Composites y selladores dentales : análisis cromatográfico y demostración de actividad estrogénica

Se ha realizado un estudio químico analítico sobre los selladores y composites dentales asi como la comprobación del efecto biológico de sus monómeros constituyentes en el ensayo e-screen. tras la aplicación de un sellador a adultos sanos se ha demostrado, así mismo, la elución de los monómeros a la saliva y el efecto estrogénico de estas muestras sobre el test antes citado. se confirma la polimerización incompleta de estos productos y la existencia de una fuente de exposición humana a xenoestrógenos de origen odontológicoTesis Univ. Granada. Facultad de MedicinaEl trabajo experimental de esta Tesis Doctoral ha sido realizado en parte gracias al Proyecto nº 95/1959 del Fondo de Investigaciones Sanitarias (FIS) que lleva por título "Factores etiológicos en cáncer de mama: xenobioticos estrogénicos contenidos en tejido adiposo"

Josep Pascual i Prats (1854-1931 ) y el " Index Medicus Hispanus " (1904-1906 ): una contribución española en los inicios de la documentación científica

El Index Medicus Hispanus (1904-1906) es, probablemente, el primer repertorio español de bibliografía médica de actualidad. Su publicación se debió al médico catalán Josep Pascual i Prats (1854-1931), que se atuvo a las normas internacionales más exigentes de ese momento para su confección. Debido a la falta de respuesta de la sociedad médica, Pascual i Prats suspendió la publicación del Index en 1906. Trece años después, en colaboración con Gregono Marañón y Augusto Pi i Suñer, quiso revitalizar este repertorio, pero fracasó en su intento por la misma razón por la que se vió obligado a interrumpir la edición del Index en 1906

The influence of printing angle on color and translucency of 3D printed resins for dental restorations

Objectives: To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins. Methods: Four 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FPFormlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC TemporaryLight, Medium) were evaluated. Three samples (10x10x1.2 mm) from each material were printed at two different printing orientations (0 degrees and 90 degrees) and polished to 1.00 +/- 0,01 mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45 degrees/0 degrees geometry. Color and translucency differences were evaluated using CIEDE2000 metric (AE00) and 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. Results: In general, color changes due to printing orientation at (0 degrees and 90 degrees) were mainly produced by AL* or AC* . AE00 were above PT00 for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, AE00 was above AT00. ARTP00 values were above TPT00 for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT00. The direction of the changes in translucency (ARTP00) depends on the material and shade. Significance: The selection of building orientation (0 degrees and 90 degrees) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.FEDER/Government of Andalusia P20-00200Spanish Government PGC2018-101904-A-100State of Rio Grande do Sul, FAPERGS 19/2551-0001721-9Universidad de Granada/CBU

Optical behavior of 3D-printed dental restorative resins: Influence of thickness and printing angle

The authors also acknowledge Detax GmbH, Formlabs Inc. and GC Corporation for providing the polymer-based 3D printing restorative resins used in this study.Objectives To evaluate the influence of thickness and printing angle on the optical properties of 3D-printed dental restorative resins. Methods Four 3D printing resin systems were evaluated: DFT-Detax Freeprint Temp; FP- Formlabs Permanent Crown; FP- Formlabs Temporary CB; and GCT- GC Temporary-. Samples from each material were printed at 0° and 90°, and polished up to 0.5, 1.0, 1.5 and 2.0 mm thickness. Scattering (S), absorption (K) and albedo (a) coefficients, transmittance (T%), light reflectivity (RI) and infinite optical thickness ( ) were calculated using Kubelka-Munk’s model. Data were statistically analyzed using Kruskal–Wallis¸ Mann-Whitney tests, and VAF coefficient. Results The spectral distribution on S, K, T%, RI, were wavelength dependent. Although the spectral behaviors were similar for all the specimens evaluated, the values of S, K, T% and presented significant differences between specimen thicknesses for all the materials used and for both printing orientations. Values for S and K increased, and T% and decreased. Significant differences between 0° and 90° were found for RI values at 0.5 and 1.0 mm thick samples, for S and K at 2.0 mm, for at 0.5 and 1.0 mm for DFT, and at 0.5 mm for FT. Conclusions Optical properties of 3D-printed restorative resins vary between thicknesses, and could be affected by the building orientation. Therefore, these factors should be considered in order to improve the biomimetic potential of 3D-printed dental restorative resins. Clinical significance Understanding the optical behavior of the 3D-printed restorative resins is essential to optimize their clinical performance.FEDER/ Government of Andalusia P20-00200support from the FEDER/ Government of Andalusia P20-00200 and State of Rio Grande do Sul, FAPERGS (grant #19/2551-0001721-9)Funding for open access charge: Universidad de Granada / CBU

