1. X-ray Detection
The outer layer of teeth (the enamel) is the hardest material in your body, and it is difficult for the bacteria to make a hole in it. However, once the bacteria get through the enamel and into the softer second layer (the dentine), they rapidly destroy the dentine, making a large cavern of decay underneath seemingly intact enamel.
X-rays are used to show up these areas of decay in the dentine, and are especially useful for decay that occurs in-between teeth. The sooner the decay is detected, then the simpler will be the necessary treatment to repair the damage, and the stronger the tooth will remain.
How often are X-rays taken?
It is usually advised that first X-rays for children commence at 6-8 years old. Follow-up X-rays may be taken at:
- Every 12 months where there are many previous fillings and where there are many areas of fresh decay;
- Every 18-24 months where ther are many previous fillings but the teeth have no current decay and are well cared-for;
- Every 24-36 months for teeth very few or nil previous fillings, and are well cared-for.
What if I am pregnant?
With dental X-rays, the direction of the beam is always directed sideways into the head of the patient, well away from the abdomen and the developing child. Modern X-ray machines have insignificant scatter. There is no longer a requirement for lead shielding as was necessary with older, less accurate machines.
2. Laser detection with the Diagnodent
Traditionally, dentists use a metal probe to feel in the biting grooves of teeth to try and detect softened decay. This is not very accurate, and can miss some of the smaller holes.
Whereas X-rays are very good for detecting holes in-between teeth, the Diagnodent is better for detecting holes in the top grooves of teeth. A laser is directed into the grooves and bounces off the deeper layers. If there is decay, then the reflected laser changes wavelength. This is detected and measured by the control unit to give a numerical read-out.
