Scanning electron microscope assessment of several resharpening techniques on the cutting edges of gracey curettes

Aim: Treatment of periodontal diseases is based on efficient scaling and root planing (SRP) and adequate maintenance of the patient. The effectiveness of SRP is influenced by operator skill, access to the subgingival area, root anatomy, and the quality and type of instrument used for SRP. The aim of this study was to evaluate the cutting edges of Gracey curettes after manufacturing and after resharpening using several techniques. Methods and Material: The cutting edges of a total of 41 new #5-6 stainless steel Gracey curettes were evaluated blindly using scanning electron microscopy (SEM). The quality of the cutting edges was evaluated blindly by a calibrated examiner using micrographs. Data were analyzed using a Kruskal Wallis test and nonparametric two-way multiple comparisons. Results and Conclusions: Different sharpening techniques had significantly different effects on the sharpeness of cutting edges (p<0.05). Sharpening by passing the lateral face of curettes over a sharpening stone and then a #299 Arkansas stone produced a high frequency of smooth, sharp edges or slightly irregular edges between the lateral and coronal faces of the curettes. Sharpening by passing a blunt stone over the curette's lateral face produced the poorest quality cutting edge (a bevel). Sharpening of the coronal curette face produced extremely irregular cutting edges and non-functional wire edges. Sharpening with rotary devices produced extremely irregular cutting edges.

Meio de cultura e tipo de explante no estabelecimento in vitro de espécies de maracujazeiro

Brazil is one of the main centers of genetic variability dispersion of the Passiflora genera. Its self incompatibility as well as disease incidence in its leaves and root system and, deforestation and monocultivation, promote loss of genetic material. Considering the risk of genetic erosion, the conservation of the variability in germplasm banks, which is of great interest in plant breeding, is necessary. Studies regarding the type of expiant and concentration of the culture media are necessary in order to determine protocols of establishment and in vitro conservation of passion-fruit germplasm. The objective of the present work was to evaluate the influence of the salt and nutrient concentration in the MS culture medium and types of expiants in the establishment and growth of the Passion fruit species: Passiflora giberti N. E.Brown, P. edulis Sims and P. laurifolia L. Each Passiflora species presented its own characteristics regarding in vitro development. The complete MS medium and nodal segments the second axilliary bud promoted better development of the genotypes studied.

Fatigue resistance of bovine teeth restored with resin-bonded fiber posts: Effect of post surface conditioning

This study evaluated the effect of post surface conditioning on the fatigue resistance of bovine teeth restored with resin-bonded fiber-reinforced composite (FRC). Root canals of 20 single-rooted bovine teeth (16 mm long) were prepared to 12 mm using a preparation drill of a double-tapered fiber post system. Using acrylic resin, each specimen was embedded (up to 3.0 mm from the cervical part of the specimen) in a PVC cylinder and allocated into one of two groups (n = 10) based on the post surface conditioning method: acid etching plus silanization or tribochemical silica coating (30 μm SiOx + silanization). The root canal dentin was etched (H2PO3 for 30 seconds), rinsed, and dried. A multi-step adhesive system was applied to the root dentin and the fiber posts were cemented with resin cement. The specimens were submitted to one million fatigue cycles. After fatigue testing, a score was given based on the number of fatigue cycles until fracture. All of the specimens were resistant to fatigue. No fracture of the root or the post and no loss of retention of the post were observed. The methodology and the results of this study indicate that tribochemical silica coating and acid etching performed equally well when dynamic mechanical loading was used.

Desenvolvimento e nutrição do capim-Tanzânia em função da aplicação de zinco

It was aimed to assess the effects of zinc in the development and nutrition of Tanzania grass. The experimental design used was fully randomized, consisting of six doses of zinc (0, 15, 30, 60, 120 and 240 mg dm'3) and four repetitions. The experimental unit was formed in a vase filled with a Red Latosol dystrophic (Zn = 0.4 mg dm). There were two cuts, the first after 53 days of transplanting seedlings and the second 35 days after the first cut. Was evaluated the concentration of zinc in the soil, the content of zinc leaf, the number of tillers, number of leaves, plant height, the dry mass of the shoot, root system and the whole plant. The doses of zinc influenced the concentration of zinc in soil and plant, and production of dry mass of Tanzania grass, especially the first cut. The Tanzania grass shows high tolerance to the toxicity of zinc, and toxic critical level of 273 mg kg-1.

