin

Purpose: This study evaluated the effectiveness of different exposure times of microwave irradiation on the disinfection of a hard chairside reline resin. Materials and Methods: Sterile specimens were individually inoculated with one of the tested microorganisms (Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Bacillus subtilis) and incubated for 24 hours at 37°C. For each microorganism, 10 specimens were not microwaved (control), and 50 specimens were microwaved. Control specimens were individually immersed in sterile saline, and replicate aliquots of serial dilutions were plated on selective media appropriate for each organism. Irradiated specimens were immersed in water and microwaved at 650 W for 1, 2, 3, 4, or 5 minutes before serial dilutions and platings. After 48 hours of incubation, colonies on plates were counted. Irradiated specimens were also incubated for 7 days. Some specimens were prepared for scanning electron microscopic (SEM) analysis. Results: Specimens irradiated for 3, 4, and 5 minutes showed sterilization. After 2 minutes of irradiation, specimens inoculated with C. albicans were sterilized, whereas those inoculated with bacteria were disinfected. One minute of irradiation resulted in growth of all microorganisms. SEM examination indicated alteration in cell morphology of sterilized specimens. The effectiveness of microwave irradiation was improved as the exposure time increased. Conclusion: This study suggests that 3 minutes of microwave irradiation can be used for acrylic resin sterilization, thus preventing cross-contamination. © 2008 by The American College of Prosthodontists.

Utilização de nitrato de amônio e de uréia como fontes de nitrogênio na micropropagação de amoreira-preta

The high cost allied to the difficulty in the acquisition of the ammonium nitrate has been taking the accomplishment of works looking for an alternative for the substitution of this source of nitrogen. It was aimed at to study the technical viability of the substitution of the ammonium nitrate for urea, as source of nitrogen in the culture media for the blackberry in vitro cv. Tupy (Rubus sp). Nodal segments were used, already established in vitro, were inoculated in culture media MS and 50% MS, added of 1.0 mg. dm-3 of BAP, solidified with 6 g.dm-3 of agar, pH was adjusted for 5,8 and sterilized to 121 °C and 0,1 MPa for 20 min. The treatments consisted of the substitution of 0; 20; 40; 60; 80 and 100% of NH4NO3 for urea, and the swinging of nitrogen supplied by the culture media MS it was not altered. The explants were maintained by 60 days in growth room with temperature of 27±1 °C, photoperiod of 16 h and luminous intensity of 32 mmol m'2 s'1. The experiment was arranged in a completely randomized design, in factorial (6 x 2) using four repetitions with 16 plants each one. From the obtained results it can be concluded that the urea doesn't substitute NH 4NO3 in the culture media MS as nitrogen source in the culture vitro of blackberry.

Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

The purpose of this study was to evaluate the effect of 5% sodium bicarbonate on the adherence of Candida albicans to thermally activated acrylic resin. Fifty 4 mm specimens of acrylic resin were obtained using a metallic matrix. The specimens received chemical polishing, were sterilized and then immersed in Sabouraud broth, inoculated with Candida albicans standardized suspension. After 24 hours of incubation at 37°C, the specimens were divided into four groups according to the substance used for disinfection (5% sodium bicarbonate, 0.12% digluconate chlorhexidine, vinegar and Corega Tabs). A control group was included, in which distilled water was used. The adhered microorganisms were dispersed, diluted and plated onto culture media to determine the number of colony-forming units (cfu/mL). The results were analyzed through the Mann-Whitney statistical test at the 5% level of significance. Only 0.12% digluconate chlorhexidine and 5% sodium bicarbonate presented a statistically significant difference (p = 0.0010 and p = 0.0156, respectively) compared to the control group, decreasing the number of cfu/mL. However, when the different disinfecting solutions were compared with each other, only 0.12% digluconate chlorhexidine presented a statistically significant difference in the reduction of cfu/mL. It was concluded that although 0.12% digluconate chlorhexidine was more effective in the reduction of Candida albicans adherence values to thermally activated acrylic resin, 5% sodium bicarbonate also proved to be a viable alternative.

