Prótese overdenture: sistema o'ring / Overdenture prosthesis: o'ring system

Overdenture é uma prótese total que se caracteriza por usar apoios retentivos para que aumente sua estabilidade e retenção na cavidade bucal, gerando assim menor desconforto ao paciente e melhor adaptação. A Prótese overdenture dentossuportada necessita de elementos dentais remanescentes com canais tratados endodonticamente e que possuam suporte periodontal adequado. O objetivo deste relato de caso clínico é expor a sequência de confecção de uma prótese overdenture dentossuportada maxilar associada a uma prótese total convencional mandibular, com os passos clínicos detalhados por meio de uma abordagem teórica e visual. Esse tipo de reabilitação favorece a adaptação do paciente à nova condição, visto que o uso de próteses totais convencionais pode causar certo desconforto ao paciente devido à falta de retenção e estabilidade. Essa manutenção dos dentes remanescentes favorece à manutenção óssea e a futura decisão do paciente em optar pela instalação de implantes dentários, podendo confeccionar próteses implantorretidas (overdentures) ou implantossuportadas (protocolo).O Paciente demonstrou-se satisfeito com o resultado estético e funcional após a instalação da prótese concretizando que o tratamento é viável(AU)

Overdenture is a denture that utilizing retentive supports for increase stability and retention in oral cavity. The tooth-supported overdenture require dental elements with root canal therapy and good periodontal support. The aim of this study is to report the confection of a maxillary tooth-supported overdenture associated with mandibular denture and your clinical steps. This rehabilitation promotes the patient's adaptation the new condition, since the use of conventional dentures may cause discomfort due to lack of retention and stability. The preservation of dental elements promotes bone maintenance and forthcoming decision of the patient in the installation of dental implants that can choose implantretained or implant-supported prosthesis. Patient was satisfied with aesthetic and functional result after installation of prosthesis(AU)

Avaliação do tipo de retenção e o uso de diferentes intermediários na adaptação de próteses unitárias sobre implantes / Evaluation of the type of retention and the use of different abutments in the adaptation of single prostheses on implants

Atualmente, devido a perda do elemento dentário e a procura por um tratamento estético e principalmente funcional, a reabilitação com próteses sobre implante tem sido amplamente empregada, com elevada previsibilidade a longo prazo. Com isso, muito tem sido relatado na literatura acerca das possíveis complicações dessa modalidade de tratamento, principalmente relacionado às possibilidades de falhas mecânicas das próteses implantossuportadas. Por isso, o objetivo do presente projeto foi avaliar a influência na adaptação marginal e interna, da utilização do intermediário protético e do tipo de retenção das próteses (parafusada e cimentada) em implantes cone morse submetidos à ciclagem mecânica. Foram confeccionados 40 corpos de prova, no qual cada um tinha a presença de um implante, com as dimensões de 4mm de diâmetro e 11,5mm de comprimento cone morse (n = 40). Dessa forma, foi avaliado a influência da utilização do intermediário e dos sistemas de retenção em cada conexão de maneira específica. Metade dos corpos de prova de cada sistema de conexão foram confeccionados em UCLA (n=20, sendo 10 parafusadas e 10 cimentadas), enquanto que a outra metade foi utilizado um intermediário pré-fabricado (Pilar Universal (n=20, sendo 10 parafusadas e 10 cimentadas). Os corpos de prova foram submetidos à ciclagem mecânica submersos em água destilada simulando um tempo clínico de cinco anos. Além disso, foram avaliados quanto ao torque e destorque (N) e adaptação marginal e interna (µm) antes e após a ciclagem mecânica. Os dados provenientes das mensurações foram organizados em tabela em formato Excel (Microsoft Office Excel, Redmond, WA, Estados Unidos) e submetidos ao software SigmaPlot (SigmaPlot, San Jose, CA, EUA) versão 12.0. Todos os dados foram analisados inicialmente com a utilização da estatística descritiva. Em seguida, os dados para intrusão (valores positivos), extrusão (valores negativos), destorque inicial, destorque final, e descimentação foram analisados em relação a distribuição de normalidade (teste Shapiro-Wilk e igualdade de variância) e, posteriormente, foi adotada a Análise de Variância (ANOVA) a um fator (Grupos diferentes materiais: G1 a G4), quando houve normalidade dos dados, o pós teste de Tukey foi adotado para as comparações múltiplas, quando não foi identificado uma distribuição normal, empregou-se o teste de Kruskall-Wallis e pós-teste de Dunn's ou Tukey, semelhantemente foi realizada a análise específica das variáveis pilares (UCLA e Pilar Universal) e sistemas de retenção (Parafusado e Cimentado). Para todos os testes aplicou-se nível de significância de 5% (α=0,05). A análise gráfica foi considerada através de um gráfico de barras para os dados que apresentaram normalidade com valores de média e desvio padrão, e as demais análises que não apresentaram normalidade foi considerado a confecção de um boxplot para cada grupo comparativo. As próteses sobre implante utilizando pilares em zircônia tem ganhado cada vez mais espaço, além do estudo in vitro, foi realizada uma revisão sistemática para comparar a perda óssea marginal e as complicações próteticas de reabilitações utilizando pilares de zircônia cimentado e parafusado. Em relação as próteses cimentadas e parafusadas, devido as evidências conflitantes e a presença de muitas revisões sistemáticas sobre o tema, foi realizada uma overview de revisões sistemáticas, com o objetivo de compilar as informações disponiveis e avaliar a qualidade metodologica desses estudos a respeito das complicações presentes nas próteses sobre implante cimentadas ou parafusadas(AU)