Avaliação de Diferentes Compósitos na Resistência à Fratura de Núcleos de Preenchimento

Objective: To evaluate and compare the fracture strength of different composite resins used for core buildup. Method: Thirty-six bovine teeth were decoronated at the cervical third to standardize the length of specimens at 20 mm. Under constant irrigation, the canals were prepared with #5 Largo drills corresponding to the size and diameter of #3 Reforpost fiberglass post. The posts were cemented with Enforce resin sealer, being 16 mm inside the root canal and 4 mm outside the root canal, and the material was light-activated for 30 seconds at each side. The specimens were divided into 3 groups (n=12), in which cores (4 mm diameter and 5 mm high) were prepared from a prefabricated standard with three types of composite resins: Group 1: Z100 (3M), Group 2: Z250 (3M) and Group 3: P60 (3M). The specimens were fixed in a cylindrical device with an adaptor at 45o inclination. This device was adapted to a universal testing machine (EMIC) to simulate the force until fracture of the specimen. Data were subjected to ANOVA (p<0.05). Results: The Z250 resin cores presented the highest mean fracture strength (45.453 kgf), while the mean fracture strengths in Group 1 and Group 3 were 38.014 and 39.506 kgf, respectively. P60 caused the largest number of root fractures. Conclusion: Considering the characteristics and properties of the tested resins, Z250 appears as the most indicated for core buildup.

Three-year follow up of customized glass fiber esthetic posts

Customized glass fiber posts that is well adjusted into the root canal and have mechanical properties similar to those of dentin may be a suitable treatment for severely compromised endodontically treated teeth. This article reports a 3-year follow up of severely damaged endodontically treated teeth restored with unidirectional fiber glass customized post and core system instead of a conventional fiber post. The fabrication of this glass fiber customized post is a simple technique, providing an increased volume of fibers into the root canal, and an adequate polymerization of the post-core system. Over a three-year period, the treatments demonstrated good clinical and radiographic characteristics, with no fracture or loss of the post and/or crown. This technique can be considered effective, less invasive, and suitable for restore endodontically treated teeth.

Conservative prosthetic-periodontal treatment for molar class iii furcation involvement: Case report

Purpose: The treatment for furcation involvement is a great challenge to the general dentists. Tunneling may be a treatment alternative for class II and III furcation involvements in mandibular molars with large angle separation and great divergence between the mesial and distal roots. This alternative is a conservative treatment that allows a great condition to oral hygiene maintenance by the patient. Thus, the aim of this case report was to describe a conservative and therapeutic treatment modality for the horizontal defect of periodontal tissues in the furcal area with buccal-lingual extension (class III furcation involvement). Case Report: A patient with class III furcation involvement in the first mandibular molar was submitted to root resection and periodontal surgery to expose the clinical crown for the full-coverage restoration with tunnel preparation. Results: The final result of the treatment with tunneled crown was favorable and predictable due to adequate hygiene condition to avoid plaque accumulation and occurrence of root caries. Clinical Significance: A multidisciplinary approach is essential to achieve a correct treatment plan including surgical-periodontal procedures integrated to the prosthetic rehabilitation. Besides, the recommendation for oral hygiene maintenance is essential for the treatment longevity with tunneled crown. © 2011 Nova Science Publishers, Inc.

Níveis de fertirrigação na avaliação das características morfofisiológicas em mudas de pimenta malagueta

O presente trabalho teve o objetivo de avaliar as características morfofisiológicas de mudas de pimenta malagueta (Capsicum frutescens) sob diferentes níveis de fertirrigação, utilizando-se fertilizante líquido 10-10-10 (N-P-K). O experimento foi realizado na Faculdade de Ciências Agrárias da Universidade Federal da Grande Dourados. O delineamento experimental foi em blocos casualizados (DBC), com seis doses de fertilizante líquido (0; 2,5; 5,0; 10,0; 20,0 e 40 mL L-1) diluídos na água de irrigação e quatro repetições. As mudas foram produzidas em viveiro telado, em bandejas de 128 células preenchidas com substrato. Realizou-se uma fertirrigação, aos 15 dias após a semeadura ( DAS). Avaliou-se, aos 30 dias após a semeadura, o número de folhas, o comprimento da parte aérea e da raiz, a massa fresca e seca da parte aérea e da raiz, a área foliar e o teor de clorofila. A dose de 25 mL L-1 do fertilizante líquido 10-10-10, aplicada via fertirrigação, é recomendada para a produção de mudas de pimenta malagueta, embora tenha havido aumento da massa seca de raízes e parte aérea em dose maior.

