Adhesión convencional en dentina, dificultades y avances en la técnica / Conventional dentin bonding. Difficulties and progress in the technique

RESUMEN

INTRODUCCIÓN: estudios respecto a la adhesión en dentina han reportado que, contrario a la estabilidad lograda sobre esmalte dental, en dentina los mecanismos adhesivos todavía son sensibles, impredecibles e inestables. El objetivo de este trabajo es revisar la literatura actual sobre la adhesión en dentina, con el fin de caracterizar la adhesión convencional describiendo las modificaciones actuales del protocolo convencional, encaminadas a mejorar el desempeño adhesivo de los materiales dentales. Métodos: se hizo una revisión de la literatura evaluando 3 bases de datos ScienceDirect, Springer y Medline, de las cuales se escogieron los 52 artículos más relevantes, publicados entre los años 2004 y 2013. Se usaron, como criterios de búsqueda, las palabras clave dentin, dentin bonding, bond strength y acid etching. Resultados: al revisar los artículos seleccionados, se logró una descripción del protocolo de adhesión convencional que muestra la formación del barrillo dentinario (smear layer), la acción del ácido fosfórico y la formación de la interfase adhesiva propiamente dicha, junto con las dificultades propias de la técnica y las posibles soluciones planteadas hasta la fecha. Conclusión: la adhesión convencional sobre dentina es un procedimiento estricto y delicado, que evidencia inconvenientes como la degradación hidrolítica y proteolítica de la matriz de colágeno por parte de enzimas liberadas en el momento de la desmineralización, lo que deteriora la interfase adhesiva. Por tanto, se han sugerido sustancias que pueden ser utilizadas como agentes de protección del colágeno, sin alterar e incluso mejorando la resistencia adhesiva.

ABSTRACT

INTRODUCTION: studies on dentin bonding have reported that, contrary to the achieved stability on dental enamel, adhesive mechanisms on dentine are still sensitive, unpredictable, and unstable. The objective of this study is to review the current literature on dentin bonding in order to characterize conventional bonding, describing current modifications of the conventional protocol aimed at improving the adhesive performance of dental materials. METHODS: a literature review was conducted within 3 databases ScienceDirect, Springer, and Medline, choosing the 52 most relevant articles published between 2004 and 2013. The following key words were used as search criteria dentin, dentin bonding, bond strength, and acid etching. RESULTS: the review of the selected articles provided a description of the conventional adhesion protocol showing the formation of smear layer, the action of phosphoric acid, and the actual formation of adhesive interface, as well as the difficulties of the technique and possible solutions suggested to date. CONCLUSIONS: conventional dentin bonding is a precise and delicate procedure that shows disadvantages such as the hydrolytic and proteolytic degradation of collagen matrix by enzymes released at the time of demineralization, which damages the adhesive interface. Therefore, several substances have been suggested to be used as agents of collagen protection without altering adhesive strength, and even improving it.studies on dentin bonding have reported that, contrary to the achieved stability on dental enamel, adhesive mechanisms on dentine are still sensitive, unpredictable, and unstable. The objective of this study is to review the current literature on dentin bonding in order to characterize conventional bonding, describing current modifications of the conventional protocol aimed at improving the adhesive performance of dental materials. Methods: a literature review was conducted within 3 databases ScienceDirect, Springer, and Medline, choosing the 52 most relevant articles published between 2004 and 2013. The following key words were used as search criteria dentin, dentin bonding, bond strength, and acid etching. Results: the review of the selected articles provided a description of the conventional adhesion protocol showing the formation of smear layer, the action of phosphoric acid, and the actual formation of adhesive interface, as well as the difficulties of the technique and possible solutions suggested to date. Conclusion: conventional dentin bonding is a precise and delicate procedure that shows disadvantages such as the hydrolytic and proteolytic degradation of collagen matrix by enzymes released at the time of demineralization, which damages the adhesive interface. Therefore, several substances have been suggested to be used as agents of collagen protection without altering adhesive strength, and even improving it.