Implantes Platform Switching: longevidade e preservação óssea: revisão crítica da literatura

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.

Regeneração óssea guiada em implantodontia: relato de caso

Objective: The use of methods for tissue regeneration has been widely applied in Implantology, in clinical situations with disabilities or anatomical limitations that prevent the placement of osseointegrated dental implants. The evolution of the development of biomaterials revolutionized this therapeutic modality, facilitating the resolution of clinical cases with tissue deficiencies. Thus, this study aimed to describe a clinical case approaching the methods, techniques, and materials used in guided bone regeneration applied to Implantology. Case report: A clinical case of a patient who received a Morse taper dental implant (region 15) is described. The use of biomaterial and membrane on the buccal wall of the socket was required. After the osseointegration period, a reopening surgery was performed, and an immediate provisional implant was produced. After 2 months of follow-up, the final prosthesis was made involving other adjacent elements. Final considerations: The guided bone regeneration technique employed showed satisfactory performance. The patient was positive regarding esthetics and function. However, more controlled studies with longer follow-up period are needed for analyses of predictability

Influência da angulação do implante e tipo de intermediário na distribuição das tensões

The aim of this study was to evaluate the influence of implant angulation and abutment type (UCLA and Estheticone) on stress distribution in screw-retained implant-supported prostheses through photoelasticity. Three models were fabricated with photoelastic resin PL-2 (Vishay, Micro-Measurements Group, Inc Raleigh, N.C., USA) containing one external hexagon implant with 3.75x10mm (Master screw, Conexão Sistemas de Prótese Ltda., Arujá, São Paulo) with 0°, 17° and 30° degrees and a screw-retained prostheses with UCLA and Estheticone abutments. The assembly was positioned in a circular polariscope; axial and oblique (45° degrees) loads of 100N were applied in fixed points on the occlusal crown surfaces by a universal testing machine. The stress generated was photographed and analyzed qualitatively with appropriate software (Adobe Photoshop®). The results demonstrated the same number of fringes for both abutment types for each angulation, with fringes increasing in the same way. A higher number of fringes were closer in the oblique loading mode. It was concluded that there was no significant difference in stress distribution in prostheses with UCLA and Estheticone abutments. Higher stress concentrations were observed with increased implant angulation. Stress concentration and intensity were higher in the oblique load than in axial load application.

O impacto das próteses implantosuportadas na harmonia facial

Many patients seeking dental care wish to improve facial and smile aesthetics to be accepted in modern day society. In denture wearers, the physiological resorption causes atrophy mainly in the maxilla, being necessary to carry out reconstruction techniques and sometimes orthognathic surgery to improve occlusal stability and facial harmony. The aim of this study is to discuss the features related to the rehabilitation of edentulous patients with indication for reconstruction of the maxilla using bone grafts and orthognathic surgery by means of a clinical case. In the present case, after the prosthetic rehabilitation, the patient was full satisfied with obtained results and dismissed the initially proposed surgical protocol. Therefore, professionals should provide therapeutic options but the patient’s opinion should prevail provided its clinical feasibility.

Reabilitação estética com enfoque nas diferentes cores de substratos e na escolha da cor do cimento adesivo

The evolution of techniques and materials applied to adhesive ceramic restorations resulted in the intensification of its use, proving to be an excellent method of aesthetic restoration. Some important features of this technique are its conservative preparation, which avoids an excessive loss of tooth structure and its high aesthetic value provided by the ceramic even when utilized under different color of dental substrates. The aim of this paper was to report a clinical case with full crowns, porcelain veneers and non-prep veneers, enhancing peculiarities related to the material used, tooth preparation techniques, cementing, indications and contraindications.

Tratamento de superfície de implantes dentários: SBF

Various surface treatments of dental implants have been developed in order to ensure anchorage to bone tissue, optimization of the determinants of electronic structure, crystallinity, composition and properties. Coating techniques have been proposed in order tocreate unionbiochemicalable to accelerate the early stages ofbone tissue, combining the positive properties of titanium and its alloys bioactivity of ceramic materials. This paper discusses protocol for handling the SBF coating of titanium alloys. The apatite phase nucleation occurs by immersing the substrate in synthetic solution simulating blood plasma (Simulated Body Fluid). The protocol allows manipulation of the SBF solution to establish guidelines regarding the usestreamlinedand organized to make practical application.

The influence of the alveolar ridge shape on the stress distribution in a free-end saddle removable partial denture supported by implant

The alveolar ridge shape plays an important role in predicting the demand on the support tooth and alveolar bone in the removable partial denture (RPD) treatment. However, these data are unclear when the RPD is associated with implants. This study evaluated the influence of the alveolar ridge shape on the stress distribution of a free-end saddle RPD partially supported by implant using 2-dimensioanl finite element analysis (FEA). Four mathematical models (M) of a mandibular hemiarch simulating various alveolar ridge shapes (1-distal desceding, 2- concave, 3-horizontal and 4-distal ascending) were built. Tooth 33 was placed as the abutment. Two RPDs, one supported by tooth and fibromucosa (MB) and other one supported by tooth and implant (MC) were simulated. MA was the control (no RPD). The load (50N) were applied simultaneously on each cusp. Appropriate boundary conditions were assigned on the border of alveolar bone. Ansys 10.0 software was used to calculate the stress fields and the von Mises equivalent stress criteria (σvM) was applied to analyze the results. The distal ascending shape showed the highest σvM for cortical and medullar bone. The alveolar ridge shape had little effect on changing the σvM based on the same prosthesis, mainly around the abutment tooth.

