“Titanium Exposure to Ozone Increases Osteoblastic Cells Mineralization"
“Dental materials, Titanium, Ozone, Osteoblasts, Alkaline phosphatase, Mineralization"
“It is consensus that the only machined titanium (Ti) surface does not present ideal properties for bone cells. Roughness, chemical composition, and wettability (hydrophilicity) are characteristics of the titanium surface that play a determining role in osseointegration. Objectives: This work aimed to evaluate in vitro the potential of titanium surface treated with ozone to induce mineralization in human osteoblastic cells. Methods: First, we produced discs of titanium grade 5 with 5mm diameter and 2mm thickness by machining. Part of the samples were exposed to ozone as gas at 16µg/cm3 in a continuous flow chamber for 15 hours. Then, Saos-2 osteoblastic cells (ATCC® HTB-85) were cultured with the samples treated with ozone (D-TiOZ) and without ozone treatment (D-Ti). Cells not cultured with titanium disks were the control group (CT). After that, the cells were submitted to 3-(4,5-dimethyl-thiazoyl)-2,5- diphenyl-tetrazolium-bromide (MTT; 1, 2, 3 days); alkaline phosphatase activity assays (ALP; 3, 5, 7 days) and Alizarin Red Staining (ARS, 14 days). The experiments were repeated four times independently (n=12/group). Statistics: ANOVA, Bonferroni post-test (p<0.05). Results: At two days of cell culture, the D-TiOz group had significantly higher mitochondrial dehydrogenase activity than the other groups. At 1d of culture, the D-TiOz group also showed increased ALP (D-TiOz > D-Ti ~ CT). The ALP of the D-Ti group was high only at 5d (D-Ti > D-TiOz > CT). Notably, the ARS results in D-TiOz were consistent with the ALP activity as an early marker of osteoblasts differentiation. After 14d in culture, the D-TiOz had a high concentration of calcium nodules (D-TiOz > D-Ti > CT).
Conclusions: In this study, the titanium treatment with ozone gas improved the material potential to induce osteoblast mineralization. The titanium treatment with ozone gas is a promising strategy to enhance the properties of orthopedics and dental implants.