Antimicrobial effects of ozonated water on the sanitization of dental instruments contaminated with E. coli, S. aureus, C. albicans, or the spores of B. atrophaeus

Objectives: Ozone has been used as an alternative method for the decontamination of water, food, equipment and instruments. The objective of this study was to evaluate the antimicrobial effects of ozonated water on the sanitization of dental instruments that were contaminated by Escherichia coli, Staphylococcus aureus, Candida albicans and the spores of Bacillus atrophaeus. Methods: A total of one hundred and twenty standardized samples of diamond dental burs were experimentally contaminated with E. coli (ATCC 25922), S. aureus (ATCC 6538) and C. albicans (ATCC 18804) and the spores of B. atrophaeus (ATCC 6633) for 30min. After the contamination, the samples were exposed to ozonated water (10mg/L O3) for 10 or 30min. The control group was composed of samples that were exposed to distilled water for 30min. After the exposure to the ozonated water, 0.1mL aliquots were seeded onto BHI agar to count the colony-forming units per milliliter (CFU/mL) of E. coli, S. aureus, and B. atrophaeus. Sabouraud dextrose agar was used to count the CFU/mL of C. albicans. The results were subjected to an analysis of variance and the Tukey test. Results: For all of the microorganisms studied, the ozonated water reduced the number of CFU/mL after 10 and 30. min of sanitization, and this microbial reduction was dependent on the duration of the exposure to the ozonated water. E. coli exhibited the greatest reduction in CFU/mL (2.72-3.78. log) followed by S. aureus (2.14-3.19. log), C. albicans (1.44-2.14. log) and the spores of B. atrophaeus (1.01-1.98. log). Conclusion: The ozonated water was effective in reducing the CFU of E. coli, S. aureus, C. albicans and B. atrophaeus spores, suggesting that ozonated water can be used for the sanitization of dental instruments. © 2012 King Saud Bin Abdulaziz University for Health Sciences.

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.

Caracterização morfométrica de sementes e plântulas e germinação de anadenanthera macrocarpa (benth.) brenan

Anadenanthera macrocarpa (Benth.) Brenan is a tree species belonging to the family Leguminosae-Mimosoideae which is popularly known as mimosa-black. It features characteristics of early successional, natural occurrence in Brazil and can form clusters almost homogeneous, with great potential in the recovery of degraded areas. This study was conducted at the Center for Agricultural Sciences, University Federal of Alagoas state, aiming at the physical and morphological characterization of seeds, describing the various stages of post-seminal development, and to evaluate various conditions of temperature and substrate to perform the test germination. The seeds were manually extracted, then homogenized, where two samples of 50 seeds were used to determine the initial moisture. Another sample, consisting of eight repetitions of 100 seeds was used to measure the biometry and the number of seeds per fruit. The morphological characterization and the seeds were immersed in distilled water to allow the cuts to the observed structure in microscopes. In the post-seminal study, it was observed the daily processes of seedling growth in rolled paper filter and constant temperature of 30 °C. To assess the germination behavior, the constant temperatures of 15 °C, 25 °C, 30 °C, 40 °C and 20-30 °C as well as the paper and the sand substrates were tested and it was evaluated the percentage, the rate of germination, the relative frequency distribution, and the tests conducted in a randomized design in factorial 5 x 2 (x substrate temperature) with four replicates of 25 seeds, and the averages compared by Duncan 5 % probability. The fruits of black angico show great variation in the seed number per fruit. The embryonic axis occupies part of the central region of the seed with axial and linear positions. The germination is epigeal and the seedlings are fanerocotylar. The temperature determines the 30 °C and the filter paper substrate provided higher average percentage and germination rate.

