Table 1 Inclusion and exclusion criteria

Inclusion criteria

 I. Be completely edentulous and aged 65 years or more;

 II. Not have had a tooth extraction within the past six months;

 III. Request implant stabilization of a mandibular conventional complete denture;

 IV. Have clinically acceptable maxillary and mandibular complete dentures. Individuals without clinically acceptable dentures will be referred to receive prosthodontic care before inclusion. In any case, dentures shall present acceptable base extension and fit, maxillo-mandibular relationships, tooth wear, and aesthetics, as evaluated by a prosthodontist;

 V. Have adequate bone in the anterior mandible for the placement of a single 3.3-mm-wide implant in the midline;

 VI. Be able to maintain adequate oral hygiene and clean dentures;

 VII. Present no systemic conditions for which minor oral surgery would be counter-indicated, e.g. severe cardiovascular diseases or uncontrolled type 2 diabetes mellitus;

 VIII. Have an adequate understanding of written and spoken English or French;

 IX. Be capable of giving written informed consent.

Exclusion criteria

 Clinical criteria:

  I. Severe/serious illness that requires frequent hospitalization;

  II. Impaired cognitive function;

  III. Unable to return for evaluations/study recalls;

  IV. Have a history of radiation therapy to the orofacial region;

  V. Have specific conditions that may jeopardize the treatment, such as alcoholism or smoking (> 10 cigarettes/day);

  VI. Have acute or chronic symptoms of parafunctional or temporomandibular disorders;

  VII. Previous dental implant treatment.

 Radiographic criteria:

  I. Any area suggestive of bony pathologic lesions;

  II. Lack of minimum vertical mandibular bone height of 11 mm in the symphyseal region or width for planned implants;

  III. Evident endosseous vascular structures in the planned implant site as described by Kalpidis and Setayesh [52];

  IV. Mandibular ridges graded as I or II according to Cawood and Howell [28].