Analysis of pH and hydrogen peroxide concentration in professional bleaching gels

The objective of the present in vitro study was to measure the pH and hydrogen peroxide concentration of professional bleaching gels and to compare these values with those specified by the manufacturer. Different bleaching agents for professional use whose active agent is hydrogen peroxide in high concentrations were selected. The pH and hydrogen peroxide concentration were analyzed in accordance with the international standard ISO 28399 and the American Dental Association Standard for bleaching agents. In the analysis of the results of the pH measurements, statistically significant differences were found between the values of all the products analyzed. All the groups showed a statistically significant decrease in the H2O2 concentration measured experimentally, with respect to that specified by their respective manufacturer. The discrepancies observed could affect the whitening efficacy expected for both patient and dentist, and must be considered when establishing a treatment plan.El objetivo del presente estudio in vitro, fue medir el pH y la concentración de peróxido de hidrogeno de geles blanqueadores de uso profesional y comparar dichos valores con los especificados por el fabricante. Fueron seleccionados diferentes agentes blanqueadores de uso profesional cuyo agente activo es el peróxido de hidrógeno en altas concentraciones. El pH y la concentración de peróxido de hidrógeno fueron analizados de acuerdo con lo establecido en la norma internacional ISO 28399 y la norma para agentes blanqueadores de la Asociación Dental Americana. En el análisis de los resultados de las mediciones de pH se encontraron diferencias estadísticamente significativas entre los valores de todos los productos analizados. Todos los grupos mostraron una disminución estadísticamente significativa en la concentración de H2O2 medida experimentalmente, con respecto a la especificada por su respectivo fabricante. Las discrepancias observadas pueden afectar la eficacia de blanqueamiento esperada tanto por el paciente como por el dentista, y debe ser considerado a la hora de establecer un plan de tratamiento

Human dentin bond strength of chlorhexidine containing universal adhesive system used in total-etch and self-etch modes

Objetivos: Evaluar la resistencia de unión a la microtracción en dentina humana de un sistema adhesivo universal con clorhexidina en su composición, en modo de grabado y lavado en 2 pasos, y en modo de autograbado. Metodología: 20 terceros molares divididos aleatoriamente en 4 grupos según el tipo de sistema adhesivo utilizado (Single Bond Universal®, 3MESPE y Peak Universal Bond®, Ultradent Products) y modo de uso (grabado total y autograbado). Se confeccionaron cuerpos de prueba sometidos al ensayo de microtracción utilizando una máquina de ensayos universales. Resultados: No se encontraron diferencias estadísticamente significativas entre los cuatro grupos estudiados. Conclusiones: La resistencia de unión de una resina compuesta a dentina humana no fue afectada por el uso de un sistema adhesivo universal que contiene clorhexidina en su composición aplicado en los modos de grabado total y autograbado.Objectives: To evaluate the microtensile bond strength to human dentin of chlorhexidine containing universal adhesive system applied in the total-etch and selfetch modes. Methods: Twenty third molars were randomly divided into four groups according to the universal adhesive system (Single Bond Universal ®, 3M ESPE and Peak Universal Bond®, Ultradent) and application mode used (total-etch and self-etch). Specimens were prepared and subjected to a microtensile bond strength using a MTS SANS universal testing machine. Results: No statistically significant differences were found in the microtensile bond strength between the four groups studied. Conclusions: The bond strength of a composite resin to human dentin was not affected by the use of a universal adhesive system with chlorhexidine in its composition applied in the total-etch and self-etch modes

Residual Adhesive Removal Methods for Rebonding of Debonded Orthodontic Metal Brackets: Systematic Review and Meta-Analysis

Debonding of orthodontic brackets is a common occurrence during orthodontic treatment. Therefore, the best option for treating debonded brackets should be indicated. This study aimed to evaluate the bond strength of rebonded brackets after different residual adhesive removal methods. This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Web of Science, The Cochrane Library, SciELO, Scopus, LILACS, IBECS, and BVS databases were screened up to December 2020. Bond strength comparisons were made considering the method used for removing the residual adhesive on the bracket base. A total of 12 studies were included for the meta-analysis. Four different adhesive removal methods were identified: sandblasting, laser, mechanical grinding, and direct flame. When compared with new orthodontic metallic brackets, bond strength of debonded brackets after air abrasion (p = 0.006), mechanical grinding (p = 0.007), and direct flame (p < 0.001) was significantly lower. The use of an erbium-doped yttrium aluminum garnet (Er:YAG) laser showed similar shear bond strength (SBS) values when compared with those of new orthodontic brackets (p = 0.71). The Er:YAG laser could be considered an optimal method for promoting the bond of debonded orthodontic brackets. Direct flame, mechanical grinding, or sandblasting are also suitable, obtaining clinically acceptable bond strength values

La tecnología de impresión 3D utilizada en odontología

El desarrollo de la tecnología digital abre una puerta de oportunidad en el avance de técnicas y procedimientos que mejoran la eficiencia de las Ciencias de la Salud, entre ellas la Odontología; esta revisión desarrolla algunos avances en diferentes procedimientos clínicos, auxiliados por la impresión 3D, considerando los conceptos básicos y su aplicación clínica en las diferentes ramas de la clínica buco-dental