It cautions that RF ablation devices have not been cleared specifically for lung tumor ablation, and their manufacturers cannot market them for that purpose. The agency said that if a doctor wishes to use these devices for lung tumor ablation, he or she should enroll patients in an approved clinical study, where training is available. The agency has also received reports of serious patient injuries, including third-degree burns, associated with the use of poorly maintained electric dental handpieces. If they are poorly maintained, they may not send any signals about, for example, the bur being too dull or the gears being worn or clogged. Instead, they will send increased power to the handpiece to make up for sluggish performance. This can generate too much heat, leading to patient burns. The agency suggests that practitioners check for worn drills or burs before use, properly maintain their handpieces in accordance with manufacturer recommendations, train personnel to properly clean and maintain them, and not use poorly maintained devices.