Effect of the number of screws on the stability of locking mandibular reconstruction plates

Atrophic mandible fractures are frequently a challenge to stabilize. This study evaluated, through mechanical testing in vitro, the number of locking screws that is sufficient to withstand loading when applied with a locking reconstruction plate in the fixation of atrophic mandible fractures. Polyurethane mandibles with a simulated linear fracture at the midline were used as substratum. Results show that resistance of the fixation is poor when one and two screws are used on each side of the fracture. Three screws on each side of the fracture significantly increases the resistance to displacement. However, no additional strength is added to the construct when more than three screws per side are used. © 2013 International Association of Oral and Maxillofacial Surgeons.

Comparison of different designs of implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress distribution in edentulous mandible - A computed tomography-based three-dimensional finite element analysis

A finite element analysis was used to compare the effect of different designs of implant-retained overdentures and fixed full-arch implant-supported prosthesis on stress distribution in edentulous mandible. Four models of an human mandible were constructed. In the OR (O'ring) group, the mandible was restored with an overdenture retained by four unsplinted implants with O'ring attachment; in the BC (bar-clip) -C and BC groups, the mandibles were restored with overdentures retained by four splinted implants with bar-clip anchor associated or not with two distally placed cantilevers, respectively; in the FD (fixed denture) group, the mandible was restored with a fixed full-arch four-implant-supported prosthesis. Models were supported by the masticatory muscles and temporomandibular joints. A 100-N oblique load was applied on the left first molar. Von Mises (σvM), maximum (σmax) and minimum (σmin) principal stresses (in MPa) analyses were obtained. BC-C group exhibited the highest stress values (σvM=398.8, σmax=580.5 and σmin=-455.2) while FD group showed the lowest one (σvM=128.9, σmax=185.9 and σmin=-172.1). Within overdenture groups, the use of unsplinted implants reduced the stress level in the implant/prosthetic components (59.4% for σvM, 66.2% for σmax and 57.7% for σmin versus BC-C group) and supporting tissues (maximum stress reduction of 72% and 79.5% for σmax, and 15.7% and 85.7% for σmin on the cortical and trabecular bones, respectively). Cortical bone exhibited greater stress concentration than the trabecular bone for all groups. The use of fixed implant dentures and removable dentures retained by unsplinted implants to rehabilitate edentulous mandible reduced the stresses in the periimplant bone tissue, mucosa and implant/prosthetic components. © 2013 Elsevier Ltd.

The influence of topic and systemic administration of copaiba oil on the alveolar wound healing after tooth extraction in rats

The Copaiba oil has been used as an auxiliary treatment of inflammations, skin disorders and stomach ulcers, however, in dentistry, this alternative medicine has not been investigated yet. The purpose of this study was to evaluate the influence of topic and systemic administration of copaiba oil on the alveolar wound healing after tooth extraction. Twenty-eight wistar male rats had their lower first molar teeth extracted. Subsequently, they were divided in four groups, according to the treatment performed: (a) alveolar socket irrigation with copaiba oil; (b) alveolar socket irrigation with physiological serum; (c) daily gavage with copaiba oil or (d) daily gavage with physiological serum. After the sacrifice, the mandibles were removed and processed in order to obtain decalcified histological sections. The results demonstrated high level of epithelial migration, small number of inflammatory cells and vascular enhancement in the animals which received systemic administration of copaiba oil. The rats treated with topic administration of copaiba oil presented ulcerations and large number of inflammatory cells. An increased bone neoformation was observed in both groups treated with copaiba oil when compared with placebo group. It could be concluded that topic or systemic administration of copaiba oil leads to a better alveolar bone healing, however the topic application on connective tissue should be carefully considered, regarding the whole socket wound healing. © Medicina Oral S. L. C.I.F. B 96689336 - eISSN: 1989-5488.

Dietas e conteúdo alimentar de alguns Carabidae (Coleoptera) observados na região nordeste do Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo radiográfico digital e densitométrico em mandíbulas de suínos, submetidas a osteotomia com brocas de alta e baixa rotação, com refrigeração líquida

Pós-graduação em Odontologia - FOA

Estudo da precisão da análise de tomografias espirais de mandíbulas humanas secas realizadas pelo tomógrafo X-Mind Tome

Pós-graduação em Odontologia - FOA

Influência de drogas antiplaquetárias na reparação da doença periodontal experimental em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ação de biomateriais e laser de baixa intensidade na reparação tecidual óssea: estudo histológico em ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação ortopantomográfica das angulações mesiodistais de caninos, pré-molares e molares inferiores com e sem a presença dos terceiros molares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise histológica de defeitos ósseos preenchidos com biomateriais e associados a implantes osseointegrados. Estudo em cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A glândula frontal e musculatura associada: morfologia e aplicação como indicador taxonômico de gêneros neotropicais de Nasutitermitinae (Isoptera, termitidae)

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Efeitos da osteopenia no reparo ósseo alveolar de ratas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de diferentes tempos de deficiência estrogênica na perda óssea resultante da periodontite experimental em ratas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo comparativo dos efeitos da calcitonina e do plumbum metallicum 30ch na reparação óssea em mandíbula de ratos

Pós-graduação em Biopatologia Bucal - ICT

Reparação inicial de enxertos ósseos autógenos em bloco ou em particulas: estudo microscópico em mandíbula de cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)