The biological activity, biocompatibility, and corrosion resistance of implants depend primarily on titanium dioxide (TiO₂) film on biomedical titanium alloy (Ti6Al4V). This research is aimed at getting an ideal temperature range for forming a dense titanium dioxide (TiO₂) film during titanium alloy cutting. This article is based on Gibbs free energy, entropy changes, and oxygen partial pressure equations to perform thermodynamic calculations on the oxidation reaction of titanium alloys, studies the oxidation reaction history of titanium alloys, and analyzes the formation conditions of titanium dioxide. The heat oxidation experiment was carried out. The chemical composition was analyzed with an energy dispersive spectrometer (EDS). The results revealed that titanium dioxide (TiO₂) is the main reaction product on the surface below 900°C. Excellent porous oxidation films can be obtained between 670°C and 750°C, which is helpful to improve the bioactivity and osseointegration of implants.

In a study published in 2022 in the journal Particle and Fibre Technology, researchers examined the impact of maternal exposure to titanium dioxide nanoparticles in newborn offspring mice. They found that “a chronic exposure to TiO2 NPs during pregnancy alters the respiratory activity of offspring, characterized by an abnormally elevated rate of breathing.” Breathing was also shown to be “significantly and abnormally accelerated,” and the ability for neural circuitry to effectively adjust breathing rates was impaired. The researchers concluded: “Our findings thus demonstrate that a maternal exposure to TiO2 NPs during pregnancy affects the normal development and operation of the respiratory centers in progeny.”

In a small study published in the European Journal of Nutrition in 2020, researchers examined the effects of several food additives, including titanium dioxide, along with artificial sweeteners and cleaning products by testing the fecal samples of 13 people. Titanium dioxide was among the samples that “induced significant shifts in microbiome community structure.”  The growth of the bacterium species belonging to C. leptum, which has been shown to decrease in patients with inflammatory bowel disease, “significantly decreased in the presence of … titanium dioxide” among other additives and sweeteners tested.

For a mini-review published in the journal Particle and Fibre Technology in 2021, scientists wanted to evaluate whether Ti02 particles contributed to the development and/or exacerbation of irritable bowel disease, and whether they altered the four elements of intestinal barrier function: the intestinal microbiota, the immune system, the mucus layer, and the epithelium. The breakdown of these four elements can contribute to autoimmune, neurological, inflammatory, infectious, and metabolic diseases. Following their review, the researchers concluded: “Data indicate that TiO2 is able to alter the four compartments of IBF and to induce a low-grade intestinal inflammation associated or not with pre-neoplastic lesions.” 

In addition to sunscreen, titanium IV oxide is also used in the production of paints. Titanium dioxide is a popular pigment in the paint industry because of its brightness and opacity. It provides excellent coverage and durability, making it an ideal choice for exterior and interior paints. Titanium dioxide is often used in white paints, but it can also be used to create a wide range of colors by mixing it with other pigments.

In a study published in the journal Environmental Toxicology and Pharmacology in 2020, researchers examined the effects of food additives titanium dioxide and silica on the intestinal tract by grouping and feeding mice three different food-grade particles — micro-TiO2, nano-TiO2, and nano-SiO2.  With all three groups, researchers observed changes in the gut microbiota, particularly mucus-associated bacteria. Furthermore, all three groups experienced inflammatory damage to the intestine, but the nano-TiO2 displayed the most pronounced changes. The researchers wrote: “Our results suggest that the toxic effects on the intestine were due to reduced intestinal mucus barrier function and an increase in metabolite lipopolysaccharides which activated the expression of inflammatory factors downstream. In mice exposed to nano-TiO2, the intestinal PKC/TLR4/NF-κB signaling pathway was activated. These findings will raise awareness of toxicities associated with the use of food-grade TiO2 and SiO2.”