Currently, due to the loss of the dental element and the search for an aesthetic and mainly functional treatment, rehabilitation with implant prostheses has been widely used, with high long-term predictability. Thus, much has been reported in the literature about the possible complications of this treatment modality, mainly related to the possibility of mechanical failure of implant-supported prostheses. Therefore, the objective of the present project was to evaluate the influence on the marginal and internal adaptation, the use of the prosthetic intermediate and the type of retention of the prostheses (screwed and cemented) in morse taper implants submitted to mechanical cycling. 40 specimens were made, in which each one had an implant, with dimensions of 4 mm in diameter and 11.5 mm in length (n = 40). In this way, the influence of the use of intermediaries and retention systems in each connection was evaluated in a specific way. Half of the specimens of each connection system were made in UCLA (n=20, being 10 screwed and 10 cemented), while the other half was used a prefabricated intermediate (Universal Abutment (n=20, being 10 screwed) and 10 cemented). The specimens were submitted to mechanical cycling submerged in distilled water simulating a clinical time of five years. In addition, they were evaluated for torque and detorque (N) and marginal and internal adaptation (µm) before and after mechanical cycling. Data from measurements were organized in a table in Excel format (Microsoft Office Excel, Redmond, WA, USA) and submitted to SigmaPlot software (SigmaPlot, San Jose, CA, USA) version 12.0. All data were initially analyzed using descriptive statistics. Then, data for intrusion (positive values), extrusion (negative values), initial detorque, final detorque, and debonding were analyzed in relation to dist determination of normality (Shapiro-Wilk test and equality of variance) and, later, the one-way Analysis of Variance (ANOVA) was adopted (Different material groups: G1 to G4), when there was normality of the data, the Tukey post test was adopted for multiple comparisons, when a normal distribution was not identified, the Kruskall-Wallis test and Dunn's or Tukey post-test were used, similarly the specific analysis of the pillar variables (UCLA and Universal Pillar) and systems retainer (Screwed and Cemented). For all tests, a significance level of 5% (α=0.05) was applied. The graphical analysis was considered through a bar graph for the data that presented normality with mean and standard deviation values, and the other analyzes that did not present normality was considered the creation of a boxplot for each comparative group. Implant prostheses using zirconia abutments have gained more and more space, in addition to the in vitro study, a systematic review was performed to compare marginal bone loss and prosthetic complications of rehabilitations using cemented and screwed zirconia abutments. Regarding cemented and screw-retained prostheses, due to conflicting evidence and the presence of many systematic reviews on the subject, an overview of systematic reviews was performed, with the objective of compiling the available information and evaluating the methodological quality of these studies regarding complications present in cemented or screw-retained implant prostheses(AU)

Consensos referidos a conceptos rehabilitadores en la enseñanza de la odontología. Parte I: conceptos generales y diseño de la prótesis parcial removible / Consensus referring rehabilitative concepts in the teaching of dentistry. Part I: general concepts and design of removable partial prosthesis

En este artículo se desarrolla el consenso alcanzado entre profesores, referido a los conceptos generales, componentes y la secuencia del diseño de la prótesis parcial removible, durante la formación del odontó-logo en el ámbito de la Facultad de Odontología de la Universidad de Buenos Aires (AU)

This article develops the consensus between professors on the general concepts, components, and the sequence of the design of the partial removable prosthesis during the training of the dentist in the field of the Faculty of Dentistry of the University of Buenos Aires (AU)

A study comparing patient satisfaction and retention of CAD/CAM milled complete dentures and 3D printed CAD/CAM complete dentures versus conventional complete dentures: a randomized clinical trial / Um estudo comparando a satisfação do paciente e a retenção de próteses totais fresadas em CAD/CAM e próteses totais 3D impressas com tecnologia CAD/CAM versus próteses totais convencionais: um ensaio clínico randomizado

Objective: To compare the three different methods of complete denture fabrication assessing patient satisfaction and retention after insertion for six months' follow-up period. Material and Methods: The study was conducted in the Prosthodontic Department where a total of forty-eight patients were recruited from the outpatient clinics fulfilling the inclusion criteria. This study was designed as a randomized controlled clinical trial. All patients followed the steps of complete denture construction till jaw relation record. Then, all eligible patients were randomized to intervention and control groups. For intervention groups digital scanning, designing, manufacturing of complete dentures was done; 3D printing for first and milling for second intervention. For the comparator group, complete dentures were manufactured the conventional way. After 2 weeks of delivery of the dentures, patients received a patient satisfaction questionnaire, retention was measured by retention force gauge. Both readings were also recorded after 3 months and at 6 months. The mean and standard deviation values were calculated for each group in each test. The significance level was set at P≤ 0.05. Results: No statistical difference was found in terms of patient satisfaction and retention between the three groups at different time intervals. Conclusion: The manufacturing technique seemed to have no influence on patient satisfaction and retention with milled showing the least results.(AU)

Objetivo: Comparar três métodos diferentes de fabricação de prótese total avaliando a satisfação do paciente e a retenção após a inserção por um período de acompanhamento de seis meses. Material e Métodos: O estudo foi conduzido no departamento de Prótese onde um total de quarenta e oito pacientes foram recrutados das clínicas ambulatoriais atendendo os critérios de inclusão. Este estudo foi designado como um ensaio clínico randomizado controlado. Todos os pacientes seguiram as mesmas etapas de confecção de prótese total até o registro da relação maxilo-mandibular. Então, todos os pacientes qualificados foram divididos de forma aleatória nos grupos de intervenção e grupo controle. Para os grupos de intervenção foram realizados escaneamento digital, projeto e fabricação de próteses totais; Impressão 3D para o primeiro e fresagem para o segundo grupo de intervenção. Para o grupo de comparação, próteses totais foram feitas com o método convencional. Depois de 2 semanas após a entrega das próteses os pacientes receberam um questionário de satisfação e a retenção foi mensurada com um medidor de força de retenção. Ambas as leituras também foram registradas após 3 e 6 meses. Os valores de média e desvio padrão foram calculados para cada grupo em cada teste. O nível de significância foi estabelecido em P ≤ 0,05. Resultados: Nenhuma diferença estatística foi encontrada em termos de satisfação do paciente e retenção entre os três grupos em diferentes intervalos de tempo. Conclusão: A técnica de fabricação pareceu não ter influência na satisfação do paciente e retenção da prótese, com o grupo fresado apresentando o mínimo de resultados.(AU)