Morfofisiologia da cunhã cultivada sob estresse salino

The experiment was developed based on the importance of the nutritional factor cunhã for large and small, animals and on the growth of this forage in typical soils of the semiarid region, generally with salinity from natural or anthropogenic action. The experiment was performed in vessels with a capacity of 5kg prepared in a protected environment with full sunshine in the Department of Technology and Social Sciences (DTCS) of UNEB Campus III in Juazeiro - BA. It evaluated the effect of seven different salt concentrations on increasing levels of irrigation water electrical conductivity - ECw (0, 2, 4, 6, 8, 10 and 12 dS/m), at room temperature. The analysis of culture were taken every seven days observing the number of leaves, stem diameter, plant, plant length and total chlorophyll content at 13; 20; 27; 34 and 40 days after the start of irrigation with saline. The contents of proline, the ratio aero part/Root (AP/Rt), the root length and water content were evaluated in the 40 th day after the onset of treatment. The results showed that the elevation of ECw affected all variables.

Propriedades físico-hídricas, desenvolvimento radicular e produtividade da soja em dois tipos de manejos de solo

The soybean culture is part of crop rotation used by irrigators from the southwestern region of São Paulo State that perform no-tillage soil management as a form of sustainable soil use. The objective of this work was to evaluate the effect of this conservationist practice on physicalhydric properties, soil compaction, root development, and soybean culture production components in relation to the conventional management. The experiment was conducted at the Buriti-Mirim Farm, Angatuba, SP, in Brazil, using an area irrigated by a center pivot system divided into two types of soil management: conventional and no-tillage. Although the no-tillage management presented higher soil density, lower water available and lower soil resistance to penetration, both soil managements showed no difference in relation to root development.

Ultrasonic activation of internal bleaching agents

Aim: To evaluate the effectiveness of ultrasonic activation of bleaching agents during ex vivo internal bleaching. Methodology: Fifty canine human teeth were artificially stained, root filled and divided into five groups (n = 10) that received SP - sodium perborate plus deionized water (control group), CP - 37% carbamide peroxide gel, CPUS - 37% carbamide peroxide gel plus ultrasonic application, HP - 35% hydrogen peroxide gel or HPUS - 35% hydrogen peroxide gel plus ultrasonic application. In groups CP and HP, the bleaching agent was left inside the pulp chamber for three applications of 10 min. In groups CPUS and HPUS, the same process was performed, but ultrasonic vibration was applied to the bleaching agent by an alloy tip for 30 s, with 30 s intervals. Two sessions were performed. The colour was measured initially and after each session by an intraoral dental spectrophotometer. The variation (Δ) of the colour parameters based on the CIELab system L*, a* and b*, and the colour alteration ΔE* were calculated after first and second section. Data were analysed by one-way anova and Tukey's test. Results: There was no significant difference amongst groups for ΔL*, Δa* and ΔE*, but there was a significant difference for Δb* in the first and second sessions (P = 0.0006 and 0.0016, respectively). After the first session, Δb* was significantly greater for groups HP and HPUS, without a significant difference between them. For the second session, group HPUS had the greatest Δb* values, but they were similar to groups HP and SP; group CP had the lowest values, which were similar to groups CPUS and SP. Conclusion: Ultrasonic activation of bleaching agents during ex vivo internal bleaching was no more effective than conventional internal bleaching procedures, without activation. © 2012 International Endodontic Journal.

Importance of periodontal ligament thickness

This study evaluated whether periodontal ligament (PL) thickness varied with root size and examined the possible influence of this variation on orthodontic mechanics. Measurements were taken of the maxillary left first molar in 54 male Wistar rats. Mean mesial and distal PL thicknesses were compared between the intermediate buccal and mesiobuccal roots using paired Student's t-tests with a 5% significance level. Mean values differed significantly between roots (p < 2.2 × 10-16). PL thickness in rats is directly proportional to root dimensions.