A randomized and controlled trial about the use of oral isotretinoin for photoaging

Topical retinoids are used to treat photoaging; oral isotretinoin is gold standard for acne; off label indications, including photoaging, have been reported with insufficient evidence of efficacy. This is a randomized controlled phase II trial with clinical and histological assessment to evaluate efficacy and safety of oral isotretinoin for photoaging. Study population was comprised of 32 menopausal or sterilized women, aged 40-55, divided in 2 groups: A (21) received 20mg isotretinoin, 3 times per week, nightly moisturizer, and daily sunscreen, for three months; B (11) just moisturizer/sunscreen. Main outcome measures were: overall clinical assessment; profilometry, corneometer and elasticity tests in periocular regions and left forearm; before/after biopsies from left forearm in patients of B and in 10 randomly selected of A. Microscopic blinded evaluation of epidermal thickness, dermal elastosis, new collagen, p53 epidermal expression was performed by quantitative digital image analysis. All data were submitted to statistical analysis. Clinical evaluation showed slight improvement; profilometry, corneometer and skin elasticity tests presented significant difference in pre/post values (P = 0.001 to 0.028), but no differences between A/B. Histological findings and p53 expression were comparable between groups before treatment (P > 0.1); microscopic analysis showed no differences between groups for most variables, after treatment. Slight but significant difference between A/B for p53 with major reduction post isotretinoin [0.66±0.31 vs. 0.94±0.34 respectively (P = 0.04) was observed. There were minor side effects and no significant laboratory test alterations. We concluded that no significant clinical, microscopic changes but p53 epidermal expression reduction were observed. The role of ultra-violet induced p53 mutation in skin carcinogenesis reinforces retinoids chemoprevention. Oral isotretinoin seemed safe but not effective to treat photoaging. Caution should be considered for women prone to pregnancy. Further controlled studies are necessary. © 2010 The International Society of Dermatology.

Avaliação das condutas de biossegurança em laboratórios de prótese dentária de João Pessoa, PB, Brasil

Objective: To evaluate the biosecurity measures adopted in dental prosthesis laboratories of the city of João Pessoa, PB, Brazil with respect to prosthetic works sent by dentists. Method: Twenty-five dental prosthesis technicians (DPT) of the city of João Pessoa, PB, filled out a questionnaire referring to their knowledge of the biosecurity principles, disinfection of impressions and other prosthetic items, and the use of individual protection equipment (IPE). Results: Although 92% of the interviewees believed in the possible occurrence of cross-infection between dental prosthesis laboratories and dental offices, 64% declared that the prosthetic works received in their laboratories do not undergo any disinfection procedure. It was also observed that, for disinfection of impressions and stone casts, the chemical substances are not used as recommended by the manufacturers or are innocuous to microorganisms. Regarding the use of IPE, 60% of the DPT used mask, but only 4% used gowns. With respect to the measures taken regarding the impressions received from dental offices, 56% of the interviewees only wash them in running tap water, and 56% of the stone casts that arrive at the laboratory are not disinfected in any way. Conclusion: There is a need for more motivation and instructions to DPT regarding the prevention of cross-contamination during sending and receiving of prosthetic works between dental prosthesis laboratories and dental offices because the DPT evaluated in this study were found negligent with respect to disinfection procedures.

Othonella araguaiana (Bivalvia, Megadesmidae) from the Corumbataí formation (Midlle Permian), eastern margin of the Paraná Basin: Systematic, evolutionary and biostratigraphic significances

In this study, the occurrence of Othonella araguaiana Mendes, a rare bivalve species is reported for the fi rst time in the Pinzonella illusa biozone, Middle Permian Corumbataí Formation, in the State of São Paulo. This species was originally described in coeval rocks of the Estrada Nova Formation (= Corumbataí) from the Alto Araguaia and Alto Garças regions, State of Mato Grosso. The specimens of O. araguaiana were found in the base of a bioclastic sandstone bed, a proximal tempestite, in the middle of the Corumbataí Formation, in the city of Rio Claro, São Paulo State. The silicifi ed shells and internal molds are well preserved, showing impressions of muscle scars and other internal anatomic characters (e.g., hinge), never illustrated by previous authors. In his original description, Mendes (1963) called attention to the similarity between O. araguaiana and Terraia aequilateralis, a common veneroid of the Corumbataí Formation. Conversely, Runnegar and Newell (1971) suggested that O. araguaiana belongs to Megadesmidae, being a junior synonym of Plesiocyprinella carinata (the commonest megadesmid of the Passa Dois Group). Our study indicates that O. araguaiana is indeed a megadesmid, but is distinct from the P. carinata. The new occurrence of O. araguaiana demonstrates that a) the paleobiogeographic distribution of this species is wider than previously thought (that it was restricted to the northern part of Paraná Basin, Mato Grosso State); b) the molluscan fauna of the Corumbataí Formation (P. illusa biozone) in the State of São Paulo is more diverse and dominated by megadesmids; and c) the composition of the molluscan fauna of the Corumbataí Formation in Alto Garças, State of Mato Grosso, is essentially the same as that of the P. illusa biozone of the eastern margin of the Paraná Basin.