Confección de prótesis de carga inmediata mediante barras articuladas: componentes, modo de uso y longitud de la barra en función de la localización / Fabrication of immediately loaded prostheses using articulated bars: components, method of use and bar length depending on the location

En la implantología actual, la confección de prótesis de carga inmediata se ha convertido en un procedi-miento de rutina. Contar con elementos pre-formados con un correcto ajuste al implante o transepitelial so-bre el que se trabaja, minimiza el tiempo de trabajo sin renunciar a la eficiencia. En el presente trabajo se muestran elementos preformados articulados para la realización de prótesis de carga inmediata y su forma de uso, así como un análisis biomecánico de las estructuras para conocer su repercusión en las distintas fuerzas recibidas durante la masticación. Resultados: Al aplicar la carga en la zona central de la barra (paralela a los implantes), la tensión máxima recibida en la zona correspondiente al extremo de la barra sufre variaciones importantes, desde 128 Mpa en la longitud de 13 mm hasta un máximo de 391 Mpa (megapascales) en la longitud de 5 mm, siendo la ten-sión máxima, media para todas las medidas, de 242 Mpa (+/-96,76). En el ensayo de las diferentes medi-das de la barra se observa también una tensión cre-ciente para longitudes de barra a partir de 7 mm, al aplicar la tensión en la zona media de la estructura, por lo que longitudes entre 5 y 7 mm pueden consi-derarse prácticamente con la misma distribución de tensiones hacia los extremos y en la zona de unión. En conclusión, las barras articuladas son un elemento de confección de prótesis provisionales de carga in-mediata de gran utilidad, que pueden confeccionarse de forma rápida y generan un comportamiento bio-mecánico predecible (AU)

In current implantology, the fabrication of immediately loaded prostheses has become a routine procedure. Being able to have pre-formed elements with a correct fit to the implant or transepithelial on which we are working minimizes working time without sacrificing efficiency. Material and methods: We show articulated preformed elements for immediate loading prostheses and how they are used, as well as a biomechanical analysis of the structures to determine their repercussion on the different forces received during mastication. Results: When the load is applied in the central area of the bar (parallel to the implants) the maximum stress received in the area corresponding to the end of the bar undergoes significant variations, from 128 Mpa in the 13 mm length to a maximum of 391 Mpa in the 5 mm length, the average maximum stress for all the measurements being 242 Mpa (+/-96.76). In the test of the different bar sizes we can also observe an increasing stress for bar lengths from 7 mm onwards when applying the stress in the middle zone of the structure, so that lengths between 5 and 7 mm can be considered to have practically the same stress distribution towards the ends and in the joint zone. Conclusions: Hinged bars are a very useful fabrication element for immediately loaded provisional prostheses, which can be fabricated quickly and generate a predictable biomechanical behavior (AU)

Estabilidad primaria en implantes inmediatos versus implantes colocados en hueso maduro: un estudio clínico retrospectivo / Primary stability in immediate implants versus implants placed in mature bone: a retrospective clinical study

La estabilidad primaria es un requisito importante para la supervivencia y éxito de los implantes durante la osteointegración. En los últimos años, los implantes inmediatos postextracción han demostrado ser una opción de tratamiento exitosa y predecible para la reposición de dientes con mal pronóstico, pero surge la duda de si dichos implantes alcanzan valores de estabilidad primaria comparables a aquellos colocados en hueso maduro. Comparar la estabilidad primaria de implantes inmediatos colocados en alveolos postextracción con la de implantes colocados en hueso maduro. Se llevó a cabo un estudio clínico retrospectivo, con los datos recogidos sobre 175 implantes, colocados en 175 pacientes. Todos los implantes colocados pertenecían al modelo Essential Cone (Klockner Implant System) y se dividieron en dos grupos: implantes inmediatos (Grupo A, n=31) e implantes colocados en hueso maduro (Grupo B, n=144). La estabilidad primaria de todos los implantes se midió mediante torque de inserción y análisis de frecuencia de resonancia con Osstell ISQ. No se encontraron diferencias estadísticamente significativas respecto a la estabilidad medida a través del torque de inserción (26,29+10,07 Vs 25,76+9,72 N/cm) pero sí que se encontraron diferencias significativas en la medida de la estabilidad primaria mediante AFR, siendo inferiores los valores correspondientes a los implantes colocados en los alveolos post exodoncia (60,74 ± 6,17 en sentido VL y 62,19 ± 7.64 en sentido MD frente a 68,34 ± 6.26 en sentido VL y 69,29 ± 7.98 en sentido MD obtenidos en los implantes colocados en hueso maduro). El torque de inserción de los implantes inmediatos es similar al de los implantes colocados en hueso maduro, pero sus valores ISQ son significativamente inferiores, lo que demuestra un mayor grado de micromovimiento, y por consiguiente, un mayor riesgo de fracaso durante el período de osteointegración.

Primary stability is an important requirement for the survival and success of implants during osseointegration. In recent years, immediate post-extraction implants have proven to be a successful and predictable treatment option for the replacement of teeth with a poor prognosis, but the question arises as to whether these implants reach primary stability values comparable to those placed in mature bone. The objective of the study was to compare the primary stability of immediate implants placed in post-extraction alveoli with that of implants placed in mature bone. A retrospective clinical study was carried out, with data collected on 175 implants, placed in 175 patients. All implants placed belonged to the Essential Cone model (Klockner Implant System) and were divided into two groups: immediate implants (Group A, n = 31) and implants placed in mature bone (Group B, n = 144). The primary stability of all implants was measured by insertion torque and resonance frequency analysis with Osstell ISQ. No statistically significant differences were found regarding the stability measured through the insertion torque (26.29 + 10.07 Vs 25.76 + 9.72 N / cm) but significant differences were found in the measurement of primary stability by means of AFR, the values corresponding to implants placed in the post-exodontic alveoli being lower (60.74 ± 6.17 in the VL direction and 62.19 ± 7.64 in the MD direction versus 68.34 ± 6.26 in the VL direction and 69.29 ± 7.98 in the MD direction obtained in implants placed in mature bone). The insertion torque of immediate implants is similar to that of implants placed in mature bone, but their ISQ values are significantly lower, which demonstrates a higher degree of micromotion, and therefore, a greater risk of failure during the period of osseointegration.

