Background: The new frontiers of computer-based surgery, technology, and material advances, have allowed for customized 3D printed manufacturing to become widespread in guided bone regeneration (GBR) in oral implantology. The shape, structural, mechanical, and biological manufacturing characteristics achieved through 3D printing technologies allow for the customization of implant-prosthetic rehabilitations and GBR procedures according to patient-specific needs, reducing complications and surgery time. Therefore, the present narrative review aims to elucidate the 3D-printing digital radiographic process, materials, indications, 3D printed manufacturing-controlled characteristics, histological findings, complications, patient-reported outcomes, and short- and long-term clinical considerations of customized 3D printed mesh, membranes, bone substitutes, and dental implants applied to GBR in oral implantology. Methods: An electronic search was performed through MEDLINE/PubMed, Scopus, BioMed Central, and Web of Science until 30 June 2024. Results: Three-dimensionally printed titanium meshes and bone substitutes registered successful outcomes in vertical/horizontal bone defect regeneration. Three-dimensionally printed polymeric membranes could link the advantages of conventional resorbable and non-resorbable membranes. Few data on customized 3D printed dental implants and abutments are available, but in vitro and animal studies have shown new promising designs that could improve their mechanical properties and tribocorrosion-associated complications. Conclusions: While 3D printing technology has demonstrated potential in GBR, additional human studies are needed to evaluate the short- and long-term follow-up of peri-implant bone levels and volumes following prosthetic functional loading.

Performing endodontic treatment on a tooth with an immature apex can be challenging due to the risk of irrigant extrusion beyond the apex. This narrative review investigates the over-apex extrusion of activated irrigants in teeth with open and immature apices and aims to provide crucial insights for practice and research. Two hundred fifty-two results were found from the electronic search. Sixteen duplicates were removed before selection, and 24 were excluded. Of the 212 remaining results, the full text was evaluated for eligibility. One hundred ninety-four results were excluded: in one hundred sixty-five, irrigant activation was not performed; twenty-nine were animal studies; in seven, irrigant activation was not performed to disinfect the canal. Finally, 13 studies were included. They cover a range of topics, from the types of irrigants used to the techniques of activation, and their findings contribute to our understanding of the risks and consequences of irrigant extrusion. All the activation techniques investigated can, to varying degrees, cause the irrigant to extrude beyond the apex. Extrusion may not always be clinically relevant; however, the consequences of excessive irrigant leakage from the apex are dangerous, so try to assess all the variables that may cause it and adopt techniques to reduce it.