Dental research in Spain. A bibliometric analysis on subjects, authors and institutions (1993-2012)

Background: Bibliometrics is defined as the use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Our objective was to characterize Spanish scientific output in Dentistry through the analysis of Web of Science database in a 20- year period. By means of a bibliometric study documents were statistically analyzed using indicators that showed quantitative and qualitative aspects of the production. Specifically, time course of the scientific production within the time span was analysed, as were the journals where the article was published and the categories of Journal Citation Reports (JCR) in which they belong, thematic areas, authorship, and finally authors and institutions with the highest production in Spain. Material and Methods: By means of the design of a specific search strategy previously described in the scientific literature, we recovered all citable documents about Dentistry signed by Spanish researchers and included in the WoS database between 1993 and 2012. Results: A total of 3006 documents fulfilled the search criteria, of which 2449 (81.5%) were published in journals within the category Dentistry Oral Surgery and Medicine and 557 (18.5%) within other categories of the JCR. During the four quinquenniums studied, the production increased quantitatively (8.6-fold) and qualitatively. Finally, the universities of Granada and Complutense of Madrid were the institutions with the highest production and most prolific authors. Conclusions: The Spanish dental production sharply increased in the last two decades, reaching quantitative and qualitative levels similar to those of the other medical specialties in the country

Effect of thickness on color and translucency of a multi-color polymer-infiltrated ceramic-network material

Objectives: To evaluate the effect of thickness on color and translucency of a multi-color polymer-infiltrated ceramic-network (PICN) material. Methods: Specimens of 0.5, 1.0, 1.5 mm thicknesses were obtained by sectioning VITA ENAMIC® multiColor (E-MC) High Translucent CAD-CAM blocks (1M1-HT, 1M2-HT, 2M2-HT, 3M2-HT, and 4M2-HT). Spectral reflectance and color coordinates were measured on white and black backgrounds using a spectroradiometer, CIE D65 illuminant and CIE 45 /0 geometry. CIEDE2000 color and translucency differences (ΔE00 and ΔTP00) between thicknesses and adjacent layers were evaluated using their respective 50:50% perceptibility and acceptability thresholds (PT00 and AT00). Results: In general, ΔE00 between thicknesses for all shades and layers were above AT00 in general. Chroma decreased from cervical to incisal layers with statistically significant differences (p < 0.05), and ΔE00 between sequential layers were above PT00, for all shades and thicknesses. TP00 decreased from 0.5 to 1.5 mm and increased from cervical to incisal layers for all shades with statically significant translucency differ- ences (p < 0.05). In general, for all thicknesses, TPT00 < ΔTP00 < TAT00 for sequential layers. Conclusions: The gradient in color and translucency of E-MC PICN material was influenced by the thickness of the CAD-CAM block. In addition, color and TP transi- tion values between the layers depends on the thickness and shade. Clinical significance: The effect of thickness must be taken into account by dental technicians and dentists when CAD-CAM multicolor PICN materials are used.University of Granada, Grant/Award Number: A.TEP.280.UGR18Spanish Ministry of Science, Innovation and Universities, Grant/ Award Number: PGC2018-101904-A-I00Government of Andalusia, Spain, Grant/Award Number: P20-0020

Optical and colorimetric evaluation of a multi-color polymer-infiltrated ceramic-network material

