Patients must challenge dentists who insist they return for a check-up every six months, the country's most senior dentist has urged - amid warnings that dental treatment is becoming a "rich man's hobby".

Dr Sara Hurley compared dentists to mechanics and said patients should not "blindly adhere" to instructions to come back frequently.

Current guidelines say that time between check-ups should depend on the state of a patient’s teeth, with intervals of up to two years for those in good oral health.

But the chief dental officer for England said too many dentists are failing to stick to this and seeing patients more regularly.

Private check-ups can cost up to £120, while NHS visits are £19.70.