This prospective single-cohort study was designed and conducted following the principles of the World Medical Association Helsinki Declaration of 1975 for biomedical research involving human subjects, as revised in 2000. Ethical approval for the study was obtained by the review board of the IRCCS Istituto Ortopedico Galeazzi. All patients were informed about the study aims and design and gave written informed consent.

Patient inclusion criteria were the following:

• Partial of full edentulism in either maxilla or mandible
• Impossibility of placing an implant ≥10 mm without any prior bone grafting procedure as independently assessed by 2 clinicians (S.T. and S.C.) during treatment planning; if there was no agreement about the possibility of placing a longer implant, the case was excluded from the study
• At least 18 years old
• Absence of general medical contraindications for oral surgery procedures (American Society of Anesthesiologists 1 or 2; http://www.asahq.org/For-Members/Clinical-Information/ASA-Physical-Status-Classification-System.aspx)
• Full-mouth bleeding score and full-mouth plaque score <25% at baseline
• Ability to sign the informed consent form

Patients were not enrolled in the study if they had one of the following exclusion criteria:

• Any disease or condition that might compromise or negatively influence tissue healing and osseointegration, such as hematologic disease, disease of the immune system (eg, autoimmune diseases or acquired immunodeficiency syndrome), uncontrolled diabetes, metabolic disease affecting bone, pregnancy, or lactation
• Inability or unwillingness to return for follow-up visit
• Inability or unwillingness to maintain a good level of oral hygiene

Inclusion and exclusion criteria were verified after diagnosis and before definitive treatment planning by one of the authors (S.C.). One experienced surgeon with >10 years of experience in implant surgery (S.T.) performed all the surgeries.

In total, 54 implants <10 mm were placed in 42 patients from February 2009 to November 2011. The surgeries were performed in a private office and a university clinic using the same equipment and in comparable surgical settings. One patient failed to attend the 12-month follow-up visit and was excluded from the data analysis. Hence, the present article reports data for 53 implants, placed in 41 patients (22 women and 19 men; mean age, 55.7 ± 12.3 years). Implant characteristics are summarized in Table 1. Follow-up periods ranged from 6.2 to 41.7 months after surgery (mean, 15.4 ± 10.3 months).

Table 1. Implant size distribution