Case report: Cornelia de Lange Syndrome (CDLS)

The Cornélia of Lange´s syndrome is a genetic anomaly, described and published by Cornelia Catharina of Lange in 1933, however, their aspects were described previously by Winfried Robert Clemens Brechmann in 1916, that’s why it is also known as Brachmann of Lange’s syndrome. The most frequent clinical characteristics include typical face dismorfia, variable degree of mental delay, anomalies of the hands and feet, multiple malformations, retardation of the pre and postnatal physical development and microcephaly variable intellectual compromising. Some facial characteristics are peculiar and they are mixed with the inherited lines of their own family, the united brows, the long lashes, the small nose, the round face, the fine lips and lightly inverted. As oral manifestations they present micrognathia, dental crowding, periodontal disease, delayed dental eruption, enamel hypoplasia, erosion of the enamel and dentine caused by stomach acids of the gastroesophageal reflux and atresia of the dental arches. The purpose of this paper is to present a clinical report of a boy bearer of this syndrome assisted at CAOE - FOA - UNESP, emphasizing the importance of multiprofessional team for the diagnosis and treatment of this syndrome.

Fios ortodônticos superelásticos e sua aplicabilidade na clínica ortodôntica: revisão da literatura

During clinical routine, the orthodontist uses several materials, which include metallic alloys in the form of metallic wires. However, it is necessary that the professional has some knowledge of the properties of those wires. Different types of wires are commercially available: stainless steel wires, chrome-cobalt wires, nickel-titanium wires and beta-titanium wires. Among the nickel-titanium wires, there are three subdivisions: a conventional alloy and two superelastic alloys. The superelasticity, associated to the effect of form memory, is a property used in orthodontics to initiate the dental movement in the first phase of the orthodontic treatment. This property is considered to be biologically compatible with the effective dental movement. These wires are available at the market in different transformation temperatures, and they offer the best adaptation in the groove of the bracket, simplicity and a faster treatment. However, they present little formability, and they don’t accept solder. They are also more onerous than other wires. Moreover, the low rigidity of these wires doesn’t allow them to be used for the retraction of the anterior teeth or closing of spaces. Therefore, the coherent use of superelastic orthodontic wires is recommended, accompanied by a detailed diagnosis and planning, so the result will be an efficient orthodontic correction, accomplished in a shorter period of time.

Histórico de traumatismo dentoalveolar e movimentação ortodôntica: uma relação perigosa?

O traumatismo dentoalveolar é uma ocorrência cada vez mais comum na população em geral e está relacionado, na maioria das vezes à violência no trânsito, violência urbana e à prática esportiva. Esse aspecto, por conseguinte, tem aumentado sobremaneira o número de pacientes que procuram o tratamento ortodôntico e que relatam ter passado por algum episódio de trauma em seus dentes. Dentro desse contexto, muitas questões surgem com relação ao manejo de dentes com histórico de traumatismo dentoalveolar. Do ponto de vista histológico, quais as diferenças em movimentar-se um dente com histórico de trauma? O fato de um dente ter sido traumatizado pode influenciar no planejamento e no tratamento ortodôntico? E o protocolo das ativações do aparelho deveria ser alterado? O objetivo desse trabalho é apresentar uma breve revisão de literatura, bem como dois casos clínicos de pacientes que sofreram trauma dentário prévio à movimentação ortodôntica, no sentido de gerar subsídios técnicos e científicos para o especialista em Ortodontia, de modo que busque conhecer as implicações e limitações em movimentar dentes traumatizados.

Restauração transcirúrgica como alternativa na resolução das perfurações endodônticas

The endodontic perforations are iatrogenic communications that result in a communication between the endodonto and periodontium. This occurrence represents about 10 % of cas- es of failure in endodontic treatment. The management may vary and is related to the drilling site endodontic. This paper aims to report a case of iatrogenic perforation and one of the possible alternatives for the treatment of endodontic perforations -level cervical tooth. During the opening coronary perforation occurred due to improper slope cervical penetration drill. Considering the drilling site, we opted for sealing com- posite resin after surgical access and absolute isolation. After sealing, the channel was filled with medication and instru- mented based on calcium hydroxide. Later the canal was obturated by lateral condensation technique with Sealapex. The radiographic follow-up showed regression of the lesion and the clinical silence confirmed the success of the treatment.

