989 resultados para longevity


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Cotton cultivars expressing Cry proteins are widely used to control lepidopteran pests. The effects of transgenic plants containing insecticidal Cry proteins on non-target species must be comprehended for a better and rational use of this technology for pest management. We investigated the influence of the Bt cotton cultivars NuOPAL and FM 975 on biological parameters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a non-target pest of Bt cotton cultivars and on its parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae). The experiments were conducted in a climatized room, and the non-transgenic near isolines were used for rearing whiteflies as control hosts. The effects of the Bt cotton cultivars on the period of embryonic and larval development and the percentage of adult emergence of B. tabaci were assessed. The period required for embryonic, larval, and pupal development and the percentage of emergence and longevity of E. desantisi females were determined using Bt cotton-fed and non-Bt cotton-fed B. tabaci as hosts. Both Bt cotton cultivars resulted in a decrease of approximately 20% of adult emergence of B. tabaci. Differently, an increase of approximately 10% of adult emergence of E. desantisi was observed for parasitoids that used hosts fed with both Bt cotton cultivars. However, female parasitoid longevity decreased when their hosts were fed on Bt cotton cultivars. Our data suggest that the use of Bt cotton cultivars in association with the biological control agent E. desantisi could be functional for the management of B. tabaci in Bt cotton crops.

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Pós-graduação em Agronomia - FEIS

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With the advances of osseointegration principles, the use of implant-supported prosthesis has become a routine treatment option. The success of an implant is initially associated to the surgical technique, primary stability and absence of bacterial contamination on the implant site. Subsequently, the absence of mechanical trauma (overload) and peri-implantitis are sine qua non conditions to the longitudinal success of implant treatment. Therefore, the strict maintenance of oral hygiene is highly important to avoid biofilm accumulation around the implant and consequently to provide last-long implant-supported dentures. The clinician has the responsibility to supply a favorable prognosis to the patient so that the rehabilitation succeed. For this reason, during prosthesis fabrication the clinician should observe the design and emergency profile of the prosthesis, the peri-implant sulcus depth as well as the presence of motor or psychological impairment by the patient. Subjects with missing teeth and that will be submitted to the implant treatment should be motivated and adequate instructed regarding oral hygiene and its importance since the best option to obtain treatment longevity and consequently patient’s satisfaction is the prevention. Therefore, this study aimed to perform a literature review about the hygiene of implant-supported prosthesis.

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The demand for esthetic restorations has resulted in an increased use of dental ceramics and is the main alternative restorative material to tooth structure due to its favorable properties. Therefore, the aim of this work is to study the evolution of ceramic systems, involving different types and properties, indications, and clinical issues as aesthetic, cementing and longevity. In a detailed and advanced search in the database PubMed, 98 articles were found using the following key words: dental porcelain dental all-ceramic and ceramic according to the criteria for inclusion and exclusion left only 35 articles for review. Several ceramic systems are available in the market, making the prosthetic professionals need a constant recycling about their properties and directions, since good results are due to the selection of the best material for a particular case in all the skill of the practitioner.

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The maintenance of Implant-supported Prosthesis is essential to the success of dental implants. Therefore, the aim of the study was to conduct a review the literature addressing maintenance Implant-Supported Prosthesis in order to guide planning for the longevity of oral rehabilitation. We conducted a detailed search strategy for the Pubmed / Medline Dentistry and Oral Science, used as descriptors: “Oral Hygiene“ and “Dental Implant until July, 2013. The results were grouped together in topics (Clinical Exam and Oral Hygiene) and discussed. Conclusion: A regular maintenance program for oral patient implantprosthesis is essential to the longevity of the treatment. Different methods and devices are effective for cleansing. However one orientation (in writing) must be offered to patients, since inadequate cleaning can create regions of abrasion on the surfaces of abutments and dental implants.

