How can I further prevent the decay of my teeth?

Cut out sugar. Cut down on carbs, especiallu sugar. Brush more.
Dentist,good hygiene. Maintain good oral hygiene by brushing your teeth thoroughly at least twice a day with a fluoridated toothpaste, and flossing at least once a day. Regular dentist visits for cleaning and a checkup are crucial and recommended at least every 6 months. If you have any cavities, get them filled; and if you smoke, stop. Avoiding sugary drinks & sodas, plus avoiding sugary starchy snacks, also helps.
See dentist and... Seeing a dentist 2-3 times a year, brushing and flossing well, not drinking sugared nor acidic drinks, not smoking, keeping healthy gums, using Fluoride if needed, etc... Will keep teeth healthy. Saliva is needed, so conditions that decrease saliva need treatment.
Sugars/Acidity. Along with reducing your consumption of sugars and acidic foods and bevs make sure that your salivary glands are working properly. Many medications and nicotine can cause the mouth to dry out. Dry mouth will increase your risk for cavities. Brush with fluoridated tooth paste, don't snack too much, chew sugarless gum with xylitol. Go to www.Carifree.Com for more info about prevention. Great site.