7 research outputs found
La evolución de la adhesión a dentina
[email protected] realiza una revisión a la historia de la adhesión comenzando en las culturas precolombinas ("era pre-adhesiva"),
para continuar en la "era adhesiva" con las aportaciones de Buonocuore y la aparición del Bis-GMA, pasando
por la incorporación al mercado dental de los fosfatos, los oxalatos, el sistema Gluma. Se analiza también la
descripción la capa híbrida por Nakabayashi, después aparecen los primers acuosos y la hibridación de tejidos
duras hasta llegar a los sistemas adhesivos autograbadores.An overview of dentin bonding history is done by the author since early south American cultures (pre-adhesive age)
to continued in the adhesive age with Buonoccore's findings and the rise of Bis-GMA and the first dentin adhesives
based on phosphate, oxalate and Gluma system. Nakabayashi's hybrid layer is described and the evolution of
aqueous primers and hard tissues hybridation until arrival of newest self-etching [email protected]
Aesthetic dentistry : chromatic appreciation in the clinic and the laboratory
Aesthetic requirement in dentistry is getting more and more important every day. One of its basic principles is the correct selection of colour for the restorations. Colour is a quality which is modulated by a series of factors, environmental and individual, that the clinic must know. Colour measurement by the human eye can induce to an appreciation mistake if it doesn?t follow a correct protocol of light conditions and observation technique, checked by the authors, simplifying it with a practical focusing. Colour measurement instruments have appeared recently, trying to correct the problems of conventional technique
Relationship between resolution and accuracy of four intraoral scanners in complete-arch impressions
The scanner does not measure the dental surface continually. Instead, it generates a point cloud, and these points are then joined to form the scanned object. This approximation will depend on the number of points generated (resolution), which can lead to low accuracy (trueness and precision) when fewer points are obtained. The purpose of this study is to determine the resolution of four intraoral digital imaging systems and to demonstrate the relationship between accuracy and resolution of the intraoral scanner in impressions of a complete dental arch. A master cast of the complete maxillary arch was prepared with different dental preparations. Using four digital impression systems, the cast was scanned inside of a black methacrylate box, obtaining a total of 40 digital impressions from each scanner. The resolution was obtained by dividing the number of points of each digital impression by the total surface area of the cast. Accuracy was evaluated using a three-dimensional measurement software, using the ?best alignment? method of the casts with a highly faithful reference model obtained from an industrial scanner. Pearson correlation was used for statistical analysis of the data. Of the intraoral scanners, Omnicam is the system with the best resolution, with 79.82 points per mm2, followed by True Definition with 54.68 points per mm2, Trios with 41.21 points per mm2, and iTero with 34.20 points per mm2. However, the study found no relationship between resolution and accuracy of the study digital impression systems (P >0.05), except for Omnicam and its precision. The resolution of the digital impression systems has no relationship with the accuracy they achieve in the impression of a complete dental arch. The study found that the Omnicam scanner is the system that obtains the best resolution, and that as the resolution increases, its precision increases
Comparative characterization of a novel cad-cam polymer-infiltrated-ceramic-network.
Background: The field of dental ceramics for CAD-CAM is enriched with a new innovative material composition
having a porous three-dimensional structure of feldspathic ceramic infiltrated with acrylic resins.The aim of this
study is to determine the mechanical properties of Polymer-Infiltrated-Ceramic-Network (PICN) and compare its
performance with other ceramics and a nano-ceramic resin available for CAD-CAM systems.
Material and Methods: In this study a total of five different materials for CAD-CAM were investigated. A polymer-
infiltrated ceramic (Vita Enamic), a nano-ceramic resin (Lava Ultimate), a feldspathic ceramic (Mark II), a lithium
disilicate ceramic (IPS-e max CAD) and finally a Leucite based ceramic (Empress - CAD). From CAD-CAM
blocks, 120 bars (30 for each material cited above) were cut to measure the flexural strength with a three-point-
bending test. Strain at failure, fracture stress and Weibull modulus was calculated. Vickers hardness of each material was also measured.
Results: IPS-EMAX presents mechanical properties significantly better from the other materials studied. Its strain
at failure, flexural strength and hardness exhibited significantly higher values in comparison with the others. VITA
ENAMIC and LAVA ULTIMATE stand out as the next most resistant materials.
Conclusions: The flexural strength, elastic modulus similar to a tooth as well as having less hardness than ceramics
make PICN materials an option to consider as a restorative materia
In vivo study of different methods for diagnosing pit and fissure caries
Background: In recent years the early detection of such caries has gained importance, since it may avoid unnecessary dental tissue damage and allow minimally invasive dental treatment. A study is made of 5 systems for diagnosing caries: traditional visual and tactile methods, DIAGNOdent, VistaProof and CarieScan.
Material and Methods: A prospective study was made in the Department of Stomatology, Dental Pathology and
Therapeutics Teaching unit of the University of Valencia (Valencia, Spain), involving the analysis of 32 teeth
(molars or premolars of both arches scheduled for filling or for use as posts in dental bridges) in 28 patients.
The following caries diagnostic methods were applied: visual, tactile, DIAGNOdent (KAvo, Biberach, Germany),
VistaProof (Dürr Dental AG, Bietigheim-Bissingen, Germany) and CarieScan (IDMoS Dental Systems, Dundee,
Scotland, United Kingdom). Fissurotomy was subsequently performed for histological validation.
Results: Visual inspection showed an area under the receiver operating characteristic curve (AUC-ROC) of 0.75,
with a sensitivity and specificity of 0.75. Tactile diagnosis in turn showed AUC = 0.714, with maximum sensitivity
(100%) and a specificity of 42.9%. DIAGNOdent (cutoff point 22.5) and VistaProof (cutoff point 1.1) showed AUC
= 0.969, while CarieScan (cutoff point 21.5) presented AUC = 0.973. These latter three methods all had a sensitivity
of over 92%. The specificity of DIAGNOdent was maximum, while that of CarieScan and VistaProof was 75%.
Conclusions: The emergent methods in the diagnosis of caries (DIAGNOdent, VistaProof and CarieScan) yielded
similar results, and in all cases proved superior to the traditional visual and tactile methods. DIAGNOdent was seen
to be the most effective technique, followed by CarieScan and VistaProof
Nuevas Imágenes. Resúmenes y abstracts de comunicaciones. VI Congreso Internacional CONFOCO.
Se presentan los resúmenes de las comunicaciones del VI Congreso Internacional CONFOCO