Utilização de extratos de plantas medicinais e óleo de Eucaliptus no controle in vitro de Microsporum canis

INTRODUCTION: Microsporum canis is the most common cause of canine and feline dermatophytosis and thus has an important zoonotic role. OBJECTIVES: the aim of this study was to determine the antifungal action of medicinal plant extracts and of eucalyptus oil against pathogenic fungus Microsporum canis. METHODS: the extracts were prepared by mixing 300 g of previously washed leaves with 450 mL of distilled water. Then the material was triturated, filtered, sterilized and conserved at 10 + 2 oC. Fifteen milliliters of sterilized medium Sabouraud dextrose (Difco) at a temperature of 55 + 1 oC was added in Petri dishes containing the extracts in one, two, three, four and five mm concentrations. The fungus was inoculated once the medium was solidified. The inoculated dishes were maintained in B.O.D. incubator at 36 ± 0,5 oC until the fungus developed in the controls. RESULTS: the extracts from Punica granatum, Mangifera indica and Eucalyptus spp reduced the growth of fungus, but the extracts from Cymgopogom nardus, Tagetes minuta, Ruta graviolens, Cyperus rotundus, Annona moricata and Calendula spp leaves and flowers boosted the growth of fungus. The other extracts and the eucalyptus oil neither show any fungicidal action nor encourage mycelium growth. CONCLUSIONS: the use of most tested extracts and eucalyptus oil is not suitable for the treatment of Microsporum canis dermatophytosis due to lack of inhibitory effects. The extracts from Cymgopogom nardus, Tagetes minuta, Ruta graviolens, Cyperus rotundus, Annona moricata and from of Calendula spp leaves and flowers help the development of the fungus making clear that phytotherapy should be properly used, otherwise it can worsen the problem. However; extracts from Mangifera indica, Punica granatum and Eucalyptus spp. can be used as fungistatic.

Evaluation of a two-step pouring technique for implant-supported prostheses impression

The aim of this study was to evaluate the efficacy of a pouring technique for implant-supported prostheses impressions. A metallic matrix (control group) with two implants positioned at 90 and 65 degrees was fabricated. The matrix was submitted to the direct transfer impression technique. In group CP (conventional pouring - n = 10), casts were obtained by the conventional pouring technique. In group EP (experimental pouring - n = 10), the analogs were embraced with latex tubes before the first pouring and then submitted to a second pouring. Vertical misfit and implants/analogs inclinations were evaluated. Data were analyzed by analysis of variance and Tukey's test (p < .05). Results demonstrated significant difference (p < .05) between control and experimental groups for misfit measurement in perpendicular implant/analog and between control group and group EP in leaning implant/analog. Considering inclination, there were significant differences (p < .05) between control and experimental groups for leaning analogs. Independently of the pouring technique, perpendicular implants produced more accurate casts.

Evaluation of a digital methodology for human identification using palatal rugoscopy

Palatal rugoscopy, or palatoscopy, is the process by which human identification can be obtained by inspecting the transverse palatal rugae inside the mouth. Aim: This study evaluated a digital method for human identification using palatoscopy, by comparing photographs of the palate against the images of cast models of the maxilla photographed with and without highlighting of the palatal rugae. Methods: Condensation silicone impressions were made from the upper arches of 30 adult subjects of both genders and their palates were then photographed. The first impression was made with heavy silicone, the second impression with light silicone, and then the models were cast in improved type IV dental stone. The casts were photographed, the palatal rugae of each one were highlighted with a pencil, and then the models were photographed again. Using a free image-editing software, the digital photographs were overlapped over the images of the palatal rugae of the models with and without highlighting of the palatal rugae, in order to identify the pairs. Results: The result of overlapping the digital photographs with the images of the models without highlighted palatal rugae resulted in 90% positive identification. For the overlapping of the digital photographs with the images of models with highlighted palatal rugae, there was 100% positive identification. Conclusions: The digital method evaluated in this study was proven effective for human identification.

