Tea Tree has a long history as an antimicrobial oil, and has been researched for its effectiveness on many bacteria, fungi and even viruses. It is a strong oil with a strong aroma and should be used sparingly. It is a useful first aid option for cuts, scrapes and bruises, and has traditionally been used in many oral hygiene products to help with mouth sores and infections as well as sore throats. Some studies have shown that tea tree in combination with other essential oils, such as geranium and oregano, may be able to control MRSA (a common drug-resistant staph infection).