Prótesis sobre implantes: ¿atornillada o cementada? / Implant supported prosthesis: screw retained or bonded?

El objetivo de este artículo es revisar la evidencia científica existente acerca de los tipos de retención protética fija sobre implantes: atornillada, cementada y cemento-atornillada. Fueron evaluadas sus ventajas y desventajas a fin de facilitar al clínico la elección del sistema de retención en el tratamiento rehabilitador con implantes. Si bien la evidencia científica no es concluyente, la prótesis atornillada presentaría más complicaciones técnicas, y las cementadas, más complicaciones biológicas. Por ello, las prótesis cemento-atornilladas podrían ser en la actualidad una opción de elección, por su versatilidad en la rehabilitación implanto-soportada, combinando las ventajas de cada tipo de retención (AU)

The objective of this article is to review the existing scientific evidence about the different types of retention of fixed prosthetic on implants: screwed, cemented and cement-screwed. The advantages and disadvantages of them were evaluated in order to facilitate the clinician's choice of the retention system in the rehabilitation treatment with implants. Although the scientific evidence is inconclusive, the screwed prosthesis would present more technical complications, while the cemented, more biological complications. Therefore, cement-screwed prostheses could be an option of choice, due to their versatility when rehabilitating an implant, combining the advantages of each type of retention (AU)

Grinding of composite cores using diamond burs with different grit sizes: the effects on the retentive strength of zirconia crowns

Aim: To evaluate the retention of Y-TZP crowns cemented in aged composite cores ground with burs of different grit sizes. Methods: Sixty composite resin simplified full-crown preparations were scanned, while 60 Y-TZP crowns with occlusal retentions were milled. The composite preparations were stored for 120 days (wet environment-37°C) and randomly distributed into three groups (n=20) according to the type of composite core surface treatment. The groups were defined as: CTRL (control: No treatment), EFB (extra-fine diamond bur [25µm]), and CB (coarse diamond bur [107µm]). The grinding was performed with an adapted surveyor standardizing the speed and pressure of the grinding. The intaglio surfaces on the crowns were air-abraded with silica-coated alumina particles (30 µm) and then a silane was applied. The crowns were cemented with self-adhesive resin cement, thermocycled (12,000 cycles; 5/55°C), stored (120 days) and submitted to a retention test (0.5mm/min). The retentive strength data (MPa) were analyzed using one-way analysis of variance and Tukey test, as well as Weibull analysis. Failures were classified as 50C (above 50% of cement in the crown), 50S (above 50% of cement in the substrate) and COE (composite core cohesive failure). Results: No statistical difference was observed among the retention values (p=0.975). However, a higher Weibull modulus was observed in the CTRL group. The predominant type of failure was 50S (above 50% of cement in the substrate composite). Conclusion: The retention of zirconia crowns was not affected by grinding using diamond burs with different grit sizes (coarse/extra-fine) or when no grinding was performed

A multi-center retrospective assessment of monolithic zirconia restorations on posterior teeth and implants / Una evaluación retrospectiva multicéntrica de restauraciones monolíticas de circonio en dientes posteriores e implantes

Objective: the purpose of this multicenter retrospective study was to report on survival, success, and complication rates in monolithic zirconia restorations on teeth and implants. Materials and Methods: data on 671 monolithic zirconia restorations was collected by five prosthodontists from three different specialty practice centers, including a dental school and two private practice centers. Restorations included single crowns and multiple-unit fixed dental prostheses on teeth and implants in the posterior area (premolar and molars). Follow-up time was up to 62 months. Results: mean follow-up time was 28.1±12.9 months. A total of 671 units, 534 single crowns, and 137 multi-unit restorations. Cumulative survival and success rates at 5 years were 97.4%, and 93.8% respectively. Complications presented in 11 restorations out of 671 and included: decementation, abutment screw loosening, restoration crack, restoration fracture, and tooth fracture. No significant differences were observed between tooth-supported and implant-supported restoration (p=0.42), single crowns and multiple-unit restorations (p=0.07), bruxers and non-bruxers (p=0.57). Patients with group function occlusal scheme had significantly less survival rates (p=0.001). Conclusion: the use of monolithic zirconia for restorations on the posterior teeth and implants seems to be promising as it provides a durable solution with a low rate of complications.

Objetivo: el propósito de este estudio retrospectivo multicéntrico fue informar sobre las tasas de supervivencia, éxito y complicaciones en restauraciones monolíticas de circonio en dientes e implantes. Materiales y Métodos: cinco prostodoncistas recolectaron datos de 671 restauraciones monolíticas de zirconia de tres centros de práctica especializados: una escuela de odontología y dos centros de práctica privados. Las restauraciones incluyeron coronas individuales y prótesis dentales fijas de unidades múltiples en dientes e implantes en el área posterior (premolares y molares). El tiempo de seguimiento fue de hasta 62 meses. Resultados: el tiempo medio de seguimiento fue de 28,1±12,9 meses. Un total de 671 unidades, 534 coronas individuales y 137 restauraciones de unidades múltiples. La supervivencia acumulada y las tasas de éxito a los 5 años fueron del 97,4% y del 93,8%, respectivamente. Las complicaciones se presentaron en 11 restauraciones de 671 e incluyeron: fracaso del cementado, aflojamiento del tornillo del pilar, grieta en la restauración, fractura de restauración y fractura de dientes. No se observaron diferencias significativas entre la restauración con soporte dental y con implante (p=0,42), coronas individuales y restauraciones de unidades múltiples (p=0,07), pacientes con bruxismo y sin bruxismo (p=0,57). Los pacientes con esquema oclusal de función grupal tuvieron tasas de supervivencia significativamente menores (p= 0,0 01). Conclusión: el uso de zirconia monolítica para restauraciones en los dientes posteriores y en implantes parece ser prometedor, ya que proporciona una solución duradera con una baja tasa de complicaciones.