Effectiveness of mechanical brushing with different denture cleansing agents in reducing in vitro Candida albicans biofilm viability

The adhesion of Candida albicans to surfaces is the prerequisite for occurrence of denture stomatitis, a common disease diagnosed among denture wearers. A routine of denture cleansing is essential to prevent biofilm formation and the onset of this infection. The aim of this study was to investigate the effectiveness of combining brushing and cleansing agents in killing C. albicans biofilm. Disks of acrylic resin were made, sterilized, and inoculated with C. albicans (107 cfu/mL). After incubation (37°C/48 h), specimens were randomly assigned to 10 experimental groups (n=9): 5 subjected to brushing with distilled water or cleansing agents - dentifrice slurry, 2% chlorhexidine gluconate (CHX), 1% sodium hypochlorite (NaOCl), and Polident fresh cleanse® (combined method) - and 4 exposed to the cleansing agents without brushing (immersion). Non-cleansed specimens were used as positive controls. The viability of cells was evaluated by XTT reduction method. Results were analyzed by Mann-Whitney and Kruskal-Wallis tests (α=0.05). The combined method was significantly more effective (p<0.0001) in reducing biofilm viability than the immersion. Brushing with CHX and NaOCl resulted in 100% removal of the biofilm. Immersion in the agents reduced significantly (p<0.0001) the biofilm viability, with CHX being the most effective (p<0.0001). The use of the combined method of brushing with cleansing agents is an effective method to reduce C. albicans biofilm, being CHX and NaOCl the most effective solutions.

Automatic segmentation of latent fingerprints

Latent fingerprints are routinely found at crime scenes due to the inadvertent contact of the criminals' finger tips with various objects. As such, they have been used as crucial evidence for identifying and convicting criminals by law enforcement agencies. However, compared to plain and rolled prints, latent fingerprints usually have poor quality of ridge impressions with small fingerprint area, and contain large overlap between the foreground area (friction ridge pattern) and structured or random noise in the background. Accordingly, latent fingerprint segmentation is a difficult problem. In this paper, we propose a latent fingerprint segmentation algorithm whose goal is to separate the fingerprint region (region of interest) from background. Our algorithm utilizes both ridge orientation and frequency features. The orientation tensor is used to obtain the symmetric patterns of fingerprint ridge orientation, and local Fourier analysis method is used to estimate the local ridge frequency of the latent fingerprint. Candidate fingerprint (foreground) regions are obtained for each feature type; an intersection of regions from orientation and frequency features localizes the true latent fingerprint regions. To verify the viability of the proposed segmentation algorithm, we evaluated the segmentation results in two aspects: a comparison with the ground truth foreground and matching performance based on segmented region. © 2012 IEEE.

Gesture-based teleoperation using a holonomic robot

This work presents the development and integration of an user interface (UI) framework based on various current input devices that take advantage of our ergonomics. The purpose is to teleoperate a holonomic robot using upper member gestures and postures for studying the suitable of such interfaces when programming and interacting with a mobile robot. As performance vary from UI to UI the framework is focused to be used as a complementary industrial or didactic tool thus, changing how inexperience users tackle their first impressions when working with mobile robots while performing simple gesture-based teleoperation tasks. © 2012 ICROS.

Surface Roughness of Acrylic and Silicone-Based Soft Liners: In Vivo Study in a Rat Model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparison of the accuracy for three dental impression techniques and index: An in vitro study

Objectives: This in vitro study compared the dimensional accuracy of stone index (I) and three impression techniques: tapered impression copings (T), squared impression copings (S) and modified squared impression copings (MS) for implant-supported prostheses. Methods: A master cast, with four parallel implant abutment analogs and a passive framework, were fabricated. Vinyl polysiloxane impression material was used for all impressions with two metal stock trays (open and closed tray). Four groups (I, T, S and MS) were tested (n = 5). A metallic framework was seated on each of the casts, one abutment screw was tightened, and the gap between the analog of implant and the framework was measured with a stereomicroscope. The groups' measurements (80 gap values) were analyzed using software (LeicaQWin - Leica Imaging Systems Ltd.) that received the images of a video camera coupled to a Leica stereomicroscope at 100× magnification. The results were statistically analyzed with Kruskal-Wallis One Way ANOVA on Ranks test followed by Dunn's Method, 0.05. Results: The mean values of abutment/framework interface gaps were: Master Cast = 32 μm (SD 2); Group I = 45 μm (SD 3); Group T = 78 μm (SD 25); Group S = 134 μm (SD 30); Group MS = 143 μm (SD 27). No significant difference was detected among Index and Master Cast (P = .05). Conclusion: Under the limitations of this study, it could be suggested that a more accurate working cast is possible using tapered impression copings techniques and stone index. © 2013 Japan Prosthodontic Society.

O teatro, a educação e a experiência de si

Pós-graduação em Artes - IA