Efecto del blanqueamiento dental con peroxido de hidrógeno al 35% en la resistencia de unión de dientes restaurados con resina compuesta

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

Effect of different bleaching protocols on dental enamel and composite resin

To evaluate changes in microhardness, roughness and surface morphology of dental enamel and composite resin after different tooth bleaching techniques. Material and Methods: Dental fragments from bovine incisors with composite resin restorations were submitted to different bleaching protocols: G1 – daily 8 hours application of a 10% carbamide peroxide (CP) gel during 21 days; G2: 3 applications of 15 minutes of a 38% hydrogen peroxide (H2O2) gel; G3: 38% H2O2 gel associated to irradiation with LED (470nm) during 6 minutes. The Knoop micro hardness of enamel and composite resin were evaluated at 1, 7, 14 and 21 days for G1, and after 1, 2 and 3 sessions for G2 and G3. The roughness and superficial morphology (atomic force microscopy) were evaluated before and at the end of the bleaching treatment. The data were analyzed by Mann-Whitney and Wilcoxon tests (=5%). Results: Significant reduction on enamel hardness was observed after 2 and 3 sessions for G2 and G3. For composite, the reduction occurred after 21 days for G1, and after 3 sessions for G2 and G3 (p<0.05). Significant reduction on roughness and superficial morphology were observed only for enamel of G1 group (p<0.05). Conclusion: The 10% CP gel promoted only superficial alterations on dental enamel, while the 38% H2O2 gel promoted mineral reduction of this dental tissue. All the bleaching protocols promoted reduction on hardness of composite resin.

Correlación entre diferentes métodos de evaluación de color en el clareamiento dental. Correlation between different methods for co

The aim of this study was to evaluate the correlation of color change on bleaching tooth through delta E (ΔE) by the spectrophotometer Spectroshade (SS) and digital program Scanwhite (SW). Methods: 25 patient volunteers were recruited from Operative Dentistry at Universidad de Chile Dental School, between 18 to 30 years, with good oral hygiene. Exclusion criteria: Previous experienced tooth bleaching, anterior restorations, cervical lesions, pain dental, pregnant patient, stained teeth, malposition of the teeth and periodontal pathology. The bleaching was made in two sessions with three different bleaching systems which were randomly. The assessment of color change through ΔE was made on the two upper central incisors (N=50) by the SS and SW. The color in the same teeth were measured before (T0) and after (T1) of the bleaching treatment. Data were analyzed using test Spearman correlation coefficient (Rho) with a significant level of 95%. Results: The results showed a positive and significant correlation (0.676), with a statistically significant difference (p<0.05). Conclusion: There is correlation in the measurement of color change on bleaching tooth by SS and SW.

Operatoria clase IV con llave de silicona

Fil: Palmili, Rodrigo. Universidad Nacional de Cuyo. Facultad de Odontología

Adhesión de ionómeros vítreos convencionales a ditintos tipos de dentina

Desde su aparición en el año 1972, los cementos de ionómero vítreo han tenido una gran aplicación en varias disciplinas odontológicas tales como, operatoria dental, endodoncia, prótesis, etcétera. (10) La técnica desarrollada por los investigadores preconiza el pretratamiento dentinario con el fin de exponer los grupos calcio de la hidroxiapatita de la dentina para lograr una buena adhesión química de este cemento al elemento dentario. (10) El desarrollo de los ionómeros de alta densidad constituye el comienzo de una nueva manera de encarar el ejercicio profesional con un criterio más biológico, más preventivo y menos invasivo. (5) Dado que este tipo de cemento es muy utilizado en las técnicas de restauración atraumática que se implementan a nivel comunitario y que son realizadas en lugares físicos que no poseen todos los requisitos tecnológicos de un consultorio odontológico, se propuso como objetivo de este estudio medir la eficacia del pretratamiento con ácido poliacrílico al 10% en distintos sustratos dentinarios (normal, cariado y esclerótico) (13) evaluando los resultados mediante la determinación de la resistencia adhesiva del cemento a dichos sustratos.

Obturaciones protegidas

Se presenta una técnica combinada (directa–indirecta) para la restauración de elementos dentarios posteriores que combina las ventajas de las obturaciones convencionales con las de las incrustaciones metálicas y no metálicas.

