Mecanismos preventivos de la degradación de la capa híbrida

One of the biggest challenges in dentistry is to achieve a long-lasting and stable bond between restorative materials and dental tissues. The adhesive protocols have been changing over time to meet this objective, trying to maintain the integrity of the hybrid layer, so the factors that cause the degradation of the hybrid layer and the mechanisms proposed to prevent this degradation were reviewed. An investigation and compilation of specialized bibliographic information on the subject was carried out, in scientific search engines such as PubMed, Scielo, Redalyc, Medigraphic, Scopus, among others, as well as books. For the inclusion criteria, years of publication between 2002 and 2022 were considered, focused on research works related to the degradation of the resin-dentin bonding interface and mechanisms to prevent this degradation in the hybrid layer. The placementof CHX is used after the application of phosphoric acid and before the adhesive, it inhibits the proteolytic activity of matrix metalloproteinases (MMPs) and the degradation of collagen fibers, thus achieving a longer life of resin dental restorations.Uno de los mayores retos de la odontología actual es lograr una adhesión duradera y estable entre los materiales de restauración y los tejidos dentales. Los protocolos adhesivos han ido cambiando a lo largo del tiempo para cumplir con dicho objetivo, tratando de mantener la integridad de la capa hibrida, por lo que se revisaron los factores que provocan la degradación de la capa hibrida y los mecanismos propuestos para prevenir esta degradación. Se realizó una investigación y recopilación de información bibliográfica especializadas en el tema, en buscadores científicos como PubMed, Scielo, Redalyc, Medigraphic y Scopus. Para los criterios de inclusión se consideraron años de publicación entre el año 2002 al 2022, enfocados en trabajos de investigación relacionados con la degradación de la interfaz de unión resina-dentina y mecanismos para prevenir esta degradación en la capa híbrida. El mecanismo mas estudiado a corto y largo plazo es la aplicación de clorhexidina, la cual se utiliza después del ácido fosfórico y antes del adhesivo, inhibe la actividad proteolítica de las metaloproteinasas de la matriz (MMPs) y retarda la degradación de las fibras colágenas, consiguiendo de esta manera una mayor vida de las restauraciones adhesivas

Valoración estética en pacientes clase III antes y después del tratamiento quirúrgico de acuerdo con la proporción divina

RESUMENEste estudio fue diseñado para valorar estéticamente a los pacientes clase III antes y después del tratamiento quirúrgico de acuerdo con la proporción divina. La clase III o mesioclusión, se caracteriza por la relación mesial de la arcada dentaria mandibular con respecto a la maxilar tomando como referencia la cúspide mesiovestibular del primer molar superior ocluyendo mesial al surco del primer molar inferior. Esta patología compromete mucho la estética facial y el estado psicosocial, que influye desfavorablemente en la autoestima de quien lo padece. Constituye uno de los retos más difíciles con los que se puede encontrar el clínico; si se dejan sin tratar pueden avanzar a un grado tan severo, que en la mayoría de los casos, la única alternativa de tratamiento se reduce a intervenciones de cirugía ortognática en edad adulta. Las técnicas quirúrgicas tuvieron su origen en el siglo XX. A partir de entonces, han sido modificadas hasta convertirlas en métodos versátiles y predecibles en la corrección de malformaciones maxilofaciales. La afectación estética es el principal motivo de consulta de los pacientes de Ortodoncia. La proporción divina está siendo estudiada cada día más, con fines diagnósticos y terapéuticos relacionados con la estética facial.Material y métodosVeinte pacientes se incluyeron en la muestra de este estudio, cefalografías laterales y fotografías pre-/post-tratamiento (escala 1.1), siete razones angulares se midieron pre/post-tratamiento en cefalografías laterales y siete medidas lineales fueron medidas desde fotos frontales.ResultadosSe realizó el coeficiente de correlación interclase como análisis de calibración, en las proporciones medidas. Así como la Prueba t-Student para muestras relacionadas. Se marca con un asterisco (*) los grupos con diferencias estadísticamente significativas (p < 0.05).ConclusionesConsideramos de que en veinte y ocho razones estudiadas, diez y seis se diferenciaron de forma estadísticamente significativa, acercándose al número áureo después del tratamiento quirúrgico en pacientes clase III.ABSTRACTThis study was designed to aesthetically assess class III patients before and after surgical treatment according to the divine proportion. Class III or mesio-occlusion, is characterized by the mesial relationship of the mandibular dental arch with respect to the maxillary dental arch taking as reference the mesial buccal cusp of the upper first molar which occludesmesial to groove of the lower first molar. This pathology greatly compromises facial esthetics and psychosocial status and adversely affects the self-esteem of those who suffer from it. It is one of the most difficult challenges that the clinician can face; if left untreated it can progress to a degree so severe, that in most cases, the only treatment option is orthognathic surgery in adulthood. Surgical techniques had their origin in the twentieth century from then on, they have been modified into versatile and predictable methods for the correction of maxillofacial malformations. The aesthetic problem is the main reason for consultation in orthodontics. The divine proportion is being studied more and more every day for diagnostic and therapeutic purposes related to facial aesthetics.Materials and methodsTwenty patients were included in the sample for this study. Pre and post-treatment cephalograms and photographs (scale 1.1) were obtained. Seven angular measurements were taken from the pre/post-treatment cephalograms and seven linear measurements were obtained from frontal photographs.ResultsAn inter-class correlation coefficient was conducted as calibration analysis in the measured proportions as well as a Student's t-test for related samples.ConclusionsIt was considered that in twenty-eight studied measurements, sixteen presented a statistically significant difference approximating to the golden number after surgical treatment in class III patients

