Treatment options for the occlusal surface of first permanent molars

Restorative dentistry has been increasingly concerned with preservation of the dental structure. For that reason, ultraconservative cavity preparations have been performed with air abrasion systems. The aim of this study was to present treatment options for the occlusal surface of first permanent molars with employment of the conventional method and the air abrasion system for accomplishment of the cavity preparation and a composite occlusal matrix for an accurate reproduction of the tooth surface.

Radiografia intra-oral e convencional da hemiarcada superior direita de gatos domésticos

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

Influência do tempo de exposição ao meio ambiente, da desinfecção química e da pigmentação sobre a estabilidade dimensional e a manutenção da reprodução de detalhes de silicones nacionais para uso em prótese facial

Pós-graduação em Odontologia - FOA

Avaliação clínica dos efeitos da associação do peróxido de hidrogênio a 38% com o peróxido de carbamida a 10%

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

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)

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.

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.

Evaluation of Impression Accuracy for Implant at Various Angulations

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

A comparison of profilometer and AutoCAD software techniques in evaluation of implant angulation in vitro

Purpose: The aim of this study was to compare 2 different methods of assessment of implants at different inclinations (90 degrees and 65 degrees)-with a profilometer and AutoCAD software. Materials and Methods: Impressions (n = 5) of a metal matrix containing 2 implants, 1 at 90 degrees to the surface and 1 at 65 degrees to the surface, were obtained with square impression copings joined together with dental floss splinting covered with autopolymerizing acrylic resin, an open custom tray, and vinyl polysiloxane impression material. Measurement of the angles (in degrees) of the implant analogs were assessed by the same blinded operator with a profilometer and through analysis of digitized images by AutoCAD software. For each implant analog, 3 readings were performed with each method. The results were subjected to a nonparametric Kruskal-Wallis test, with P <= .05 considered significant. Results: For implants perpendicular to the horizontal surface of the specimen (90 degrees), there were no significant differences between the mean measurements obtained with the profilometer (90.04 degrees) and AutoCAD (89.95 degrees; P=.9142). In the analyses of the angled implants at 65 degrees in relation to the horizontal surface of the specimen, significant differences were observed (P=.0472) between the mean readings with the profilometer (65.73 degrees) and AutoCAD (66.25 degrees). Conclusions: The degrees of accuracy of implant angulation recording vary among the techniques available and may vary depending on the angle of the implant. Further investigation is needed to determine the best test conditions and the best measuring technique for determination of the angle of the implant in vitro.

Influence of polishing procedures on the surface roughness of dental ceramics made by different techniques

The aim of this study was to evaluate the influence of 2 different surface polishing procedures - glazing (GZ) and manual polishing (MP) - on the roughness of ceramics processed by computer-aided design/computer-aided manufacturing (CAD/CAM) and conventional systems (stratification technique). Eighty ceramic discs (diameter: 8 mm, thickness: 1 mm) were prepared and divided among 8 groups (n = 10) according to the type of ceramic disc and polishing method: 4 GZ and 4 MP. Specimens were glazed according to each manufacturer's recommendations. Two silicone polishing points were used on the ceramic surface for manual polishing. Roughness was measured using a surface roughness tester. The roughness measurements were made along a distance of 2 mm on the sample surface and the speed of reading was 0.1 mm/s. Three measurements were taken for each sample. The data (μm) were statistically analyzed using analysis of variance (ANOVA) and Tukey's test (α = 0.05). Qualitative analysis was performed using scanning electron microscopy (SEM). The mean (± SD) roughness values obtained for GZ were: 1.1 ± 0.40 μm; 1.0 ± 0.31 μm; 1.6 ± 0.31 μm; and 2.2 ± 0.73 μm. For MP, the mean values were: 0.66 ± 0.13 μm; 0.43 ± 0.14 μm; 1.6 ± 0.55 μm; and 2.0 ± 0.63 μm. The mean roughness values were significantly affected by the ceramic type (P = 0.0001) and polishing technique (P = 0.0047). The SEM images confirmed the roughness data. The manually polished glass CAD/CAM ceramics promoted lower surface roughness than did the glazed feldspathic dental ceramics.

Methods to evaluate and strategies to improve the biocompatibility of dental materials and operative techniques

Objective. The general aim of this article is to describe the state-of-the-art of biocompatibility testing for dental materials, and present new strategies for improving operative dentistry techniques and the biocompatibility of dental materials as they relate to their interaction with the dentin-pulp complex.Methods. The literature was reviewed focusing on articles related to biocompatibilty testing, the dentin-pulp complex and new strategies and materials for operative dentistry. For this purpose, the PubMed database as well as 118 articles published in English from 1939 to 2014 were searched. Data concerning types of biological tests and standardization of in vitro and in vivo protocols employed to evaluate the cytotoxicity and biocompatibility of dental materials were also searched from the US Food and Drug Administration (FDA), International Standards Organization (ISO) and American National Standards Institute (ANSI).Results. While there is an ongoing search for feasible strategies in the molecular approach to direct the repair or regeneration of structures that form the oral tissues, it is necessary for professionals to master the clinical therapies available at present. In turn, these techniques must be applied based on knowledge of the morphological and physiological characteristics of the tissues involved, as well as the physical, mechanical and biologic properties of the biomaterials recommended for each specific situation. Thus, particularly within modern esthetic restorative dentistry, the use of minimally invasive operative techniques associated with the use of dental materials with excellent properties and scientifically proved by means of clinical and laboratory studies must be a routine for dentists. This professional and responsible attitude will certainly result in greater possibility of achieving clinical success, benefiting patients and dentists themselves.Signcance. This article provides a general and critical view of the relations that permeate the interaction between dental materials and the dentin-pulp complex, and establish real possibilities and strategies that favor biocompatibility of the present and new products used in Dentistry, which will certainly benefit clinicians and their patients. (C) 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

MODIFIED INDEXING TECHNIQUE FOR THE IMMEDIATE INTERIM RESTORATION OF A DENTAL IMPLANT

Because of the functional and esthetic requirements of patients, different techniques have been proposed to reduce the time between dental implant placement and interim restoration fabrication. This article describes a modified indexing technique by using a surgical template for open-tray impression and definitive cast development during immediate loading procedures. This technique does not use a complete impression of the oral cavity and, therefore, is more comfortable, less time consuming, and less expensive. It also allows the fabrication of interim restorations with the optimal shape for developing an adequate emergence profile.