Adhesión de ionómeros vítreos convencionales a dentina tratada con distintas sustancias

El objetivo de este trabajo fue evaluar la fuerza adhesiva de los ionómeros vítreos convencionales a la dentina tratada con ácido fosfórico, con ácido poliacrílico y con solución de hipoclorito de sodio. Los ensayos se realizaron sobre dentina de premolares extraídos por razones ortodóncicas o periodontales, los cuales se asignaron al azar en tres grupos de 10 elementos cada uno. A cada grupo se le practicó un tratamiento distinto (descalcificación, desproteinización o eliminación del barro dentinario). Sobre cada espécimen se le adhirió un cilindro de ionómero vítreo convencional preparado según las especificaciones de su fabricante. Posteriormente las muestras fueron sometidas a fuerzas de cargas de corte utilizando una máquina de ensayos universal (Instron). Los resultados obtenidos fueron sometidos a análisis de ANOVA de una entrada y a post test de comparación múltiple de Tukey. Por lo que puede expresarse que no hubo diferencia estadísticamente significativa (p>0,05) en la fuerza adhesiva de los ionómeros vítreos que fueron adheridos a dentina con tratamiento de ácido poliacrílico, y los que fueron adheridos a dentina con tratamiento de descalcificación (acción del ácido fosfórico). Se encontró diferencia estadísticamente significativa en las muestras adheridas a dentina tratadas con poliacrílico y ácido fosfórico (p<0.01 y p<0.05 respectivamente), con respecto a las que fueron tratadas con hipoclorito.

El nuevo ojo clínico en Odontología

Fil: Martín, G.. Universidad Nacional de Cuyo. Facultad de Odontología

Lograr estética y función en el sector posterior con resinas compuestas

La operatoria dental actual cuenta con un conocimiento más profundo de las diferentes estructuras dentarias que sumado al gran adelanto tecnológico y científico en la ciencia de los biomateriales; fruto de innumerables investigaciones, nos permiten contar hoy, con una nueva generación de materiales restauradores, lo que hace más crítico y exigente el conocimiento y análisis por parte del profesional, de las técnicas a efectuar, la realización depurada de procedimientos y los biomateriales a utilizar, con el fin de realizar tratamientos que sean biocompatibles, eficientes y de importante longevidad.

Evaluación de la eficacia de la remoción de caries en dientes temporales utilizando dos métodos químico-mecánicos.

La Odontología Pediátrica Contemporánea al igual que la Odontología de Mínima Intervención, comprende la máxima conservación de tejido dental subyacente con la finalidad de evitar la invasión a tejidos pulpares que derivan en tratamientos radicales tales como pulpotomías y pulpectomías; las técnicas de operatoria dental actuales comprenden en tratar el complejo dentino-pulpar lo más conservadoramente posible, con la finalidad de prevenir la extensión. Una de las propuestas del concepto de Mínima Intervención consiste en el uso de agentes químicos para la remoción de tejido cariado, auxiliado por instrumentos manuales que permitan remover solo la dentina infectada, sin necesidad de piezas rotatorias, reduciendo tiempos operatorios y costos. Objetivo: Evaluar cuál es el método más eficaz para eliminar la caries dental entre métodos químico-mecánicos para así establecer un protocolo de atención no invasivo para pacientes pediátricos y poder llevarlo a cabo en las campañas de brigadas Odontológicas, para que un mayor número de población sea beneficiada con éstas. Materiales y Métodos: Se evaluaron 10 piezas posteriores deciduas, extraídas de niños de 6 a 8 años que cumplían con los criterios de inclusión de la Maestría en Ciencias Odontológicas en el área de Odontopediatría de la UANL, Monterrey, Nuevo León, México. Las piezas a evaluar fueron seccionadas y tratadas con Carisolv y Papacárie, ambos productos de remoción químico mecánicos, mientras se medía el tiempo de trabajo y la calidad de dentina remanente tras la remoción de caries para posteriormente describir los hallazgos observados.

Springboards into design : exploring multiple representations of interaction in a dental surgery

This paper demonstrates that in order to understand and design for interactions in complex work environments, a variety of representational artefacts must be developed and employed. A study was undertaken to explore the design of better interaction technologies to support patient record keeping in a dental surgery. The domain chosen is a challenging real context that exhibits problems that could potentially be solved by ubiquitous computing and multi-modal interaction technologies. Both transient and durable representations were used to develop design understandings. We describe the representations, the kinds of insights developed from the representations and the way that the multiple representations interact and carry forward in the design process.

