Midline diastema closure using a lithium disilicate glass ceramic fragment: increased long-term color stability"

ABSTRACT: Nowadays, maxillary midline diastema (MMD) can be treated with different multidisciplinary approaches. When restorative dentistry is needed, glass-matrix ceramic materials is one of the best choices, since they present good optical behavior and high survival rates in the anterior dentition. To obtain an adequate interphase, and color integration are one of the main restorative goals, and for that purpose, specific finishing and polishing procedures must be employed to avoid staining and ensure the restoration's color stability. In the case report presented in this article, a single lithium disilicate ceramic fragment was performed to close a MMD produced by the shape alteration of one of the maxillary central incisors. Also, the finishing and polishing procedure is discussed.

The effect of different finishing and polishing procedures on the surface gloss of Bulk-Fill resin composites

STATEMENT OF THE PROBLEM: The literature still lacks evidence regarding which polishing techniques have the ideal clinical outcomes for bulk-fill resin composites. PURPOSE: This study evaluated the surface gloss of two commercially available bulk-fill resin composites after different polishing procedures and characterized their micromorphology via scanning electron microscopy. MATERIAL AND METHODS: 80 bulk-fill compactable composite resin discs were created. The control group was left untreated, and remaining samples were subjected to different polishing techniques. Gloss units were measured and surface morphology of disc samples was assessed. The Tukey post-hoc test was used to identify any differences. RESULTS: Statistically significant differences were found between the different polishing systems applied to Filtek BulkFill Posterior and Tetric N Bulk-Fill. No differences were found when the same polishing system was applied for both resins. The highest gloss values were obtained in the control group and the ENA Shiny system; the lowest were obtained with SofLex XT and Soflex Spiral Wheels for the bulk-fill composite resins studied. CONCLUSIONS. Diamond pastes have the highest gloss behavior, followed by diamond rubber points. The systems with aluminum oxide discs present the lower gloss behavior. SEM images provided useful evidence, and future studies should include an evaluation over time.

The use of direct composite resin to close maxillary midline diastema complementary to orthodontic treatment

ABSTRACT: The maxillary midline diastema is a common esthetic problem in patients. Assess and diagnose may be challenging due to the many factors that influences the alteration of tooth eruption process and tooth shape. Due to the various advantages and the reversibility of treatments, composite resins are today a suitable aesthetic and functional option, even so, its management and technique require a trained and experienced clinician in order to obtain an optimal outcome. The following report, is a clinical case of a 21-year old female with a main complaint of a maxillary midline diastema produced by the alteration in tooth shape and size of both upper central incisors, which was closed and corrected with direct composite resins.

Anterior composite resin crown in an adverse situation: A dental technique with a 3-year follow-up.

Endodontically treated teeth often exhibit severe coronal structure loss. Given the reversibility and tissue conservation of adhesive procedures, a conservative approach using an indirect resin crown with an adhesively cemented custom fiber-reinforced composite resin post provided a predictable and esthetic solution. The 24-hour and 3-year follow-ups of this technique showed good function, marginal adaptation, and esthetics.

Evaluation of color change using CIE LAB coordinates on tooth structure subjected to different concentrations of peroxide carbamide

ABSTRACT: Aim: The aim of this study was to evaluate the optical behavior of tooth color using CIE L*A*B* space; the teeth were subjected to novel bleaching gels containing peroxide carbamide with potassium oxalate. Materials and Method: Three different carbamide peroxide gels were experimentally fabricated. They consisted of 10% (G10), 16% (G16) and 37% (G37) concentrations. Sixty recently extracted premolars were subjected to different bleaching protocols. Color change (ΔE) was assessed using the CIE L*a*b* system after the application of each gel. The data were analyzed using one-way ANOVA with Tukey's post hoc test (α=5%) and a t-test. Results: The G10 and G16 gels exhibited an increase in ΔE*ab parameters from T0 to T1 (T0: application day of the gels. T1: 14th day measurement); a small decrease from T1 to T2 was also noted (T2: control measurement, 28th day). However, no statistically significant differences were found (p=0,22 for G10 and p=0,10 for G16). The G37 gel also exhibited an increase in ΔE*ab parameters, with similar results after the first application of 45 min, the second application of 45 min, and the third application of 45 min (T1, T2 and T3, respectively. T4: control measurement, 14th day). No statistically significant differences were observed between the three times of application (p>0,69), and an appreciable difference was noted between times T3 and T4 (p=0,000). Conclusions: The presented formulations of peroxide carbamide at 10%, 16%, and 37% are clearly effective. The G10 and G16 gels exhibited better effectiveness than the G37 gel.

