The effects of total-etch, wet-bonding, and light-curing of adhesive on the apical seal of a resin-based root canal filling system / 대한치과보존학회지

OBJECTIVES: This study evaluated the effects of adhesion variables such as the priming concepts of canal wall and the curing modes of adhesives on the sealing ability of a resin-based root canal filling system. MATERIALS AND METHODS: Apical microleakage of the Resilon-RealSeal systems filled with 3 different combinations of adhesion variables was compared with the conventional gutta-percha filling using a dye penetration method. Experimental groups were SEDC, Resilon (Resilon Research LLC) filling with self-etch RealSeal (SybronEndo) primer and dual-cure RealSeal sealer; NELC, Resilon filling with no etching, Scotchbond Multi-Purpose (3M ESPE) primer application and light-curing adhesive; and TELC, Resilon filling with Scotchbond Multi-Purpose primer and adhesive used under total etch / wet bonding and light-cure protocols. GPCS, gutta-percha filling with conventional AH26 plus sealer, was the control group. RESULTS: The median longitudinal dye penetration length of TELC was significantly shorter than those of GPCS and SEDC (Kruskal-Wallis test, p < 0.05). In the cross-sectional microleakage scores, TELC showed significant differences from other groups at 2 to 5 mm from the apical foramen (Kruskal-Wallis test, p < 0.05). CONCLUSIONS: When a resin-based root canal filling material was used, compared to the self-etching primer and the dual-cure sealer, the total etch/wet-bonding with primer and light-curing of adhesive showed improved apical sealing and was highly recommended.

Reflections about adhesive systems / Reflexiones acerca de los sistemas adhesivos

The adhesive systems are responsible for an efficient union between teeth and resin, resulting in a longevity restoration. They are organic molecules di or multifunctional that contain reactive groups that interact with dentin and with the resin monomer of composite resin. The adhesive systems are characterized by wet adhesion, which is a result of presence of hidrophylics radicals in their compositions, to promote a better bond and the best properties of the adhesion. Adhesive systems may use two different strategies to interact with the dental structure: total-etching and self-etching technique. The total-etching systems require a conditioning, a rinsing and a priming step in order to allow involvement of collagen fibers by the resin monomers and the formation of the so-called ‘hybrid layer’. The total-etching promotes the cleaning of dentin, also promotes superficial demineralization and delivers collagen fibrils to participate of an interface union mechanism teeth/ adhesive system/restorative material. Self-etching adhesive systems are characterized by demineralization and infiltration of resin monomers simultaneously. This technique is attractive because reduced sensitivity associated with retaining the smear layer and smear plugs, thereby, minimize the possibility of inadvertent contamination of the bonding surface with dentinal surface through dentinal fluid transudate.

Los sistemas adhesivos son responsables de una unión eficaz entre los dientes y la resina, dando como resultado una restauración durable. Son moléculas orgánicas bi o multifuncionales que contienen grupos reactivos que interactúan con la dentina y con el monómero de resina de composite. Los sistemas adhesivos se caracterizan por la adhesión húmeda, que es el resultado de la presencia de radicales hidrofílicos en sus composiciones, para promover una mejor adherencia y las mejores propiedades de la adhesión. Los sistemas adhesivos pueden utilizar dos estrategias diferentes para interactuar con la estructura dental: Técnica de grabado total y auto-grabado. Los sistemas de grabado total requiere un acondicionamiento, un lavado y un paso de priming con el fin de permitir la participación de las fibras de colágeno por los monómeros de resina y la formación de la llamada capa híbrida. El grabado total promueve la limpieza de la dentina, también promueve la desmineralización superficial y condiciona a las fibrillas de colágeno para participar de un mecanismo de interfaz de unión diente/sistema adhesivo /material de restauración. Los sistemas adhesivos autograbantes se caracterizan por la desmineralización y la infiltración de los monómeros de resina de forma simultánea. Esta técnica es atractiva debido a la sensibilidad reducida asociada a conservar la capa de barro dentinario y tapones de barro dentinario, reduciendo al mínimo la posibilidad de contaminación accidental de la superficie de unión con la superficie de la dentina a través del líquido dentinario trasudado.