i've had dentures (upper and lower) for the last 15 years. best thing i've ever done due to neglected care, my health actually improved (less gum and teeth infections) . i've had 3 heart attacks, triple by pass, cancer, fatty liver and as my med team says "you have a host of issues" .you will have to listen to your self enunciate your words when you sing (try recording your singing to tweak your style) other than that no major problems will happen. best of luck , you'll be glad you did it. at 72 be proud of the fact that you are still performing. i'm 65 and i miss it. i stopped playing 6 years ago.