Evaluation of the anti-resorptive ability of an experimental acetazolamide paste for the treatment of late replanted teeth: A study in rats

When late replantation is performed, the root surface and root canal should be treated. Notwithstanding failures still occur, because of the high rates of root resorption, evidencing the need to search for substances that may inhibit root resorption. The acetazolamide is a known anti-resorptive agent, and its use as root canal dressing may increase the success rates in the treatment of root resorption. Therefore, this study evaluated the effect of an acetazolamide paste used as root canal dressing in late replanted teeth. The study was conducted on 24 maxillary right incisors of rats, which were avulsed and divided in two groups. In group I, the teeth were kept dry for 30min, had their root surfaces rubbed with a blade, and were treated with 2% sodium fluoride at pH 5.5 for 20min; the root canals were instrumented and filled with acetazolamide paste; and then the teeth were replanted. In group II, the treatment was similar to group I, except for the root canal dressing, with utilization of calcium hydroxide in group II. At 15 and 60days after replantation, the animals were killed and the specimens were processed in a histotechnical laboratory for microscopic and morphometric analysis. The results demonstrated the ability of both intracanal substances to limit root resorption, yet they were unable to completely inhibit the root resorption. Replacement resorption lacunae were present in greater proportion in group II, at 60days. It was concluded that the acetazolamide paste was effective to limit the root resorption, being more effective in limiting the replacement resorption compared with calcium hydroxide. © 2012 John Wiley & Sons A/S.

Micorrização e crescimento de progênies de hymenaea stignocarpa mart. ex. Hayne em subsolo de área degradada degraded area

In tropical ecosystems, little is known about the relationship between arbuscular mycorhizal fungi (AMF) and the host genetic variability, especially among tree species. This study aimed to examine the response of 19 progenies of jatobá-do-cerrado (Hymenaea stignocarpa Mart. Ex. Hayne) inoculated with AMF, the root colonization and seedlings early growth were evaluated, growing in cultivated in subsoil from the loading area, under greenhouse conditions. The seedlings, germinated in the laboratory, were transferred to plastic bags containing subsoil and sand mixture (4:1). For the inoculation, each replicate received 100 g of soil (with about 48 spores of AMF) from a preserved Cerrado area, to reintroduce microorganisms. After 120 days, the mycorrhiza colonization (COL), the number of spores of AMF, the plant height (PH), the weight of shoot dry matter (SDM) and the root fresh matter (RFM) were assessed. The highest values of COL, SDM and RFM were observed in the progenies JC7, JC18, JC29, JC27 and JC14; the JC7 andJC18 also increased number of spores. There were significant and positive correlations between COL and the others variables (AP, NE, RFM and SDM, and between RFM and other variables (NE, AP and SDM). The conclusion is that, there is variability among the genotypes of Hymenaea stignocarpa growth (AP MFSR and DMAP) and mycorrhization (COL and NE), with emphasis on two progenies (JC7 and JC18), that showed the highest values, which can be resulted of a greater affinity to strains of AMF- soil inoculum.

Pulp fruit added to culture medium for in vitro orchid development

As an additive in in vitro culture media, fruits have a great potential for facilitating economical orchid production because of lower technology requirements and the ease of obtaining raw materials to formulate culture media. We studied the in vitro growth of Cattleya bicolor Lindl. grown in a simplified culture medium supplemented with different kinds of fruit pulp. The experimental design was completely randomised, with eight seedlings per replication and ten replications per treatment, for a total of 80 seedlings per treatment. The culture medium was made using 150 g L -1 of pulp (without peel or seed) from the following fruits: ripe Santa Cruz tomatoes (Solanum lycopersicum L.), dwarf bananas (Musa cavendishii L.) of intermediate ripeness, light green chayote (Sechium edule (Jacq.) Sw), ripe papaya (Carica papaya L.) or green coconut (Cocos nucifera L.).The treatment control was MS 50 %. The treatments and the control were kept in a growth chamber for seven months before evaluating seedling survival percentage, shoot height, number of leaves, rooting percentage, root number, root length and dry masses of shoot and roots. The highest percentages of seedling survival were obtained using MS 50 %, banana and coconut medium. The seedling survival and rooting percentages illustrate that it is possible to emphasise the culture medium MS 50% and the culture medium supplemented with coconut on the most traditional culture medium with banana or tomato pulp. For the in vitro development of Cattleya bicolor Lindl., a simplified culture medium supplemented with coconut pulp is the most suitable for use as an alternative to MS 50%. A simplified culture medium supplemented with papaya pulp is not recommended for the in vitro development of Cattleya bicolor Lindl.