Sol-gel dip-coated TiO 2 nanofilms reduce heat production in titanium alloy implants produced by microwave diathermy.

Objective: To verify that the TiO 2 nanofilm dip-coated by sol-gel can reduce titanium alloy implants (TAI)'s heat production after microwave diathermy (MD). Methods: The effect of 40 W and 60 W MD on the titanium alloy substrate coated with TiO 2 nanofilm (Experimental Group) and the titanium alloy substrate without film (Control Group) were analyzed in vitro and in vivo . Changes in the skeletal muscle around the implant were evaluated in ex vivo by histology. Results: After 20 min of MD, in vitro the temperature rise of the titanium substrate was less in the Experimental Group than in the Control Group (40 W: 1.4 °C vs. 2.6 °C, p  < .01, 60 W: 2.5 °C vs. 3.7 °C, p  < .01) and in vivo , the temperature rise of the muscle tissue adjacent to TAI was lower in the Experimental Group than in the Control Group (40 W: 3.29 °C vs. 4.8 °C, p  < .01, 60 W: 4.16 °C vs. 6.52 °C, p  < .01). Skeletal muscle thermal injury can be found in the Control Group but not in the Experimental Group. Conclusion: Sol-gel dip-coated TiO 2 nanofilm can reduce the heat production of TAIs under single 40～60 W and continuous 40 W MD and protect the muscle tissue adjacent to the implants against thermal injury caused by irradiation.