Influence of a retentive shoulder design to prevent early failure of three core build-ups

Abstract This study evaluated the influence of a retentive shoulder design to prevent early failure of three resin composite build-ups on molars. Ninety-six intact extracted human maxillary third molars were assigned to two groups (n=48) based on occlusal, buccal cusps only and all cusps reduction. The groups were divided into two subgroups: pin retained and non-pin retained build-ups resulting in four groups (n=24), according the cusps reduction: pin retained/partial, pin retained/complete, non-pin retained/partial, non-pin retained/complete. Occlusal reduction was 3 mm with a semi-lunar retentive shoulder of 3 mm and an axial wall height of 1.5 mm. Groups were restored using a microhybrid, flowable or titanium reinforced resin composite. Modified self-curing acrylic resin provisional crowns were fabricated, cemented with non-eugenol temporary cement and thermal cycled. An instron machine applied tension to the provisional crowns parallel to the long axis of the tooth until dislodgement. A three-way analysis of variance was conducted on the influence of the variables on the retention of the core build-up. Ninety-three build-ups were retained under tensile load, while three core build-ups without pins were dislodged. Three-way analysis of variance showed no statistically significant difference between core build-ups using a retentive shoulder and pin retained core build-ups when tested under tensile load. With the advent of adhesive systems, increased surface area and retentive shoulder design can provide a retentive core foundation to prevent early failures of core build-ups during indirect restoration fabrication which will contribute to the longevity of final restorations.

Resumo Este estudo avaliou a influência de um preparo retentivo em forma de ombro para prevenir a falha precoce de núcleos de preenchimento realizados em molares com 3 diferentes tipos de resina composta. Noventa e seis terceiros molares superiores hígidos extraídos de humanos, foram divididos em dois grupos (n=48) de acordo com o tipo de redução oclusal: em todas as cúspides (total) ou nas cúspides vestibulares (parcial). Os grupos foram divididos em dois subgrupos: núcleos retidos a pinos e não retidos a pinos, resultando em quatro grupos (n=24): redução oclusal total/retido a pino, redução oclusal parcial/retido a pino, redução oclusal total/não retido a pino, redução oclusal parcial/não retido a pino. A redução oclusal foi de 3 mm com um ombro retentivo semilunar de 3 mm e uma altura de parede axial de 1,5 mm. Os grupos foram restaurados utilizando resina composta microhíbrida, fluível ou reforçada com titânio. Foram confeccionadas coroas provisórias de resina acrílica autopolimerizável modificada, cimentadas com cimento provisório sem eugenol e termocicladas. Uma máquina universal de ensaios foi utilizada para tracionar as coroas provisórias paralelamente ao longo eixo do dente até o seu deslocamento. Análise de variância de 3 fatores foi aplicada para avaliar o efeito dos fatores na retenção do núcleo. Noventa e três núcleos de preenchimento permaneceram retidos sob a carga de tração, enquanto três núcleos de preenchimento sem pinos foram deslocados. A análise de variância não mostrou diferença significante entre os núcleos de preenchimento com desenho retentivo e os núcleos de preenchimento retidos a pinos. Com o advento dos sistemas adesivos, o aumento da área de superfície e o desenho retentivo dos ombros podem fornecer um preparo retentivo para evitar falhas precoces nos núcleos de preenchimento durante a fabricação de restaurações indiretas, o que contribuirá para a longevidade das restaurações finais.

Prosthetics on implants: cement or screw-retained? a review of the literature

Introduction: The discovery of titanium osseointegrated implants enabled the development of screw or cement-retained dental prostheses. However, each retention method involves different aspects. Objective: this study aims at reviewing the literature of in vitro and in vivo studies of the last 7 years on the mechanical, biological, aesthetic and occlusal properties and the cost of screw and cement- retained prostheses to identify what can promote greater longevity and economy by considering the patient's clinical framework. Data sources: Our method was based on the collection of scientific articles published in English from 2012 to 2018 in the PubMed database. Summary of the findings: we noted that in some clinical cases, a retention method was more appropriate than the other, as seen in the access to the posterior region or the palatal face of the crowns, the position/ angulation of implants in the anterior region, the patient's health and economic conditions. Both protheses can suffer or not from mechanical and biological complications. Reversibility can also be associated to cement-retained protheses. There are alternatives to screwed prosthetics to achieve satisfactory aesthetics in the anterior region despite being more expensive. Ideal occlusion tends to be more easily achieved by cemented prosthesis as it avoids prosthetics screws and the formation of crown holes, despite the contributions of correct planning followed by the analysis of static and in motion occlusions. Conclusion: eachretention method has its advantages and disadvantages. Therefore,the best method is the one that best fits the characteristics and needs of each patient.

