Contemporary restorative ion-releasing materials: current status, interfacial properties and operative approaches

Minimally invasive (MI) concepts in restorative dentistry in the year 2020 request from the practitioner not only a scientifically supported rationale for carious tissue removal/excavation and defect-oriented, biological cavity preparation, but also a deep understanding of how to ensure a biomechanically stable and durable restoration in different clinical situations by applying different restorative options. Bio-interactive materials play an increasingly relevant role, as they not only replace diseased or lost tissue, but also optimise tissue mineral recovery (among other properties) when used in restorative and preventive dentistry. Indeed, this is of certain interest in MI restorative dentistry, especially in those cases where gap formation jeopardises the integrity of the margins along resin composite restorations, causing penetration of bacteria and eventually promoting the formation of secondary caries. Recently, the interest in whether ion-releasing materials may reduce such biofilm penetration into margin gaps and reduce such a risk for development and propagation of secondary caries is growing significantly among clinicians and scientists. The aim of this article was to explore mechanisms involved in the process that allow mineral deposition at the interface between such materials and dentine, and to describe how conventional 'bioactive' restorative materials currently available on the market may benefit treatments in MI dentistry. Key points Explores the mechanisms involved in the process that allows mineral deposition at the interface between such materials and dentine, and describes how conventional 'bioactive' restorative materials currently available on the market may be beneficial for treatments in minimally invasive (MI) dentistry. Different carious tissue removal methods are currently available. However, chemo-mechanical methods reach a compromise between MI tissue removal to protect the pulp and an 'adhesion-friendly' substrate to enable successful restoration placement and interfacial longevity. Contemporary 'therapeutic' bio-interactive materials should now be used for tissue replacement, as they may be able to reduce the susceptibility of tooth mineral to dissolution and/or to recover its mechanical properties via remineralisation.