Detecting early biomechanical effects of zoledronic acid on femurs of osteoporotic female rats

Aim. To investigate the biomechanical effects of zoledronic acid (ZA) on femurs of female osteoporotic rats after follow-up periods of 9 and 12 months. Methods. Eighty female Wistar rats were prospectively assessed. At 60 days of age, the animals were randomly divided into two groups: bilateral oophorectomy (O) (n=40) and sham surgery (S) (n=40). At 90 days of age, groups O and S were randomly subdivided into four groups, according to whether 0.1 mg/kg of ZA or distilled water (DW) was intraperitoneally administered: OZA (n=20), ODW (n=20), SZA (n=20), and SDW (n=20). The animals were sacrificed at 9 and 12 months after the administration of the substances, and then their right femurs were removed and analyzed biomechanically. Axial compression tests that focused on determining the maximum load (N), yield point (N), and stiffness coefficient (N/mm) of the proximal femur were performed in the biomechanical study. Results. ZA significantly increased the maximum load and yield point, reducing the stiffness coefficient concerning the oophorectomy status and follow-up period. Conclusion. Zoledronic acid, at a dose of 0.1 mg/kg, significantly increased the maximum loads and yield points and reduced the stiffness coefficients in the femurs of female rats with osteoporosis caused by bilateral oophorectomy. © 2012 Evandro Pereira Palacio et al.

Effect of disinfectant solutions on a denture base acrylic resin.

The aim of this study was to evaluate the hardness, roughness and mass loss of an acrylic denture base resin after in vitro exposure to four disinfectant solutions. Forty specimens (Clássico, Brazil) were prepared and randomly assigned to 4 groups n = 10) according to the disinfectant solution: G1: control, stored in distilled water at 37 degrees C; G2: 1% sodium hypochlorite; G3: 2% glutaraldehyde; G4: 4% chlorhexidine. G2 to G4 were immersed for 60 minutes in the disinfectant solution. Measurements were carried out both before and after immersion in the solution. The surface was analyzed with a surface roughness tester (Surfcorder SE 1700 KOZAKALAB), a microdurometer FM-700 (Future Tech) and a scanning electron microscope (DSM 962-ZEISS). Loss of mass was determined with a digital weighing scale. After disinfection procedures, values were analyzed statistically. The acrylic denture base resin may be vulnerable to surface changes after in vitro immersion in the disinfectant solutions studied.

Fluazuron-induced morphophysiological changes in the cuticle formation and midgut of Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) nymphs

The present study demonstrated the effects of the arthropod growth regulator, fluazuron (Acatak®), in the formation of the integument and digestive processes of Rhipicephalus sanguineus nymphs fed on rabbits treated with different doses of this chemical acaricide. For this, three different doses of fluazuron (20, 40, or 80 mg/kg) were applied pour on to the hosts (groups II, III, and IV), as well as distilled water to the control group. On the first day after treatment (24 h), the hosts were artificially infested with R. sanguineus nymphs. After full engorgement (7 days), the nymphs were removed, placed on labeled Petri dishes, and kept in biochemical oxygen demand incubator for 7 days. The engorged nymphs were then taken for morphological, histochemical, and histological analyses. The results showed the occurrence of cytological, morphohistological, and histochemical alterations in the integument and midgut of nymphs from all the different treated groups. These alterations occurred at cuticular level in the subdivisions of the cuticle, related to the size of the digestive cells, amount of accumulated blood elements, and digestive residues, as well as the presence of vacuoles in the cytoplasm of the digestive cells. Thus, this study demonstrated that fluazuron acts on the integument and midgut cells of R. sanguineus nymphs fed on treated rabbits and pointed out the possibility of the use of this chemical - which is more specific, less toxic, and less harmful to the environment and nontarget organisms - in the control of R. sanguineus, at least in the nymphal stage of its biological cycle. © 2012 Springer-Verlag.

Analysis of the bioactive surface of Ti-35Nb-7Zr alloy after alkaline treatment and solution body fluid

The purpose of this work was to evaluate the Ti-35Nb-7Zr experimental alloy after surface treatment and soaking in solution body fluid (SBF) to form bonelike apatite. The Ti-35Nb-7Zr alloy was produced from commercially pure materials (Ti, Nb and Zr) by an arc melting furnace. All ingots were submitted to sequences of heat treatment (1100 °C/2 h and water quenching), cold working by swaging procedures and heat treatment (1100 °C/2 h and water quenching). Discs with 13 mm diameter and 3 mm in thickness were cut. The samples were immersed in NaOH aqueous solution with 5 M at 60 °C for 72 h, washed with distilled water and dried at 40 °C for 24 h. After the alkaline treatment, samples were heat treated in both conditions: at 450 and 600 °C for 1 h in an electrical furnace in air. Then, they were soaking in SBF for 24 h to form an apatite layer on the surface. The surfaces were investigated by using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), infrared spectroscopy (FTIR) and contact angle measurements. The results indicate that calcium phosphate could form on surface of Ti-35Nb-7Zr experimental alloy. © Springer-Verlag Berlin Heidelberg 2013.