Introdução: A descoberta de implantes osteointegrados de titânio possibilitou o desenvolvimento de próteses dentárias parafusadas ou cimentadas. No entanto, cada método de retenção envolve diferentes aspectos. Objetivo: este estudo tem como objetivo revisar a literatura de estudos in vitro e in vivo dos últimos 7 anos sobre as propriedades mecânicas, biológicas, estéticas e oclusais e o custo de próteses parafusadas e cimentadas para identificar o que pode promover maior longevidade e economia, considerando o quadro clínico do paciente. Fontes de dados: Nosso método foi baseado na coleção de artigos científicos publicados em inglês de 2012 a 2018 no banco de dados PubMed. Síntese dos achados: notamos que em alguns casos clínicos, um método de retenção foi mais adequado que o outro, como visto no acesso à região posterior ou na face palatina das coroas, a posição / angulação dos implantes na região anterior , saúde do paciente e condições econômicas. Ambas as próteses podem sofrer ou não de complicações mecânicas e biológicas. A reversibilidade também pode ser associada a próteses cimentadas. Existem alternativas às próteses parafusadas para alcançar uma estética satisfatória na região anterior, apesar de serem mais caras. A oclusão ideal tende a ser mais facilmente alcançada por próteses cimentadas, pois evita parafusos protéticos e a formação de orifícios coronários, apesar das contribuições do planejamento correto, seguido pela análise de oclusões estáticas e em movimento. Conclusão: cada método de retenção tem suas vantagens e desvantagens. Portanto, o melhor método é aquele que melhor se adapta às características e necessidades de cada paciente.

Prótesis completa implanto-asistida II / Implant-supported complete denture II

En este artículo espero poder hacer llegar al lector a la comprensión de la evolución protética implanto-asistida, desde el mejoramiento de la retención otorgada a la prótesis completa inferior (PCI) con solo 2 implantes, hasta la rehabilitación totalmente implanto-asistida en paciente edéntulos. Para lograr este objetivo tan ambicioso tendremos que valernos de varios artículos en diferentes números de revista del AAO. En este artículo continuaremos describiendo las resoluciones protéticas para los siguientes casos: A- Sobredentaduras retenidas sobre dos implantes con Ball Attach. B- Sobredentaduras retenidas por Barras utilizando dos implantes. C- Soluciones protéticas para casos con implantes en mal posición. D- Casos en que se agrega un implante por haber dos implantes en mal posición (AU)

The goal of this article is to show the evolution of implant retained prosthesis driven by enhancements on retention of complete lower jaw prosthesis in edentulous patients. This could be reached by a different array of options, ranging from a simple one such as two implants retaining the lower jaw complete prosthesis, to a complex one completely supported and retained by implants prosthesis. Therefore, to reach such an ambitious goal, it will be necessary to devote several AAO series of journal´s articles to describe all these possibilities. In this paper we will continue describing the four following prosthetic cases: A- Ball Attachment retained Over Denture using two implants. B- Bar retained Over Dentures using two implants. C- Prosthetic solution for cases of misplaced implants. D - Adding a third implant for cases of two misplaced implants (AU)

Can intra-radicular cleaning protocols increase the retention of fiberglass posts? A systematic review

Abstract The presence of residues within the root canal after post-space preparation can influence the bond strength between resin cement and root dentin when using fiberglass posts (FGPs). Currently, there is no consensus in the literature regarding what is the best solution for the removal of debris after post-space preparation. This systematic review involved "in vitro" studies to investigate if cleaning methods of the root canal after post-space preparation can increase the retention of FGPs evaluated by the push-out test. Searches were carried out in PubMed (MEDLINE) and Scopus databases up to July2017. English language studies published from 2007 to July 2017 were selected. 475 studies were found, and 9 were included in this review. Information from the 9 studies were collected regarding the number of samples, storage method after extraction, root canal preparation, method of post-space preparation, endodontic sealer, resin cement, cleaning methods after post-space and presence of irrigant activation. Five studies presented the best results for the association of sodium hypochlorite (NaOCl) and ethylenediamine tetra-acetic acid (EDTA), while in the other 4 studies, the solutions that showed improved retention of FGPs were photon-induced photoacoustic streaming (PIPS), Qmix, Sikko and EDTA. The results showed heterogeneity in all comparisons due to a high variety of information about cleaning methods, different concentrations, application time, type of adhesive system and resin cements used. In conclusion, this review suggests that the use of NaOCl/EDTA results in the retention of FGPs and may thus be recommended as a post-space cleaning method influencing the luting procedure.

Effects of strontium ranelate on alveolar ridge morphology augmentation / Efectos del ranelato de estroncio en el aumento del rebforde alveolar

SUMMARY: The objective of this study was to compare the Primary and Secondary stability of immediate implant placement with Alveolar Ridge Augmentation (ARA) and Strontium Ranelate (SR) as aids to enhance the stability using Resonance Frequency Analysis (RFA). Fifty eight subjects ideal for immediate implants were assigned to two groups to compare the primary and secondary stability of the implant using Alveolar Ridge Augmentation and oral strontium ranelate. They were tested for primary stability on placement of the implant and after eight weeks of placement for secondary stability. The stability was measured using resonance frequency analysis. Both the procedures showed an improvement in the stability but the Alveolar Ridge Augmentation procedure showed a significantly better primary stability (P< .03) and the secondary stability (P<.00). The means of the implant stability quotient value (ISQ) for the Alveolar ridge augmentation procedure was 74.2 for primary stability, and 83.34 for secondary stability. With the enhancement of stability with both the procedures Alveolar Ridge Augmentation proved to be a better procedure to achieve successful results of an immediately placed implant.

RESUMEN: El objetivo de este estudio fue comparar la estabilidad primaria y secundaria de la colocación inmediata del implante con el aumento de reborde alveolar (ARA) y el ranelato de estroncio (SR) como ayudas para mejorar la estabilidad mediante el análisis de frecuencia de resonancia (RFA). Cincuenta y ocho sujetos, ideales para implantes inmediatos, fueron asignados a dos grupos para comparar las estabilidades primaria y secundaria del implante usando el aumento del reborde alveolar y el ranelato de estroncio oral. Se efectuaron pruebas de estabilidad primaria en la colocación del implante, y después de ocho semanas para la estabilidad secundaria. La estabilidad se midió utilizando análisis de frecuencia de resonancia. Ambos procedimientos mostraron una mejora en la estabilidad, sin embargo el procedimiento del aumento del reborde alveolar mostró una estabilidad primaria significativamente mejor (P <0,03) que la estabilidad secundaria (P <0,00). Las medias del valor de cociente de estabilidad del implante (ISQ) para el procedimiento de aumento de reborde alveolar fueron 74,2 para la estabilidad primaria y 83,34 para la estabilidad secundaria. Se observó una mejora de la estabilidad en ambos procedimientos, el aumento del reborde alveolar demostró ser un mejor procedimiento para lograr resultados exitosos del posicionamiento de implante inmediato.

