936 resultados para Biomedical and dental daterials


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A cutia espécie Dasyprocta prymnolopha (D. prymnolopha) é um roedor de tamanho médio, diurno e característico do Nordeste do Brasil, sul da Amazônia. Vários estudos têm sido feitos sobre estes roedores. No entanto, há uma carência de estudos do sistema estomatognático, em particular, a morfologia dos dentes. Assim, esta pesquisa procura descrever aspectos anatômicos e histológicos dos dentes cutia. Para isto, nós utilizamos cutias adultas, em que as mensurações e as descrições dos dentes e dos tecidos dentais foram feitas. Observou-se que a arcada dentária de D. prymnolopha é composta por vinte dentes, distribuídas uniformemente no arco superior e inferior, sendo os dentes inferiores, maiores do que os seus correspondentes superiores. Os incisivos são maiores, e entre os pré-molares e molares posteriores, existe um aumento gradual no comprimento do arco anterior-posterior. No exame microscópico, uma forma prismática foi observada o que consiste de prismas de esmalte dispostos em diferentes direções, atrás do esmalte e dentina com túbulos dentinários com padrão tubular de diâmetro variável e distantes entre si, mostrando também um caminho sinuoso a partir da parte interna da junção com o esmalte mais superficial. A análise morfológica dos tecidos dentários mostrou um esmalte com a organização estrutural adaptada para o ato de mastigar e dentina de alto impacto compatível com a função do padrão tubular de resiliência e amortecimento mecânico de forças mastigatórias, como encontrado em animais maiores, confirmando o entendimento de hábitos alimentares que definem muito das suas funções ecológicas dentro do ecossistema em que vivem.

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A espécie Pyrostegia venusta é uma liana trepadeira popularmente conhecida como flor-de-São-João. É utilizada na medicina popular para o tratamento de diversas doenças. Na literatura científica, vários compostos bioativos já foram isolados e algumas atividades biológicas importantes, como a atividade antimicrobiana e imunomoduladora, já foram atribuídas a esta espécie. A cárie e a doença periodontalsão as doenças bucais mais prevalentes na população brasileira, sendo o biofilme dental o seu fator etiológico primário. A candidíase oral ocorre devido à infecção por espécies do gênero Candida que, em determinadas situações, podem se comportar como patógenos oportunistas. O objetivo deste trabalho foi realizar um estudo físico, químico e biológico da espécie vegetal Pyrostegia venusta e investigar seu potencial na prevenção das principais doenças bucais. Foram realizados ensaios de citotoxicidade do extrato bruto e frações em células mononucleares do sangue periférico e em macrófagos murinos. Para avaliar a atividade imunomoduladora do extrato bruto e frações, foi realizada dosagem de óxido nítrico (NO) produzido por macrófagos estimulados com lipopolissacarídeo (LPS). Foi realizado ensaio de microdiluição em caldo para determinar a concentração inibitória mínima (CIM), concentração bactericida mínima (CBM) e concentração fungicida mínima (CFM) do extrato bruto, frações e marcadores. Também foram avaliados o efeito na inibição da aderência de Streptococcus mutans em lamínula de vidro, o efeito na redução do pH e a capacidade de inibição do brotamento de Candida albicans do extrato bruto e frações. A espécie Pyrostegia venusta não foi citotóxica em baixas concentrações. A produção de NO foi inibida pelas frações acetato de etila e n-butanólica. O extrato bruto, frações e marcadores apresentaram atividade antimicrobiana contra Streptococcus mutans, Streptococcus mitis, Streptococcus oralis e Candida albicans, capacidade de inibição da aderência e redução do pH. O extrato bruto e frações hexânica, acetato de etila e n-butanólica apresentaram capacidade de inibição do brotamento. A espécie Pyrostegia venusta pode ser uma alternativa na prevenção e tratamento das principais doenças bucais. No entanto, mais estudos são necessários antes de considerá-la realmente promissora.

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OBJECTIVE: The purpose of the study was to evaluate the influence of the skeletal maturation in the mandibular and dentoalveolar growth and development during the Class II, division 1, malocclusion correction with Balters bionator. METHODS: Three groups of children with Class II, division 1, malocclusion were evaluated. Two of them were treated for one year with the bionator of Balters appliance in different skeletal ages (Group 1: 6 children, 7 to 8 years old and Group 2: 10 children, 9 to 10 years old) and the other one was followed without treatment (Control Group: 7 children, 8 to 9 years old). Lateral 45 degree cephalometric radiographs were used for the evaluation of the mandibular growth and dentoalveolar development. Tantalum metallic implants were used as fixed and stable references for radiograph superimposition and data acquisition. Student's t test was used in the statistical analysis of the displacement of the points in the condyle, ramus, mandibular base and dental points. Analysis of variance one-fixed criteria was used to evaluate group differences (95% of level of significance). RESULTS: The intragroup evaluation showed that all groups present significant skeletal growth for all points analyzed (1.2 to 3.7 mm), but in an intergroup comparison, the increment of the mandibular growth in the condyle, ramus and mandibular base were not statically different. For the dentoalveolar modifications, the less mature children showed greater labial inclination of the lower incisors (1.86 mm) and the most mature children showed greater first permanent molar extrusion (4.8 mm).