Objective To evaluate color, translucency parameter and optical properties (scattering (S), absorption (K) and transmittance (T)) of a multi-color polymer-infiltrated ceramic-network (PICN) material. Methods Samples of shades 1M1-HT, 1M2-HT, 2M2-HT, 3M2-HT, and 4M2-HT from VITA ENAMIC® multiColor (E-MC) High Translucent were fabricated (n = 3). CAD-CAM blocks were cut and polished to 1.00 ± 0.01 mm of thickness. Diffuse reflectance and color coordinates were measured against white and black backgrounds, using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry. Color and translucency differences were evaluated using 50:50% perceptibility (PT and TPT) and 50:50% acceptability (AT and TAT) thresholds. S and K coefficients and T were calculated using Kubelka–Munk’s equations. Data was statistically analyzed using Kruskal–Wallis, Mann–Whitney tests, and VAF coefficient. Result Mean C* and b* values increased from incisal to cervical layers with statistically significant differences (p < 0.05). In general, ΔE00 between sequential layers were above PT for all shades. In addition, translucency parameter (TP) increased from cervical to incisal and ΔTP00 values were greater than TPT00 and lower than TAT00 between all sequential layers. Layers from all shades showed similar spectral behavior for S (97.4% ≤ VAF), K (85.0% ≤ VAF) coefficients and T (95.3% ≤ VAF). However, these values presented significant differences (p < 0.05) from cervical to incisal layers. Significance The gradient in color and translucency of this novel CAD-CAM multi-color PICN material can assist dental technicians and dentists to reach greater esthetics than the pre-existing CAD-CAM monolithicmaterials.Project JA TEP-1136 from “Junta de Andalucía”, SpainMAT2013-43946R from the Spanish Ministry of Economy and CompetitivenessCNPq Brazil grant #302587/2017-

Applications of artificial intelligence in dentistry: A comprehensive review

This work was funded by the Spanish Ministry of Sciences, Innovation and Universities under Projects RTI2018-101674-B-I00 and PGC2018-101904-A-100, University of Granada project A.TEP. 280.UGR18, I+D+I Junta de Andalucia 2020 project P20-00200, and Fapergs/Capes do Brasil grant 19/25510000928-3. Funding for open-access charge: Universidad de Granada/CBUAObjective: To perform a comprehensive review of the use of artificial intelligence (AI) and machine learning (ML) in dentistry, providing the community with a broad insight on the different advances that these technologies and tools have produced, paying special attention to the area of esthetic dentistry and color research. Materials and methods: The comprehensive review was conducted in MEDLINE/ PubMed, Web of Science, and Scopus databases, for papers published in English language in the last 20 years. Results: Out of 3871 eligible papers, 120 were included for final appraisal. Study methodologies included deep learning (DL; n = 76), fuzzy logic (FL; n = 12), and other ML techniques (n = 32), which were mainly applied to disease identification, image segmentation, image correction, and biomimetic color analysis and modeling. Conclusions: The insight provided by the present work has reported outstanding results in the design of high-performance decision support systems for the aforementioned areas. The future of digital dentistry goes through the design of integrated approaches providing personalized treatments to patients. In addition, esthetic dentistry can benefit from those advances by developing models allowing a complete characterization of tooth color, enhancing the accuracy of dental restorations. Clinical significance: The use of AI and ML has an increasing impact on the dental profession and is complementing the development of digital technologies and tools, with a wide application in treatment planning and esthetic dentistry procedures.Spanish Ministry of Sciences, Innovation and Universities RTI2018-101674-B-I00 PGC2018-101904-A-100University of Granada project A.TEP. 280.UGR18Junta de Andalucia P20-00200Fapergs/Capes do Brasil grant 19/25510000928-3Universidad de Granada/CBU

Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography

'Reproduced with permission from Environmental Health Perspectives'Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 microg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 microg/mg), bisphenol A diglycidylether (6. 1 microg/mg), Bis-GMA (2.0 microg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure.This research was supported by grants from the Spanish Ministry of Health (FIS, 95/1959) and Education (CICYT, AMB97-1194-CE) and the Andalusian Regional Government, Department of Health (Consejeria de Salud, JA, 231/97)

Reseñas

Malvin E. RING, Historia ilustrada de la Odontologí