Study of the relationships between bur diameter and dental implant diameter / Estudio de las relaciones entre diámetro de fresas y diámetro de implantes dentales

The bur used to construct the bed where a dental implant is installed is extremely important to treatment success. The aim of this investigation was to analyze the relationship between bur diameter and implant diameter in different areas. A descriptive study was designed to analyze 5 commercial brands currently on the market. The manufacturer's instructions were followed to establish the size and type of bur indicated for the study implants, which were regular, with a width between 3.5 mm and 4.0 mm and a length from 12 mm to 13 mm. Drilling from the most apical region, the first measurement of width was established 3 mm cervically, the lower middle measurement 6 mm cervically, the upper middle measurement at 9 mm and the cervical measurement at 12 mm. A scanning electron microscope was used standardized for all measurements; the data were analyzed using the Shapiro-Wilk test and the t-test, having considering a value of p<0.05 for significant differences. At apical level, all the implants were wider than the bur. The greatest differences between bur width and implant were observed at cervical level, maintaining a relation where the implant was always wider. In medium-sized areas, it was observed that in some systems the burs have a larger diameter than the study implants. A significant relation was established in the apical, upper middle and cervical areas. Bur morphology is related to implant morphology; no implant system is the same as another in terms of the implant-bur relation.

La relación entre la fresa utilizada para construir el lecho donde se instala el implante dental tiene alta importancia en el éxito del tratamiento. El objetivo de esta investigación fue analizar la relación entre el diámetro de fresa y el diámetro de implantes en diferentes áreas. Se diseñó un estudio descriptivo analizando utilizando 5 marcas comerciales vigentes en el mercado; se siguió las instrucciones del fabricante para establecer el tamaño y tipo de fresa indicada para el implante en análisis, los cuales fueron de tipo regular considerando medidas en ancho de entre 3,5 mm y 4,0 mm y en largo de 12 mm a 13 mm. Desde la región mas apical de implantes y fresar se estableció 3 mm hacia cervical la primera medición de ancho, 6 mm hacia cervical la medición media inferior, a 9 mm la medición media superior y a 12 mm la medición cervical; para esta medición se utilizó microscopio electrónico de barrido estandarizado para todas las mediciones; los datos fueron analizados con pruebas estadísticas de Shapiro-Wilk y la prueba t-test, considerando un valor de p<0,05 para considerar diferencias significativas. A nivel apical, todos los implantes fueron mas anchos que las fresas utilizadas. A nivel cervical es donde se observan las mayores diferencias entre el ancho de la fresa y del implante manteniendo una relación donde el implante siempre es mas ancho. En áreas medianas, se observó que en algunos sistemas las fresas son de mayor diametro a los implantes analizados. Se estableció relación significativa en las regiones apical, media superior y cervical. La morfología de fresas presenta relación con la morfología implantaría; ningún sistema de implantes es igual a otro en términos de relación implante y fresa.

3-year survival rates of retained composite resin and ART sealants using two assessment criteria

Abstract The aim was to test the null-hypothesis that there is no difference in the cumulative survival rate of retained composite resin (CR) sealants and a high-viscosity glass-ionomer Atraumatic Restorative Treatment (ART) sealant in first permanent molars calculated according to the traditional and the modified retention assessment criteria over a period of 3 years. This cluster-randomized controlled clinical trial consisted of 123 schoolchildren, 6–7-years-old. At baseline, high-caries risk pits and fissures of fully erupted first permanent molars were treated with CR and ART sealants. Evaluations were performed after 0.5, 1, 2 and 3 years. Retention was scored for free-smooth surface and for each of three sections into which the occlusal surface had been divided. The modified criterion differed from the traditional in that it determined an occlusal sealant to be a failure when at least one section contained no visible sealant material. Data were analysed according to the PHREG model with frailty correction, Wald-test, ANOVA and t-test, using the Jackknife procedure. The cumulative survival rates for retained CR and ART sealants in free-smooth and occlusal surfaces for both criteria were not statistically significantly different over the 3 years. A higher percentage of retained CR sealants on occlusal surfaces was observed at longer evaluations. Cumulative survival rates were statistically significantly lower for the modified criterion in comparison to the traditional. The modified retention assessment criterion should be used in future sealant-retention studies.

Estabilidade em implantes dentários: análise da frequência de ressonância e torque de inserção / Stability in dental implants: analysis of resonance frequency and insertion torque

As pesquisas clínicas na área da implantodontia apresentam uma grande dificuldade em relação à avaliação da osseointegração e estabilidade dos implantes. Dessa forma, a análise de frequência de ressonância (AFR) têm se tornado uma das principais ferramentas utilizadas, já que oferece, de forma simples e não invasiva, a possibilidade de se monitorar a estabilidade durante todo o período desejado. Outra medida também bastante usada na prática clínica é o torque de inserção dos implantes. No entanto, essa medida é limitada ao trans-cirúrgico e nos fornece unicamente a estabilidade primária dos implantes, o que a torna mais indicada para avaliação da possibilidade de se submeter à carga imediata. Este estudo apresenta como objetivos avaliar, por meio de um estudo transversal, se os valores do coeficiente de estabilidade do implante (ISQ) são similares em diferentes alturas do componente protético e diretamente na plataforma, quando mensurados por meio da AFR e avaliar por meio de uma revisão sistemática e meta-análise a relação entre o torque de inserção e a AFR, investigando se estes dois instrumentos fornecem avaliações similares da estabilidade primária de em um mesmo implante. Para tal, foi realizado um estudo transversal em 31 implantes osseointegrados com plataforma de hexágono externo, com 4.1 mm de diâmetro e comprimento maior ou igual a 10mm e uma revisão sistemática com ensaios clínicos que reportassem valores de ISQ e torque de inserção. Assim, nossos estudos recomendam que explorar e desenvolver a AFR como método de avaliação da estabilidade implantar deve ser uma busca ainda necessária das pesquisas científicas para melhor compreensão do comportamento dos implantes dentários, nos seus diversos momentos e situações na cavidade oral, bem como determinar um bom nível de estabilidade que consequentemente determinaria uma maior longevidade e funcionalidade dos implantes dentários