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

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

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

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

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Piezosurgery is a new and modern technique of bone surgery in implantology. Selective cutting is possible for different ultrasonic frequencies acting only in hard tissues (mineralized), saving vital anatomical structures. With the piezoelectric osteotomy technique, receptor site preparation for implants, autogenous bone graft acquistition (particles and blocks), osteotomy for alveolar bone crest expansion, maxillary sinus lifting, and dental implant removal can be performed accurately and safely, providing excellent clinical and biological results, especially for osteocyte viability. The aim of this review was, through literature review, to present clinical applications of piezosurgery in implant dentistry and outline their advantages and disadvantages over conventional surgical systems. Moreover, this study addressed the biological aspects related to piezosurgery that differentiate it from those of bone tissue approaches. Overall, piezosurgery enables critical operations in simple and fully executable procedures; and effectively, areas that are difficult to access have less risk of soft tissue and neurovascular tissue damage via piezosurgery.

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Purpose: Temporomandibular disorders (TMD) are recognized as one of the mostcontroversial topics in dentistry, despite the fact that both basic science and clinicalresearchers have currently reached some degree of consensus. This study aimed toconduct a questionnaire-based survey about the management of TMD patients bygeneral dental practitioners (GDPs).Materials and Methods: One hundred fifty-one GDPs with a private practice in a cityof southern Brazil were included, independent of school of origin, gender, graduationyear, and curriculum content. All participants were administered a questionnaire aboutthe management of patients with TMD, and the responses were analyzed by binomialand chi-square tests (α = 0.05).Results: Of the GDPs, 88.7% received TMD patients, who were primarily diagnosedon the basis of medical history (36.6%) or physical examination (30.4%). Of these,65.4% referred the patients elsewhere, primarily to specialists in occlusion (36.1%) ororthodontics (29.7%). Occlusal splinting was the most commonly used managementmodality (20.8%), followed by occlusal adjustment (18.1%) and pharmacotherapy(16.6%). Splints were fabricated in maximum habitual intercuspation or centric re-lation depending on individual patient (54.8%). The hard stabilization form was themost common type of appliance used (35.0%). Moreover, 73.8% of the GDPs didnot employ semi-adjustable articulators, and 69.5% adjusted the appliances at thetime of fixing. The duration of splint use and the frequency of follow-up were con-sidered patient dependent by 62.1% and 72.8%, respectively. GDPs considered thetwo major TMD etiologic categories as multifactorial (20.8%) and occlusion (19.9%).Multidisciplinary medical and dental treatment was considered necessary by 97.9%.Conclusions: The evaluated general dental practitioners manage TMD patients ac-cording to international guidelines.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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To evaluate the oral health indicators by determining the experience of dental caries and periodontal disease and identification of self-perceived oral health status of pregnant adolescents and to assess the association between the studied variables. A transversal study, survey type and survey of the oral health status of 127 adolescents, 10-19 years of age, pregnant, accompanied by the Unified Health System of Araçatuba-SP was performed. The self-perceived oral health and socio-demographic data were recorded using an adapted questionnaire. The oral health statuses were analyzed using the DMFT and CPI indices in accordance with the criteria established by the WHO for epidemiological survey. Descriptive statistical analyzes and the Fisher's exact test with a significance level of 5% was performed, as well as a logistic regression analysis to verify the association between the variables. Of the total, 41.0% reported having satisfactory oral health, while 63.0% believed they had problems with their teeth and gums. The DMFT index was 12.51 (SD = 4.21). The percentage of caries-free was 6.3%, and 91.3% had periodontal problems. A statistically significant association was found between the variables: self-perceived oral health and periodontal disease p = 0.0166 and self-reported gum disease and periodontal disease p = 0.0039. Most patients considered their oral health as poor and reported having dental and gum problems, which can also be observed in the clinical examination since the caries experience of the pregnant women examined was considered high and the symptoms of periodontal disease were observed in most of the volunteers.

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Case Report. An 8-year-old girl with amelogenesis imperfecta (AI) reported unsatisfactory aesthetics, difficulty in mastication, and dental hypersensitivity. The intraoral examination observed mixed dentition, malocclusion in anteroposterior relationships, anterior open bite, and dental asymmetry. A hypoplastic form of AI was diagnosed in the permanent dentition. A multidisciplinary planning was performed and divided into preventive, orthopedic, and rehabilitation stages. Initially, preventive treatment was implemented, with fluoride varnish applications, in order to protect the fragile enamel and reduce the dental sensitivity. In the second stage, the patient received an interceptive orthopedic treatment to improve cross-relationship of the arches during six months. Finally, the rehabilitation treatment was executed to establish the vertical dimension. In the posterior teeth, indirect composite resin crowns were performed with minimally invasive dental preparation. Direct composite resin restorations were used to improve the appearance of anterior teeth. Follow-Up. The follow-up was carried out after 3, 6, 12, and 18 months. After 18 months of follow-up, The restoration of integrity, oral hygiene, and patient satisfaction were observed . Conclusion. Successful reduction of the dental hypersensitivity and improvement of the aesthetic and functional aspects as well as quality of life were observed.

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To discuss important characteristics of the use of dental implants in posterior quadrants and the rehabilitation planning. An electronic search of English articles was conducted on MEDLINE (PubMed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations (bone quantity and density), radiographic techniques, implant selection (number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.

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The palatal radicular groove is a morphological tooth defect, which act as local predisposing risk factor favoring accumulation of the bacterial plaque, permitting microbial invasion via root groove way, directly into periodontal structures. A patient diagnosed with palatal radicular groove and a localized periodontal disease was treated by procedures to control bacterial action and procedures to eliminate local predisposing risk factor. To treat the periodontal bone defect a sequelae of periodontal disease, a guided tissue regeneration technique was applied by using allograft and xenograft materials associated with a resorbable demineralized bovine cortical bone membrane. The objective of surgical regenerative procedure was to recover the periodontal tissues nearly as they were before periodontal disease destruction.