Effects of cement-curing mode and light-curing unit on the bond durability of ceramic cemented to dentin

The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid/60s and silanized. The dentin was treated with37% phosphoric acid/15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement/RC curing type(dual-and photocured), light-curing unit (halogen light/QTH and LED), and storage conditions (dry and storage/150 days + 12,000 cycles/thermocycling). All blocks were stored in distilled water (37°C/24h) and sectioned (n = 10): G1-QTH + RC Photo, G2-QTH + RC Dual, G3-LED + RC Photo, G4-LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1-12.95 (6.40)ab; G2-12.02 (4.59)ab; G3-13.09 (5.62)ab; G4-15.96 (6.32)a; G5-6.22 (5.90)c; G6-9.48 (5.99)bc; G7-12.78 (11.30)ab; and G8-8.34 (5.98)bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength betweenceramic cemented to dentin when the photocured cement was used, and only after aging (LED>QTH). There was no difference between the effects of dual-and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

Compressive strength of dental composites photo-activated with different light tips

The aim of this study was to evaluate the compressive strength of microhybrid (Filtek™ Z250) and nanofilled (Filtek™ Supreme XT) composite resins photo-activated with two different light guide tips, fiber optic and polymer, coupled with one LED. The power density was 653 mW cm -2 when using the fiber optic light tip and 596 mW cm-2 with the polymer. After storage in distilled water at 37 ± 2 °C for seven days, the samples were subjected to mechanical testing of compressive strength in an EMIC universal mechanical testing machine with a load cell of 5 kN and speed of 0.5 mm min-1. The statistical analysis was performed using ANOVA with a confidence interval of 95% and Tamhane's test. The results showed that the mean values of compressive strength were not influenced by the different light tips (p > 0.05). However, a statistical difference was observed (p < 0.001) between the microhybrid composite resin photo-activated with the fiber optic light tip and the nanofilled composite resin. Based on these results, it can be concluded that microhybrid composite resin photo-activated with the fiber optic light tip showed better results than nanofilled, regardless of the tip used, and the type of the light tip did not influence the compressive strength of either composite. Thus, the presented results suggest that both the fiber optic and polymer light guide tips provide adequate compressive strength to be used to make restorations. However, the fiber optic light tip associated with microhybrid composite resin may be an interesting option for restorations mainly in posterior teeth. © 2013 Astro Ltd.

Effect of immersion cleansers on the bond strength between a denture base resin and acrylic resin teeth

The aim of the present study was to assess the shear bond strength between a heat-polymerized denture base resin and acrylic resin teeth after immersion in different denture cleansers by simulating a 180-day use. Two acrylic teeth (Biotone, Biotone IPN, Dentsply Ind. e Com., Rio de Janeiro, RJ, Brazil) were chosen for bonding to a heat-polymerized denture base resin (Lucitone 550- Dentsply Ind. e Com., Rio de Janeiro, RJ, Brazil). Eighty specimens were produced and divided into eight groups (n=10) according to their experimental condition (distilled water, 2% chlorhexidine digluconate, 1% sodium hypochlorite and Corega Tabs). Shear bond strength tests (MPa) were performed with a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by two-way analysis of variance (ANOVA) and Student-Newman-Keuls' multiple comparisons post hoc analysis (α=.05). The shear bond strength results revealed statistically significant differences between the groups. For the Biotone IPN tooth, significantly lower shear bond strength values were found for the group immersed in sodium-perborate solution (4.48±2.18 MPa) than for the group immersed in distilled water (control group) (10.83±1.84 MPa). For Biotone, significantly higher bond strength values (10.04±3.28 MPa) were found for the group immersed in Corega Tabs than for the control group (5.45±2.93 MPa). The immersion in denture cleanser solutions was more detrimental to the conventional acrylic denture tooth (Biotone) than to the highly cross-linked denture tooth (Biotone IPN). However, this effect was not observed for the groups immersed in Corega Tabs solution, regardless of the type of denture tooth. © 2013 Elsevier Ltd.

