ABSTRACT
Los sistemas adhesivos autograbadores han permitido mejorar los procedimientos clínicos tanto en la evolución de los componentes y su funcionamiento, como en la disminución del tiempo operatorio de aplicación de cada uno de ellos. Estos sistemashan sido sometidos en la última década a constantes pruebas clínicas y de laboratorio, con el objetivo de valorar su desempeño. Sus múltiples ventajas contrastan con su baja efectividad en cuanto resistencia de unión y su permeabilidad que permite formar gotas de agua en la interfase adhesiva favoreciendo la nanofiltración. Como los sistemas adhesivos autograbadores presentan menor confiabilidaden cuanto a resistencia de unión y nanofiltración, comparados con los adhesivos de cuarta y quinta generación, son estos los que semantienen como estándar de oro para estudios comparativos, ya que continúan con el protocolo de grabado ácido con ácido ortofosfóricoal 35 o 37%. El objetivo de este artículo de revisión es presentar la evolución de los sistemas adhesivos autograbadores y discutir las variables de resistencia de unión y nanofiltración que intervienen en su pobre desempeño, permitiendo al clínico tener fundamentos para la crítica y adecuada selección del sistema adhesivo empleado.
Self-etching adhesive systems have greatly enhanced clinical procedures as they have allowed not only developingcomponents and their functions but also reducing application times. During the latest decade they have been subjected to permanent clinical and experimental tests in order to assess their performance. Their multiple advantages contrast to their low effectiveness interms of bond strength and permeability, as water drops develop on the adhesive interface, thus favoring nanofiltration. As self-etching adhesive systems offer lower reliability in relation to bond strength and nanofiltration in comparison to adhesives of fourth and fifthgeneration, the latter stand as the golden standard for comparative studies, as they keep using the acid etching protocol, by means of 35 or 37% ortophosphoric acid. The goal of this review article is to present the evolution of self-etching adhesive systems and to discuss bond strength and nanofiltration as variables that intervene in their poor performance, providing dentists with the fundamentals for a critical accurate selection of etching systems.
Subject(s)
Dental Cements , Dental LeakageABSTRACT
The objectiveness of this study was to evaluate whether low-viscosity composite can bond effectively to dentin surface without bonding resin. The low-viscosity composites being 50wt% filler content were made by the inclusion of bonding resin of two self-etching systems(Clearfil SE Bond, Unifil Bond) varied with contents as 0, 10, 20, 30, 40, 50wt%. Exposed dentin surfaces of extracted 3rd molars are used. Dentin bond strengths were measured. The tests were carried out with a micro-shear device placed testing machine at a CHS of 1mm/min after a low-viscosity composite was filled into an iris cut from micro tygon tubing with internal diameter approximately 0.8mm and height of 1.0mm. 1. Flexural strength and modulus was increased with the addition of bonding resin. 2. Micro-shear bond strength to dentin was improved according to content of bonding resin irrespective of applying or not bonding resin in bonding procedure, and that of Clearfil SE Bond groups was higher than Unifil Bond. 3. There were no significant difference whether use of each bonding resin in bonding procedure for S-40, S-50, U-50(p>0.05). 4. In SEM examination, resin was well infiltrated into dentin after primed with self-etching primer only for S-50 and U-50 in spite of the formation of thinner hybrid layer. Low viscosity composite including some functional monomer may be used as dentin bonding resin without an intermediary bonding agent. It makes a simplified bonding procedure and foresees the possibility of self-adhesive restorative material.