Bond strength of adhesive systems to calcium silicate-based materials: a systematic review and meta-analysis of in vitro studi

"Since the adhesion of resin composites to calcium silicate-based cement is considered challenging. Therefore, the best adhesion strategy should be indicated. This review aimed to assess the effect of different adhesive systems on the bond strength of resin composite to calcium silicate-based cement through a systematic review and meta-analysis. The subsequent PICOS framework used was: population, calcium silicate-based cement; intervention, use of self-etch adhesive systems; control, use of total-etch adhesive systems; outcome, bond strength; study design, in vitro studies. The literature search was conducted independently by two reviewers up to 18 February 2021. Electronic databases (PubMed, ISI Web of Science, SciELO, Scopus, and Embase) were searched for applicable articles. In vitro manuscripts studying the effect of adhesive systems on the bond strength of calcium silicate-based cement were considered. The meta-analyses were performed using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). Bond strength comparisons were made considering the type of calcium silicate-based cement (Mineral Trioxide Aggregate (MTA), Biodentine™, or TheraCal LC®)"

Estimación de la cantidad de trióxido de bismuto como agente radiopacificador en dos cementos minerales trióxido agregado mediante una prueba de radiopacidad

"Se dice que el cemento mineral trióxido agregado (MTA) contiene 20%wt de trióxido de bismuto (Bi2O3) que le provee radiopacidad; sin embargo, la radiopacidad reportada en varias marcas de estos cementos ha sido variable, lo que sugiere que presentan diversa cantidad de bismuto, pudiendo afectar sus propiedades mecánicas. Objetivo: Estimar la concentración de trióxido de bismuto en dos marcas comerciales disponibles en México a partir de una prueba de radiopacidad"

Percepción de la estética de la sonrisa por odontólogos especialistas y pacientes

"El objetivo del presente estudio fue conocer la percepción de los parámetros estéticos de la sonrisa, por odontólogos especialistas y pacientes que acuden al Departamento de Ortodoncia de la DEPeI, UNAM. Método: Se realizó un estudio observacional descriptivo en el que se observaron tres series de cinco fotografías de sonrisas por 284 participantes hombres y mujeres, de los cuales 144 eran odontólogos especialistas y 140 pacientes. Ambos grupos calificaron fotografías de sonrisas que fueron modificadas con el programa PhotoShop®"

Radiographical assessment of initial and fi nal tipping in 60 patients treated without extractions at the Orthodontics Clinic of the DEPeI, UNAM 2010-2012

"Tipping, mesiodistal root inclination, torque and in-out movements; they are information prescribed in the bracket. They locate the tooth in the three planes of space; it is thought that by fi lling the slot, expression of the prescription is obtained. Prescription provides specifi c measurements of tipping to distribute forces adequately on the long axis of the tooth thus resulting in treatment stability and health of the stomatognathic system. When these conditions are not obtained, trauma might develop (widening of the periodontal space, root resorption, bone defects). Objective: To compare tipping expression before and during treatment as well as the trans-treatment tipping against the one established by MBT and Roth prescriptions"

Microfiltración en un cemento dental tipo MTA modificado con wollastonita y vidrio bioactivo

"Un material de retroobturación como el MTA (Mineral Trioxide Aggregate) debe de ser de fácil manejo, biocompatible, tener baja o nula solubilidad y ser dimensionalmente estable para evitar filtraciones asociadas a los cambios volumétricos"

Comparative study between cone-beam and digital lateral head film cephalometric measurements

"Objective: The objective of the present study was to determine the differences between cephalometric measurements obtained by two different methods: cone-beam tomography and digital lateral head film"

Esthetic assessment of class III patients before and after surgical treatment according to the divine proportion

"This study was designed to aesthetically assess class III patients before and after surgical treatment according to the divine proportion. Class III or mesio-occlusion, is characterized by the mesial relationship of the mandibular dental arch with respect to the maxillary dental arch taking as reference the mesial buccal cusp of the upper fi rst molar which occludesmesial to groove of the lower fi rst molar. This pathology greatly compromises facial esthetics and psychosocial status and adversely affects the self-esteem of those who suffer from it. It is one of the most diffi cult challenges that the clinician can face; if left untreated it can progress to a degree so severe, that in most cases, the only treatment option is orthognathic surgery in adulthood. Surgical techniques had their origin in the twentieth century from then on, they have been modified into versatile and predictable methods for the correction of maxilofacial malformations. The aesthetic problem is the main reason for consultation in orthodontics. The divine proportion is being studied more and more every day for diagnostic and therapeutic purposes related to facial aesthetics"