Those same antiseptic qualities also make frankincense oil a useful preventative measure against oral issues, like bad breath, toothaches, cavities, mouth sores, and other infections. Look for natural oral care products that include frankincense oil if you enjoy the flavor or aroma, and want to include a strong antiseptic in your health regimen. You can even create your own all-natural toothpaste with frankincense oil and baking soda or a mouthwash with water and peppermint oil.