Avaliação sensorial quantitativa da sensibilidade dentária com o uso de um dessensibilizante

O tratamento clareador se destaca por ser uma técnica conservadora, que pode proporcionar elevação da autoestima e melhorar o convívio social das pessoas. No entanto, pacientes expostos a essa terapia experimentam diferentes níveis de ocorrência e de intensidade de sensibilidade dentária. Essa sintomatologia é preocupante, pois tem sido apontada como o reflexo de uma eventual resposta pulpar frente ao tratamento realizado. Por outro lado, a presença de dor é desestimulante aos pacientes, prejudicando a evolução do tratamento e reduzindo o sentimento de satisfação. Apesar dessa importância, a maior parte dos estudos de sensibilidade dentária ainda emprega métodos subjetivos, dificultando a reprodutibilidade e interpretação dos resultados. Objetivo: nesse sentido, o presente artigo objetiva analisar a resposta neurossensorial proporcionada pela aplicação de estímulos térmicos gerados pelo equipamento TSA II (Medoc TSA II Neurosensory Analyzer, Israel), em um paciente submetido ao tratamento clareador, seguido pelo uso ou não uso de um dessensibilizante. Métodos: as análises foram realizadas antes do clareamento (AC), depois do clareamento (DC) e depois da aplicação ou não do dessensibilizante (DD) em cada hemiarcada estudada. Os dados foram submetidos ao teste t de Student, com nível de significância de 5%. Resultados: observou-se que o clareamento dentário alterou o limiar de sensação ao frio, provocando aumento da sensibilidade dentária, e que o uso do dessensibilizante foi efetivo. Conclusão: o uso de testes sensoriais quantitativos mostrou-se promissor para o estudo da sensibilidade dentária, podendo colaborar no estabelecimento de terapias seguras e confortáveis.

Avaliação histológica da ação da raioterapia na região odontogênica de incisivos de ratos

Inúmeras alterações dentárias podem ocorrer em crianças submetidas ao tratamento radioterápico. O objetivo neste trabalho foi avaliar histologicamente a ação da radiação X na região odontogênica do incisivo inferior de ratos com doses de 5 e 15 Gy. Foram utilizados 30 ratos machos (Rattus norvegicus, Albinus, Wistar), os quais foram divididos em três grupos: controle; radioterapia 5 Gy (irradiados com 5 Gy); e grupo 15 Gy (irradiados com 15 Gy). As doses foram administradas na região de cabeça e pescoço, em dose única, no segundo dia do experimento. As mandíbulas foram preparadas em lâminas histológicas. Na porção inicial da região odontogênica do grupo 5 Gy, os odontoblastos apresentaram-se alterados morfologicamente e menos organizados. Já no grupo 15 Gy foram observadas irregularidades na organização dos odontoblastos e ameloblastos, além de alteração na formação da alça epitelial e hemorragia. Na porção média da região odontogênica, o grupo 5 Gy apresentou alterações na face lingual, bem como leves alterações nos odontoblastos na região distal do dente; o órgão dentário do grupo 15 Gy apresentou visível redução do tamanho, hemorragia, odontoblastos não polarizados e produção de dentina para diferentes direções; observando-se ainda na porção distal, extensa destruição com visível redução no tamanho e vasta desorganização nos odontoblastos e ameloblastos. Conclui-se que a dose de 5 Gy causou leves e pequenas alterações morfológicas, e a dose de 15 Gy provocou intensas alterações histológicas e estruturais na região odontogênica do incisivo de rato.

Biofilmes orais como um possível fator de risco ao câncer bucal

Introduction: much studies regarding risk factors associated with oral cancer. Factors such as smoking and alcohol and solar radiation are well established, but others, such as bacterial influence in the development or progression of a tumor still remain unexplained. Interest in the possible relationship between bacteria and different stages of cancer development has increased since the classification of H. pylori by the WHO as a definite carcinogen. Subsequently, links between infection and the onset of cancer in various sites in the body were discovered. Review of literature: this literature review attempts to show the influence of poor oral hygiene, with consequent bacterial accumulation as a possible important risk factor for the initiation and development of mouth cancer, and correlate the possible mechanisms by which bacteria can initiate or promote carcinogenesis. Conclusion: there is much evidence that bacteria in the oral cavity and periodontopathic are present in tumor tissue, however, still can not affirm that these bacteria initiate or promote carcinogenesis.

Utilização de biomateriais poliméricos associados a implantes dentários: revisão de literatura

A remodelação óssea é um processo contínuo, que possibilita a substituição de osso envelhecido e danificado por tecido novo. A reparação ao redor de implantes osseointegráveis e enxertos ósseos em situações desfavoráveis depende do estabelecimento de um adequado contato entre tecido ósseo e implante por meio da estabilidade primária. Tendo em vista a importância da estabilidade primária do implante na biomecânica e conseqüente osseointegração, a associação de biomateriais reabsorvíveis ao sítio de instalação dos implantes se torna relevante. Destes biomateriais, destaca-se o copolímero de ácido polilático/ poliglicólico (PLA/PGA), que poderia contribuir com a estabilidade temporária dos implantes.