It depends on many factors such as the available bone, chewing, general health of the patient and finally the economic factor. No matter the age, but certainly plays a role meticulous oral hygiene of the patient.
Cases where the implants may be affected or have an increased risk of failure are heavy smokers, who make excessive use of alcohol, patients with untreated periodontitis, patients undergoing radiation therapy, patients with uncontrolled diabetes, patients who have taken intravenous bisphosphonates, patients with osteoporosis (specific cases), patients with poor bone quality, patients with inadequate bone height or width, economic and psychological factor and patients with untreated bruxism