Causes of degradation of titanium dental implants

Abstract

Corrosion is one of the main processes that cause problems when using metal implants in the environment of the human body. Due to its properties, titanium and its alloys are currently the most widely used biocompatible materials. But the use of implants made of titaniumbased alloys is not always successful. The purpose of our research was to establish the reasons for the rejection of a Swiss firm’s dental implant made of Grade 5 titanium alloy. Implanted in the patient’s jawbone, it worked as a support for an artificial tooth. But after 1 year of operation, inflammatory processes began at the implantation site, which ultimately led to rejection of the implant. To establish the material science reasons for this, we conducted microstructural studies using an electron microscope Zeiss EVO 40XVP. The sample was metallograpically prepared by grinding, polishing, and etching by using Kroll’s Reagent. A statistical image processing program was used to estimate the quantitative ratio of the phase components of the implant alloy Image J. Elemental analysis and mapping elements were also performed to know the compositional and distribution of each element Ti, Al and V by using energy dispersive X-Ray spectroscopy coupled in SEM. The hardness value was determined using Vickers microhardness tester. The conducted studies established that the working surface of the implant suffered corrosion damage during operation. The edges of the implant are uneven with open and closed pitting. In some places, the merging of several pittings is observed, which leads to the occurrence of ulcerative corrosion. Elemental analysis established the redistribution of chemical elements in the surface layers as a result of contact with the biological environment of the human body. Unstable compounds are created on the surface, which dissolves in the human body during use. As it follows from the conducted studies, the degraded surface of the dental implant needs additional protection.