The recommendations are:
For decay assessment:
If it is your first visit at the dentist and you have had a lot of fillings in the past or decay is detected in your teeth, radiographs are recommended.
If it is a recall visit and you have had decay in the past and considered high risk of recurring decay, radiographs are recommended at 6-18 months interval for adults and 6-12 months interval for children of up to 11 years of age.
If it is a recall visit and you have not had fillings and is considered at low risk of decay, radiographs are recommended at 24- 36 months interval for adults and 12-24 months interval for children.
For gum disease monitoring:
When gum disease is present, specific radiographs a required to assess its severity atdifferent intervals depending on the case to determine whether there is progression or stabilisation of the disease. The frequency is decided by the dentist based on clinical judgement.
For post-treatment monitoring:
In cases where a patient has received more complex treatment like implants, root canal treatment or crown and bridge work, radiographs might be necessary to ensure the restoration or treatment site is being maintained in good health. Again, frequency is determined by clinical judgement.
Reference: Dental radiographic examinations: recommendations for patient selection and limiting radiation exposure. American Dental Association. Council on Scientific Affairs. 2012