Creación de un Currículo de Competencias en Cariología para Estudiantes de Pregrado de Odontología en Chile / Development of a Competency-based Curriculum in Cariology for Undergraduate Dental Students in Chile

RESUMEN: Objetivo: Creación de un currículo de competencias mínimas en Cariología, para la formación de los Cirujano-Dentistas egresados de las escuelas de Odontología de Chile. Metodologías: A partir de una reunión de académicos de las Universidades de Talca y de Chile (año 2011), se elaboró una propuesta de currículo inicial, basado en los dominios propuestos por la Unión Europea (Schulte AG y cols). Durante el año 2016, dicha propuesta fue analizada mediante diálogos digitales y grupos de trabajo, con la participación del 96% de las Escuelas de Odontología existentes en el país, que concluyeron en un documento intermedio. Este documento fue analizado, discutido y perfeccionado durante el Taller para el Desarrollo de un Currículo de Competencias Mínimas en Cariología para las Escuelas de Odontología Chilenas (22/Mayo/2017, Talca, organizado por la Universidad de Talca y la Universidad de Chile) con la asistencia de representantes del 96% de las escuelas dentales chilenas, Ministerio de Salud de Chile, Colegio de Cirujano-Dentistas de Chile y con la asesoría de los profesores de Cariología Dres. Margherita Fontana y Carlos González-Cabezas (Universidad de Michigan, Ann Arbor, EEUU). Cada grupo de trabajo revisó el documento y envió nuevos comentarios, los que fueron incorporados en el documento final por una comisión asesora. Resultados: El documento del Currículo en Cariología se organizó en 5 Dominios: 1. Conocimientos base; 2. Determinación de Riesgo, diagnóstico de caries y detección de lesiones de caries; 3. Toma de decisiones y manejo preventivo no operatorio; 4. Toma de decisiones y manejo operatorio y 5. Cariología basada en la evidencia, en la práctica clínica y de salud pública. Se consensuaron las definiciones operacionales, las competencias principales y las sub-competencias para cada uno de los dominios. Las sub-competencias fueron clasificadas en tres niveles: A: Ser competente en; B: Tener conocimientos sobre y C: Estar familiarizado con. El documento final fue enviado a todos los participantes del taller para su aprobación y difusión en cada una de las instituciones involucradas. Conclusiones: Se logró, por medio de consenso, la construcción del Currículo de Competencias mínimas en Cariología para estudiantes de pregrado de Odontología en las universidades chilenas.

ABSTRACT: Objective: Development of a minimum set of competencies in Cariology that every dentist graduated from a Dental School in Chile must have. Methodology: Starting from a meeting of scholars from the Universities of Talca and Chile (year 2011), an initial proposal for a curriculum was developed, based on the domains proposed by the European Cariology Curriculum (Schulte, et al, 2011). During 2016, this proposal was discussed through online dialogues and working groups, with the participation of 95.2% of the Chilean dental schools, which resulted in an intermediate document. This document was analyzed, discussed and refined during the Workshop for the Development of a Curriculum of Minimum Competencies in Cariology for Chilean Dental Schools (May 22, 2017, Talca, organized by the Universities of Talca and Chile) with the attendance of representatives from 95.2% of the Chilean dental schools, the Chilean Ministry of Health, Chilean College od Dentists and with the assistance of the professors of Cariology Margherita Fontana and Carlos González-Cabezas (University of Michigan, Ann Arbor, USA). Each working group revised the document and provided feedback, which was incorporated in the final document by an advisory committee, elected on the day of the workshop, including the authors of the present article. Results: The Cariology Curriculum was organized in 5 Domains: 1. Basic knowledge; 2. Risk assessment, caries diagnosis and caries lesion detection; 3. Decision-making and non-operative preventive treatment; 4. Decision making and operative treatment; and 5. Evidence-based, clinical and public health practice. Operational definitions, main competencies and sub-competencies for each domain were agreed. Sub-competencies were classified into three levels: A: Be competent in; B: Have knowledge about, and C: Be familiar with. The final document was sent to all the participants of the workshop for dissemination in each of the institutions involved. Conclusions: The development of the Competency-based Curriculum in Cariology for undergraduate dental students at Chilean universities was achieved through consensus.

