Stability of a dental implant is very important when planning immediate loading and design of a final restoration. The aim of this study was to compare the primary and the secondary stability of dental implants inserted by three different surgical techniques: conventional (standard) technique using a sequence of drills for implant bed preparation, osteotome technique using tapered hand instruments for creating implant sites by condensing the bone and guided flapless implant surgery with surgical templates.

The study included 150 patients (80 males and 70 females), 46–71 years old, who required implant supported fixed partial dentures in the posterior maxilla of D3 or D4 bone density. Patients were randomly assigned into one of the three surgical insertion technique groups. All patients received tapered implants of the same manufacturer of the same length and two different widths (3.3 × 11.5 mm or 4.2 × 11.5 mm). Primary and secondary implant stability were measured by means of resonance frequency analysis (RFA) at the time of implant placement and 5 months after surgery using the Ostell ISQ device (Osstell AB, Sampgatan, Goteborg, Sweden). Statistical analysis included one-sample Kolmogorov Smirnov test, descriptive statistics, multivariate analysis (Bonferoni post-hoc tests) and paired t-tests.

Patients in the osteotome group exhibited higher primary stability (P < 0.01) than in the conventional and surgically guided flapless groups. There were no significant differences in the secondary stability (p >  0.05). Wider implants presented higher ISQ values (P<0.01).

The osteotome technique led to the highest implant primary stability, therefore it can be recommended when immediate loading is planned or for one-piece implant insertion.