In dentistry, estimations of the risk of failure of treatments focused on dental fear reduction are particularly high (about 60%). Research data on this subject are lacking. Failure has been defined as a treatment whose aim, sufficient reduction of fear to make possible treatment in a general dental practice, has not been achieved. Nine different types of risk may be the cause of a treatment failure: insufficient motivation, fear greater than the capacity to cope with it, co-morbidity, trouble with entering into a patient-care provider relation, inaccurate treatment indication or treatment strategy, patient too dependent on care provider, treatment insufficiently fulfilling demand, damage to the patient-care provider relation, and accident during treatment.