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The identification and treatment of peri-implant infections are an essential stage in the maintenance of dental implants, reflecting the longevity of rehabilitation. Therefore, the aim of the study was to conduct a literature review addressing peri-implantitis in dental implants in order to guide planning for the longevity of oral rehabilitation. It was conducted a detailed search strategy by the PubMed / Medline Dentistry and Oral Science, it was used as descriptors: “peri-implantitis” and “Dental Implant”, until July 2013. From 566 articles, after a review, according to the inclusion criteria, 34 articles were selected. The results were grouped together in topics (concept, etiology, diagnosis, surgical and nonsurgical, and aspects of oral rehabilitation) for further discussion and conclusions. Conclusions: The accumulation of plaque has been associated with a higher propensity to peri-implantitis. There is a higher incidence of the peri-implantitis disease among patients with previous history of periodontal disease. The local administration of antibiotics and association with mouthwashes / topical use are indicated as suitable for the treatment of moderate peri-implantitis.

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Rehabilitation of edentulous patients has been a challenge for professionals since the primary concepts and fundaments of occlusal rehabilitation. However, this philosophy has been improved by implant-supported fixed dentures that represent a predictable clinical modality on modern dentistry. Nevertheless, considering that the traditional protocol requires a long period for bone healing and definitive rehabilitation, immediate loading of implants has been advantageous for functional and esthetic rehabilitation of patients in a reduced period. The aim of this study is to discuss the biomechanical and functional fundaments of occlusion for implant-supported fixed dentures with mediate and immediate loading to provide clinical evidences for longevity of this treat ment modality based on the current literature. According to this, some prerequisites as proper bone quality, excellent primary stability, sufficient number of implants, rigid splinting, and control and mastering of biomechanical fundamentals of static and dynamic occlusion are mandatory for treatment predictability and longevity.

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The modalities of treatment with prostheses over implants for total edentulous patients can be divided in fixed and removable prostheses (overdentures). The fixed prostheses modality has proven to offer better results as to the functional aspects and, results in higher longevity. Overdentures are considered as a modality of rehabilitation utilized to compensate the need for better retention, aside from augmenting chewing efficiency. Its use is justified by its facilitated hygiene, reduced surgical and prosthetic costs, reestablishment of labial support and elimination of the possibility of air escape. However, this option presents psychosocial downside, since the fact that it is considered a removable rehabilitation modality does not please the majority of patients. Although many patients prefer a fixed implant-supported prosthesis to a removable overdenture, frequently it is necessary to utilize an implant retained overdenture as an alternative to the treatment, due to anatomical, physiological, aesthetic, hygienic, and financial limitations regarding the patient. The objective of this study was to discuss a clinical case of a partially edentulous patient treated in the Implantodontic Surgery Post-Graduation Course from the Kenedy Dentistry Institute Mozarteum/Famosp Unit – Goiânia-Brazil), and submitted to osseointegrated implants surgical fixation techniques. A modality of differential diagnosis was established after osseointegration period, it aimed at facilitating the choice of a rehabilitation model that could favor the patient’s and professional`s expectations. Therefore the appreciated aspects were function, comfort, aesthetics, and especially the patient satisfaction.

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The concept of switching platform is the use of an implant by platform wider than the abutment. Recently, researches have shown that this type of dental implant design tends to offer a higher preservation of crestal bone when compared to the traditional pattern of bone loss. The present study aims to perform a critical review on the switching platform concept establishing possible advantages of the technique. A search was performed on Medline/Pubmed about the topic “dental implant” and “platform switching”, and after applying inclusion criteria 40 studies were selected. The literature on longevity present prospective studies that show less bone loss, studies in biomechanics exhibit better or similar stress distribution around the bone crest, however, is not yet defined the role of the biological width. Thus, studies of longevity, and randomized prospective studies are of a great relevance to be performed in order to confirm the benefits of this technique and to establish a protocol indication. It is possible, based on this literature review, to conclude that longitudinal and randomized studies show that the platform switching implants have longevity and less bone loss. Biomechanically, the technique is possible.

