This study aims to evaluate the treatment with single implant overdenture for the edentulous mandible. The investigators hypothesize that treatment with lower overdenture retained by a single implant appears to have satisfactory effectiveness as a treatment for patients with specific conditions (such as maladaptive patients), with the advantages of simplicity and greater immediate benefits when compared to the conventional full denture, improving the retention and stability of the denture and better oral-related quality of life.

This study is a longitudinal evaluation of clinical and patient-reported outcomes related to the single-implant mandibular overdenture treatment. Sixty completely edentulous individuals will be included. First, new complete dentures will be fabricated for all of them. Panoramic radiographs and conventional tomograms of the mandibular midline region will be obtained in order to plan the implant placement surgery. After the adaptation period related to the use of the new dentures, a single implant (Titamax IT Cortical, Neodent, Curitiba, Brazil) will be installed in the mandibular midline of all participants. According to the primary stability obtained in the implant placement patients will be treated with an immediate loading protocol when achieving torque of at least 30 Ncm and implant stability quotient (ISQ) of at least 60. In cases of values below cited, conventional loading protocol will be adopted. Ball O-ring will be used as the attachment system for the mandibular overdenture. Clinical and patient-reported outcomes will be collected after 1, 3, 6 and 12 months after the installation of the overdentures.

Inclusion Criteria:

• Fully edentulous patients
• Need of replacement of the mandibular denture or patient without mandibular denture
• Patients with poor adaptation to the mandibular denture
• Patients with good general health

Exclusion Criteria:

• Patients who refuse to receive a conventional dentures opposed to a mandibular overdenture retained by a single implant
• Patients with local intraoral diseases that influence denture stability, retention and adaptation of the lower denture (such as changes or anatomical deformations of the jaws, mucosal changes caused by fungi and bacteria, tumor changes and absolute xerostomia)
• Patients with systemic, psychological or neurological diseases that preclude or hinder oral movements of the patient for clinical care and/or clinical follow-up in all stages of the research
• Patients who choose other treatment modalities not covered by the study
• Patients with alcoholism or other severe behavioral disorders that compromise their participation in the study