Darren Gardner DDS, Provo Dentist
Diet is the Most Important Factor
While many credit "soft teeth" for their cavities, tooth decay is caused by a diet where sugar is frequently contacting the teeth in some form or another throughout the day. Almost everyone who is is prone to decay has a specific habit (like sipping on a soda all day) in which sugar soaks the teeth multiple times a day. These habits account for almost 100% of all decay! If you can identify the habit and eliminate it, the decay will stop developing. Substituting the habit with sugarless foods or diet beverages can also help reduce decay. We can eliminate the decay through dental restorations, but if the habit continues, it will come back and become more and more expensive each time the restorations have to be replaced. Restorations won't last as long, and eventually, you will lose teeth.
Cavities are Contagious!
Decay is caused by a specific bacteria in dental plaque that takes sugars and starchy foods and turns them into acid. This acid dissolves the teeth and forms holes, or cavities in the teeth. Cavities are basically a bacterial infection.
These bacteria multiply in the presence of sugar. If there are high levels of this bacteria multiplying within cavities, teeth that don't have cavities are more likely to get cavities, and existing cavities will progress more rapidly. (This is why removing all decay ASAP is important.) This bacteria may also be transmitted to other people through saliva and cause them to get cavities! Read this for more about contagious cavities! http://healthland.time.com/2011/04/07/are-cavities-really-contagious/
Controlling Decay
Decay can be controlled by removing and killing this bacteria by: limiting the frequency of sugar intake, having cavities filled with dental fillings, regular 6 month cleanings and exams, frequent brushing (2-3 times daily), daily flossing, using a fluoride toothpaste and mouthwash, and using xylitol products. Eating sugary foods only at mealtimes (breakfast, lunch, and dinner), also gives the saliva time to wash and protect the teeth from decay and prevents cavities from developing.