Less invasive surgical procedures using narrow-diameter implants: A prospective study in 20 consecutive patients

Abstract

Narrow-diameter implants (NDIs) are increasingly produced and used in implant dentistry, especially since the introduction of new, more resistant materials. The objective of the present study was to evaluate the clinical performance of NDIs (3.3 mm) placed in thin alveolar crests. Twenty consecutive patients needing implant-supported fixed partial dentures and presenting an alveolar thickness ≤6 mm were treated with 1 or several NDIs. The surgical protocol was chosen according to the clinical situation: (1) flapless, (2) mini-cervical flap, (3) wide flap, (4) wide flap guided bone regeneration (GBR). Implants were immediately loaded if the primary stability was higher than 20 Ncm. Implant survival and success, prosthodontic success rates, and patient-centered outcomes were evaluated after a follow-up period of 1 year. A total of 39 implants were placed in 20 patients, 12 and 27 implants in the anterior regions and in the posterior mandible, respectively. All but 1 implant reached an insertion torque higher than 20 Ncm and were loaded within 48 hours. The implant survival and success rates both reached 94.7%. The need for GBR was avoided in 60% of the implant sites. The mean peri-implant bone remodeling after a follow-up period of 1 year was 0.35 mm at the implant level. Periimplant bone remodeling was higher in the posterior region, when the alveolar crest was thinner than 4 mm and GBR was required in addition. In conclusion, use of NDIs to restore partial edentation in sites with limited horizontal thickness seems to be an effective treatment option that prevented GBR in the majority of the present cases. Immediate provisionalization of NDIs does not seem to impair the results.