Effect of the root canal final rinse protocols on the debris and smear layer removal and on the push-out strength of an epoxy-based sealer

The aim of the present study was to evaluate the efficacy of QMiX, SmearClear, and 17% EDTA for the debris and smear layer removal from the root canal and its effects on the push-out bond strength of an epoxy-based sealer by scanning electron microscopy (SEM). Forty extracted human canines (n=10) were assigned to the following final rinse protocols: G1-distilled water (control), G2-17% EDTA, G3-SmearClear, and G4-QMiX. The specimens were submitted to a SEM analysis to evaluate the presence of debris and smear layer, respectively, in the apical or cervical segments. In sequence, forty extracted human maxillary canines with the root canals instrumented were divided into four groups (n=10) similar to the SEM analysis study. After the filling with AH Plus, the roots were transversally sectioned to obtain dentinal slices. The specimens were submitted to a push-out bond strength test using an electromechanical testing machine. The statistical analysis for the SEM and push-out bond strength studies were performed using the Kruskal-Wallis and Dunn tests (α=5%). There was no difference among the G2, G3, and G4 efficacy in removing the debris and smear layer (P>0.05). The efficacy of these groups was superior to the control group. The push-out bond strength values of G2, G3, and G4 were superior to the control group. The ability to remove the debris and smear layer by SmearClear and QMiX was as effective as the 17% EDTA. The final rinse with these solutions promoted similar push-out bond strength values. © 2013 Wiley Periodicals, Inc.

In vitro comparisons of casting retention on implant abutments among commercially available and experimental castor oil-containing dental luting agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efficacy of four irrigation needles in cleaning the apical third of root canals

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2 mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Resistência de genótipos de eucalipto a ceratocystis spp

Eucalyptus is the most important plantation forest species in Brazil. Wilt and canker caused by Ceratocystis fimbriata on eucalyptus were first reported in 1998 in plantations of an E. grandis × E. urophylla hybrid in southern Bahia, Brazil. This work aimed at studying the reaction of different eucalyptus genotypes after inoculation with C. fimbriata isolates, in order to find a possible source of resistance. The study included four isolates of Ceratocystis collected from eucalyptus in different regions. One disc of fungal mycelium with 1-cm-diameter (from colonies growing for 10 days on malt extract agar medium-MEA) was inoculated on the stem of thus injured eucalyptus plants (six months old). A cotton wool moistened with sterile distilled water was wrapped with plastic film. Control plants were inoculated with discs of MEA without fungal colonies. The inoculated plants were kept in a greenhouse. Wilt symptoms were observed 90 days after inoculation. The seedlings were cut in the longitudinal direction of the stem in order to observe the colonization of fungus in the plant xylem. We tested twenty eucalyptus genotypes, but only five showed resistance to all isolates of Ceratocystis, belonging to different species of Eucalyptus: E. urophylla (C2 and C9), E. grandis (C3), E. saligna (C6 and C13) Most E. gramdis genotypes were more susceptible to all four fungal isolates. These results support future studies related to eucalyptus resistance to Ceratocystis.

Atividade inseticida e Modos de Ação de Extratos Vegetais Sobre Mosca Branca (Bemisia tabaci)

Insecticide potential and efficaciousness of vegetal extracts concentrations from six botanic families in three different modes were analyzed on the nymphs of the silverleaf whitefly Bemisia tabaci (Genn. 1889) on a tomato plantation Lycopersicon esculentum Mill. Nymph breeding was kept in cherry tomato shrubs. Test solutions were obtained from successive extractions with ethanol and evaporation in a rotary evaporator. Tests consisted of 10 solutions in four concentrations (500; 1,000; 1,500 and 3,000 μg/mL) and control treatment (distilled water + 1% DMSO) under three different modes of activity, namely, contact, translaminar and systemic. Experimental design was totally randomized with four repetitions and eleven treatments. Means were compared by Scott-Knott test at 5% probability and lethal concentrations (CL50) were calculated by POLO. In the case of contact activity mode, all extracts had efficiency above 50% with the highest concentration (3,000 μg/mL) in which the highest efficiency for all extracts tested was verified. There was a need for dose increase in translaminar activity mode for similar results, whereas in the case of systemic activity the best performance was obtained with extracts of Nerium oleander, Derris amazonica and Ipomoea carnea. Extracts of the last two caused a higher percentage when compared with that of other extracts in all activity modes lower than CL50.