Análise comparativa na influência da técnica de moldagem funcional em arcos parcialmente edêntulos sobre os pontos de contato oclusais, a integridade da fibromucosa e a extensão da base da prótese

There is a lack of clinical studies evaluating techniques of functional impression for partially edentulous arches. The aim of this double-blind non-randomized controlled clinical trial was to compare the efficacy of altered cast impression (ACI) and direct functional impression (DFI) techniques. The efficacy was evaluated regarding the number of occlusal units on denture teeth, mucosa integrity at 24-hour follow-up and denture base extension. The sample included 51 patients (female and male) with mean age of 58.96 years treated at Dental Department of UFRN. The patients, exhibiting edentulous maxilla and mandibular Kennedy class I, were divided into two groups (group ACI, n=29; group DFI, n=22). Clinical evaluation was based on the number of occlusal units on natural and/or artificial teeth, mucosa integrity at 24-hour follow-up, and denture base extension. Statistical analysis was conducted using the software SPSS 17.0® (SPSS Inc., Chicago, Illinois). Student T-test was used to reveal association between number of occlusal units and impression technique while chi-square test showed association between mucosa integrity and impression technique. Fischer s exact test was applied for association between denture base extension and impression technique at 95% level of significance. No significant difference was observed between the groups regarding number of occlusal units, mucosa integrity and denture base extension. The altered cast technique did not provide significant improvement in comparison to the direct technique when the number of occlusal units, mucosa integrity and denture base extension

Avaliação da precisão das técnicas de moldagem para próteses implantossuportadas sobre implantes alinhados e implantes não-alinhados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Precisão das técnicas de moldagem e vazamento para próteses implantossuportadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise comparativa de técnicas de moldagem para próteses implantossuportadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação tridensional da precisão das técnicas de moldagem para próteses implantossuportadas sobre pilares alinhados e não-alinhados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Precisão das técnicas de moldagem para próteses implantossuportadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência de técnicas de moldagem e de dois vazamentos na precisão dimensional de modelos de gesso e adaptação marginal de infraestruturas CAD/CAM em Y-TZP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da alteração dimensional de modelos obtidos a partir de moldagens com alginato tradicional e outro com desinfetante

The present study aims at evaluating dimensional alteration of stone casts made from impressions with a standard irreversible hydrocolloid and an antimicrobial one. For this, an alginate without disinfectant (Type II Jeltrate) and other containing chlorhexidine (Type II Avagel) were used, which rose by the same regime of treatment: without disinfection; immersion; and spraying. A 1% sodium hypochlorite solution was used for 10 minutes. To obtain the impressions, a perforated impression tray was made from a standard metal model. After molding, the molds were washed in running water for 30 seconds to simulate removal of saliva. Then, with the exception of the control group, these molds were subjected to disinfection treatment. After 10 minutes they were washed again. 60 samples poured with type V special gypsum (Durone) were obtained, that were measured 3 times in a stereomicroscope (SZX12, Olympus) to record the average of dimensional alterations. The disinfection treatment did not bring significant changes in the models obtained from both alginate tested (standard p = 0.7102; with chlorhexidine p = 0.5832). The results showed a statistically significant and additional advantage of the traditional alginate on alginate with chlorhexidine, with respect to dimensional alteration (p < 0.05).

Compatibilidade entre alginato e gesso ortodônticos: capacidade de umedecimento sob influência da desinfecção do molde

The dental trade has offered dental impression and dental stone for orthodontic use ensuring accurate models. The compatibility between these materials is defined by the wetting of the model surfaces by the mixture water/stone poured over it and the influenced by the method of disinfection of model and disinfectant solution used. It was evaluated the influence of spray disinfection with sodium hypochlorite 1% on the wettability of two commercial alginate (Jeltrate ® - Dentsply and Orthoprint ® - Zhermack) at two commercial type III gypsum (Rio ® - ME and AOBussoli Orthogesso Orthogesso ®-SA). Twenty models were fabricated for each type of alginate, which were divided into two groups (water and sodium hypochlorite), receiving respectively water and sodium hypochlorite 1% spray. Each group of models was then further divided into two subgroups, and on their surface were poured 2 ml of type III gypsum (Gesso Rio® or Orthogesso®). Reached the final setting of the gypsum specimens were sectioned vertically and medially, settled water with sandpaper No. 400 and mounted on suitable device for reading (in the right and left) of the contact angle Carl Zeiss microscope (precision, 001). The results were submitted to ANOVA and founded statistical significance for solutions used. It was concluded that sodium hypochlorite spray improved wettability of alginates studied.

Efeito da desinfecção e do tempo de armazenagem na molhabilidade de moldes de alginato

