Dear Colleagues,

In the last years, the endodontic and adhesive dentistry fields have been thoroughly changed thanks to great innovations proposed both in terms of materials and techniques. The advances in technology have led to the introduction of performant materials, especially regarding the chemo-mechanical disinfection and obturation of endodontic systems. As a matter of fact, the development of innovative designs of nickel-titanium rotary instruments in combination with heat treatments has guaranteed levels of predictability of root canal shaping never seen before. Despite this, the success of orthograde endodontics does not depend exclusively on mechanical root canal debridement but is based mainly on its chemical disinfection. The introduction of irrigants activators has led to an increase in bacteria eradication and smear layer removal, guaranteeing a higher percentage of long-term success. Regarding this, researchers have proposed alternative irrigants to the traditional sodium hypochlorite and EDTA, introducing the concept of continuous chelation. The actual potential of those innovations should be addressed more intensively, providing scientific data to support those concepts. Moreover, the its relationship with the healing process and inflammation pathways in terms of cytotoxicity, biological effects and bacterial eradication are still unclear.

Nevertheless, the long-term outcome is not influenced only by the chemo-mechanical disinfection of the endodontic system but also by the obturation quality of both coronal and apical zones, preventing the recolonization or replication of persisting bacteria. Also regarding this, the innovations have allowed clinicians to count on efficient materials with interesting biological and physio-chemical properties such as hydraulic sealers. Despite this, current data are still scarce and further research is needed, especially regarding in vivo studies with long-term follow-ups.

Moreover, recent studies have investigated the effects of those innovative materials on the human periodontal ligament and particularly on its stem cell. Despite this, the data are still scarce and further research should be conducted, particularly on the consequences of hydraulic sealers extrusion and its effect on the inflammation pathway and healing process.

In conclusion, this special issue will include all articles regarding the whole endodontic process, particularly focusing on all areas of cellular and molecular biology related to endodontic and adhesive restorative procedures.

Dr.  Alessio Zanza, Prof. Luca Testarelli and Dr. Rodolfo Reda
Guest Editors