Ultramorphology of pre-treated adhesive interfaces between self-adhesive resin cement and tooth structures

Abstract

Introduction Convencional resin cements can be used in combination with a total-etch system in a conventional mode or as self-adhesive resin cements. The latter are less technique sensitive and able to bond to dental tissues without previous treatment or adhesive layer and requires only a single step to be applied to dental structures. Objective To compare qualitatively the adhesive interfaces of two self-adhesive resin cements and one conventional resin cement after different tooth surface treatments under scanning electron microscopy. Material and method 42 crowns of bovine incisors were sectioned and flattened exposing enamel (E) or dentine (D) substrate. Subgroups were defined according to conditioning type and time: E1—no treatment, E2—37% phosphoric acid for 15 seconds, E3—37% phosphoric acid for 30 seconds; D1—no treatment, D2—37% phosphoric acid for 5 seconds; D3—11.5% polyacrylic acid for 15 seconds. A resin block was bonded to each substrate using the self-adhesive resin cements RelyX U100 (3M ESPE) and RelyX U200 (3M ESPE). As a reference hybrid layer, six resin blocks were luted with RelyX ARC and Scotchbond Multi-Purpose adhesive system (3M ESPE) (enamel—EA; dentine—DA). After aging for 7 days in a moist environment at 37±1°C, samples were prepared for microscopy analysis. Result and Discussion In the ARC specimens, there was hybrid layer formation in both EA and DA. U100 E1 showed gaps at the adhesive interface, while E2 and E3 showed interaction for both self-adhesive cements. There was superficial interaction with bothU100 and U200 in D1, while in D2 and D3, resin tags were only observed in the case of U100. Conclusion It was concluded that substrate conditioning may enhance the interaction between self-adhesive resin cements and dental tissues, although this is not the case for RelyX U200 and dentine.

Development of a Hybrid Biomimetic Enamel-Biocomposite Interface and a Study of Its Molecular Features Using Synchrotron Submicron ATR-FTIR Microspectroscopy and Multivariate Analysis Techniques

“…Current breakthrough studies demonstrate that the use of buffer systems when forming a hybrid biomimetic layer, including amino acids and alkalis, should contribute to the improved integration of synthetic systems with the dental hard tissue [ 25 , 26 , 27 , 28 ]. The introduction of amino acids and alkalinization under given conditions should increase the hierarchical organization of the pretreated organomineral matrix of apatite [ 8 , 29 , 30 , 31 ]. Thus, in our previous work, it was shown that the pretreatment of enamel in the alkaline solution of Ca(OH) 2 and an amino acid booster, and the following mineralization performed with the use of hydroxyapatite (HAp), resulted in the formation of a mineralized layer with homogeneous micromorphology and presumable orientation of HAp nanocrystals [ 32 , 33 ].…”

Organic-Mineral Interaction between Biomimetic Materials and Hard Dental Tissues

“…At the same time, numerous studies focus on the interaction of synthetic material with dental tissues as well as formation of a biomimetic buffer layer at the interface between the natural hard dental tissue and the dental composite [2][3][4][5] supposed to act as a link between two heterogeneous materials.…”

“…Despite the recent advances in dental materials science, the cements and filling materials employed to restore the anatomic bases of human teeth or their parts have low affinity for the teeth enamel and dentin [ 1 , 2 ]. As a result, there is poor adhesion and secondary caries most likely to occur at the boundary of dental filling materials and the enamel [ 2 ]. In this regard, improving the integration of applied or developed materials with the dental matrix is a challenge of modern dentistry [ 1 , 3 ].…”

Efecto de la aplicación de ácido poliacrílico a dentina en dos intervalos de tiempo sobre la resistencia de unión de tres cementos resinosos autoadhesivos

“…Esta capa formada por dentina subyacente contiene restos de colágeno, hidroxiapatita en polvo mezclados con restos contaminantes como saliva, bacterias y otros. 17,29 Se adhiere firmemente y es difícil de remover con aire y/o agua, posee un espesor de 0.5 a 5.0 µm reduciendo la permeabilidad dentinaria hasta en 86%. 17 Si bien es cierto que estos agentes cementantes tienen en su composición monómeros ácidos, estos no son lo suficientemente fuertes para infiltrarse a través del barro dentinario y formar tags de resina.…”

“…Regularmente se utiliza el ácido poliacrilico entre el 10% y el 25% de concentración para modificar o disolver el barro dentinario, limpiar la preparación e impregnan los tejidos, todo esto para mejorar la adhesión del cemento a la dentina. 16,28 El ácido poliacrílico remueve parcialmente el barro dentinario y contaminantes superficiales, cambiando así la energía superficial, 29,30 mejorando la humectabilidad superficial y exponiendo la estructura mineralizada dental para la difusión del ácido de los cementos autoadhesivos mejorando el intercambio iónico. 22,23 El pH en promedio del ácido poliacrílico es de 1.5 a 2 y esto dependerá de la concentración que tenga, a pesar de su naturaleza acida produce una irritación mínima en la pulpa ya que es un ácido de naturaleza débil.…”