The cares at the manipulation of the alginate (condensation, disinfection of the impression and the time elapsed until the leak of the plaster) deserve special attention considering the great amount of distortions occurring every time the impression is not fill of plaster in a brief space of time and appropriate storage conditions. Besides its adaptation to the plaster suffers influence of the events happened after the impression is removed of the mouth. The purpose of this research was to evaluate the wetting capacity of three brands of alginate (Jeltrate™,Hydrogum™ e Orthoprint™) by the plaster type III (Rio™) under the influence of disinfection by sodium hypochlorite 1% sprays and the time of storage of 15 minutes,30 minutes, 1 hour, 6, 12 and 24 hours. There were made 60 impressions of each brand of alginate divided in two groups (water and sodium hypochlorite 1%) rearranged after the application of the sodium hypochlorite spray according to the storage time (15 or 30 minutes and 1,6,12, or 24 hours). On the surface of the impressions 2ml of plaster were flowed, proportioned and condensed in agreement with manufacturer‘s instructions. After the final setting expansion the casts were sectioned vertically and medially, regularized at the cut surface (emery paper 400) and setted for reading the contact angle at the microscope Carl Zeiss. The obtained results, submitted to statistical treatment (ANOVA) revealed significant differences when compared the employed solutions (water and sodium hypochlorite 1%) and the time of storage. The sodium hypochlorite 1% exhibited the smallest contact angles and the times of storage of 15 minutes and 6 hours the smallest and larger angles, respectively. It can be concluded that the alginate impressions exhibited larger adaptation to the plaster when disinfected by hypochlorite of sodium 1% and stocked by 15 minutes.

Moldagens em prótese total

The anatomical and functional impressions philosophies are presented to the professionals who are active in the area, so that they can review concepts and thus obtain more precise molds, based on scientific knowledge. In parallel, impression techniques recommended by the Prosthodontics subject from Araçatuba Dental School – UNESP are also commented.

Effect of framework soldering on the deformation of implant abutments after framework seating: a study with strain gauges

Introduction: Passive fit has been considered an important requirement for the longevity of implant-supported prostheses. Among the different steps of prostheses construction, casting is a feature that can influence the precision of fit and consequently the uniformity of possible deformation among abutments upon the framework connection. Purpose: This study aimed at evaluating the deformation of abutments after the connection of frameworks either cast in one piece or after soldering. Materials and Methods: A master model was used to simulate a human mandible with 5 implants. Ten frameworks were fabricated on cast models and divided into 2 groups. Strain gauges were attached to the mesial and distal sides of the abutments to capture their deformation after the framework’s screw retentions were tightened to the abutments. Results: The mean values of deformation were submitted to a 3-way analysis of variance that revealed significant differences between procedures and the abutment side. The results showed that none of the frameworks presented a complete passive fit. Conclusion: The soldering procedure led to a better although uneven distribution of compression strains on the abutments.

La relación entre la calidad de la enseñanza y la mala práctica odontológica: relato de caso clínico

Las actividades desarrolladas en el área de la salud son de gran importancia, pues tienen como finalidad preservar la vida de los individuos y para eso deben ser desempeñadas por personas habilitadas. El aumento del número de facultades de Odontología, la disminución en la calidad de la enseñanza y el mayor ingreso de alumnos con baja capacidad para ejercer la profesión son hechos que traen consecuencias desastrosas para la sociedad. Estos hechos también se reflejan en el desempeño moral, ético y técnico-científico del profesional. El objetivo de ese relato de caso clínico es enseñar que, aunque hay una considerable oferta de instituciones de enseñanza, existe un desconocimiento científico y de técnicas adecuadas por parte de los cirujanos dentistas graduados. La paciente MSL, 17 años, sexo femenino, compareció al consultorio odontológico usando un molde tipo Vernis, sujeto al arco inferior. Tras evaluación clínica, se observó la utilización de un material incorrecto para la toma de impresión, siendo imposible su retiro con el método convencional. La planificación para su retiro se hizo por medio de seccionamiento. De esta manera, la consecuencia de la falta de conocimiento en el uso de materiales para la impresión causó gran trastorno a la paciente. Se puede concluir que el índice de impericia está relacionado directamente con la formación profesional, evidenciando la importancia de la enseñanza odontológica de calidad para una práctica clínica responsable.

Produção de implantes de titânio, via moldagem por injeção de pós de hidretos de titânio

O objetivo deste trabalho foi a produção e caracterização de componentes sinterizados de titânio para aplicação biomédica, obtidos através do processo de fabricação chamado de Moldagem de Pós por Injeção ( MPI ), ou “Metal Injection Molding” ( MIM ) na língua inglesa. Para a produção dos componentes de titânio, utilizou-se de pós de hidreto de titânio produzidos pelo processo de Hidretação-Dehidretação ( HDH ), no Laboratório de Transformação Mecânica - UFRGS. Foram realizados ensaios para a caracterização dos componentes sinterizados quanto às suas propriedades mecânicas, resistência à corrosão, características morfológicas e de biocompatibilidade. Este trabalho concentra-se no desenvolvimento e produção de componentes para área odontológica ( implantodontia ) e médica, visando a implementar a técnica de Moldagem de Pós por Injeção ( MPI ) de hidreto de titânio para aplicação na produção de implantes, tendo em vista que, atualmente, este processo não é utilizado para tal fim. Para as análises de biocompatibilidade foram produzidos parafusos corticais para utilização como implantes. Após a caracterização morfológica e química dos implantes produzidos foram realizados ensaios in vitro de corrosão e in vivo de biocompatibilidade onde foi possível observar algumas características da superfície do implante como, por exemplo, a susceptibilidade à corrosão por frestas e elevado recobrimento ósseo do implante.

Como realizar o selamento periférico e a moldagem funcional?

The functional impression technique is one of the most important steps for complete and/or partial edentulism treatment. So, correct analysis and record of supporting structures are essential to determine the denture extension. The functional impression technique has two stages - a customized final impression tray and a border impression - which aims to record the optimal denture supporting area. The aim of this study was to review the literature related to border impression and functional impression techniques, describing the technique and materials, and identifying the procedure’s objectives and function.