Buonocore Memorial Lecture 2023: Changing Operative Mindsets with Universal Adhesives and Cements
Adhesive dentistry has undergone significant advancements since its inception, marked by continuous improvements in material performance and adaptability to various dental and restorative substrates. Initially, the anatomical differences between enamel and dentin made adhesive approaches challenging. Early systems were often complex and operator dependent, leading to the development of multistep protocols. However, advancements have led to the creation of more user-friendly self-etch systems and the emergence of universal adhesives (UAs). These UAs can be applied with equal effectiveness to different substrates, including enamel and dentin, simplifying the clinical workflow and enhancing reliability. The concept of universality has recently been extended to other dental materials, most notably universal resin cements. These cements offer a versatile approach as they are capable of both adhesive and self-adhesive bonding, thereby accommodating a wide range of restorative scenarios. The advent of these materials represents a significant advance toward simplifying procedures, reducing technique sensitivity and the likelihood of operator error, and achieving consistently high quality restorations. Current research focuses on further refining these universal materials to enhance their performance, making them a cornerstone of modern adhesive dentistry.SUMMARY
Representative scanning electron microscope (SEM; 15000x) image of enamel surface after 37% phosphoric acid etching. The etching procedure was able to completely remove the smear layer, dissolve hydroxyapatite crystals and create micropatterns intended to enhance the penetration and retention of resin monomers.
SEM image of aprismatic enamel. It is possible to observe the orientation of apatite crystals and the absence of interprismatic organic material. This composition makes this enamel layer particularly resistant to traditional etching procedures (eg, phosphoric acid). The image clearly shows the incomplete response to phosphoric acid etching with the persistence of islets of aprismatic enamel that hamper the creation of microretentive spaces.
SEM image of enamel surface after experimental self-limiting etchant application for 1 minute. Self-limiting etching could be a promising feature to avoid the problem of over-etching while providing effective physio-mechanical modification of the dental substrate surfaces.
Comparison of two phosphoric acid etchants differing in viscosity. Less viscous gels are beneficial for enhancing adhesion, but they are not operator-friendly. More viscous etchants are more manageable and easier to remove.
Characteristics of etch-and-rinse adhesives, traditionally intended as multi-step systems (three or two steps).
Characteristics of two-step self-etch adhesive systems.
The latest simplified version of adhesive systems is referred to as universal and is characterized by versatility and more operator-friendly properties.
Contributor Notes