Dental Implants: Modern Materials and Methods of Their Surface Modification

Abstract

The development of dental implantology is based on the detailed study of the interaction of implants with the surrounding tissues and methods of osteogenesis stimulation around implants, which has been confirmed by the increasing number of scientific publications presenting the results of studies related to both the influence of the chemical composition of dental implant material as well as the method of its surface modification on the key operational characteristics of implants. The main materials for dental implant manufacturing are Ti and its alloys, stainless steels, Zr alloys (including ceramics based on ZrO2), and Ta and its alloys, as well as other materials (ceramics based on Al2O3, Si3N4, etc.). The review presents alloy systems recommended for use in clinical practice and describes their physical–mechanical and biochemical properties. However, when getting into the body, the implants are subjected to various kinds of mechanical influences, which are aggravated by the action of an aggressive biological environment (electrolyte with a lot of Cl− and H+); it can lead to the loss of osteointegration and to the appearance of the symptoms of the general intoxication of the organism because of the metal ions released from the implant surface into the biological tissues of the organism. Since the osteointegration and biocompatibility of implants depend primarily on the properties of their surface layer (it is the implant surface that makes contact with the tissues of the body), the surface modification of dental implants plays an important role, and all methods of surface modification can be divided into mechanical, physical, chemical, and biochemical methods (according to the main effect on the surface). This review discusses several techniques for modifying dental implant surfaces and provides evidence for their usefulness.