A participatory design agenda for ubiquitous computing : a case study in dental practice

This paper reflects upon our attempts to bring a participatory design approach to design research into interfaces that better support dental practice. The project brought together design researchers, general and specialist dental practitioners, the CEO of a dental software company and, to a limited extent, dental patients. We explored the potential for deployment of speech and gesture technologies in the challenging and authentic context of dental practices. The paper describes the various motivations behind the project, the negotiation of access and the development of the participant relationships as seen from the researchers' perspectives. Conducting participatory design sessions with busy professionals demands preparation, improvisation, and clarity of purpose. The paper describes how we identified what went well and when to shift tactics. The contribution of the paper is in its description of what we learned in bringing participatory design principles to a project that spanned technical research interests, commercial objectives and placing demands upon the time of skilled professionals.

Maintaining human agency in the design on context-aware systems : Design games in a dental surgery

This paper describes a series of design games, specifically aimed at exploring shifts in human agency in order to inform the design of context-aware applications. The games focused on understanding information handling issues in dental practice with participants from a university dental school playing an active role in the activities. Participatory design activities help participants to reveal potential implicit technical resources that can be presented explicitly in technologies in order to assist humans in managing their interactions with and amidst technical systems gracefully.

Stem cell regulatory gene expression in human adult dental pulp and periodontal ligament cells undergoing odontogenic/osteogenic differentiation

Introduction During development and regeneration, odontogenesis and osteogenesis are initiated by a cascade of signals driven by several master regulatory genes. Methods In this study, we investigated the differential expression of 84 stem cell–related genes in dental pulp cells (DPCs) and periodontal ligament cells (PDLCs) undergoing odontogenic/osteogenic differentiation. Results Our results showed that, although there was considerable overlap, certain genes had more differential expression in PDLCs than in DPCs. CCND2, DLL1, and MME were the major upregulated genes in both PDLCs and DPCs, whereas KRT15 was the only gene significantly downregulated in PDLCs and DPCs in both odontogenic and osteogenic differentiation. Interestingly, a large number of regulatory genes in odontogenic and osteogenic differentiation interact or crosstalk via Notch, Wnt, transforming growth factor β (TGF-β)/bone morphogenic protein (BMP), and cadherin signaling pathways, such as the regulation of APC, DLL1, CCND2, BMP2, and CDH1. Using a rat dental pulp and periodontal defect model, the expression and distribution of both BMP2 and CDH1 have been verified for their spatial localization in dental pulp and periodontal tissue regeneration. Conclusions This study has generated an overview of stem cell–related gene expression in DPCs and PDLCs during odontogenic/osteogenic differentiation and revealed that these genes may interact through the Notch, Wnt, TGF-β/BMP, and cadherin signalling pathways to play a crucial role in determining the fate of dental derived cell and dental tissue regeneration. These findings provided a new insight into the molecular mechanisms of the dental tissue mineralization and regeneration

The role of self-efficacy in dental patients’ brushing and flossing: Testing an extended Health Belief Model

Objective: In an effort to examine the decreasing oral health trend of Australian dental patients, the Health Belief Model (HBM) was utilised to understand the beliefs underlying brushing and flossing self-care. The HBM states that perception of severity and susceptibility to inaction and an estimate of the barriers and benefits of behavioural performance influences people’s health behaviours. Self-efficacy, confidence in one’s ability to perform oral self-care, was also examined. Methods: In dental waiting rooms, a community sample (N = 92) of dental patients completed a questionnaire assessing HBM variables and self-efficacy, as well as their performance of the oral hygiene behaviours of brushing and flossing. Results: Partial support only was found for the HBM with barriers emerging as the sole HBM factor influencing brushing and flossing behaviours. Self-efficacy significantly predicted both oral hygiene behaviours also. Conclusion: Support was found for the control factors, specifically a consideration of barriers and self-efficacy, in the context of understanding dental patients’ oral hygiene decisions. Practice implications: Dental professionals should encourage patients’ self-confidence to brush and floss at recommended levels and discuss strategies that combat barriers to performance, rather than emphasising the risks of inaction or the benefits of oral self-care.