Clinical research in the implantology presents a great difficulty regarding the evaluation of the osseointegration and stability of the implants. Thus, resonance frequency analysis (RFA) has become one of the main tools used, since it offers, in a simple and non-invasive way, the possibility of monitoring the stabiblity during the desired period. Another measure also widely used in clinical practice is the insertion torque of the implants. However, this measureis limited to the transsurgical and provides only the primary stability of the implants, which makes it more suitable for evaluation the possibility of undergoing immediate loading. This study aims to evaluate, through a cross-sectional study, whether implant stability coefficient (ISQ) values are similar at different heights...

Evaluación y comparación de la estabilidad de implantes dentales en el maxilar y la mandíbula en tres tiempos distintos, mediante análisis de frecuencia de resonancia / Comparison of dental implants stability in maxilla and mandible at three different times using resonance frequency analysis

El propósito de este estudio fue medir y comparar la estabilidad de implantes dentales en maxilar y mandíbula en tres tiempos distintos, mediante análisis de resonancia de frecuencia (RFA). Mediante un diseño no experimental prospectivo, fueron evaluados 103 Implantes 3i Osseotite en 57 pacientes (50 en el maxilar y 53 en mandíbula). Mediante un dispositivo electrónico (Osstell-Mentor®) se registró el coeficiente de estabilidad para cada implante (ISQ) al momento de la cirugía de implantes, a las 6 semanas y a las 8 semanas siguientes. Respecto al maxilar, las medianas aumentan progresivamente después de la cirugía de implantes. En la mandíbula, parecen ser similares entre la primera y la tercera medición, pero decrecen en la segunda. Independiente tanto para el maxilar como para la mandíbula, los valores de las medianas fueron altamente significativas, lo cual indica que estas difieren en los tres tiempos estudiados (p<0,001). Se encontró diferencia significativa entre las medianas del maxilar y la mandíbula solamente al momento de la colocación de implantes. En los demás tiempos evaluados, no se observaron diferencias significativas (p>0,05). En el maxilar, la estabilidad de los implantes aumenta con el tiempo. En la mandíbula, disminuye en la sexta semana y aumenta en las 8 siguientes, alcanzando valores similares a los iniciales. La estabilidad de los implantes es mayor en la mandíbula que en el maxilar, solo al momento de la cirugía. A las 8 semanas, la estabilidad alcanzada por los implantes en el maxilar y la mandíbula son similares.

The aim of this study was to test and compare dental implant stability placed in the maxilla and the mandible during three time periods, by resonance frequency analysis (RFA). Using a non experimental prospective study we evaluated 103 3i Biomet Osseotite Implants in 90 patients (50 in maxilla and 53 in mandible). An electronic RFA device (Osstell Mentor®) was used to record the Implant Stability Quotient (ISQ values) at implant surgery, at six weeks and at eight weeks. Concerning the maxilla, median values increase continuously after implant placement. In the mandible, median values seem to be similar in mandibular at the first and the third evaluation time, but decrease in the second one. Separately for both maxilla and mandible, the median values were highly significant, indicating that these differ in the three time periods studied (p<0.001). Significant difference between the median of the maxilla and mandible was found only at the time of implant placement. At 6 and 8 weeks, no significant differences were observed (p>0.05). In the maxilla, the initial stability of implants is increased in time. In the mandible, initial stability decreases at 6 weeks but increases again at 8 weeks, reaching values similar to the initial. The implant stability was higher in mandible than maxilla only at implant placement. At 8 weeks the stability achieved by the implants in the maxilla and mandible was similar.

Onde se encontra o travamento posterior da maxila de uma prótese total superior? / Where is the postpalatal seal in a complete upper denture?

Na confecção de uma prótese total superior, a delimitação correta do travamento posterior é uma responsabilidade do clínico. Para evidenciá-lo, esse deve basear-se em referências anatômicas e fatores fisiológicos individuais de cada paciente.

During the fabrication of a complete denture the practitioner is responsible for a proper postpalatal seal. Thus it must be based on anatomic structures and physiologic aspects of each patient.

Retenção e estabilidade em prótese total convencional ­ revisão de literatura 0 / Retention and stability in total convencional prosthesis ­ literature review

O sucesso das próteses totais depende, fundamentalmente, do aproveitamento total da área basal, da perfeita adaptação das bases a esta área, e da justeza da borda ao fórnix, desta forma, o resultado será uma adequada retenção. Entretanto, a retenção obtida será comprometida se os "princípios fundamentais da estabilidade", que são os grandes responsáveis pela sua manutenção, não forem obedecidos. O presente estudo tem como objetivo fazer uma revisão da literatura sobre a retenção e estabilidade de próteses totais convencionais.

The success of the retention of total prosthesis depends fundamentally on the full use of basal area, on the perfect adaptation of the bases to this area, and on the fairness of the edge to a fornix. however the obtained retention can be compromised when fundamental principles of stability ­ responsible for its maintenance ­ are not followed. The aim of the present study is to conduct a literature review on the retention and stability of total conventional prosthesis.