Determining the effectiveness of Candida guilliermondii in the biological control of Rhizopus stolonifer in postharvest tomatoes / Determinación de la efectividad del control biológico de Rhizopus stolonifer en tomates poscosecha utilizando candida guilliermondii / Determinação da efetividade do controlo biológico de Rhizopus stolonifer em tomates poscosecha utilizando candida guilliermondii

Las alteraciones de frutos de tomate poscosecha por causas microbiológicas conllevan a su deterioro fisiológico produciendo su descomposición. En este estudio, Candida guilliermondii fue examinada en ensayos in vitro e in vivo para determinar su eficacia en el control biológico contra Rhizopus stolonifer en tomates (Lycopersicon esculentum). El efecto antagónico se llevo a cabo usando biomasa de la levadura y sus metabolitos los cuales se identificados en un cromatógrafo gases-masas. Los ensayos in vitro mostraron que la única fase con respuesta antagónica al patógeno fue la fase acuosa sin filtrar. En los ensayos in vivo, la biomasa de Candida guilliermondii presento el mayor porcentaje de protección contra el patógeno (87 %) en comparación con la fase acuosa sin filtrar y la fase orgánica sin concentrar que presentaron el 77 y 80 % de protección respectivamente. Estos resultados son de gran importancia para evitar las perdidas económicas además de garantizar un tiempo de vida mas largo del tomate asegurando una mejor distribución del producto y evitando sus perdidas en estos tiempos de crisis alimentaria en especial en países en desarrollo.

Post-harvest losses in tomato crops can be accredited to a number of causes, which include biological causes that produce physiological deterioration; infection caused by diseases and pests that cause rotting. In this study, we assayed, in vitro and in vivo, the yeast Candida guilliermondii to determine its effectiveness as a biocontrol to reduce the rotting produced by Rhizopus stolonifer on tomatoes (Lycopersicon esculentum). The antagonistic effect was tested using a yeast biomass suspension; gas chromatography and a mass selective detector were used to identify its metabolites. According to the in vitro test, the only phase with an antagonistic response against Rhi%opus stolonifer was the unfiltered water phase. In the in vivo tests, the biomass of Candida guilliermondii presented the highest percentage of protection of the tomato (87 %) compared with the unfiltered aqueous phase and the unconcentrated organic phase, which reached only 77 and 80 % respectively. These results are essential to avoid economic losses caused by fungi and to increase the shelf life of tomatoes improving the distribution of the product and preventing postharvest losses in this time of food crises, especially in developing countries.

As perdas pós-colheita de frutos de tomate são creditadas em várias fontes, incluindo causas biológicas que levam ao deterioro fisiológico e infecção por doenças e pragas que podem levar à sua decomposição. Neste estudo, a levedura Candidaguilliermondii foi examinada in vitro e in vivo para determinar a sua eficácia no controlo biológico de Rhizopus stolonifer em tomates (Lycopersicon esculentum). O efeito antagonista realizou-se utilizando biomassa de levedura e os seus metabolitos, os quais foram identificados por cromatografia gasosa acoplada a um detector selectivo de massa. Os ensaios in vitro mostraram que a única fase com resposta antagonista a Rhizopus stolonifer foi a fase aquosa não filtrada. Nos ensaios in vivo, a biomassa Candida guilliermondii teve a maior percentagem de protecção contra o patógeno (87%) em comparação com a fase aquosa não filtrada e a fase orgânica não concentrada apresentando 77 e 80 % de protecção, respectivamente. Estes resultados são muito importantes para evitar perdas económicas causadas por fungos, além de garantir ao tomate uma vida útil mais longa, o que assegura uma melhor distribuição do produto e evita perdas pós-colheita neste momento de crise alimentar, especialmente nos países em desenvolvimento.