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Color stability of restorative materials is essential for longevity of esthetic composite restoration over time. The aim of this investigation was assess the effect of prior water immersion on the color stability of a composite resin to red wine staining. Seventy disccshaped specimens (6mm x 1.5mm) were carried out and randomized in 7 groups (n = 10), according to distilled water immersion time at 0 (control), 24, 48, 72,120,192, and 240 h. Baseline color was measured according to the ciel*a*b* system using a reflection spectrophotometer(uvc2450, shimadzu).After that, the specimens were storage in red wine for 7 days. Color difference (∆e) after aging was calculated based on the color coordinates before(baseline) and after storage period.Data were subjected to onecway anova(alpha=0.05).The different times of immersion in.Water before to the red wine storage showed similar behavior on the color stability, without statistical difference compared to control group, immersed directly in the wine(p=0.7057).The previous water uptake of composite resin evaluated did not decrease the susceptibility to red wine staining.

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OBJECTIVE: The aim of this study was to gather information and discuss the predictability of implant-supported prostheses in patients with bruxism by performing a literature review. METHODS: In order to select the studies included in this review, a detailed search was performed in PubMed and Medline databases, using the following key words: bruxism, dental implants, implant supported prosthesis, and dental restoration failure. Items that were included are: case reports, randomized controlled trials, in vitro studies, literature and systematic reviews, with or without meta-analysis, of the last 20 years that addressed the theme. Articles without abstracts, animal studies, articles in languages other than English and articles from journals unrelated to the dental field were excluded. RESULTS: after analysis according to inclusion and exclusion criteria, 28 articles were selected from a total of 54. It is known from the array of scientific articles which have assessed, either through retrospective, prospective or experimental studies, that the biomechanical and biological impact of bruxism on implant-supported prostheses is small, and that the literature has contributed little to exemplify the prosthetic limits of safety for the specialist from a clinical point of view. CONCLUSION: Although there is still no general consensus on this matter, most of the literature review articles do provide clinical guidelines that contribute to implant supported prostheses longevity and stability in patients with bruxism.

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The rehabilitation with mandibular distal extension removable partial dentures (DERPD) is complex and the use of implants has been improving the functioning of this approach. The insertion bony level around of the last support tooth is an aggravating factor, since it can harm the longevity of the treatment. Thus, the aim of this research was to evaluate the displacement tendency of a mandibular DERPD associated to an implant, with different insertion bony levels and different connections between the RPD and the support tooth, by finite element analysis. Eight models were made: MA - DERPD, incisal rest, no bony loss; MB - DERPD, distal plate, no bony loss; MC - DERPD, incisal rest, no bony loss, with implant and ERA system; MD - DERPD, distal plate, no bony loss, with implant and ERA system; ME - DERPD, incisal rest, bony loss; MF - DERPD, distal plate, bony loss; MG - DERPD, incisal rest, bony loss, with implant and ERA system; MH - DERPD, distal plate, bony loss, with implant and ERA system. Loads of 50 N in each peak were applied. Displacement maps were obtained and showed that implant favors this association and the bony loss harms the prognostic of the prosthesis. It is concluded that: the introduction of the implant with ERA system reduced the displacement tendency of the tooth and supporting structures; introduction of distal plate reduced the movement tendency of the support tooth; the decrease of the periodontal support didn't influence significantly the displacement tendency of the models with distal plate distal, but it influenced the models with distal incisal rest.

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Superficial stains and irregularities of the enamel are generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mineralized white spots, or fluorosis, for which enamel microabrasion is primarily indicated. Enamel microabrasion involves the use of acidic and abrasive agents, such as with 37% phosphoric acid and pumice or 6% hydrochloric acid and silica, applied to the altered enamel surface with mechanical pressure from a rubber cup coupled to a rotatory mandrel of a low-rotation micromotor. If necessary, this treatment can be safely combined with bleaching for better esthetic results. Recent studies show that microabrasion is a conservative treatment when the enamel wear is minimal and clinically imperceptible. The most important factor contributing to the success of enamel microabrasion is the depth of the defect, as deeper, opaque stains, such as those resulting from hypoplasia, cannot be resolved with microabrasion, and require a restorative approach. Surface enamel alterations that result from microabrasion, such as roughness and microhardness, are easily restored by saliva. Clinical studies support the efficacy and longevity of this safe and minimally invasive treatment. The present article presents the clinical and scientific aspects concerning the microabrasion technique, and discusses the indications for and effects of the treatment, including recent works describing microscopic and clinical evaluations.