In a perfect world everyone would brush and floss twice a day. Plaque builds up over time and this sticky bacterial film can solidify and turn into calculus or tartar. This cement-like substance is removed by the hygienist at your regular cleaning visits. A six-month interval not only serves to keep your mouth healthy and clean, it allows potential problems to be found and diagnosed earlier.
In some instances a six-month schedule in not enough. Based on your dental history, rate of calculus buildup, and pattern of decay a 3 or 4 month interval may be needed. Your dentist can work with you to determine what will be best for you.
Also, Dental insurance companies came up with the idea for people to have two teeth cleanings per year. An insurance company recommends what is average. At Blue Apple, and many other dental offices in CA and the US, three teeth cleanings per year is becoming more standard to help battle gum disease and keep a healthy mouth.