Complete dentures represent the traditional dental treatment for patients without teeth. However, retention and stability of this type of denture are often lacking, so dental implants are indicated in order to improve the stability of the denture, along with the satisfaction of the patient. Usually, the dental implants are inserted and then a period of 3-6 months is waited before any denture is connected to them. Recent studies have demonstrated that connecting the lower denture to the implants immediately after the implant placement, leads to an improvement in the result, with a social and psychological benefit for the patient. Therefore, the aim of this research project is to evaluate the application of the immediate connections of the implants for the upper dentures. 15-40 patients wearing an upper denture will receive 4 dental implants and the denture will be immediately connected. To simplify the surgical procedure, the implants will be placed without exposing the bone. This surgical technique is called guided surgery. Secondary objective of this research project will be the evaluation of the precision of the implant positioning, using this specific technique. The patients will be followed up for 12 months, for the implant and denture evaluation, as well as the evaluation of patient satisfaction and impact on quality of life through questionnaires.

Inclusion Criteria:

• Fully edentulous maxilla
• The implant site has to be healed for at least 4 months after extraction
• Wearing complete dentures deemed adequate
• Orthopantomogram available (OPT)
• Adequate amount of bone at least at the 2nd premolar position to house a 3.75 x 10 mm implant
• No bone grafting required
• Implant IT ≥ 20 N/cm

Exclusion Criteria:

• Conditions requiring chronic routine prophylactic use of antibiotics
• Conditions requiring prolonged use of steroids
• History of leukocyte dysfunction and deficiencies
• Bleeding disorders
• History of neoplastic disease requiring use of radiation or chemotherapy
• Metabolic bone disorders
• Uncontrolled endocrine disorder
• Use of any investigational drug or device within the 30-day period prior to implant surgery
• Smoking more than 10 cigarettes a day
• Alcoholism or drug abuse
• Patient infected with HIV
• Condition or circumstances, in the opinion of the investigator, which would prevent completion of study participation or interfere with analysis of study results, such as history of non-compliance, unreliability.

Local exclusion criteria:

• Local inflammation including untreated periodontitis
• Mucosal disease such as erosive lichen planus
• History of local irradiation therapy
• Osseous lesion
• Severe bruxism and clenching habits
• Active infection with suppuration or fistula track
• Persistent intraoral infection
• Lack of primary stability <20Ncm. In this instance, the patient must be withdrawn and treated according to the standard protocol.
• Inadequate oral hygiene or unmotivated home care.
• Bone grafting
• Inadequate bone volume for implants insertion as measured on the per-treatment CBCT.

12 Months